Combined 70- and 80-gene signatures identify tumors with genomically luminal biology responsive to neoadjuvant endocrine therapy and are prognostic of 5-year outcome in early-stage breast cancer.

BACKGROUND: As more patients with early-stage breast cancer receive neoadjuvant endocrine therapy (NET), there is a need for reliable biomarkers that can identify patients with HR+ HER2- tumors who are likely to benefit from NET. NBRST (NCT01479101) compared the prognostic value of the 70-gene risk classification and 80-gene molecular subtyping signatures with conventional pathological classification methods in response to neoadjuvant therapy. We evaluated the association of these signatures with clinical response and 5-year outcome of patients treated with NET. METHODS: 1091 patients with early-stage breast cancer scheduled to receive neoadjuvant therapy were prospectively enrolled into NBRST, and a sub-analysis of 67 patients treated with NET was performed. Patients received standard of care genomic testing using the 70-gene and 80-gene signatures and were treated with NET, per physician's discretion. The primary endpoint was pathologic partial response (pPR) and secondary endpoints were distant metastasis-free survival (DMFS) and overall survival (OS). Clinical benefit was defined as having a pPR or stable disease (SD) with NET. RESULTS: Overall, 94.4% of patients with genomically (g) Luminal A-Type (50.0% pPR and 44.4% SD) and 95.0% with Luminal B-Type tumors (55.0% pPR and 40.0% SD) exhibited clinical benefit. At 5 years, patients with gLuminal B tumors had significantly worse DMFS (75.6%, 95% CI 50.8-89.1) than patients with gLuminal A (91.1%; 95% CI 74.8-97.1; p = 0.047), with a similar trend for OS, albeit not significant (81.0%, 95% CI 56.9-92.4 and 91.1%, 95% CI 74.8-97.1, respectively; p = 0.13). CONCLUSIONS: Genomic assays offer a broader understanding of the underlying tumor biology, which adds precision to pathology as a preoperative risk classifier. Patients with 70-gene signature Low Risk, gLuminal A tumors treated with endocrine therapy alone have excellent 5-year outcomes. Most patients with genomically-defined Luminal A- and B-Type tumors respond well to NET, suggesting these patients may be safely treated with NET, while those with gLuminal B tumors will also require post-operative chemotherapy or CDK4/6 inhibitors to improve long-term outcomes. Overall, these findings demonstrate that genomic classification, defined by the combined 70- and 80-gene signatures, is associated with tumor response and prognostic of long-term outcomes.

Genomic Classification of HER2-Positive Patients With 80-Gene and 70-Gene Signatures Identifies Diversity in Clinical Outcomes With HER2-Targeted Neoadjuvant Therapy.

PURPOSE: The prospective Neoadjuvant Breast Registry Symphony Trial compared the 80-gene molecular subtyping signature with clinical assessment by immunohistochemistry and/or fluorescence in situ hybridization in predicting pathologic complete response (pCR) and 5-year outcomes in patients with early-stage breast cancer. METHODS: Standard-of-care neoadjuvant chemotherapy combined with trastuzumab or trastuzumab plus pertuzumab was given to patients with human epidermal growth factor receptor 2 (HER2)-positive tumors (n = 295). pCR was the primary end point, with secondary end points of distant metastasis-free survival and overall survival at 5 years. RESULTS: Among clinically defined HER2-positive (cHER2) tumors, the 80-gene assay identified 29.5% (87 of 295) as Luminal-Type (cHER2/gLuminal), 14.9% (44 of 295) as Basal-Type (cHER2/gBasal), and 55.6% (164 of 295) as HER2-Type (cHER2/genomically classified as HER2 [gHER2]). Patients with cHER2/gHER2 tumors had a higher pCR rate (61.6%) compared with non-gHER2 tumors (26.7%; P < .001). Dual targeting for cHER2/gHER2 tumors yielded a higher pCR rate (75%) compared with those treated with single HER2-targeted therapy (54%; P = .006). For cHER2/gBasal tumors, the 42.9% pCR rate observed with dual targeting was not different from that with trastuzumab alone (46.4%; P = .830). Among those with cHER2/gBasal tumors, 5-year distant metastasis-free survival (68.6%; 95% CI, 49.1 to 81.9) was significantly worse than in patients with cHER2/gLuminal tumors (88.9%; 95% CI, 78.0 to 94.6) and cHER2/gHER2 tumors (87.4%; 95% CI, 80.2 to 92.2; P = .010), with similar corresponding overall survival differences. CONCLUSION: The 80-gene assay identified meaningful genomic diversity in patients with cHER2 disease. Patients with cHER2/gHER2 tumors, who benefitted most from dual HER2-targeted therapy, accounted for approximately half of the cHER2 cohort. Genomically Luminal tumors had low pCR rates but good 5-year outcomes. cHER2/gBasal tumors derived no benefit from dual therapy and had significantly worse 5-year prognosis; these patients merit special consideration in future trials.

