Distant Breast Cancer Research Articles

Prognostic value of PAM50 and risk of recurrence score in patients with early-stage breast cancer with long-term follow-up

BackgroundThe aim of this study was to investigate the prognostic value of the PAM50 intrinsic subtypes and risk of recurrence (ROR) score in patients with early breast cancer and long-term follow-up. A special focus was placed on hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2−) pN0 patients not treated with chemotherapy.MethodsPatients with early breast cancer (n = 653) enrolled in the observational Oslo1 study (1995–1998) were followed for distant recurrence and breast cancer death. Clinicopathological parameters were collected from hospital records. The primary tumors were analyzed using the Prosigna® PAM50 assay to determine the prognostic value of the intrinsic subtypes and ROR score in comparison with pathological characteristics. The primary endpoints were distant disease-free survival (DDFS) and breast cancer-specific survival (BCSS).ResultsOf 653 tumors, 52.2% were classified as luminal A, 26.5% as luminal B, 10.6% as HER2-enriched, and 10.7% as basal-like. Among the HR+/HER2− patients (n = 476), 37.8% were categorized as low risk by ROR score, 22.7% as intermediate risk, and 39.5% as high risk. Median follow-up durations for BCSS and DDFS were 16.6 and 7.1 years, respectively. Multivariate analysis showed that intrinsic subtypes (all patients) and ROR risk classification (HR+/HER2− patients) yielded strong prognostic information. Among the HR+/HER2− pN0 patients with no adjuvant treatment (n = 231), 53.7% of patients had a low ROR, and their prognosis at 15 years was excellent (15-year BCSS 96.3%). Patients with intermediate risk had reduced survival compared with those with low risk (p = 0.005). In contrast, no difference in survival between the low- and intermediate-risk groups was seen for HR+/HER2− pN0 patients who received tamoxifen only. Ki-67 protein, grade, and ROR score were analyzed in the unselected, untreated pT1pN0 HR+/HER2− population (n = 171). In multivariate analysis, ROR score outperformed both Ki-67 and grade. Furthermore, 55% of patients who according to the PREDICT tool (http://www.predict.nhs.uk/) would be considered chemotherapy candidates were ROR low risk (33%) or luminal A ROR intermediate risk (22%).ConclusionsThe PAM50 intrinsic subtype classification and ROR score improve classification of patients with breast cancer into prognostic groups, allowing for a more precise identification of future recurrence risk and providing an improved basis for adjuvant treatment decisions. Node-negative patients with low ROR scores had an excellent outcome at 15 years even in the absence of adjuvant therapy.

Clinical outcomes in patients with node-negative breast cancer treated based on the recurrence score results: evidence from a large prospectively designed registry

The 21-gene Recurrence Score® (RS) assay is a validated prognostic/predictive tool in ER + early-stage breast cancer. However, clinical outcome data from prospective studies in RS ≥ 11 patients are lacking, as are relevant real-life clinical practice data. In this retrospective analysis of a prospectively designed registry, we evaluated treatments/clinical outcomes in patients undergoing RS-testing through Clalit Health Services. The analysis included N0 ER + HER2-negative breast cancer patients who were RS-tested from 1/2006 through 12/2010. Medical records were reviewed to verify treatments/recurrences/survival. The cohort included 1801 patients (median follow-up, 6.2 years). Median age was 60 years, 50.4% were grade 2 and 81.1% had invasive ductal carcinoma; 48.9% had RS < 18, 40.7% RS 18–30, and 10.4% RS ≥ 31, with chemotherapy use of 1.4, 23.7, and 87.2%, respectively. The 5-year Kaplan–Meier estimates for distant recurrence were 0.8, 3.0, and 8.6%, for patients with RS < 18, RS 18–30 and RS ≥ 31, respectively; the corresponding 5-year Kaplan–Meier estimates for breast cancer death were 0.0, 0.9, and 6.2%. Chemotherapy-untreated patients with RS < 11 (n = 304) and 11–25 (n = 1037) (TAILORx categorization) had 5-year Kaplan–Meier estimates for distant recurrence risk/breast cancer death of 1.0%/0.0% and 1.3%/0.4%, respectively. Our results extend those of the prospective TAILORx trial: the 5-year Kaplan–Meier estimates for distant recurrence and breast cancer death rate for the RS < 18 patients were very low supporting the use of endocrine therapy alone. Furthermore, in chemotherapy-untreated patients with RS 11–25 (where TAILORx patients were randomized to chemoendocrine or endocrine therapy alone), 5-year distant recurrence rates were also very low, suggesting that chemotherapy would not have conferred clinically meaningful benefit.

195P - The 70-gene signature in node positive breast cancer: 10-year follow-up of the observational RASTER study

