BRCA Status Doesn't Affect Survival in Young-Onset Breast Cancer

January 11, 2018

After undergoing treatment, women with young-onset breast cancer and BRCA mutations had similar survival rates as those women who were not mutation carriers, according to the results of a prospective study.

After undergoing treatment, women with young-onset breast cancer and BRCA mutations had similar survival rates as those women who were not mutation carriers, according to the results of a prospective study published in Lancet Oncology.

Previous studies or meta-analyses comparing outcomes in women with BRCA1 and BRCA2 mutations and those with sporadic breast cancer have reported inconsistent effects of these mutations on patient outcomes. The Prospective Outcomes in Sporadic vs Hereditary breast cancer (POSH) study recruited 2,733 young women with breast cancer between 2000 and 2008. At that time, BRCA testing and risk-reducing surgery were not routine for early breast cancer.

Diana M. Eccles, MD, University of Southampton and University Hospital Southampton NHS Foundation Trust, United Kingdom, and colleagues looked at survival following treatment for the initial breast cancer diagnosed only.

“Our study is the largest of its kind, and our findings suggest that younger women with breast cancer who have a BRCA mutation have similar survival to women who do not carry the mutation after receiving treatment,” Eccles said in a press release. “Women diagnosed with early breast cancer who carry a BRCA mutation are often offered double mastectomies soon after their diagnosis or chemotherapy treatment, however, our findings suggest that this surgery does not have to be immediately undertaken along with the other treatment. In the longer term, risk-reducing surgery should be discussed as an option for BRCA1 mutation carriers in particular, to minimize their future risk of developing a new breast or ovarian cancer. Decisions about timing of additional surgery to reduce future cancer risks should take into account patient prognosis after their first cancer, and their personal preferences.”

Patients were recruited from 127 hospitals in the United Kingdom and were aged 40 years or younger at first diagnosis. The primary outcome was overall survival for all BRCA1 and BRCA2 mutations carriers compared with all non-carriers at 2, 5, and 10 years post-diagnosis.

Twelve percent of patients had either a BRCA1 or BRCA2 mutation. There was no significant difference in overall survival between patients who were BRCA positive and those who were BRCA negative at 2 years (97% vs 96.6%, respectively), 5 years (83.8% vs 85%), or 10 years (73.4% vs 70.1%; hazard ratio, 0.96; 95% CI, 0.76–1.22; P = 0.76).

A subgroup analysis of 558 patients with triple-negative breast cancer, however, did show a significant survival advantage during the first few years after diagnosis in BRCA mutation carriers. Mutations carriers had a better overall survival than non-carriers at 2 years (95% vs 91%; P = .047). There was no significant difference in survival at 5 or 10 years.

“This important topic needs more prospective research as preventive surgical measures might have an effect on what might be a very long life after a diagnosis of breast cancer at a young age,” wrote Peter Fasching, MD, of Friedrich-Alexander University Erlangen-Nuremberg, Germany, in an editorial published with the study. “Understanding prognosis in young patients is important because patients with BRCA mutations are at increased risk of developing specific conditions, such as secondary cancers, including ovarian cancer, contralateral breast cancer, and de novo breast cancer in the same breast. These risks determine treatment, and knowing that BRCA1 or BRCA2 mutations do not result in a different prognosis might change the therapeutic approach for these risks.”