Clinical Utility of Universal Germline Genetic Testing for Patients With Breast Cancer.

Importance: National Comprehensive Cancer Network guidelines currently recommend germline testing for high-risk genes in selected patients with breast cancer. The clinical utility of recommending testing all patients with breast cancer with multigene panels is currently under consideration. Objective: To examine the implications of universal testing of patients with breast cancer with respect to clinical decision-making. Design, Setting, and Participants: Patients from a previously reported cohort were assessed as in-criteria or out-of-criteria according to the 2017 guidelines and underwent testing with a multigene germline panel between 2017 to 2018. Patients were women and men aged 18 to 90 years, with a new and/or previous diagnosis of breast cancer who had not undergone either single or multigene testing. Clinicians from 20 community and academic sites documented patient clinical information and changes to clinical recommendations made according to test findings. Association between prevalence of pathogenic or likely pathogenic germline variants and previously unreported clinical features, including scores generated by the BRCAPRO statistical model, was determined. Data were analyzed from April 2020 to May 2022. Exposure: New and/or previous diagnosis of breast cancer. Main Outcomes and Measures: Disease management recommendations that were changed as a result of genetic testing results are reported. Results: Clinicians were asked to assess changes to clinical management as a result of germline genetic testing for 952 patients. Informative clinician-reported recommendations were provided for 939 (467 in-criteria and 472 out-of-criteria) of the patients with breast cancer (936 [99.7%] female; 702 [74.8%] White; mean [SD] age at initial diagnosis, 57.6 [11.5] years). One or more changes were reported for 31 of 37 (83.8%) in-criteria patients and 23 of 34 (67.6%) out-of-criteria patients with a pathogenic or likely pathogenic variant. Recommendations were changed as a result of testing results for 14 of 22 (63.6%) out-of-criteria patients who had a variant in a breast cancer predisposition gene. Clinicians considered testing beneficial for two-thirds of patients with pathogenic or likely pathogenic variants and for one-third of patients with either negative results or variants of uncertain significance. There was no difference in variant rate between patients meeting the BRCAPRO threshold (≥10%) and those who did not (P = .86, Fisher exact test). No changes to clinical recommendations were made for most patients with negative results (345 of 349 patients [98.9%]) or variants of uncertain significance (492 of 509 patients [96.7%]). Conclusions and Relevance: In this cohort study, germline genetic testing was used by clinicians to direct treatment for most out-of-criteria patients with breast cancer with pathogenic or likely pathogenic germline variants, including those with moderate-risk variants. Universal germline testing informs clinical decision-making and provides access to targeted treatments and clinical trials for all patients with breast cancer.

Distinct Neoadjuvant Chemotherapy Response and 5-Year Outcome in Patients With Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Breast Tumors That Reclassify as Basal-Type by the 80-Gene Signature.

