Breast Cancer Index Research Articles

Breast Cancer Index in Premenopausal Women With Early-Stage Hormone Receptor–Positive Breast Cancer

Adjuvant ovarian function suppression (OFS) with oral endocrine therapy improves outcomes for premenopausal patients with hormone receptor-positive (HR+) breast cancer but adds adverse effects. A genomic biomarker for selecting patients most likely to benefit from OFS-based treatment is lacking. To assess the predictive and prognostic performance of the Breast Cancer Index (BCI) for OFS benefit in premenopausal women with HR+ breast cancer. This prospective-retrospective translational study used all available tumor tissue samples from female patients from the Suppression of Ovarian Function Trial (SOFT). These individuals were randomized to receive 5 years of adjuvant tamoxifen alone, tamoxifen plus OFS, or exemestane plus OFS. BCI testing was performed blinded to clinical data and outcome. The a priori hypothesis was that BCI HOXB13/IL17BR ratio (BCI[H/I])-high tumors would benefit more from OFS and high BCI portended poorer prognosis in this population. Settings spanned multiple centers internationally. Participants included premenopausal female patients with HR+ early breast cancer with specimens in the International Breast Cancer Study Group tumor repository available for RNA extraction. Data were collected from December 2003 to April 2021 and were analyzed from May 2022 to October 2022. Primary end points were breast cancer-free interval (BCFI) for the predictive analysis and distant recurrence-free interval (DRFI) for the prognostic analyses. Tumor specimens were available for 1718 of the 3047 female patients in the SOFT intention-to-treat population. The 1687 patients (98.2%) who had specimens that yielded sufficient RNA for BCI testing represented the parent trial population. The median (IQR) follow-up time was 12 (10.5-13.4) years, and 512 patients (30.3%) were younger than 40 years. Tumors were BCI(H/I)-low for 972 patients (57.6%) and BCI(H/I)-high for 715 patients (42.4%). Patients with tumors classified as BCI(H/I)-low exhibited a 12-year absolute benefit in BCFI of 11.6% from exemestane plus OFS (hazard ratio [HR], 0.48 [95% CI, 0.33-0.71]) and an absolute benefit of 7.3% from tamoxifen plus OFS (HR, 0.69 [95% CI, 0.48-0.97]) relative to tamoxifen alone. In contrast, patients with BCI(H/I)-high tumors did not benefit from either exemestane plus OFS (absolute benefit, -0.4%; HR, 1.03 [95% CI, 0.70-1.53]; P for interaction = .006) or tamoxifen plus OFS (absolute benefit, -1.2%; HR, 1.05 [95% CI, 0.72-1.54]; P for interaction = .11) compared with tamoxifen alone. BCI continuous index was significantly prognostic in the N0 subgroup for DRFI (n = 1110; P = .004), with 12-year DRFI of 95.9%, 90.8%, and 86.3% in BCI low-risk, intermediate-risk, and high-risk N0 cancers, respectively. In this prospective-retrospective translational study of patients enrolled in SOFT, BCI was confirmed as prognostic in premenopausal women with HR+ breast cancer. The benefit from OFS-containing adjuvant endocrine therapy was greater for patients with BCI(H/I)-low tumors than BCI(H/I)-high tumors. BCI(H/I)-low status may identify premenopausal patients who are likely to benefit from this more intensive endocrine therapy.

Contemporaneous Symptom Networks of Breast Cancer-Related Upper Limb Lymphedema: A Network Analysis.

Upper limb lymphedema (ULL) is a common and deliberating complication for breast cancer survivors (BCSs). Breast cancer survivors with ULL reported a wide range of symptoms. However, little is known about symptom patterns and interrelationships among them. This study was designed to explore symptom clusters and construct symptom networks of ULL-related symptoms among BCSs and to identify the core symptoms. This study is a secondary data analysis using datasets from three cross-sectional studies of BCSs in China. A total of 341 participants with maximum interlimb circumference ≥2 cm and complete responses in Part I of the Breast Cancer and Lymphedema Symptom Experience Index were included. Symptom clusters were identified through principal component analysis, and multiple linear regression analysis was employed to explore factors associated with severity of overall ULL-related symptoms. A contemporaneous network with 20 frequently reported symptoms were constructed after controlling for covariates. Three symptom clusters, including lymph stasis symptom cluster, nerve symptom cluster, and movement limitation symptom cluster, were identified. Postsurgery time, axillary lymph node dissection, and radiotherapy were associated with the severity of ULL-related symptoms. Tightness (rs = 1.379; rscov = 1.097), tingling (rs = 1.264; rscov = 0.925), and firmness (rs = 1.170; rscov = 0.923) were the most central symptoms in both networks with and without covariates. Breast cancer survivors with ULL experienced severe symptom burden. Tightness, tingling, and firmness were core symptoms of ULL among BCSs. Our findings demonstrated that the assessment and targeted intervention of specific core symptoms might help to relive effectively the burden of ULL-related symptom among BCSs.

Correlating Predicted Adjuvant Therapy Benefit and Risk of Recurrence Between Breast Cancer Index (BCI) and the 21-Gene Oncotype DX Recurrence Score (RS)

IntroductionBreast Cancer Index (BCI) is a genomic assay that evaluates the benefit of extending endocrine therapy (ET) from 5 to 10 years and predicts recurrence risk (RR). We evaluated the association between BCI and Oncotype DX (ODX). PatientsWomen with hormone receptor (HR)-positive early-stage breast cancer (EBC) who had BCI and ODX performed were included. MethodsWe performed a retrospective review of women with HR-positive EBC. BCI was categorized as predictive of extended ET versus not and ODX recurrence score (RS) as low (0-10), intermediate (11-25), and high (26-100). Univariate and multivariable logistic and linear regression models assessed the relationship between BCI and ODX, factors associated with each, and discordance between scores. ResultsWe identified 153 women, 22% were premenopausal and 18% were lymph node positive. The univariate logistic and linear models revealed an association between BCI predictive score and ODX RS (OR 7.84, CI, 2.63-23.36, P < .001) and log of BCI RR (Beta 0.04, CI, 0.02-0.06, P < .001). Seventy-four percent of BCI predictive scores were concordant with ODX RS and 83% of BCI RR was concordant with ODX RR. In a univariate logistic regression model, BCI predictive of ET benefit was associated with discordance (OR 28.00, CI, 10.58-74.02, P < .001). Higher ODX RR was associated with discordance (OR 1.92, CI, 1.42-2.59, P < .001). ConclusionWe found a significant association between ODX and BCI predictive and prognostic scores. BCI predictive of extended ET benefit was associated with discordance with ODX RS. Higher predicted RR on ODX was associated with discordance with BCI predicted RR.

