Experts Discuss Differences in Radiotherapy Outcomes in BRCA+ Breast Cancer

During Breast Cancer Awareness Month 2023,  Rebecca M. Shulman, MD, an assistant professor in the Department of Radiation Oncology at Fox Chase Cancer Center, and Zachary Kiss, DO, a third-year resident physician in radiation oncology at Fox Chase, spoke about findings from their study, which assessed how BRCA1/2 mutations in patients with breast cancer do not appear to affect treatment outcomes with radiotherapy. 

Shulman and Kiss presented these findings as part of a poster session at the 2023 American Society for Radiation Oncology (ASTRO) Annual Meeting.

Disease-free survival (DFS) outcomes following radiation were reported to be comparable between patients with no BRCA mutations (n = 1482) and those with BRCA-mutated disease (n = 77; P = .26). Additionally, those with BRCA1/2 mutations tended to be younger (P = .004), have higher clinical stage disease (P <.006), and were more likely to undergo mastectomy (P <.001) than patients without mutated disease.

An analysis of patients with BRCA-mutated disease also indicated that those with BRCA1 mutations (n = 31) tended to be younger than those with BRCA2 mutations (n = 46; P = .006). Moreover, a higher proportion of patients with BRCA1 mutations had estrogen receptor– or progesterone receptor–negative disease (P <.001) and higher T stage (P = .032).

Shulman and Kiss also spoke about how next steps for research may include investigating potential additional mutations and other factors that may affect sensitivity to radiotherapy among patients with disease harboring BRCA mutations. They also discussed other presentations at this year’s ASTRO meeting that may support advancement towards individualized treatment approaches in patients with breast cancer. 

“Investigating the genetic and biochemical basis of cancer is a monumental task, requiring patients, ingenuity, and a continuing investment of time and resources,” Shulman said. “It’s important to communicate that progress in cancer treatment has been enormous, but that it is also incremental by nature and will require the efforts of many researchers pursuing many different ideas.”