PURPOSE: The 80-gene molecular subtyping signature (80-GS) reclassifies a proportion of immunohistochemistry (IHC)-defined luminal breast cancers (estrogen receptor-positive [ER+], human epidermal growth factor receptor 2-negative [HER2-]) as Basal-Type. We report the association of 80-GS reclassification with neoadjuvant treatment response and 5-year outcome in patients with breast cancer. METHODS: Neoadjuvant Breast Registry Symphony Trial (NBRST; NCT01479101) is an observational, prospective study that included 1,069 patients with early-stage breast cancer age 18-90 years who received neoadjuvant therapy. Pathologic complete response (pCR) and 5-year distant metastasis-free survival (DMFS) and overall survival (OS) were assessed in 477 patients with IHC-defined ER+, HER2- tumors and in a reference group of 229 patients with IHC-defined triple-negative breast cancer (TNBC). RESULTS: 80-GS reclassified 15% of ER+, HER2- tumors (n = 73) as Basal-Type (ER+/Basal), which had similar pCR compared with TNBC/Basal tumors (34% v 38%; P = .52), and significantly higher pCR than ER+/Luminal A (2%; P < .001) and ER+/Luminal B (6%; P < .001) tumors. The 5-year DMFS (%, [95% CI]) was significantly lower for patients with ER+/Basal tumors (66% [52.6 to 77.3]), compared with those with ER+/Luminal A tumors (92.3% [85.2 to 96.1]) and ER+/Luminal B tumors (73.5% [44.5 to 79.3]). Importantly, patients with ER+/Basal or TNBC/Basal tumors that had a pCR exhibited significantly improved DMFS and OS compared with those with residual disease. By contrast, patients with ER+/Luminal B tumors had comparable 5-year DMFS and OS whether or not they achieved pCR. CONCLUSION: Significant differences in chemosensitivity and 5-year outcome suggest patients with ER+/Basal molecular subtype may benefit from neoadjuvant regimens optimized for patients with TNBC/Basal tumors compared with patients with ER+/Luminal subtype. These data highlight the importance of identifying this subset of patients to improve treatment planning and long-term survival.

Age-Independent Preoperative Chemosensitivity and 5-Year Outcome Determined by Combined 70- and 80-Gene Signature in a Prospective Trial in Early-Stage Breast Cancer.

BACKGROUND: The Neoadjuvant Breast Symphony Trial (NBRST) demonstrated the 70-gene risk of distant recurrence signature, MammaPrint, and the 80-gene molecular subtyping signature, BluePrint, precisely determined preoperative pathological complete response (pCR) in breast cancer patients. We report 5-year follow-up results in addition to an exploratory analysis by age and menopausal status. METHODS: The observational, prospective NBRST (NCT01479101) included 954 early-stage breast cancer patients aged 18-90 years who received neoadjuvant chemotherapy and had clinical and genomic data available. Chemosensitivity and 5-year distant metastasis-free survival (DMFS) and overall survival (OS) were assessed. In a post hoc subanalysis, results were stratified by age (≤ 50 vs. > 50 years) and menopausal status in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) tumors. RESULTS: MammaPrint and BluePrint further classified 23% of tumors to a different subtype compared with immunohistochemistry, with more precise correspondence to pCR rates. Five-year DMFS and OS were highest in MammaPrint Low Risk, Luminal A-type and HER2-type tumors, and lowest in MammaPrint High Risk, Luminal B-type and Basal-type tumors. There was no significant difference in chemosensitivity between younger and older patients with Low-Risk (2.2% vs. 3.8%; p = 0.64) or High-Risk tumors (14.5% vs. 11.5%; p = 0.42), or within each BluePrint subtype; this was similar when stratifying by menopausal status. The 5-year outcomes were comparable by age or menopausal status for each molecular subtype. CONCLUSION: Intrinsic preoperative chemosensitivity and long-term outcomes were precisely determined by BluePrint and MammaPrint regardless of patient age, supporting the utility of these assays to inform treatment and surgical decisions in early-stage breast cancer.

Recommendations for prioritization, treatment, and triage of breast cancer patients during the COVID-19 pandemic. the COVID-19 pandemic breast cancer consortium.

The COVID-19 pandemic presents clinicians a unique set of challenges in managing breast cancer (BC) patients. As hospital resources and staff become more limited during the COVID-19 pandemic, it becomes critically important to define which BC patients require more urgent care and which patients can wait for treatment until the pandemic is over. In this Special Communication, we use expert opinion of representatives from multiple cancer care organizations to categorize BC patients into priority levels (A, B, C) for urgency of care across all specialties. Additionally, we provide treatment recommendations for each of these patient scenarios. Priority A patients have conditions that are immediately life threatening or symptomatic requiring urgent treatment. Priority B patients have conditions that do not require immediate treatment but should start treatment before the pandemic is over. Priority C patients have conditions that can be safely deferred until the pandemic is over. The implementation of these recommendations for patient triage, which are based on the highest level available evidence, must be adapted to current availability of hospital resources and severity of the COVID-19 pandemic in each region of the country. Additionally, the risk of disease progression and worse outcomes for patients need to be weighed against the risk of patient and staff exposure to SARS CoV-2 (virus associated with the COVID-19 pandemic). Physicians should use these recommendations to prioritize care for their BC patients and adapt treatment recommendations to the local context at their hospital.