Use of Oncotype vs. Breast Cancer Index (BCI) for extended endocrine therapy decisions: A single center analysis in stage IA hormone receptor positive breast cancer.

e13083 Background: Extended Endocrine Therapy (EET) for hormone receptor positive HER-2 negative early-stage breast cancer reduces late recurrence risks but raises concerns about toxicity. Biomarker tests like the Breast Cancer Index (BCI) are vital for identifying patients who could benefit from continued ET, reassuring others against unnecessary extension. This study evaluates prognostic implications for both Oncotype Dx (Recurrence score, RS) and BCI amidst concerns about added testing costs in patients with early stage, estrogen receptor (ER) positive breast cancer. Methods: This is a single institution retrospective review of Stage IA ER positive HER-2 negative breast cancer patients who underwent both Oncotype Dx and BCI testing from January 2021 to December 2023. Pearson's correlation coefficient (r) was used to assess the linear relationship between the assays (p&lt;0.05 for significance), analysis was performed with SAS software, version 9.4. Results: Fifty-eight patients with Stage IA ER positive HER-2 negative breast cancer who had both Oncotype and BCI results were identified (100% female; mean age 72.2 years [54-87]). After a median followed up of 72 months (63-75), no systemic or locoregional recurrences were reported. A low positive correlation between Oncotype and BCI was observed across the entire cohort (r=0.4058; p=0.0016). However, subgroup analysis showed no significant correlations: Oncotype &lt;11 (n=17; r=0.2415; p=0.3504), Oncotype ≤18 (n=43; r=0.0914; p=0.5600), Oncotype &lt;26 (n=51; r=0.2530; p=0.0733); Oncotype ≥26 (n=7; r=-0.5634; p=0.1878). Correlation was also not found in patients with Grade 1 tumor (n=16; r=0.3138; p=0.2365). Thirty-nine patients (67.24%) had their treatment recommendation changed based on BCI results. Side effects from ET affected 15 patients (25.86%) and included arthralgias (60%, n=9), hot flashes (26.67%, n=4), depression (13.33%, n=2), insomnia (6.67%, n=1), and others (53.3%, n=8). Twenty-two patients (37.93%) developed new osteopenia, and 6 (10.34%) new osteoporosis while on EET. Eight patients (13.79%) had ET interruption during their treatment course. Conclusions: Despite inclination towards cost-saving measures, Oncotype DX may be more useful to give prognosis in the early adjuvant period whereas BCI is more useful to evaluate late recurrence risk. Low or high Oncotype scores and tumor grade may not align with BCI findings. Considering the importance of managing toxicity against the risk of late recurrence, incorporating BCI testing can enhance EET recommendations, even for Stage I, node-negative, ER positive patients.

Examining a genomic test in predicting extended endocrine benefit and recurrence risk in a diverse breast cancer population.

e12526 Background: Extending adjuvant endocrine therapy (EET) beyond five years for early-stage hormone receptor-positive (HR+) breast cancer reduces late distant recurrence risk. The genomic test, Breast Cancer Index (BCI), has prognostic value and predicts the benefits of prolonged therapy, yet no studies have explored this testing in a diverse population. This study assesses late distant recurrence risk and predictive benefits of EET to better understand its relevance in a diverse early-stage HR+ breast cancer population. Methods: We analyzed patient demographics, clinical and pathologic characteristics, and BCI scores of 150 women in Hawaii with early-stage HR+ breast cancer, self-identifying as White, Filipino, Japanese, Native Hawaiian, or other. Tumor characteristics examined include size, grade, histology, lymph node, and ER/PR/HER2 receptor status. Logistic regression analyses used race, distant recurrence risk, and tumor features as predictor variables. BCI prediction of benefit and distant recurrence risk served as outcome variables. Results: Japanese patients had significantly lower odds of having a high risk for distant recurrence (OR = 0.02, p &lt; 0.0001) compared to White. Other Asian PIs also showed reduced odds of high distant recurrence risk (OR = 0.07, p = 0.02), albeit to a lesser extent than Japanese. Patients with high distant recurrence risk had significantly greater odds of a score predicting benefit than those with low risk (OR = 5.03, p = 0.009). Racial or ethnic differences in predicting benefit with EET were not statistically significant. Conclusions: Results show no racial or ethnic differences in predicting the benefit of EET, strengthening BCI’s universal applicability in diverse women with early-stage HR+ breast cancer. Patients with higher distant recurrence risk were predicted to benefit from EET. This suggests potential variations in tumor features or other factors affecting distant recurrence risk among racial groups. Limitations include a relatively small sample size and lack of data from patients representing other racial groups. Future studies should expand the sample size and adjust for known breast cancer risk factors to better understand the racial and ethnic implications of BCI.

Breast Cancer Index re-stratifies 21-gene assay risk groups for late distant recurrence and extended endocrine therapy benefit: Results from the BCI Registry Study.

529 Background: Patients with hormone receptor-positive (HR+) breast cancer face a prolonged risk for late distant recurrence (DR), even after 5 years of adjuvant endocrine therapy. The BCI (Breast Cancer Index, Biotheranostics) is a genomic assay that provides the risk of late DR and predicts the likelihood of benefit from extended endocrine therapy (EET) based on the H/I (HOXB13/IL-17BR) ratio. The 21-gene RS (Recurrence Score; Oncotype DX, Exact Biosciences) test provides the 9-year risk of DR and the benefit from adjuvant chemotherapy (CT) in HR+/HER2− breast cancer. However, the RxPONDER trial showed that RS was not predictive of CT benefit in premenopausal women with N1 disease. Here, we investigated the concordance between BCI prognostic score and H/I versus RS in HR+/HER2- patients from the BCI Registry study. Methods: The BCI Registry study is a prospective, multi-institutional study to evaluate the long-term clinical outcome, decision impact and medication adherence in early-stage HR+ breast cancer patients. Based on TAILORx and RxPONDER results, RS stratified patients into four risk groups: Age ≤ 50, No CT benefit (RS ≤ 15); Age ≤ 50, CT benefit (RS&gt;15); Age &gt; 50, No CT benefit (RS ≤ 25); and Age &gt; 50, CT benefit (RS &gt; 25). Kendall’s correlation coefficient (R) was used to estimate the correlation between BCI prognostic score, BCI (H/I) and RS as continuous variables. Results: BCI and RS results were reported for 847 patients (76% T1; 59% grade II; 85% N0). H/I classified 559 patients (66%) as H/I-Low and 288 (34%) as H/I-High, respectively, while BCI prognostic risk scores classified 434 patients (51%) as low-risk and 413 (49%) as high-risk for late DR. RS classified 30 patients (4%) as Age ≤ 50, No CT benefit, 38 (5%) as Age ≤ 50, CT benefit, 665 (78%) as Age &gt; 50, No CT benefit and 114 (13%) as Age &gt; 50, CT benefit. When analyzed as continuous variables, BCI H/I and prognostic score showed a weak correlation with RS with R=0.18 and R=0.2, respectively. Based on categorical groups, H/I had low concordance with RS for younger women (Age ≤ 50) but showed some correlation with RS for older women (Age &gt; 50). Among those older than Age 50, H/I identified 31% of those with no CT benefit as likely to benefit from EET while 39% of those with CT benefit as not likely to benefit from EET. Conclusions: BCI H/I and prognostic risk scores exhibited low concordance with RS risk categories. H/I consistently re-stratified RS risk categories into distinct H/I-Low and -High groups, further substantiating that prediction of CT benefit does not equate to prediction of EET benefit. [Table: see text]