Background: In early stage breast cancer patients, with axillary lymph node metastasis, the 70-gene signature, MammaPrint® (MP) identifies patients with a High or Low Risk of distant breast cancer (BC) recurrence. For MP Low Risk (G(enomic)-low) in patients with up to 3 positive lymph nodes (N1-3), the MINDACT trial (Cardoso, NEJM 2016) showed that it might be safe to forgo adjuvant chemotherapy. Here we evaluated the prognostic value of MP at 10 years follow-up in patients with lymph node positive early stage BC. Methods: Between 2004 and 2006 812 women with early stage BC participated in the observational RASTER trial (Bueno de Mesquita, Lancet Oncol, 2007). 181 patients were node positive and not included in the primary analysis, 176 of them gave consent for future research. On 164 tumor samples (FFPE) MP was performed retrospectively. Survival data was collected and samples were allocated to clinical high (C-high) or C-low risk as used in MINDACT. Patients with over 3 axillary lymph node metastases (N4+) were all considered C-high. 10-year distant-recurrence-free-interval (DRFI) was compared between subgroups based on the MP and clinical assessment. Results: In 3 patients the clinical assesment could not be determined. Over 95% of patients received chemotherapy, 82.9% (136/164) of tumors were ER-positive and 18.3% (30/164) of patients had N4+. MP identified 47% (n = 77/164) as Low Risk, including 16,9% (13/77) with N4+. 10-year DRFI in patients N1-3 and G-Low or G-High was 94.9% and 80.7% respectively (HR 4.7; 95%CI 1.3-16.2). With the clinical assessment 13.7% (n = 22/161) were low risk, only one was diagnosed with distant BC recurrence. 10-years DRFI was 94.4% in C-low and 85.8% in C-high (HR 3.7 95%CI 0.5-28.5). In N4+ 10-years DRFI was 69.7%. Combining the clinical assessment with MP risk assessment in patients N1-3 the 10-years DRFI in clinical high risk patients was 95.2% for G-Low (n = 44) and 79.6% for G-High (n = 65) (HR 4.83 95%CI 1.1-21.4). Conclusions: We again confirm the prognostic value of Mammaprintin BC patients with axillary lymph node involvement after 10 years follow up. In N1-3 patients with clinical high risk, MP can identify a subgroup with excellent prognosis after standard adjuvant systemic therapy

157PD - 10 years follow up of the RASTER study; implementing a genomic signature in daily practice

Background: In 2004 the 70-gene signature, MammaPrint® (MP), developed to predict High or Low Risk of distant breast cancer (BC) recurrence, was introduced in the observational RASTER trial. Patients (cT1–3N0M0) and their doctors took the clinical Dutch guideline and MP in to account to decide on adjuvant systemic treatment (AST). Five years follow-up data confirmed the prognostic value of the MP (Drukker, Int J Cancer, 2013). In this analysis we report the outcome at 10 years. Methods: Ten year survival data was available for all 427 Raster patients, age < 61. For the current analysis, clinical high (C-high) or low (C-low) risk was scored according to the modified version of Adjuvant! Online (Cardoso, N Engl J Med, 2016). 10-year distant-recurrence-free-interval (DRFI) probabilities were compared between risk groups based on the 70-gene signature and clinical assessment. Results: The 70-gene signature identified 51.4% (219/427) patients with a genomic Low Risk of BC recurrence (G-low). 10-year DRFI in patients with G-low or genomic High Risk (G-high) was 93.7% and 86.8% respectively (HR 1.4; 95% confidence interval{CI] 1.0-1.9). Clinical assessment identified 57% as C-low. The 10-year DRFI was 91.7% in C-low and 88.2% in C-high (HR 1.4; 95%CI 0.8-2.6). The 10-year DRFI in the combined genomic and clinical riskgroups was 94.4% in patients with a C-low/G-Low profile, only 11.6% of them received AST. In the C-low/G-High group 10-years DRFI was 88.5%, over 90% of them received AST. For C-high risk patients 10-year DRFI was 90.9% if G-Low (n = 46) and 87.3% if G-High (n = 137). In ER-positive BC (ER+) (N = 342) 10-years DRFI was 93.6% (G-Low) versus 88.8% (G-High) (HR 1.6; 95%CI 0.8-3.3). With clinical risk assessment, 10-years DRFI in ER+ was 91.6% (C-low) versus 91.9% (C-high). Conclusions: Patients who omitted chemotherapy based on MammaPrint Low Risk had an excellent 10 year DRFI, confirming the prognostic value of the MP. When C-high, the MP identified another 10.8% (46/426) of patients as G-Low who might forego adjuvant chemotherapy if ER+. In contrast to genomic risk stratification, the clinical risk assessment was unable to differentiate for survival between ER+ C-high and C-low risk patients.

Disparities in Female Breast Cancer Stage at Diagnosis in New Jersey: A Spatial-Temporal Analysis.

Background:Despite improvements in early detection of breast cancer, disparities persist in stage at diagnosis, which is an important prognostic factor.Methods:We used the space-time scan statistic in SaTScan to identify geographic areas and time periods with significantly elevated proportions of female breast cancer diagnosed at the in situ or distant stage in New Jersey. The analyses were conducted with census tracts as the geographic unit of analysis, elliptical spatial windows, 3-year temporal windows, and Poisson models. Statistical significance was determined by 999 Monte Carlo simulations (P < .05); significant clusters were mapped in ArcMap. Breast cancer cases within the clusters were compared with breast cancer cases outside the clusters on demographic, socioeconomic, and clinical factors using the Pearson chi-square test (P < .05). In addition, populations within the clusters were compared with the population outside the clusters on demographic and socioeconomic factors.Results:After exclusions, 126 756 cases of primary female breast cancer diagnosed in 1997 to 2011 from the New Jersey State Cancer Registry were included in the analysis. One distant stage breast cancer cluster was identified in northeastern New Jersey from 1997 through 2011 (n = 26 244, relative risk [RR] = 1.42, P < .001). Two in situ breast cancer clusters were found in northeastern New Jersey from 2004 through 2011 (n = 12 496, RR = 1.35, P < .001) and in central New Jersey from 2006 through 2011 (n = 29 319, RR = 1.24, P < .001). The distant stage cluster contained relatively high percentages of minority and lower socioeconomic status (SES) breast cancer cases and populations, whereas the in situ clusters had relatively low percentages of minority and lower SES breast cancer cases and populations.Conclusion:Although there have been improvements since an earlier study of distant stage breast cancer diagnosed in 1995 to 1997, disparities in stage at diagnosis continue. These findings can be used by our local cancer control partners to target specific populations for interventions such as breast cancer education and mammography screening, as well as by state legislative and public health authorities for resource allocation.

