DNA Methylation Identifies Epigenetic Subtypes of Triple-Negative Breast Cancers With Distinct Clinicopathologic and Molecular Features.

Triple-negative breast cancers (TNBC) include diverse carcinomas with heterogeneous clinical behavior. DNA methylation is a useful tool in classifying a variety of cancers. In this study, we analyzed TNBC using DNA methylation profiling and compared the results to those of mutational analysis. DNA methylation profiling (Infinium MethylationEPIC array, Illumina) and 50-gene panel-targeted DNA sequencing were performed in 44 treatment-naïve TNBC. We identified 3 distinct DNA methylation clusters with specific clinicopathologic and molecular features. Cluster 1 (phosphoinositide 3-kinase/protein kinase B-enriched cluster; n = 9) patients were significantly older (mean age, 71 years; P = .008) with tumors that were more likely to exhibit apocrine differentiation (78%; P < .001), a lower grade (44% were grade 2), a lower proliferation index (median Ki-67, 15%; P = .002), and lower tumor-infiltrating lymphocyte fractions (median, 15%; P = .0142). Tumors carried recurrent PIK3CA and AKT1 mutations and a higher percentage of low HER-2 expression (89%; P = .033). Cluster 3 (chromosomal instability cluster; n = 28) patients were significantly younger (median age, 57 years). Tumors were of higher grade (grade 3, 93%), had a higher proliferation index (median Ki-67, 75%), and were with a high fraction of tumor-infiltrating lymphocytes (median, 30%). Ninety-one percent of the germline BRCA1/2 mutation carriers were in cluster 3, and these tumors showed the highest level of copy number alterations. Cluster 2 represented cases with intermediate clinicopathologic characteristics and no specific molecular profile (no specific molecular profile cluster; n = 7). There were no differences in relation to stage, recurrence, and survival. In conclusion, DNA methylation profiling is a promising tool to classify patients with TNBC into biologically relevant groups, which may result in better disease characterization and reveal potential targets for emerging therapies.

Results of Magnetic Resonance Imaging (MRI) Screening in Patients at High Risk for Breast Cancer.

BACKGROUND: Screening MRI as an adjunct to mammography is recommended by the ACS for patients with a lifetime risk for breast cancer > 20%. While the benefits are clear, MRI screening is associated with an increase in false-positive results. The purpose of this study was to analyze our institutional database of high-risk patients and assess the uptake of screening MRI examinations and the results of those screenings. METHODS: Our institutional review board-approved High-Risk Breast Cancer Database was queried for patients enrolled from January 2017 to January 2023 who were at high risk for breast cancer in a comparative analysis between those who were screened versus not screened with MRIs. Variables of interest included risk factor, background, MRI screening uptake, and frequency and results of image-guided breast biopsies. RESULTS: A total of 254 of 1106 high-risk patients (23%) had MRI screening. Forty-six of 852 (5.3%) patients in the non-MRI-screened cohort and nine of 254 (3.5%) patients in the MRI-screened cohort were diagnosed with a malignant lesion after image-guided biopsy (p = 0.6). There was no significant difference between MRI and non-MRI guided biopsies in detecting breast cancer. All malignant lesions were T1 or in situ disease. The 254 patients in the MRI-screened group underwent 185 biopsies. Fifty-seven percent of MRI-guided biopsies yielded benign results. CONCLUSIONS: Although the addition of MRI screening in our high-risk cohort did not produce a significant number of additional cancer diagnoses, patients monitored in our high-risk cohort who developed breast cancer were diagnosed at very early stages of disease, underscoring the benefit of participation in the program.

Changes in Breast Cancer Presentation during COVID-19: Experience in an Urban Academic Center.

The COVID-19 pandemic strained healthcare systems worldwide, delaying breast cancer screening and surgery. In 2019, approximately 80% of breast cancers in the U.S. were diagnosed on screening examinations, with 76.4% of eligible Medicare patients undergoing screening at least every two years. Since the start of the pandemic, many women have been reluctant to seek elective screening mammography, even with the lifting of pandemic-related restrictions in access to routine healthcare. We describe the effect of the COVID-19 pandemic on breast cancer presentation at a tertiary academic medical center greatly impacted by the pandemic.