The Evolving Role of Genomic Testing in Early Breast Cancer: Implications for Diagnosis, Prognosis, and Therapy.

Multigene prognostic genomic assays have become indispensable in managing early breast cancer (EBC), offering crucial information for risk stratification and guiding adjuvant treatment strategies in conjunction with traditional clinicopathological parameters. The American Society of Clinical Oncology (ASCO) guidelines endorse these assays, though some clinical contexts still lack definitive recommendations. The dynamic landscape of EBC management demands further refinement and optimization of genomic assays to streamline their incorporation into clinical practice. The breast cancer community is poised at the brink of transformative advances in enhancing the clinical utility of genomic assays, aiming to significantly improve the precision and effectiveness of both diagnosis and treatment for women with EBC. This article methodically examines the testing methodologies, clinical validity and utility, costs, diagnostic frameworks, and methodologies of the established genomic tests, including the Oncotype Dx Breast Recurrence Score®, MammaPrint, Prosigna®, EndoPredict®, and Breast Cancer Index (BCI). Among these tests, Prosigna and EndoPredict® have at present been validated only on a prognostic level, while Oncotype Dx, MammaPrint, and BCI hold both a prognostic and predictive role. Oncologists and pathologists engaged in the management of EBC will find in this review a thorough comparison of available genomic assays, as well as strategies to optimize the utilization of the information derived from them.

Fit-for-Purpose Ki-67 Immunohistochemistry Assays for Breast Cancer

New therapies are being developed for breast cancer, and in this process, some “old” biomarkers are reutilized and given a new purpose. It is not always recognized that by changing a biomarker’s intended use, a new biomarker assay is created. The Ki-67 biomarker is typically assessed by immunohistochemistry (IHC) to provide a proliferative index in breast cancer. Canadian laboratories assessed the analytical performance and diagnostic accuracy of their Ki-67 IHC laboratory-developed tests (LDTs) of relevance for the LDTs’ clinical utility.Canadian clinical IHC laboratories enrolled in the Canadian Biomarker Quality Assurance Pilot Run for Ki-67 in breast cancer by invitation. The Dako Ki-67 IHC pharmDx assay was employed as a study reference assay. The Dako central laboratory was the reference laboratory. Participants received unstained slides of breast cancer tissue microarrays with 32 cases and performed their in-house Ki-67 assays. The results were assessed using QuPath, an open-source software application for bioimage analysis. Positive percent agreement (PPA, sensitivity) and negative percent agreement (NPA, specificity) were calculated against the Dako Ki-67 IHC pharmDx assay for 5%, 10%, 20%, and 30% cutoffs.Overall, PPA and NPA varied depending on the selected cutoff; participants were more successful with 5% and 10%, than with 20% and 30% cutoffs. Only 4 of 16 laboratories had robust IHC protocols with acceptable PPA for all cutoffs. The lowest PPA for the 5% cutoff was 85%, for 10% was 63%, for 20% was 14%, and for 30% was 13%. The lowest NPA for the 5% cutoff was 50%, for 10% was 33%, for 20% was 50%, and for 30% was 57%.Despite many years of international efforts to standardize IHC testing for Ki-67 in breast cancer, our results indicate that Canadian clinical LDTs have a wide analytical sensitivity range and poor agreement for 20% and 30% cutoffs. The poor agreement was not due to the readout but rather due to IHC protocol conditions. International Ki-67 in Breast Cancer Working Group (IKWG) recommendations related to Ki-67 IHC standardization cannot take full effect without reliable fit-for-purpose reference materials that are required for the initial assay calibration, assay performance monitoring, and proficiency testing.

Abstract PO1-02-03: Correlative analysis of Breast Cancer Index with CTS5 for prediction of extended endocrine benefit in the BCI Registry study

