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.

Benefit of adjuvant chemotherapy in node-negative T1a versus T1b and T1c triple-negative breast cancer.

PURPOSE: National comprehensive cancer network guidelines recommend delivery of adjuvant chemotherapy in node-negative triple-negative breast cancer (TNBC) if the tumor is > 1 cm and consideration of adjuvant chemotherapy for T1b but not T1a disease. These recommendations are based upon sparse data on the role of adjuvant chemotherapy in T1a and T1b node-negative TNBC. Our objective was to clarify the benefits of chemotherapy for patients with T1N0 TNBC, stratified by tumor size. METHODS: We performed a retrospective analysis of survival outcomes of TNBC patients at two academic institutions in the United States from 1999 to 2018. Primary tumor size, histology, and nodal status were based upon surgical pathology. The Kaplan-Meier plot and 5-year unadjusted survival probability were evaluated. RESULTS: Among 282 T1N0 TNBC cases, the status of adjuvant chemotherapy was known for 258. Mean follow-up was 5.3 years. Adjuvant chemotherapy was delivered to 30.5% of T1a, 64.7% T1b, and 83.9% T1c (p < 0.0001). On multivariable analysis, factors associated with delivery of adjuvant chemotherapy were tumor size and grade 3 disease. Improved overall survival was associated with use of chemotherapy in patients with T1c disease (93.2% vs. 75.2% p = 0.008) but not T1a (100% vs. 100% p = 0.3778) or T1b (100% vs. 95.8% p = 0.2362) disease. CONCLUSION: Our data support current guidelines indicating benefit from adjuvant chemotherapy in node-negative TNBC associated with T1c tumors but excellent outcomes were observed in the cases of T1a and T1b disease, regardless of whether adjuvant chemotherapy was delivered.

Underdiagnosis of Hereditary Breast Cancer: Are Genetic Testing Guidelines a Tool or an Obstacle?

PURPOSE: An estimated 10% of breast and ovarian cancers result from hereditary causes. Current testing guidelines for germ line susceptibility genes in patients with breast carcinoma were developed to identify carriers of BRCA1/ 2 variants and have evolved in the panel-testing era. We evaluated the capability of the National Comprehensive Cancer Network (NCCN) guidelines to identify patients with breast cancer with pathogenic variants in expanded panel testing. METHODS: An institutional review board-approved multicenter prospective registry was initiated with 20 community and academic sites experienced in cancer genetic testing and counseling. Eligibility criteria included patients with a previously or newly diagnosed breast cancer who had not undergone either single- or multigene testing. Consecutive patients 18 to 90 years of age were consented and underwent an 80-gene panel test. Health Insurance Portability and Accountability Act-compliant electronic case report forms collected information on patient demographics, diagnoses, phenotypes, and test results. RESULTS: More than 1,000 patients were enrolled, and data records for 959 patients were analyzed; 49.95% met NCCN criteria, and 50.05% did not. Overall, 8.65% of patients had a pathogenic/likely pathogenic (P/LP) variant. Of patients who met NCCN guidelines with test results, 9.39% had a P/LP variant. Of patients who did not meet guidelines, 7.9% had a P/LP variant. The difference in positive results between these groups was not statistically significant (Fisher's exact test P = .4241). CONCLUSION: Our results indicate that nearly half of patients with breast cancer with a P/LP variant with clinically actionable and/or management guidelines in development are missed by current testing guidelines. We recommend that all patients with a diagnosis of breast cancer undergo expanded panel testing.

Ablative therapies for the treatment of malignant diseases of the breast.

BACKGROUND: Because widespread screening for breast cancer is detecting more women at younger ages and earlier stages, the need for minimally invasive, cosmetically preferable approaches to its treatment is growing. Ablative techniques are now being applied to the treatment of primary breast tumors, perhaps offering an alternative to surgical excision. Techniques available for breast cancer treatment include radiofrequency ablation, cryoablation, interstitial laser ablation, microwave thermotherapy, and focused ultrasound ablation. DATA SOURCES: Literature searches for breast and cryoablation, focused ultrasound ablation, interstitial laser ablation, microwave thermotherapy, and radiofrequency ablation were performed. Over 30 articles were identified and analyzed. CONCLUSIONS: It is cautiously optimistic that these therapies can be used as a routine adjunct in the treatment of selected breast cancers. The challenge will lie in the ability to identify multifocal disease and in situ carcinoma as well as to ensure complete and effective eradication of the breast cancer.

Office-based ultrasound-guided cryoablation of breast fibroadenomas.

BACKGROUND: Fibroadenomas commonly found by palpation and routine mammography account for approximately 20% of open surgical breast biopsies. Alternatives to open surgery include tumor removal using an automated coring device and tumor ablation using heating or cooling elements. We report our initial experience with cryoablation of biopsy-proven benign fibroadenomas. METHODS: A table-top cryoablation system employing a 2.4-mm cryoprobe was used to treat biopsy-proven benign fibroadenomas up to 4 cm in maximum diameter in a prospective nonrandomized fashion. The cryoprobe was placed under ultrasound guidance. Using a treatment algorithm based on fibroadenoma size, all tumors were subjected to two freeze cycles with an interposing thaw. Skin appearance and temperature, probe temperature, iceball size, and patient comfort were closely monitored during the procedure. Follow-up examinations including ultrasonography and photographs were scheduled for up to 12 months postablation. RESULTS: Fifty patients with 57 core biopsy-proven benign fibroadenomas were treated. Seven early cases were treated in an ambulatory surgery center setting. The remaining procedures were completely office-based using only local anesthetic. Tumor diameter varied from 7 mm to 42 mm (mean 21 mm). The iceball engulfed the target lesion in each case. Transient postoperative side effects were local swelling and ecchymosis. Postoperative discomfort rarely required medication beyond acetaminophen or ibuprofen. Lesions showed progressive shrinkage and disappearance over 3 to 12 months. No skin injury was noted and appearance remained excellent. Patient satisfaction was excellent. CONCLUSIONS: With office-based use of ultrasound-guided cryoablation for fibroadenomas there was little or no pain, target lesions were reduced in size or eliminated, scarring was minimal, cosmesis outstanding, and patient satisfaction was excellent. Cryoablation offers a useful office-based alternative to surgical excision of benign fibroadenomas.