Estrogen Receptor Positive Early Stage Research Articles

Abstract GS2-04: Aromatase inhibitors versus tamoxifen in pre-menopausal women with estrogen receptor positive early stage breast cancer treated with ovarian suppression: A patient level meta-analysis of 7,030 women in four randomised trials

Abstract Background: For women with early stage hormone receptor positive breast cancer, adjuvant treatment with tamoxifen reduces their 15-year risk of death from breast cancer by about one third. Aromatase inhibitors (AIs) are even more effective than tamoxifen in post-menopausal women but, used alone, are ineffective in pre-menopausal women due to compensatory ovarian oestrogen production. Several trials have assessed whether, if administered with ovarian suppression, AIs may also be more effective than tamoxifen at preventing breast cancer recurrence in premenopausal women but trial results have been inconsistent. Methods: Individual patient data were available from four randomised controlled trials, including 7,030 pre-menopausal women with estrogen receptor positive (ER+) breast cancer. All women received ovarian suppression or ablation and were randomised to receive either an AI or tamoxifen for 3 years (in ABCSG XII) or 5 years in other trials (SOFT, TEXT and HOBOE). Primary outcomes for the meta-analysis were time to invasive breast cancer recurrence (distant, loco-regional, or new contralateral breast primary) and breast cancer mortality. Log-rank analyses were used to estimate first-event rate ratios (RR) and their confidence intervals (CIs). Results: Overall, the annual rate of recurrence averaged 21% lower (RR 0.79, 95% 0.69-0.90, p=0.0005) for women allocated AI compared to tamoxifen. The main benefit from AI was seen in years 0-4 (RR 0.68, 99% CI 0.58-0.80), during the period when treatments differed, with no further benefit, or loss of benefit, in years 5-9 (RR 0.98, 99% 0.73-1.32), and as yet limited follow up data available beyond year 10. The 5-year absolute risk of breast cancer recurrence was 3.2% lower in the AI group than the tamoxifen group (6.9% vs 10.1%, p=0.0005). Although distant recurrence was reduced with AI (RR 0.83, 95% CI 0.71-0.97, p=0.02), there was no difference in breast cancer mortality although longer follow up is needed to assess effects on mortality reliably. The proportional reduction in recurrence during the period when treatments differed did not vary by age, BMI, or by tumour size, tumour grade, histological subtype, or presence and absence of chemotherapy. In contrast to the findings of the meta-analysis of AI vs tamoxifen in postmenopausal women, AI appeared ineffective in N4+ disease (RR=0.49 in N0, RR=0.56 in N1-3, RR=1.03 in N4+; p for trend =0.0009). The only other apparent heterogeneity was between the four trial results (p=0.03), and between HER2-negative and positive disease (p=0.05), which may be chance findings given the borderline statistical significance. There were more bone fractures in women receiving AI (5.0% AI vs 3.8% Tam, p=0.02). Among these younger women, few non-breast cancer deaths occurred: 0.9% AI vs 0.7% Tam (RR 1.30, 95% CI 0.75-2.25), and the incidence of endometrial cancer was low (0.2% AI vs 0.3% tamoxifen, p=0.14). Conclusion: Using an AI rather than tamoxifen, in premenopausal women receiving ovarian suppression, reduces the risk of breast cancer recurrence by about 20%. If the surprising lack of benefit in N4+ disease is a chance finding, then the absolute benefits will be larger for women at a higher absolute risk of recurrence. Citation Format: Rosie Bradley, Jeremy Braybrooke, Richard Gray, Robert K Hills, Zulian Lui, Hongchao Pan, Richard Peto, Jonas Bergh, Sandra M Swain, Prudence Francis, Michael Gnant, Francesco Perrone, Meredith M Regan. Aromatase inhibitors versus tamoxifen in pre-menopausal women with estrogen receptor positive early stage breast cancer treated with ovarian suppression: A patient level meta-analysis of 7,030 women in four randomised trials [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS2-04.

Abstract P2-11-03: Predictive significance of an optimized immunohistochemical panel for basal-like breast cancer on the CCTG MA.12 phase III randomized clinical trial