Abstract Background Hormone receptor-positive (HR+) breast cancer patients face a prolonged risk of late distant recurrence even after 5 years of primary adjuvant endocrine therapy and derive only a modest benefit from extended endocrine therapy (EET). The Breast Cancer Index (BCI) is a validated genomic assay that provides the risk of late (post 5 years) and overall (0-10 years) distant recurrence and predicts EET benefit in patients with HR+ disease. The predictive component of BCI, HOXB13/IL17BR ratio [BCI (H/I)], stratifies patients as Low- and High-Likelihood to benefit from EET and has been validated in the MA.17, Trans-aTTom, IDEAL, and B-42 trials. The Clinical Treatment Score post-5 years (CTS5) is a prognostic tool incorporating standard clinical risk factors such as age at diagnosis, tumor size, tumor grade, and nodal involvement to inform prognosis of late distant recurrence. A previous analysis in the IDEAL trial showed that CTS5 was not predictive of EET benefit. Here, we examine the relationship between BCI (H/I) and CTS5 in a large cohort from the BCI Registry study. Methods The BCI Registry study is an ongoing prospective study to evaluate the long-term clinical outcome, decision impact and medication adherence in HR+ early-stage breast cancer patients receiving BCI testing as part of routine clinical care. BCI (H/I)-Low and BCI (H/I)-High groups were determined using pre-specified cut-points. CTS5 scores were calculated using clinical information from the ClinCapture electronic data capture system and stratified into Low-, Intermediate-, and High-risk groups using published cut-points. Pearson’s correlation coefficient (r) was used to estimate the correlation between BCI (H/I) and CTS5 as continuous variables. Descriptive statistics were used to summarize the distribution of BCI (H/I) groups across all CTS5 risk categories. Results BCI and CTS5 results were reported for 1520 patients (75.1% T1; 53.4% grade II; 80.3% N0). BCI (H/I) classified 934 patients (61.4%) as BCI (H/I)-Low and 586 patients (38.6%) as BCI (H/I)-High. BCI Prognostic classified 705 patients (46.4%) as BCI-Low risk for late distant recurrence and 815 patients (53.6%) as BCI-High risk. CTS5 classified 945 patients (62.2%) as CST5-Low, 400 patients (26.3%) as CTS5-Intermediate, and 175 patients (11.5%) as CTS5-High. When analyzed as continuous variables, BCI (H/I) showed a weak correlation with CTS5 (r=0.18). When stratifying CTS5 risk categories by BCI (H/I) groups, 65.2% (N=616) of CTS5-Low patients were classified as BCI (H/I)-Low, while 34.8% (N=329) of CTS5-High Low patients were classified as BCI (H/I)-High. In addition, 57.8% (N=231) and 42.2% (N=169) of CTS5-Intermediate patients were classified as BCI (H/I)-Low and BCI (H/I)-High, respectively. Finally, 49.7% (N=87) and 50.3% (N=88) of CTS5-High patients were classified as BCI (H/I)-Low and BCI (H/I)-High, respectively. Conclusion BCI (H/I) consistently stratified CTS5 risk categories into separate BCI (H/I)-Low and BCI (H/I)-High groups, indicating that risk prognostication does not equate to prediction of benefit from EET. These results confirm previous findings in the IDEAL study demonstrating that CTS5 is not predictive of EET benefit and further substantiate the clinical utility of BCI as the only predictive biomarker for extended endocrine therapy benefit in patients with HR+ early-stage breast cancer. Citation Format: Naomi Dempsey, Jenna Wong, Natalia Siuliukina, Yi Zhang, Kai Treuner, Reshma Mahtani. Correlative analysis of Breast Cancer Index with CTS5 for prediction of extended endocrine benefit in the BCI Registry study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-02-03.

Abstract PO5-13-04: Breast Cancer Index (BCI) results from a HER2 low breast cancer community cohort of operable stage I-II hormone receptor positive (HR+) breast cancer

Abstract Background Hormone receptor positive (HR+) breast cancer (BC) traditionally included HER2-negative or HER2-positive classifications. The BCI test is a quantitative RNA profile assay applied to HR+ early-stage breast cancers from archival pretreatment surgical specimens. The BCI assay estimates the likelihood of distant recurrence (DR) during years 5-10 (prognostic result) and predicts extended endocrine therapy benefit (ETT)(i.e., BCI (H/I)-High, yes benefit) or no benefit (i.e., BCI (H/I)- Low) for patients who have completed 5 years of adjuvant endocrine therapy (AET). Based on the Destiny Breast 04 trial, an antibody drug conjugate (ADC) anti-HER2 therapy was recently approved for treating metastatic HR+HER2 low BCs, which are currently defined as tumors with either HER2 immunohistochemical (IHC) staining of 1+ or IHC 2+ without HER2 gene amplification. Primary archival specimens were eligible for enrollment on the Destiny Breast 04 trial (35%). Quality control of IHC result categories is needed due to new clinical implications in the metastatic setting. To date, BCI results for tumors classified as HER2 low has not been reported. Objectives Determine the average BCI distant DR risk (prognostic result) and the proportion of tumors with BCI (H/I)-High, yes benefit versus BCI (H/I)-Low, no benefit (predictive result) from a small community-based retrospective study of pretreatment samples from a cohort of HER2 low, HR+ breast tumors. Methods Around completion of 5 years of AET, BCI testing was applied to 110 surgically excised archived stage I and 2 HR+ untreated tumors that were collected between 2017 and 2022. Specimens had paired HER2 local pathology IHC and in-situ hybridization (ISH) results. Results 32 tumors were identified as HER2-low including 26 specimens with HER2 IHC 1+ results and six HER2 IHC 2+ tumors with non-amplified HER2 ISH results. Given this was a small exploratory analysis, statistical significance was deliberately not evaluated. Prognostic Results: The average estimated DR risk during years 5-10 was 8% for tumors classified as HER2-low (Range 1.3-17.5%). For 26/32 patients with HER2 IHC1+, the average DR risk was 7.4% (Range 1.3-17.5%). For 6/32 patients with HER2 IHC 2+ and non-amplified HER2 ISH results, the average DR risk was 4.6% (Range 1.6-8.6%). Predictive Results: Of the 32 HER2-low tumors, 15/32 (47%) were BCI (H/I)-High (yes benefit) compared to 17/32 (53%) which were BCI (H/I)-Low (no benefit). Conclusions The prevalence of HER2 low tumors appears to be as high as 67% in reports to date. In this small series, the prevalence of HR+ HER2 low tumors was 29% (32/110). The average DR risk in these HR+ HER2 low cases was roughly 8% which represents a DR risk that is very similar to the average DR risk of 7.4% for HR+ HER2 negative tumors reported from one of the large BCI validation studies (TransATAC). In this series of HER2 low BCs, the proportions of BCI (H/I)-High (yes benefit) and BCI (H/I)-Low (no benefit) tumors were 47% and 53%, compared with 46% and 54%, respectively, in three large BCI validation studies (Trans-aTTom, B42, IDEAL) for HER2 negative tumors. Although this is a small retrospective series, these results suggest that HER2 low tumor are, by BCI testing, very similar to HER2 negative tumors in DR risk (prognostic results). Also, it appears that BCI (H/I)-High (yes benefit) and BCI (H/I)-Low (no benefit) proportions (predictive results) for HER2 low tumors appear similar to reported results for HER2 negative tumors. Follow-up data from larger series are needed to determine if BCI testing is prognostic and predictive for HER-2 low BCs. Citation Format: Milana Dolezal, Mark Pegram. Breast Cancer Index (BCI) results from a HER2 low breast cancer community cohort of operable stage I-II hormone receptor positive (HR+) breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-13-04.