Patterns and predictors of first and subsequent recurrence in women with early breast cancer

PurposeLittle is known about the occurrence, timing and prognostic factors for first and also subsequent local (LR), regional (RR) or distant (DM) breast cancer recurrence. As current follow-up is still consensus-based, more information on the patterns and predictors of subsequent recurrences can inform more personalized follow-up decisions.MethodsWomen diagnosed with stage I-III invasive breast cancer who were treated with curative intent were selected from the Netherlands Cancer Registry (N = 9342). Extended Cox regression was used to model the hazard of recurrence over ten years of follow-up for not only site-specific first, but also subsequent recurrences after LR or RR.ResultsIn total, 362 patients had LR, 148 RR and 1343 DM as first recurrence. The risk of first recurrence was highest during the second year post-diagnosis (3.9%; 95% CI 3.5–4.3) with similar patterns for LR, RR and DM. Young age (<40), tumour size >2 cm, tumour grade II/III, positive lymph nodes, multifocality and no chemotherapy were prognostic factors for first recurrence. The risk of developing a second recurrence after LR or RR (N = 176) was significantly higher after RR than after LR (50 vs 29%; p < 0.001). After a second LR or RR, more than half of the women were diagnosed with a third recurrence.ConclusionsAlthough the risk of subsequent recurrence is high, absolute incidence remains low. Also, almost half the second recurrences are detected in the first year after previous recurrence and more than 80% are DM. This suggests that more intensive follow-up for early detection subsequent recurrence is not likely to be (cost-)effective.

Diabetes, Abnormal Glucose, Dyslipidemia, Hypertension, and Risk of Inflammatory and Other Breast Cancer.

Background: Obesity has been associated with substantially higher risk of inflammatory breast cancer (IBC) than other breast cancer. Here, we assess whether comorbidities of obesity, namely diabetes, abnormal glucose, dyslipidemia, and hypertension, are differentially related to risk of IBC and other breast cancers by tumor stage at diagnosis (localized/regional/distant/unstaged).Methods: We used linked SEER-Medicare data, with female breast cancer cases ages 66+ years identified by SEER registries (years 1992-2011). We divided first breast cancers into IBC (N = 2,306), locally advanced non-IBC (LABC; N = 10,347), and other (N = 197,276). We selected female controls (N = 200,000) from a stratified 5% random sample of Medicare recipients alive and breast cancer free. We assessed exposures until 12 months before diagnosis/selection using Medicare claims data. We estimated odds ratios (OR) and 99.9% confidence intervals (CI) using unconditional logistic regression.Results: Diabetes was associated with increased risk of distant IBC (98.5% of IBC cases; OR 1.44; 99.9% CI 1.21-1.71), distant (OR 1.24; 99.9% CI, 1.09-1.40) and regional (OR 1.29 (99.9% CI, 1.14-1.45) LABC, and distant (OR 1.23; 99.9% CI, 1.10-1.39) and unstaged (OR 1.32; 99.9% CI, 1.18-1.47) other breast cancers. Dyslipidemia was associated with reduced risk of IBC (OR 0.80; 95% CI, 0.67-0.94) and other breast cancers except localized disease. Results were similar by tumor estrogen receptor status. Abnormal glucose levels and hypertension had little association with risk of any tumor type.Conclusions: Associations with diabetes and dyslipidemia were similar for distant stage IBC and other advanced tumors.Impact: If confirmed, such findings could suggest avenues for prevention. Cancer Epidemiol Biomarkers Prev; 26(6); 862-8. ©2017 AACR.

Phase 3 randomized study of adjuvant anastrozole (A), exemestane (E), or letrozole (L) with or without tamoxifen (T) in postmenopausal women with hormone-responsive (HR) breast cancer: The FATA-GIM3 trial.

515 Background: Uncertainty still exists regarding the optimal schedule of adjuvant treatment of breast cancer with aromatase inhibitors (AI) and no trial has ever compared all the three AI. Methods: FATA-GIM3 is a multicenter, open label, 2x3 factorial phase 3 randomized study of adjuvant A, E and L upfront (UP - for 5 years) or sequentially (SEQ - for 3 years after 2 years of T) in postmenopausal HR breast cancer pts. Two comparisons were planned: UP vs SEQ and A vs E vs L. DFS (including local or distant relapse, second breast or non-breast cancer, DCIS and death, whichever came first) was the primary end-point; 2% at 5 yrs (corresponding to a HR of 0.79) was defined as the minimum difference required to declare superiority of UP vs SEQ. With two-tailed alfa 0.05, power 80%, 669 events and the enrolment of 3600 patients were planned. Following Data Monitoring Committee advice, final analysis was performed after 5yrs median follow-up. For each comparison a Cox regression model was applied adjusted by stratification factors and stratified by the other treatment factor. Analyses were based on intention-to-treat. Results: from 3/2007 to 7/2012, 3697 patients were enrolled at 76 centres. Median age 64, pT1 69.7% , pN0 64.3%, ER and PgR positive 88.9%, HER2 positive 8.9%, previous chemotherapy 38.3%. At 60 months median follow-up, 401 events were reported. 5yrs DFS was 89.8 with UP and 88.5 with SEQ (delta 1.32%, 95% CI -0.90-3.54; HR 0.89, 95% CI 0.73-1.08; P=0.23). 5yrs DFS was 90.0 with A, 88.0 with E and 89.4 with L (P=0.19). Conclusions: in the FATA-GIM3 trial there is a small non statistically significant DFS advantage for UP vs SEQ. No significant difference is evident among the three AI. Supported by the FARM5K3MEE AIFA grant from the Italian Drug Agency. Clinical trial information: NCT00541086.