Abstract Background: Tamoxifen and aromatase inhibitors constitute the backbone of treatment for estrogen receptor positive early stage breast cancers based on immunohistochemical (IHC) results. While these therapies significantly reduce the risk of relapse of breast cancer, they have toxicities and add to costs. Gene expression profiling assays are widely used to quantify risk and support targeted therapies for luminal breast cancers treated with adjuvant endocrine therapy. In a prospective-retrospective analysis of the phase III CCTG MA.12 clinical trial (randomizing premenopausal women treated with adjuvant chemotherapy, to either tamoxifen or placebo for 5 years), luminal subtype by PAM50 was significantly predictive for tamoxifen benefit. However, IHC classification (as estrogen receptor positive) could not demonstrate a statistically significant benefit from tamoxifen over placebo. More accurate IHC biomarkers incorporating nestin positivity or loss of inositol polyphosphate-4-phosphate (INPP4B) have recently been optimized to identify the basal-like intrinsic subtype of breast cancer regardless of ER/PR/HER2 status. In this study, we examined the capacity of these basal biomarkers to identify intrinsic subtype and predict benefit from adjuvant tamoxifen vs. placebo in the CCTG MA.12 clinical trial Methods:492 formalin-fixed paraffin embedded blocks of primary tumor from patients randomized in the CCTG MA.12 trial were used to build tissue microarrays. IHC staining for nestin and INPP4B was done according to published methods, and interpretation was performed by pathologists with no access to molecular data. The performance of the nestin and INPP4B panel was assessed against PAM50 gene expression assay as a standard reference. A prespecified statistical plan was executed independently by the Canadian Cancer Trials Group, testing the primary hypothesis that patients with basal breast cancer, when defined as “positive for nestin or negative for INPP4B,” would not benefit from tamoxifen (primary endpoint: disease-free survival).Results: 366 primary tumor samples from the CCTG MA.12 had a full dataset available for IHCbiomarker evaluation, PAM50 subtype and clinical outcomes. Positive staining of nestin or loss of INPP4B was observed in 47 (13%) of the total cases and was significantly associated with poor prognostic factors including high grade, younger age, ER negativity, triple negative and core basal IHC status (p<0.01). “Nestin+ or INPP4B-” status was significantly associated with basal-like PAM50 gene expression subtype, while the other cases (nestin- and INPP4B+) were significantly associated with PAM50 luminal subtype. Patients assigned as basals by “nestin+ or INPP4B-” IHC status did not demonstrate a benefit from adjuvant tamoxifen vs. placebo (HR=1.39, 95%CI [0.37-5.26], p=0.63), whereas “nestin- and INPP4B+” cases displayed a significantly higher benefit from adjuvant tamoxifen vs. placebo (HR=0.67, 95% CI [0.45-0.98], p=0.04), (p-interaction=0.87). While, in this trial, ER clinical status as determined in community hospitals or centrally by single biomarker IHC was not significantly predictive for tamoxifen benefit, patients classified as IHC non-basal “nestin- and INPP4B+” within the ER+ subgroup did benefit from addition of tamoxifen (HR=0.62, 95%CI [0.38-1.01], p=0.05).Conclusions:The nestin/INPP4B IHC panel offers a feasible and inexpensive methodology to accurately identify intrinsic subtype of breast cancer. Patients assigned as IHC basal by this panel did not display a superior survival when treated with tamoxifen vs. placebo in the adjuvant setting. Within the ER+ subgroup, these cases could potentially be spared the side effects of currently recommended endocrine therapies that do not benefit this group of patients. Citation Format: Karama Asleh, Dongxia Gao, Vivien H Bramwell, Dongsheng Tu, Lois E Shepherd, Torsten O Nielsen. Predictive significance of an optimized immunohistochemical panel for basal-like breast cancer on the CCTG MA.12 phase III randomized clinical trial [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-11-03.

2420 A Rare Cause of Portal Vein Thrombosis

INTRODUCTION: Hormone therapy is the mainstay adjuvant therapy for patients with estrogen receptor positive early stage breast cancer. Anastrozole is generally considered to have lower risk of venous thromboembolism compared to tamoxifen, albeit not negligible. CASE DESCRIPTION/METHODS: 81-year-old female with history of breast cancer on anastrozole presented to the hospital with high-grade fever. Physical exam was significant for RUQ tenderness. Her labs were significant for elevated transaminases, ALP and direct hyperbilirubinemia without leukocytosis. US abdomen showed enlarged gallbladder with stones. MRI was positive for portal vein thrombosis in the main portal vein and extending into right portal vein, with possible central anterior segment of right liver lobe infarct. She had no history of liver disease or venous thromboembolism. There is no clinical or radiological evidence of recurrence of malignancy. Patient was started on anticoagulation and was discharged on apixaban. APLA testing is pending and hypercoagulability workup was otherwise negative. It was concluded that the portal vein thrombosis was secondary to anastrozole due to lack of alternative etiologies. DISCUSSION: To our knowledge, our case of hepatic portal vein thrombosis suspected to be secondary to anastrozole therapy is the first to be reported in the medical literature. A case report suggesting a causal association between pulmonary embolism and anastrozole in a patient with no prior VTE and negative hypercoagulable workup was published in 2006 by Lycette et al. It is particularly important to consider the causative role of Anastrozole in patients with otherwise unexplained venous thromboembolism in unusual vascular beds as seen in our patient.