Abstract PO5-01-11: Breast Cancer Index and comparative analysis of late distant recurrence risk with results from the TEAM trial

Abstract Background: Individualized risk assessment of distant recurrence (DR) is critical for early-stage HR+ breast cancer patients, as prolonged risk of recurrence continues even after completing 5 years of adjuvant endocrine therapy. The Breast Cancer Index (BCI) is a guideline-endorsed, validated gene expression assay that provides an individualized risk of overall (0-10y) and late (5-10y) DR and predicts the likelihood of benefit from extended endocrine therapy. The current BCI assay reports prognostic risk estimates based on tamoxifen-treated patients from the Stockholm (STO-3) cohort for node-negative (N0) patients, enrolled between 1976 through 1990 and a retrospective cohort from Massachusetts General Hospital (MGH) for patients with 1 to 3 positive nodes (N1), diagnosed between 1993 and 2007, of which approximately 50% were tamoxifen-treated. More recently, additional validation was completed in the Tamoxifen and Exemestane Adjuvant Multinational (TEAM) trial, in which patients were enrolled between 2001 and 2006. Here, individualized DR risk estimates from the TEAM trial were compared with those from Stockholm and MGH cohorts. Methods: For the TEAM translational study, BCI testing was performed blinded to clinical outcome and BCI and BCIN+ risk scores were calculated as previously described. A total of 2910 postmenopausal patients with HR+ breast cancer, including 1285 N0 and 1625 N1 patients, who remained DR-free for five years were analyzed to determine the risk of late DR. Cox proportional hazard models using Breslow estimates were used to calculate the risk of late DR as a function of continuous BCI risk scores. Results: Late DR risk estimates from both the TEAM trial and the Stockholm/MGH cohorts are summarized in the table below. In N0 patients, comparison of 5-10y risk estimates of late DR observed in TEAM patients were higher than those in the Stockholm cohort for BCI scores less than 8.0, but reduced for BCI scores greater than 8.0. Risk estimates differed by 1.5% for a BCI score of 0 and -4.3% for a BCI score of 10. A similar pattern was observed for N1 patients between the TEAM and MGH cohorts, with risk estimates from TEAM trial being higher for BCI scores less than 8.0 but reduced for BCI scores greater than 8.0 compared to those from the MGH cohort. Conclusions: BCI prognostic validation in the TEAM trial enabled the characterization of DR risk that is more compatible with the current standard of care in the US, as postmenopausal patients were all treated with at least 2-3 years or 5 years of primary adjuvant endocrine therapy with an aromatase inhibitor. Results from the TEAM study provide a more representative assessment of late DR risk to guide individualized treatment decision-making for HR+ early-stage breast cancer patients. Table. Citation Format: John MS Bartlett, Yi Zhang, Gregory Pond, Jenna Wong, Keying Xu, Melanie Spears, Elizabeth Mallon, Karen Taylor, Annette Hasenburg, Christos Markopoulos, Luc Dirix, Caroline Seynaeve, Cornelis J.H. van de Velde, Daniel Rea, Adam Brufsky, Olle Stål, Dennis Sgroi, Catherine Schnabel, Kai Treuner, Jane Bayani. Breast Cancer Index and comparative analysis of late distant recurrence risk with results from the TEAM trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-01-11.

Abstract PO2-01-08: Differential HOXB13 gene expression and promoter methylation analysis in breast cancer

Abstract Background: The Breast Cancer Index (BCI) is a gene expression-based signature comprising two functional biomarker panels: the Molecular Grade Index (MGI) and BCI (H/I), which is a ratio of the HOXB13 and IL17BR gene expression. Several studies have shown that BCI (H/I) is a predictive biomarker for extended adjuvant endocrine therapy benefit in hormone receptor-positive (HR+) early-stage breast cancer. Molecular mechanisms underlying endocrine responsiveness remain to be fully explored. The objective of this analysis is to evaluate the correlation between gene expression and methylation in breast cancer patients displaying different HOXB13 mRNA expression levels from The Cancer Genome Atlas (TCGA) project. Methods: Data from methylation microarrays and mRNA sequencing were examined in combination with clinical metadata from 1,095 TCGA breast cancer patients. After removing outliers, HR+ samples were ordered based on their HOXB13 expression levels and the top 10% of samples (HOXB13-high; n=95) and bottom 10% (HOXB13-low; n=95) were selected for further analysis. Differentially expressed genes (DEGs) were determined by comparing all protein-coding genes between the HOXB13-high and HOXB13-low sets, based on an absolute log-fold change above 2 and a Benjamini-Hochberg adjusted p-value threshold of 0.01. Among the subset of samples with matching methylation data (n=60 for the HOXB13-high group and n=48 for the HOXB13-low group), hypo-methylated and hyper-methylated differentially methylated probes (DMPs) were identified based on at least 10% change of β (i.e., average promoter methylation) and a Benjamini-Hochberg adjusted p-value threshold of 0.01. Motif and transcription factor (TF) enrichment analyses were identified at a minimum incidence of 10 and a lower boundary of 1.5 for the 95% confidence interval of the odds ratio. Results: Our analysis identified a total of 613 DEGs between the HOXB13-high and HOXB13-low groups. Gene ontology analysis of DEGs revealed a statistically significant enrichment of genes associated with PTK6 regulated cell cycle, oncogene-induced cellular senescence, and regulation of T cell activation. Analysis of protein-protein interactions of differentially expressed genes revealed differences in key biological processes including changes in cell cycle regulation, p53 pathway, and IL-17 signaling. A total of 5,295 hyper-methylated and 580 hypo-methylated DMPs were discovered when comparing HOXB13-high and HOXB13-low samples. Changes in global methylation patterns enabled classification of breast cancer samples with high or low HOXB13 expression with an accuracy of 0.90. Reconstruction of gene regulatory networks from DNA methylation and transcriptome profiles elucidated significant pairs of DMPs and differentially expressed genes. Specifically, a total of 197 differentially expressed genes were attributed to hyper-methylated DMPs, including genes involved in response to estrogen, activation of HOX genes during differentiation, and drug-mediated inhibition of CDK4/6 activity. Additionally, 8 differentially expressed genes were attributed to hypo-methylated DMPs and were associated with proteasomal protein catabolic processes. Lastly, motif analysis of transcriptional factors for the hyper-methylated DMPs revealed enrichment of binding motifs attributed to FOXA1, ESR1, XBR1, and FOXP1. Conclusion: A comprehensive and comparative analysis of mRNA expression levels and methylation patterns between TCGA breast cancer samples with high and low expression of HOXB13 revealed key signaling pathways and biological processes that may provide insights on the molecular mechanism of HOXB13 in the regulation of response to endocrine therapy in HR+ breast cancer. Citation Format: Natalia Siuliukina, Yi Zhang, Kai Treuner, Mark Pegram. Differential HOXB13 gene expression and promoter methylation analysis in breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-01-08.