Impact of fertility preservation by ovarian stimulation on breast cancer outcomes.

e21588 Background: Chemotherapy and hormone therapy results in potential ovarian toxicity and delay in child-bearing among women of reproductive age with breast cancer. Whether short term ovarian stimulation is safe is not well studied. We examined the effects of short-term ovarian stimulation on patients’ breast cancer recurrence rates. Methods: Women diagnosed with localized breast cancer between 2005 and 2011 at any one of five cancer centres and referred to a reproductive endocrinologist in British Columbia, Canada, were identified from a central database. Clinical, pathological, treatment, and outcome characteristics were compared for patients who did and did not undergo ovarian stimulation prior to systemic cancer treatment. Results: Seventy-seven patients were included: median age was 33, all were ECOG 0/1, 31 (40%) had lymph node involvement, 62 (81%) had estrogen receptor (ER) positive disease, and 18 (23%) had HER2 positive disease. Thirty-four (44%) women underwent ovarian stimulation: they were more likely to receive chemotherapy than patients who declined ovarian stimulation (p = 0.001). Age, number of existing children, radiation, and hormonal treatments were not significantly associated with decision to undergo ovarian stimulation (p &gt; 0.05). After a median follow-up of 3.7 years, 7 (21%) patients who pursued ovarian stimulation and 9 (21%) patients who did not experienced disease recurrence. There was no association between ovarian stimulation and rate of local or distant breast cancer recurrence (p = 0.658). Conclusions: We did not find a harmful effect of short term ovarian stimulation on breast cancer recurrence rates. Limitations include short follow-up, a small sample size, and few relapses. Patients who received chemotherapy were more likely to pursue ovarian stimulation, suggesting that patients were well informed about the negative impact on fertility of chemotherapy and of the importance of fertility preservation prior to potentially gonado-toxic treatments.

Abstract 22: The Y537S ESR1 mutation is a dominant driver of distant ER-positive breast cancer metastasis

Abstract Background: Estrogen receptor (ESR1) mutations occur at a high frequency in metastatic breast tumors in patients treated with hormonal therapy in the metastatic setting. We do not know if these mutations are involved in metastasis. Experimental design and methods: We generated ESR1 Y537S homozygous mutations using CRISPR Casp-9 technology. Treatment synergy was evaluated using Compusyn. Athymic mice were used in tumor xenograft studies. ChIP-Seq and transcriptome analyses were performed. Results: We generated CRISPR ESR1 Y537S mutation homozygous knock-in clones and lentiviral stable pools in MCF-7 cells. Transcriptome profiling revealed elevated expression of Hallmark pathways, including epithelial mesenchymal transition (EMT) and estrogen-regulated gene expression. Mutant cell growth was resistant to tamoxifen, but responsive to fulvestrant treatment. Synergistic treatment effects were observed with fulvestrant and the mTOR inhibitor everolimus or the CDK4/6 inhibitor palbociclib. CRISPR Y537S mutant knock-in cells grown in the mammary fat-pad of athymic mice spontaneously metastasized to distant organs including the lung, intestine, and kidneys. In the presence of estrogen, there was no difference in the frequency of distant macrometastases between parental wild-type ER and CRISPR Y537S mutant ER mice. However, in the absence of estrogen, mimicking aromatase inhibitor treatment, 80% of CRISPR Y537S mutant ER mice displayed overt distant macrometastases, but none were observed in parental wild-type ER mice (p=0.04). Distant tumors retained ER expression and hormone sensitivity. Comparison of residual tamoxifen-treated metastatic tumors with tumors grown at the primary mammary fat-pad site using immunoblot analysis demonstrated significant reduction in estrogen-regulated gene expression, but no effect on the expression of biomarkers associated with EMT, suggesting a disconnect between EMT and distant metastasis in mutant cells. EMT genes were also identified as direct binding site targets in Y537S mutant cells compared with wide-type ER using ChIPSeq. We discovered that expression of the Y537S mutant was dominant, driving the growth of distant metastatic tumors when co-expressed with wild-type ER cells. A Y537S ER mutant-specific gene expression signature predicted poor disease-free survival of ER-positive patients using the METABRIC database, and lung-specific metastasis-free survival in a Memorial Sloan Kettering dataset. Conclusion: The Y537S ER mutation is a driver of distant metastasis in ER-positive breast cancer cells. A Y537S ER mutant-specific gene expression signature predicted poor disease-free, and distant lung metastasis in ER-positive patients. Mutation status is a potential new predictive factor for hormone therapy of metastatic breast cancer patients on maintenance hormonal therapy. Citation Format: Guowei Gu, Lin Tian, Meng Gao, Yassine Rechoum, Luca Gelsomino, Derek Dustin, Arnoldo Corona-Rodriguez, Amanda R. Beyer, Anna Tsimelzon, Xiang Zhang, Sebastiano Ando', Suzanne Fuqua. The Y537S ESR1 mutation is a dominant driver of distant ER-positive breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 22.

Abstract S4-02: The Y537S ESR1 mutation is a dominant driver of distant ER-positive breast cancer metastasis

