Effects of <i>BRCA</i> Germline Mutations on Triple-Negative Breast Cancer Prognosis
Katarzyna Pogoda, Anna Niwińska, Elżbieta Sarnowska, Dorota Nowakowska, Agnieszka Jagiełło-Gruszfeld, Janusz A. Siedlecki, Zbigniew Nowecki
Abstract
Germline BRCA1 and BRCA2 mutations confer an increased lifetime risk for breast cancer and ovarian cancer. Several studies have investigated prognosis among BRCA1/2 mutation carriers and noncarriers, but the prognostic impact on outcomes of breast cancer patients has not been determined. The aim of this study was to determine the prognosis of TNBC patients with and without BRCA1/2 germline mutation. Among 502 patients diagnosed with TNBC between 2005 and 2008, 124 patients with a strong family history of breast cancer or ovarian cancer as well as TNBC patients diagnosed under 45 years were referred to the Genetic Counseling Unit for genetic counselling and genetic tests. In 30 (24%) of them, the BRCA1/2 mutation was detected (the most common 5382insC in 18 (60%) patients). The median follow-up of the entire group was 60 months. BRCA1/2 mutation carriers were statistically significantly younger at TNBC diagnosis compared with nonmutation patients (41 vs 47 years, respectively). Patients with the BRCA1/2 mutation had smaller tumors (stage I: 47% vs 24.5% in noncarriers), but there was no significant difference in the regional nodal status (58.5–63% with cN0). Contralateral breast cancer developed in 26.5% of BRCA1/2 mutation carriers and in 14% of noncarriers. Other primary cancers were also slightly more common in BRCA1/2 mutation carriers (16.5% vs 9.5%). The performed analysis did not show any significant differences between the groups in recurrence-free survival (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.312</mml:mn></mml:mrow></mml:math>). There was no significant difference between patients with or without BRCA1/2 mutation as regards overall survival (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.649</mml:mn></mml:mrow></mml:math>) and the risk of TNBC death (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.333</mml:mn></mml:mrow></mml:math>). The survival from detection of metastases was similar in two groups (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.865</mml:mn></mml:mrow></mml:math>). Our study demonstrated that the BRCA1 mutation does not affect TNBC patients’ outcomes.