Abstract PO1-04-10: Body Mass Index and Treatment Efficacy in advanced Luminal Breast Cancer: Insights from the GEICAM/2013-02 (PEARL) trial

Abstract Background: Endocrine therapy (ET) and treatment directed against molecular targets (CDK 4/6, PI3K, mTOR) constitute the basis of initial treatments for patients with advanced luminal breast cancer. Most of these treatments are oral and have been developed at a fixed dose, without weight adjusted dosing. There is little evidence on the influence that patients’ weight might have on clinical outcomes of these oral drugs in the context of a randomized clinical trial. The present study analyzes the potential impact of the weight of patients treated in the two cohorts of the PEARL trial (NCT02028507) on Progression-Free Survival (PFS), Overall Survival (OS) and the incidence of side effects in each treatment arm. Methods: GEICAM/2013-02 (PEARL) is a multicenter, phase III randomized clinical trial that enrolled patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer (MBC) who progressed to a prior aromatase inhibitor. Patients were randomized 1:1 to receive ET + palbociclib or capecitabine. Patient weight was assessed based on baseline body mass index (BMI) categories: normal (BMI ≤25 Kg/m2), overweight (BMI 25-29.9 Kg/m2) and obesity (BMI ≥30 Kg/m2). Cox's stratified proportional hazard model was used for survival analysis. Adverse events were assessed and graded according to National Cancer Institute common terminology criteria for adverse events (NCI-CTCAE) version 4.0. Results: A total of 600 patients were included in the study and all were evaluable for the weight-based analysis, including 301 in the ET +palbociclib arm and 299 in the capecitabine arm. The distribution of patient’s weights is shown in Table 1. For the Intention-to-treat (ITT) population, no significant difference in the median OS was found between the different weight categories (Normal: 32.8 months vs overweight: 31.9 months, [p=0.467]; obese: 32 months [p=0.407]). Specifically, for patients with normal weight, the median PFS was 9.3 months in the ET + palbociclib group compared to 9.0 months in the capecitabine group (hazard ratio (HR) 0.83, 95% confidence interval [CI]: 0.61-1.13; p=0.23). In the overweight group, the PFS was 7.5 months in the ET+palbociclib group and 11.1 months in the capecitabine group (HR 1.17, 95% CI: 0.87-1.58; p=0.30) while for the obese group, the PFS was 5.7 months vs 11.7 months (HR 1.14, 95% CI: 0.82-1.59; p=0.43), respectively. No substantial differences in the incidence of grade ≥ 3 events were observed when considering weight categories in the different treatment groups (capecitabine arm (Normal: 60%, Overweight: 70.4%, Obese: 61.6%) and ET+palbociclib arm (Normal: 74.5%, Overweight: 76.1%, Obese: 51.6%). Conclusions: Our findings, despite not finding statistically significant differences, suggest a potentially clinically relevant trend towards improved PFS with capecitabine in overweight and obese patients compared to those receiving palbociclib plus ET. The impact of weight on the outcomes with fixed-dose oral drugs warrants further investigation in future studies. Table 1. Citation Format: Manuel Alva, Sara López-Tarruella, Christoph Zielinski, Manuel Ruíz - Borrego, Nicholas Turner, Eva Ciruelos, Montserrat Muñoz, Begoña Bermejo, Mireia Margelí, Antonio Antón, Zsuzsanna Kahan, Tibor Csöszi, Maribel Casas, Laura Murillo, Serafin Morales Murillo, Emilio Alba, Einav Nili-Gal Yam, Angel Guerrero, Lourdes Calvo, Juan de la Haba-Rodríguez, Manuel Ramos, Isabel Álvarez, Andrés García-Palomo, María Koehler, José Ángel García-Sáenz, J. Ignacio Chacón, Claire Swift, Christiane Thallinger, Miguel Gil-Gil, Miguel Martín. Body Mass Index and Treatment Efficacy in advanced Luminal Breast Cancer: Insights from the GEICAM/2013-02 (PEARL) trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-04-10.

Abstract PO1-18-10: ANNE: A phase II single-arm clinical trial to assess the feasibility and efficacy of neoadjuvant anastrozole in patients with luminal breast cancer and low proliferative index in TNM stages II and III

Abstract Background: Neoadjuvant endocrine therapy (NET) is recommended for the treatment of invasive breast cancer (BC), particularly luminal subtypes, in locally advanced stages. Previous randomized studies have demonstrated the benefits of aromatase inhibitors (AIs) in this context. However, in clinical practice, NET is typically reserved for elderly or frail patients who may not tolerate neoadjuvant chemotherapy. Ideally, after identifying suitable candidates for NET, patients undergo tumor re-biopsy after 2 to 4 weeks of treatment, and only those with Ki67 ≤ 10% proceed with NET. Limitations of this strategy include the standardization of re-biopsy and the reliability of Ki67 immunohistochemical analysis, as treatment decisions are based on these results. Objective: To evaluate the feasibility and efficacy of NET in postmenopausal patients with stage II and III luminal BC and to identify predictive biomarkers of therapeutic response. The efficacy will be measured by the rate of patients with Ki67 ≤ 10% after 4 weeks and Preoperative Endocrine Prognostic Index (PEPI) score 0 on the surgical specimen. The feasibility of the study will be assessed by the acceptance rate of participating in the study (recruitment rate ≥ 50%) and the inclusion rate of &amp;gt;2 patients per month. Methods: This non-randomized phase II clinical trial includes postmenopausal women with invasive breast carcinoma, Scarf-Bloom-Richardson histological grades 1 or 2, Estrogen Receptor positive (Allred ≥ 6), progesterone receptor positive (any value), HER2 negative, Ki-67 antigen &amp;lt; 50% on immunohistochemistry, stages TNM II-III, with palpable tumor ≥ 2 cm, and ECOG 0-2. All eligible patients will receive anastrozole (1 mg/day) continuously until the day before the surgical procedure or exclusion from the study (in case of disease progression during endocrine therapy). After 2 to 4 weeks, a re-biopsy of the breast tumor will be performed. If Ki67 &amp;gt; 10%, endocrine therapy will be suspended, and the patient will be excluded from the study and redirected to neoadjuvant chemotherapy (routine care) or immediate surgery (as per attending clinical oncologist and surgeon). If Ki67 ≤ 10%, the patient will continue to receive NET. Extended NET will be administered for up to 10 months, with monthly physical examinations (using calipers) and bimonthly breast ultrasound. The presence of stable disease on ultrasound at 4, 6, and 8 months indicates scheduling surgery within 2 months thereafter, and disease progression at any time indicates surgery within one month. Patients will complete the EORTC QLQ-C30 and its supplemental module BR45 questionnaires every 2 months. Toxicity will be assessed using CTCAE version 4.0, and patients will respond to 11 specific items extracted from the Brazilian version of PRO-CTCAE. The radiological response will be evaluated by RECIST 1.1. Blood samples for molecular analyses will be collected at baseline and during re-biopsy. MicroRNA profiles will be evaluated using Nanostring, and extracellular vesicles will be examined using ATR-FTIR to identify predictive markers of therapeutic response (Ki67 &amp;lt; 10%) in re-biopsy. All cases will be evaluated using PAM50 at the initial biopsy and at surgery to determine the molecular phenotype (luminal A, B, or other) and molecular response (ROR score difference). Pathologic therapeutic response will be assessed using the PEPI score in all operated cases. The sample size was calculated to be 59 patients. The study was initiated in July 2022, and since then, a total of 26 patients have been enrolled. This study is registered with The Brazilian Registry of Clinical Trials (ReBEC): RBR-5pygzhj. Citation Format: Carlos Paiva, Izabella Oliveira, Vitor Guimarães, Alinne Faria, Domício Lacerda, Anapaula Uema, Nilton Onari, Bianca Paiva, Augusto Antoniazzi, Karina Oikawa, Maria Fernanda Machado, Matheus Godinho, Cristiano Souza, Chrissie Amirati, Gustavo Teixeira, Idam de Oliveira Jr, Márcia Marques, Yara Maia. ANNE: A phase II single-arm clinical trial to assess the feasibility and efficacy of neoadjuvant anastrozole in patients with luminal breast cancer and low proliferative index in TNM stages II and III [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-18-10.