Abstract Background: Estrogen receptor (ESR1) mutations occur at a high frequency in metastatic breast tumors in patients treated with hormonal therapy in the metastatic setting. We do not know if these mutations are involved in metastasis. Experimental design and methods: We generated ESR1 Y537S homozygous mutations using CRISPR Casp-9 technology. Treatment synergy was evaluated using Compusyn. Athymic mice were used in tumor xenograft studies. ChIP-Seq and transcriptome analyses were performed. Results: We generated CRISPR ESR1 Y537S mutation homozygous knock-in clones and lentiviral stable pools in MCF-7 cells. Transcriptome profiling revealed elevated expression of Hallmark pathways, including EMT and estrogen-regulated gene expression. The EMT in mutant cells was associated with a switch from E-cadherin to vimentin, and increased expression of SNAIL and TWIST. Mutant cell growth was resistant to tamoxifen, but responsive to fulvestrant treatment. Synergistic treatment effects were observed with fulvestrant and everolimus or palbociclib. CRISPR Y537S mutant knock-in cells grown in the mammary fat-pad of athymic mice spontaneously metastasized to distant organs including the lung, intestine, and kidneys. In the presence of estrogen, there was no difference in the frequency of distant macrometastases between parental wild-type ER and CRISPR Y537S mutant ER mice. However, in the absence of estrogen, 80% of CRISPR Y537S mutant ER mice displayed overt distant macrometastases, but none were observed in parental wild-type ER mice (p=0.04). Interestingly, although CRISPR Y537S mutant ER tumors grown in the mammary fat-pad were unresponsive to tamoxifen treatment, tamoxifen significantly inhibited the growth of mutant tumors at the distant microenvironment (8-fold). Distant tumors retained ER expression and hormone sensitivity. Comparison of residual tamoxifen-treated metastatic tumors with tumors grown at the primary mammary fat-pad site using immunoblot analysis demonstrated significant reduction in estrogen-regulated gene expression, but no effect on the expression of biomarkers associated with EMT, suggesting a disconnect between EMT and distant metastasis in mutant cells. EMT genes were also identified as direct binding site targets in Y537S mutant cells compared with wide-type ER using ChIPSeq. We discovered that expression of the Y537S mutant was dominant, driving the growth of distant metastatic tumors when co-expressed with wild-type ER cells. A Y537S ER mutant-specific gene expression signature predicted poor disease-free survival of ER-positive patients using the METABRIC database, and lung-specific metastasis-free survival in a Memorial Sloan Kettering dataset. Conclusion: The Y537S ER mutation is a driver of distant metastasis in ER-positive breast cancer cells. Although tamoxifen treatment was ineffective at reducing the growth of mutant cells grown at the primary site, it was effective at reducing distant metastasis. A Y537S ER mutant-specific gene expression signature predicted poor disease-free, and distant lung metastasis in ER-positive patients. Mutation status is a potential new predictive factor for hormone therapy of metastatic breast cancer patients on maintenance hormonal therapy. Citation Format: Fuqua SAW, Gu G, Rechoum Y, Gelsomino L, Dustin DJ, Corona-Rodriguez A, Beyer AR, Pejerrey SM, Gao M, Tsimelzon A, Tian L, Zhang X, Nagi C, Ando' S. The Y537S ESR1 mutation is a dominant driver of distant ER-positive breast cancer metastasis [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S4-02.

Abstract P5-14-06: The effect of adjuvant chemotherapy in a large consecutive series of ER-pos HER-2 negative early breast cancers

Abstract Background: The last EBCTCG-overview reported, in general, a significant better breast cancer outcome if adjuvant chemotherapy was added to surgery and endocrine therapy in ER-pos breast cancers, but the precise indication for adjuvant chemotherapy in this population remains controversial. We study the effect of adjuvant chemotherapy on breast cancer outcome in consecutive patients with an ER-pos HER-2 negative breast cancer treated with adjuvant antihormonal therapy. Methods: Data were collected prospectively from consecutive patients with non-metastatic breast cancer that were primary operated between 2000 and 2012 at the University Hospitals Leuven (Belgium). A Propensity Score (PS) weighted analysis was performed to estimate the average treatment effect (ATE). The primary endpoint was recurrence free interval (RFI). Secondary endpoints were distant recurrence free interval (D-RFI) and breast cancer specific survival (BCSS). Covariates used to generate the propensity score and to include in the PS weighted analysis were age at diagnosis, body mass index, tumor size, grade, pN, lymph vessel invasion, PR, and radiotherapy. Cause-specific hazard models were fitted, using death not from breast cancer as competing risk. Treatment heterogeneity was examined by evaluating interactions of each covariate with adjuvant chemotherapy, using the Bonferroni-Holm method to correct for multiple testing. Results: In the total cohort of 5609 patients, 4282 had a hormone sensitive HER-2 neg breast cancer and 4121 (96.2%) of these received adjuvant antihormonal therapy. Adjuvant chemotherapy was given in 1179/4121 patients (29%). Median follow-up was 8.5 years. Due to very strong differences between patients with and without adjuvant chemotherapy, a restricted PS weighted analysis was used according to a recent recommendation in the statistical literature. This analysis is based on 1750 patients with a PS between 0.1 and 0.9. In this group, 807 (46%) received adjuvant chemotherapy, 211 (12%) observed an event for RFI, 167 (10%) for D-RFI, and 108 (6%) for BCSS. Adjuvant chemotherapy was associated with better prognosis: the adjusted cumulative incidence of recurrence within 5 years was 9.7% without and 5.3% with adjuvant chemotherapy. The adjusted hazard ratio for RFI was 0.50 (95% CI 0.33-0.74). There were no strong interactions with adjuvant chemotherapy. Results for D-RFI and BCSS were similar. Conclusion: Based on PS analysis to reduce confounding and chemotherapy indication bias, we observed clear benefit from adjuvant chemotherapy in ER-pos HER-2 negative breast cancers. Citation Format: Van Calster B, Neven P, Wildiers H, Punie K, Jongen L, Han S, Berteloot P, Van Nieuwenhuysen E, Nevelsteen I, Smeets A, Floris G. The effect of adjuvant chemotherapy in a large consecutive series of ER-pos HER-2 negative early breast cancers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-14-06.