P004 - Decision impact of the 21-Gene Oncotype DX Recurrence Score Assay® in the Czech Republic on recommendations for adjuvant chemotherapy in estrogen receptor positive early stage breast cancer (ESBC) patients

P004 - Decision impact of the 21-Gene Oncotype DX Recurrence Score Assay® in the Czech Republic on recommendations for adjuvant chemotherapy in estrogen receptor positive early stage breast cancer (ESBC) patients

Long-term Subsequent Breast Cancer Risk and Overall Survival in Older Women with Estrogen Receptor Positive Early Stage Breast Cancer Treated in a Community Health Plan

Long-term Subsequent Breast Cancer Risk and Overall Survival in Older Women with Estrogen Receptor Positive Early Stage Breast Cancer Treated in a Community Health Plan

Changes over time in the impact of gene-expression profiles on the administration of adjuvant chemotherapy in estrogen receptor positive early stage breast cancer patients: A nationwide study.

Ten years ago gene-expression profiles were introduced to aid adjuvant chemotherapy decision making in breast cancer. Since then subsequent national guidelines gradually expanded the indication area for adjuvant chemotherapy. In this nation-wide study the evolution of the proportion of patients with estrogen-receptor positive (ER+) tumors receiving adjuvant chemotherapy in relation to gene-expression profile use in patient groups that became newly eligible for chemotherapy according to national guideline changes over time is assessed. Data on all surgically treated early breast cancer patients diagnosed between 2004-2006 and 2012-2014 were obtained from the Netherlands Cancer Registry. ER+/Her2- patients with tumor-characteristics making them eligible for gene-expression testing in both cohorts and a discordant chemotherapy recommendation over time (2004 guideline not recommending and 2012 guideline recommending chemotherapy) were identified. We identified 3,864 patients eligible for gene-expression profile use during both periods. Gene-expression profiles were deployed in 5% and 35% of the patients in the respective periods. In both periods the majority of patients was assigned to a low genomic risk-profile (67% and 69%, respectively) and high adherence rates to the test result were observed (86% and 91%, respectively). Without deploying a gene-expression profile 8% and 52% (p <0.001) of the respective cohorts received chemotherapy while 21% and 28% of these patients received chemotherapy when a gene-expression profile was used (p 0.191). In conclusion, in ER+/Her2- early stage breast cancer patients gene-expression profile use was associated with a consistent proportion of patients receiving chemotherapy despite an adjusted guideline-based recommendation to administer chemotherapy.

Abstract P5-08-06: Comparison of risk prediction with the 21-gene recurrence score (oncotype DX) and the 70-gene signature (MammaPrint) in patients with estrogen receptor-positive early stage breast cancer

Abstract Background: Gene expression profiling assays estimate prognosis &amp; predict benefit from adjuvant chemotherapy in patients (pts) with estrogen receptor positive (ER+) early stage breast cancer (ESBC). The 21-gene recurrence score (RS) and 70-gene signature (MP) are widely used assays. Pts may have both tests performed to adjudicate discordant results. We compared RS and MP in pts with both tests and evaluated their impact on adjuvant treatment decisions. Methods: This was a retrospective clinical cohort study from 5 centers from 2007-2014. Eligibility included ER+ ESBC with RS and MP results from the same tissue sample; exclusions included carcinoma in situ, primary metastatic disease, &amp; bilateral breast cancer. Two definitions of RS risk were evaluated (Genomic Health [GH] or TAILORx [TRx]): low risk (GH:0-17) or (TRx:0-10); intermediate risk (GH:18-30) or (TRx:11-25); and high risk (GH:&amp;gt;31) or (TRx:&amp;gt;26). Demographic, clinicopathologic (CP) data, and treatment decisions were extracted from medical records. Agreement was assessed between RS and MP using weighted kappa scores. CP factors were assessed with the t-test and chi-square test. Results: 123 pts were identified from UCSF or 4 US Oncology Network practices. 60 pts had low risk RS (GH); 27 were low risk by MP (45% agreement). 15 cases had a low risk RS (TRx); 9 were low risk by MP (60%). 10 pts had high risk RS (GH); 8 were high risk by MP (80.0%). Similarly, 18 cases had high risk (TRx) RS;16 were high risk by MP (88%). Using the RS GH risk definition, there was poor agreement for low risk RS/MP and high risk RS/MP (kappa=0.169). However, using the TRx RS risk definition, there was good agreement for low risk RS/ MP and high risk RS/MP (kappa=0.509). 53 pts had intermediate risk RS by (GH); by MP 16 were low risk (30%), and 37 were high risk (70%). 90 pts had an intermediate risk RS by TRx; by MP 34 were low risk (37.8%), and 56 were high risk by MP (62.2%). Using TRx RS increased the number of pts classified as intermediate risk compared to GH RS (73.2 vs 43.1%). Complete adjuvant treatment data were available for 90 patients. Of 40 pts with low risk RS (GH), 25% received chemotherapy associated with node status but not tumor size, grade, or MP. Of 10 pts with high risk RS (GH), 70% received chemotherapy without association with CP features or MP. For the 45 pts with intermediate risk RS (GH), 53% received chemotherapy, without correlation with CP features. Receipt of chemotherapy was positively associated with MP high risk, but this was not significant (odds ratio 2.08, 95% CI 0.54-8.01); p-0.29. Conclusion: Concordance in risk prediction between RS and MP was greater using RS defined by TRx compared to GH, and RS using TRx increases those categorized as intermediate risk. There appeared to be no correlation between CP features and decisions to use chemotherapy across risk groups. Interestingly, in those with intermediate risk RS (GH or TRx), there was a non-significant trend toward use of chemotherapy in those with high risk by MP. Although gene expression tests are used frequently to aid in treatment decisions in ESBC, considerable variation exists in their application in clinical practice. Citation Format: Jiang H, Denduluri N, Majure M, Favret A, Rugo HS. Comparison of risk prediction with the 21-gene recurrence score (oncotype DX) and the 70-gene signature (MammaPrint) in patients with estrogen receptor-positive early stage breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-06.