Gene Expression Assays to Tailor Adjuvant Endocrine Therapy for HR+/HER2- Breast Cancer.

Adjuvant endocrine therapy (ET) represents the standard of care for almost all hormone receptor (HR)+/HER2- breast cancers, and different agents and durations are currently available. In this context, the tailoring and optimization of adjuvant endocrine treatment by reducing unnecessary toxic treatment while taking into account the biological heterogeneity of HR+/HER2- breast cancer represents a clinical priority. There is therefore a significant need for the integration of biological biomarkers in the choice of adjuvant ET beyond currently used clinicopathological characteristics. Several gene expression assays have been developed to identify patients with HR+/HER2- breast cancer who will not derive benefit from the addition of adjuvant chemotherapy. By enhancing risk stratification and predicting therapeutic response, genomic assays have also shown to be a promising tool for optimizing endocrine treatment decisions. In this study, we review evidence supporting the use of most common commercially available gene expression assays [Oncotype DX, MammaPrint, Breast Cancer Index (BCI), Prosigna, and EndoPredict] in tailoring adjuvant ET. Available data on the use of genomic tests to inform extended adjuvant treatment choice based on the risk of late relapse and on the estimated benefit of a prolonged ET are discussed. Moreover, preliminary evidence regarding the use of genomic assays to inform de-escalation of endocrine treatment, such as shorter durations or omission, for low-risk patients is reviewed. Overall, gene expression assays are emerging as potential tools to further personalize adjuvant treatment for patients with HR+/HER2- breast cancers.

Association of Src with Nottingham Prognostic Index in Breast Cancer: Implications for Breast Cancer Prognostication

Association of Src with Nottingham Prognostic Index in Breast Cancer: Implications for Breast Cancer Prognostication

IVIM and DCE-MRI in Predicting Phenotypic Subtypes and Nottingham Prognostic Index of Breast Cancer.

To explore the value of intravoxel incoherent motion (IVIM) and dynamic contrast enhanced MRI (DCE-MRI) for predicting phenotypic subtypes and Nottingham prognostic index (NPI) of breast cancer. Descriptive study. Place and Duration of the Study: Department of Radiology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China, from March 2020 to January 2022. One hundred and forty-one breast cancer patients with preoperative IVIM and DCE imaging were collected. IVIM parameters of D, D*, f, and DCE-MRI parameters of Ktrans, Kep, and Ve were measured. Receiver operating characteristic curves were conducted to assess the diagnostic efficacies. Additionally, 40 patients collected from February 2022 to July 2022 were enrolled as validation cohort. The D value in HER2-enriched (HER2-E) was lower than that in non-HER-E, while D*, Ktrans, and Ve values were higher than that in non-HER-E (p < 0.001, 0.046, < 0.001, and < 0.001, respectively). D + Ktrans + Ve showed an optimal diagnostic efficiency (AUC = 0.868). Meanwhile, D* and f values of triple-negative breast cancer (TNBC) were higher than those of non-TNBC, and Ve value of TNBC was lower than that of non-TNBC (p = 0.013, 0.006, and < 0.001, respectively). D* + f + Ve showed the best prediction performance (AUC = 0.849). Additionally, D and Kep were independent predictors of NPI (p < 0.001, and 0.002, respectively). D + Kep showed a good diagnostic efficiency (AUC = 0.818). The combined IVIM and DCE-MRI model showed enhanced diagnostic efficiency in predicting phenotypic subtypes and NPI of breast cancer, and might thus be considered efficient in therapy decision-making for patients. Breast neoplasms, Intravoxel incoherent motion, Dynamic contrast enhanced magnetic resonance imaging, Phenotypic subtypes, Nottingham prognostic index.