Abstract P2-05-06: Analytical and clinical validation of a fully automated tissue-based quantitative assay (MetaSite Breast™) to detect the likelihood of distant metastasis in hormone receptor (HR)-positive, HER2-negative early stage breast cancer (ESBC)

Abstract Background: MetaSite Breast™ is a validated assay to predict risk of distant breast cancer metastasis in patients with HR+/HER2- ESBC. The assay measures the number of MetaSites defined as tumor microanatomic structures composed of MENA protein expressing tumor cells in contact with CD31+ endothelial cells and CD68+ macrophages. Previous studies have demonstrated that an increased number of these microanatomic structures is associated with distant metastasis (DM) in HR+/HER2- ESBC independent of clinicopathologic features. Analytical validation of MetaSite Breast™ demonstrated precision of 97-99% (repeat image analysis of the same slide) and performance of 91-96% (staining and image analysis of serial tumor sections). We sought to further understand the importance of the MetaSite in predicting distant breast cancer metastasis utilizing a fully automated prognostic assay in an independent large patient cohort. Methods: We conducted a nested case-control study within a cohort of 3,760 patients diagnosed between 1980 and 2000 with invasive breast cancer from the Kaiser Permanente Northwest health care system. Cases (n=259) were women who developed a subsequent distant metastasis; controls, selected using incidence density sampling, were matched closely to cases (1:1) on age at and calendar year of primary diagnosis. Of the 481 patient tumor samples evaluated in this study, 57% were HR+/HER2-, 19% were triple negative (TN), and 15% were HER2+ disease. Multivariate models were adjusted for clinical factors including: lymph node status, tumor size, tumor grade, and HRT; as well as matching variables: age and year of diagnosis. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression. Results: In the HR+/HER2- group, MetaSite Score (MS) ranged from 0-357 and the mean was 44.6. MS was a significant predictor of DM (P=0.039) in patients with HR+/HER2- disease. Cut-points based on tertiles of MS in all 259 controls defined intermediate (13-41) and high (&amp;gt;41) risk groups that were significantly associated with risk of DM versus the low risk group (OR=2.24; 95%CI=1.23-4.13, P=0.009) and (OR=2.94; 95%CI=1.62-5.41, P=0.0005), respectively. Univariate estimates of absolute risk of DM with cutoffs based on 90% sensitivity and specificity were 9.4% for the low risk group (MS&amp;lt;7), 14.1% for the intermediate (MS=7-91), and 23.4% for the high (MS&amp;gt;91). When adjusted for clinical factors, estimates of absolute risk of DM were 6.6%, 14.1%, and 33.0% for the low, intermediate, and high risk groups, respectively. A binary cut-point for the high risk group was determined (MS&amp;gt;14) and was significant with a 2-fold higher risk of DM versus the low risk group and adjusted for clinical covariates (P=0.036). MS was not positively associated with DM in TN or HER2+ disease. Conclusions: MetaSite Breast™ significantly predicted the risk of distant breast cancer metastasis in ESBC patients with HR+/HER2-disease, independent of classical clinicopathologic features. Citation Format: Donovan MJ, Jones JG, Entenberg DR, Condeelis JS, D'alfonso TM, Gustavson M, Molinaro A, Oktay MH, Xue X, Sparano JA, Peterson MA, Podznyakova O, Rohan TE, Shuber AP, Gertler FB, Ly A, Divelbiss ME, Hamilton DA. Analytical and clinical validation of a fully automated tissue-based quantitative assay (MetaSite Breast™) to detect the likelihood of distant metastasis in hormone receptor (HR)-positive, HER2-negative early stage breast cancer (ESBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-06.

Abstract P2-05-13: Negative progesterone receptor is associate early breast cancer relapse, even among good prognosis tumors

Abstract Background/objective: A minority of estrogen-receptor (ER) positive breast cancers lack progesterone receptor (PR) expression, but little is known of the clinical meaning of PR negativity (PR-). In the present study we sought to clarify the association between PR- and outcomes of ER+, human-epidermal growth factor (HER2)-negative breast cancers using a large, single institution database. Methods: We retrospectively analyzed consecutive, non-metastatic, unilateral HER2- invasive breast cancers diagnosed between 2000 and 2011. Records were reviewed for age at diagnosis, disease stage, tumor features, and histologically confirmed recurrence. ER+ and PR+ status was defined as ≥1% immunoreactive cells. We used Kaplan-Meier curves to determine the association between PR- and early (≤5 years) and late (&amp;gt;5 years) disease recurrence, defined as locoregional or distant breast cancer relapse &amp;gt;6 months after diagnosis. Results: We identified 1,933 patients with TN (n=337) or ER+/HER2- (n=1,596) breast cancer. Patients with ER+/PR- (n=107) vs. ER+/PR+ (n=1,489) tumors did not differ in age or disease stage at diagnosis; however, PR- tumors were more frequently high grade (37.9% vs. 17.8%, p&amp;lt;0.001), with higher median Ki67 indices (20.0% vs. 10.0%, p&amp;lt;0.001). Median ER expression was also lower in PR- as compared to PR+ tumors (80.0% vs. 90.0%, p&amp;lt;0.001). Over a median follow-up of 84 months, there were 119 early and 54 late locoregional or distant breast cancer relapses. Negative PR was strongly associated with early relapse, with PR- tumors demonstrating a 2.1-fold higher hazard of relapse in the first 5 years as compared to PR+ tumors (95% CI 1.0-4.2) Hazards of early (&amp;lt;5 years) breast cancer relapse by hormone status. Shown are univariable Cox proportional hazard ratios and 95% confidence intervals among all tumors, and in subsets defined by %ER, node status, Ki67, and grade. All tumors n=1,933High ER (80-100%) n=1,383TN3.9 (2.6-5.6)*--PR 0%2.1 (1.0-4.2)*1.7 (0.6-4.6)PR 1-100%ReferenceReference Node-negative n=1,299Node-positive n=634TN4.3 (2.5-7.5)*3.6 (2.1-6.0)*PR 0%2.7 (1.0-7.0)*1.6 (0.6-4.5)PR 1-100%ReferenceReference Ki67 &amp;lt;14% n=768Ki67 ≥14% n=997TN**2.4 (1.5-3.8)*PR 0%4.1 (1.2-14.1)*1.6 (0.7-3.8)PR 1-100%ReferenceReference Grade 1/2 n=1,337Grade 3 n=564TN3.4 (1.4-7.9)*1.9 (1.2-3.3)*PR 0%2.0 (0.7-5.7)1.2 (0.4-3.5)PR 1-100%ReferenceReference*p&amp;lt;0.05; **too few subjects/events for analysis. Negative PR remained significantly associated with a higher hazard of early relapse even in node-negative (HR 2.7, 95%CI 1.0-7.0) and low-proliferating tumors (Ki67&amp;lt;14%, HR 4.1, 95%CI 1.2-14.1). There was no significant association between PR- and late breast cancer relapse (HR 0.7, 95%CI 0.2-2.9). Conclusions: Compared to ER+/PR+ breast cancers, ER+/PR- breast cancers have a significantly greater risk of early recurrence, similar to triple-negative cancers. These results suggest that negative PR expression is importantly and independently associated with early breast cancer prognosis, and may be an indicator of unique tumor biology. Citation Format: Winner M, Rosman M, Mylander C, Jackson RS, Pozo ME, Wolff AC, Tafra L, Umbricht CB. Negative progesterone receptor is associate early breast cancer relapse, even among good prognosis tumors [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-13.