Cost-effectiveness assessment of lumpectomy cavity boost in elderly women with early stage estrogen receptor positive breast cancer receiving adjuvant radiotherapy

Background and purposeBreast radiotherapy (RT) for elderly women with estrogen receptor positive early stage breast cancer (ER+ESBC) improves local recurrence (LR) rates without benefitting overall survival. Breast boost is a common practice, although the absolute benefit decreases with age. Consequently, an analysis of its cost-effectiveness in the elderly ESBC populations is warranted. Material and methodsA Markov model was used to compare cost-effectiveness of RT with or without a boost in elderly ER+ESBC patients. The ten-year probability of LR with boost was derived from the CALGB 9343 trial and adjusted by the hazard ratio for LR from boost radiotherapy trial data, yielding the LR rate without boost. Remaining parameters were estimated using published data. ResultsBoost RT was associated with an increase in mean cost ($7139 vs $6193) and effectiveness (5.66 vs 5.64 quality adjusted life years; QALYs) relative to no boost. The incremental cost-effectiveness ratio (ICER) for boost was $55,903 per QALY. On one-way sensitivity analysis, boost remained cost-effective if the hazard ratio of LR with boost was <0.67. ConclusionsBoost RT for ER+ESBC patients was cost-effective over a wide range of assumptions and inputs over commonly accepted willingness-to pay-thresholds, but particularly in women at higher risk for LR.

The Effect of Oncotype DX Recurrence Score on Treatment Recommendations for Patients with Estrogen Receptor–Positive Early Stage Breast Cancer and Correlation with Estimation of Recurrence Risk by Breast Cancer Specialists

The Oncotype DX assay predicts likelihood of distant recurrence and improves patient selection for adjuvant chemotherapy in estrogen receptor-positive (ER-positive) early stage breast cancer. This study has two primary endpoints: to evaluate the impact of Oncotype DX recurrence scores (RS) on chemotherapy recommendations and to compare the estimated recurrence risk predicted by breast oncology specialists to RS. One hundred fifty-four patients with ER-positive early stage breast cancer and available RS results were selected. Clinicopathologic data were provided to four surgeons, four medical oncologists, and four pathologists. Participants were asked to estimate recurrence risk category and offer their chemotherapy recommendations initially without and later with knowledge of RS results. The three most important clinicopathologic features guiding their recommendations were requested. Ninety-five (61.7%), 45 (29.2%), and 14 (9.1%) tumors were low, intermediate, and high risk by RS, respectively. RS significantly correlated with tumor grade, mitotic activity, lymphovascular invasion, hormone receptor, and HER2/neu status. Estimated recurrence risk by participants agreed with RS in 54.2% ± 2.3% of cases. Without and with knowledge of RS, 82.3% ± 1.3% and 69.0% ± 6.9% of patients may be overtreated, respectively (p = 0.0322). Inclusion of RS data resulted in a 24.9% change in treatment recommendations. There was no significant difference in recommendations between groups of participants. Breast oncology specialists tended to overestimate the risk of tumor recurrence compared with RS. RS provides useful information that improves patient selection for chemotherapy and changes treatment recommendations in approximately 25% of cases.

19 The impact of tamoxifen on breast recurrence, cosmesis, complications, and survival in estrogen receptor positive early stage breast cancer

19 The impact of tamoxifen on breast recurrence, cosmesis, complications, and survival in estrogen receptor positive early stage breast cancer