Abstract A089: Influence of pre-diagnosis aspirin use on epithelial ovarian cancer tumor immune microenvironment markers: results from the Nurses’ Health Study (NHS) and NHSII

Abstract Background: Daily aspirin use versus never use is associated with a 10-20% lower risk of developing epithelial ovarian cancer (EOC). Among women with EOC, aspirin use after diagnosis compared with never use is associated with a 30% improvement in ovarian cancer-specific survival. Inhibition of enzymes in prostaglandin synthesis is a key mechanism responsible for the anti-inflammatory and anti-neoplastic effects of aspirin. Prostaglandins influence immune inflammatory cells in the tumor microenvironment therefore our objective was to evaluate how aspirin use may influence the EOC tumor immune microenvironment. Methods: Tissue microarrays (TMAs) representing EOC tumor tissues from participants in the Nurses’ Health Study (NHS) and NHSII were assessed for total T cells, T cell activation and T cell exhaustion markers within the tumor (epithelium) area using multiplex immunofluorescence. Data on aspirin use and information on EOC risk factors and lifestyle variables were collected by questionnaire every two years. Beta-binomial models were used to estimate odds ratios (ORs) and 95% CIs; these models estimate the odds that a cell was positive for the marker(s) of interest comparing recent regular aspirin use (2+ times per week in the questionnaire cycle prior to diagnosis) versus never use, accounting for the total tumor cells in each core. Former users of aspirin were excluded. Multivariable models were adjusted for cohort, histotype (type 1 versus type 2), age and year of cancer diagnosis, number of CD3+ T cells (in tertiles), hysterectomy, tubal ligation, duration of oral contraceptive use, family history of breast or ovarian cancer, parity and body mass index (as fixed effects) and the participant (random effect) to account for multiple tissue cores per case. Results: We compared tumor tissues from 209 participants with recent pre-diagnosis use of aspirin with 88 participants who never used aspirin. Compared with cases who never used aspirin, recent aspirin users had higher odds of having tumors with recently activated cytotoxic T cells (CD3+CD8+CD69+, OR=1.69, 95% CI: 1.10, 2.59) and T cells expressing exhaustion markers (CD3+Lag-3+, OR=1.63, 95% CI: 1.09, 2.43; CD3+Tim-3+, OR= 1.62, 95% CI: 0.96, 2.72). In contrast, there was no association between recent aspirin use versus never use and odds of a tumor being positive for total T cells (CD3+, OR=1.20, 95% CI: 0.80, 1.79). Conclusions: Our data suggest that recent aspirin use before diagnosis was associated with higher odds of having EOC tumors expressing both recently activated cytotoxic T cells and T cell exhaustion markers. By improving our biological understanding of how aspirin use influences the ovarian tumor immune microenvironment, these results will assist to inform the optimal use of aspirin to improve EOC patient outcomes. Future work will focus on additional immune markers, assess non-aspirin nonsteroidal anti-inflammatory drug (NSAID) use and evaluate associations between aspirin/NSAID use with EOC survival considering the context of tumor immune microenvironment biomarkers. Citation Format: Nicola S. Meagher, Cassandra Hathaway, Mary K. Townsend, Mollie E. Barnard, Jose R. Conejo-Garcia, Brooke L. Fridley, Daryoush Saeed-Vafa, Britton Trabert, Shelley S. Tworoger, Melissa A. Merritt. Influence of pre-diagnosis aspirin use on epithelial ovarian cancer tumor immune microenvironment markers: results from the Nurses’ Health Study (NHS) and NHSII [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A089.

Impact of the Breast Cancer Index for Extended Endocrine Decision-Making: First Results of the Prospective BCI Registry Study.

The Breast Cancer Index (BCI) test assay provides an individualized risk of late distant recurrence (5-10 years) and predicts the likelihood of benefitting from extended endocrine therapy (EET) in hormone receptor-positive early-stage breast cancer. This analysis aimed to assess the impact of BCI on EET decision-making in current clinical practice. The BCI Registry study evaluates long-term outcomes, decision impact, and medication adherence in patients receiving BCI testing as part of routine clinical care. Physicians and patients completed pre-BCI and post-BCI test questionnaires to assess a range of questions, including physician decision-making and confidence regarding EET; patient preferences and concerns about the cost, side effects, drug safety, and benefit of EET; and patient satisfaction regarding treatment recommendations. Pre-BCI and post-BCI test responses were compared using McNemar's test and Wilcoxon signed rank test. Pre-BCI and post-BCI questionnaires were completed for 843 physicians and 823 patients. The mean age at enrollment was 65 years, and 88.4% of patients were postmenopausal. Of the tumors, 74.7% were T1, 53.4% were grade 2, 76.0% were N0, and 13.8% were HER2-positive. Following BCI testing, physicians changed EET recommendations in 40.1% of patients (P<.0001), and 45.1% of patients changed their preferences for EET (P<.0001). In addition, 38.8% of physicians felt more confident in their recommendation (P<.0001), and 41.4% of patients felt more comfortable with their EET decision (P<.0001). Compared with baseline, significantly more patients were less concerned about the cost (20.9%; P<.0001), drug safety (25.4%; P=.0014), and benefit of EET (29.3%; P=.0002). This analysis in a large patient cohort of the BCI Registry confirms and extends previous findings on the significant decision-making impact of BCI on EET. Incorporating BCI into clinical practice resulted in changes in physician recommendations, increased physician confidence, improved patient satisfaction, and reduced patient concerns regarding the cost, drug safety, and benefit of EET.

Lifestyle Factors and Breast Cancer in Females with PTEN Hamartoma Tumor Syndrome (PHTS).

Females with PTEN Hamartoma Tumor Syndrome (PHTS) have breast cancer risks up to 76%. This study assessed associations between breast cancer and lifestyle in European female adult PHTS patients. Data were collected via patient questionnaires (July 2020-March 2023) and genetic diagnoses from medical files. Associations between lifestyle and breast cancer were calculated using logistic regression corrected for age. Index patients with breast cancer before PHTS diagnosis (breast cancer index) were excluded for ascertainment bias correction. In total, 125 patients were included who completed the questionnaire at a mean age of 44 years (SD = 13). This included 21 breast cancer indexes (17%) and 39 females who developed breast cancer at 43 years (SD = 9). Breast cancer patients performed about 1.1 times less often 0-1 times/week physical activity than ≥2 times (ORtotal-adj = 0.9 (95%CI 0.3-2.6); consumed daily about 1.2-1.8 times more often ≥1 than 0-1 glasses of alcohol (ORtotal-adj = 1.2 (95%CI 0.4-4.0); ORnon-breastcancer-index-adj = 1.8 (95%CI 0.4-6.9); were about 1.04-1.3 times more often smokers than non-smokers (ORtotal-adj = 1.04 (95%CI 0.4-2.8); ORnon-breastcancer-index-adj = 1.3 (95%CI 0.4-4.2)); and overweight or obesity (72%) was about 1.02-1.3 times less common (ORtotal-adj = 0.98 (95%CI 0.4-2.6); ORnon-breastcancer-index-adj = 0.8 (95%CI 0.3-2.7)). Similar associations between lifestyle and breast cancer are suggested for PHTS and the general population. Despite not being statistically significant, results are clinically relevant and suggest that awareness of the effects of lifestyle on patients' breast cancer risk is important.