Abstract P1-07-16: Multi-level gene expression signatures provide significant prognostic information in metastatic breast cancer patients

Abstract Background: We have previously demonstrated how transcriptional pathway activity and the molecular subtypes of breast cancer metastases significantly influence patient post-relapse survival. Here we extend our analysis to determine whether the prognostic information provided by gene expression signatures in primary breast tumours is also relevant in the metastatic setting. Specifically, we test the research versions of the Genomic Grade Index (GGI), Mammaprint, Recurrence score (RS) and PAM50 gene signatures along with our own cell-cycle based classifier (CCS). Methods: 287 patients with morphologically confirmed loco-regional or distant breast cancer relapse were enrolled in the Swedish multicenter TEX trial from December 2002 until June 2007. Of these, sufficient tumour RNA for gene expression profiling was obtained from metastatic tissue by fine needle aspiration from 111 patients (totalling 120 relapse biopsies). Gene signatures were applied as described in the original research articles and their relationship to short (1.5 year) and long-term (5 year) post-relapse survival was assessed using likelihood ratio, Kaplan-Meier and Cox regression analysis. Results: As anticipated from an aggressive metastatic cohort, the majority of samples (&amp;gt; 70%) were classified into intermediate or high risk groups by all signatures. In both short and long-term survival analysis only PAM50 provided statistically significant prognostic information (short: LRχ2 = 14.7, p = 0.005 and long: LRχ2 = 13.2, p = 0.010), with the cell cycle score signature displaying a prognostic trend in long-term survival only (LRχ2 = 5.2, p = 0.074). Kaplan-Meier curves and Cox regression analysis suggest that the strength of both signatures resides in their ability to select a group of low-risk patients with better long-term survival. Conclusions: Our findings demonstrate the prognostic utility of the multi-level PAM50 and to a lesser extent, cell cycle score signatures in predicting survival of patients with metastatic breast cancer. Simpler binary gene expression signatures (GGI and Mammaprint) do not appear to capture the same prognostic information and as such may have limited utility in a metastatic setting. Short and long term survival Likehood Ratios for five gene expression signatures in metastatic breast cancer Short term survival (1.5 year)Long term survival (5 year)Gene SignatureLRχ2P-valueLRχ2P-valueGGI1.30.2510.50.500Mammaprint1.70.1900.60.427RS3.90.1434.40.110CCS2.80.2425.20.074PAM5014.70.00513.20.010GGI: Genomic grade index; RS: Recurrence score; CCS: Cell cycle score Citation Format: Tobin NP, Lundberg A, Lindström LS, Harrell JC, Egyhazi Brage S, Frostvik Stolt M, Einbeigi Z, Loman N, Malmberg M, Perou CM, Bergh J, Hatschek T. Multi-level gene expression signatures provide significant prognostic information in metastatic breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-07-16.

Should Bone-Targeted Agents be Standard of Care in Postmenopausal Patients with Early Breast Cancer?

The role of bone-targeted agents in the adjuvant treatment of early breast cancer has been debated for decades. A recent meta-analysis of individual patient data from 18,766 women provides compelling evidence supporting the use of these agents in postmenopausal women with early-stage breast cancer. Postmenopausal women who received a bisphosphonate had a significant reduction in breast cancer mortality (14.7 vs 18%; p = 0.002) and in overall survival (21.1 vs 23.5%; p = 0.005). Some questions remain such as; what bone-targeted agent is the best? What are the optimum doses, durations and schedules? Which patients benefit the most? The decision to include a bone-targeted agent should consider the absolute risk of distant recurrence and breast cancer mortality.

Progressive APOBEC3B mRNA expression in distant breast cancer metastases.

BackgroundAPOBEC3B was recently identified as a gain-of-function enzymatic source of mutagenesis, which may offer novel therapeutic options with molecules that specifically target this enzyme. In primary breast cancer, APOBEC3B mRNA is deregulated in a substantial proportion of cases and its expression is associated with poor prognosis. However, its expression in breast cancer metastases, which are the main causes of breast cancer-related death, remained to be elucidated.Patients and methodsRNA was isolated from 55 primary breast cancers and paired metastases, including regional lymph node (N = 20) and distant metastases (N = 35). APOBEC3B mRNA levels were measured by RT-qPCR. Expression levels of the primary tumors and corresponding metastases were compared, including subgroup analysis by estrogen receptor (ER/ESR1) status.ResultsOverall, APOBEC3B mRNA levels of distant metastases were significantly higher as compared to the corresponding primary breast tumor (P = 0.0015), an effect that was not seen for loco-regional lymph node metastases (P = 0.23). Subgroup analysis by ER-status showed that increased APOBEC3B levels in distant metastases were restricted to metastases arising from ER-positive primary breast cancers (P = 0.002). However, regarding ER-negative primary tumors, only loco-regional lymph node metastases showed increased APOBEC3B expression when compared to the corresponding primary tumor (P = 0.028).ConclusionAPOBEC3B mRNA levels are significantly higher in breast cancer metastases as compared to the corresponding ER-positive primary tumors. This suggests a potential role for APOBEC3B in luminal breast cancer progression, and consequently, a promising role for anti-APOBEC3B therapies in advanced stages of this frequent form of breast cancer.

The prognostic effect of DDX3 upregulation in distant breast cancer metastases

Metastatic breast cancer remains one of the leading causes of death in women and identification of novel treatment targets is therefore warranted. Functional studies showed that the RNA helicase DDX3 promotes metastasis, but DDX3 expression was never studied in patient samples of metastatic cancer. In order to validate previous functional studies and to evaluate DDX3 as a potential therapeutic target, we investigated DDX3 expression in paired samples of primary and metastatic breast cancer. Samples from 79 breast cancer patients with distant metastases at various anatomical sites were immunohistochemically stained for DDX3. Both cytoplasmic and nuclear DDX3 expression were compared between primary and metastatic tumors. In addition, the correlation between DDX3 expression and overall survival was assessed. Upregulation of cytoplasmic (28%; OR 3.7; p = 0.002) was common in breast cancer metastases, especially in triple negative (TN) and high grade cases. High cytoplasmic DDX3 levels were most frequent in brain lesions (65%) and significantly correlated with high mitotic activity and triple negative subtype. In addition, worse overall survival was observed for patients with high DDX3 expression in the metastasis (HR 1.79, p = 0.039). Overall, we conclude that DDX3 expression is upregulated in distant breast cancer metastases, especially in the brain and in TN cases. In addition, high metastatic DDX3 expression correlates with worse survival, implying that DDX3 is a potential therapeutic target in metastatic breast cancer, in particular in the clinically important group of TN patients.

Influence of decalcification procedures on immunohistochemistry and molecular pathology in breast cancer

Distant breast cancer metastases are nowadays routinely biopsied to reassess receptor status and to isolate DNA for sequencing of druggable targets. Bone metastases are the most frequent subgroup. Decalcification procedures may negatively affect antigenicity and DNA quality. We therefore evaluated the effect of several decalcification procedures on receptor status and DNA/RNA quality. In 23 prospectively collected breast tumors, we compared ERα, PR and HER2 status by immunohistochemistry in (non-decalcified) tissue routinely processed for diagnostic purposes and in parallel tissue decalcified in Christensen's buffer with and without microwave, EDTA and Formical-4. Furthermore, HER2 fluorescence in situ hybridization and DNA/RNA quantity and quality were assessed. We found that the percentage of ERα-positive cells were on average lower in EDTA (P=0.049) and Formical-4 (P=0.047) treated cases, compared with controls, and PR expression showed decreased antigenicity after Christensen's buffer treatment (P=0.041). Overall, a good concordance (weighted kappa) was seen for ERα, PR and HER2 immunohistochemistry when comparing the non-decalcified control tissues with the decalcified tissues. For two patients (9%), there was a potential influence on therapeutic decision making with regard to hormonal therapy or HER2-targeted therapy. HER2 fluorescence in situ hybridization interpretation was seriously hampered by Christensen's buffer and Formical-4, and DNA/RNA quantity and quality were decreased after all four decalcification procedures. Validation on paired primary breast tumor specimens and EDTA-treated bone metastases showed that immunohistochemistry and fluorescence in situ hybridization were well assessable and DNA and RNA yield and quality were sufficient. With this, we conclude that common decalcification procedures have only a modest negative influence on hormone and HER2 receptor immunohistochemistry in breast cancer. However, they may seriously affect DNA/RNA-based diagnostic procedures. Overall, EDTA-based decalcification is therefore to be preferred as it best allows fluorescence in situ hybridization and DNA/RNA isolation.

The Benefit of Baseline Staging-Risk Assessment of Distant Breast Cancer Metastases by Tumor Stage.

Despite recommendations of international societies, use of baseline staging in breast cancer varies considerably. We retrospectively analyzed the prevalence of metastases in each pTN stage to estimate the benefit of staging. The prevalence of metastases at primary diagnosis (M1) and in the first year after diagnosis (M112) was determined in 2,906 patients. The prevalence of M1 was 0.95% [95% confidence interval (CI)=0.53-1.70%] in pT1pN0, 2.17% (95% CI=1.00-4.64) in pT1pN1 and 1.53% (95% CI=0.78-2.99%) in pT2pN0. The prevalence of M112 was 2.17% (95% CI=1.47-3.18%) in pT1pN0 and 3.25% in pathological stage IIA (upper confidence bound 5.14%). In pT2pN1 the prevalence of M1 and M112 was 3.49% (95% CI=1.96-6.14%) and 6.35% (95% CI=4.15-9.60%), respectively. Results for stage pT3pN0 and higher were inconclusive. Baseline staging can be safely abandoned in pathological stage I and IIA. Individual decisions should be made for pT2pN1. Staging is recommended in stages of pT3pN0 or higher.