Objective: To find out whether breast cancer (BC) patients with positive family history of concordant cancer are diagnosed at earlier TNM stages and to explore the survival in familial breast cancer compared to sporadic cases who were diagnosed at identical TNM status and staging.

Design: Nationwide prospective cohort study.

Setting and method: The nationwide Swedish Family-Cancer Database including all Swedes born after 1931 and their biological parents, totaling >14.7 million individuals. Hazard ratios (HR) were calculated for 4,709 women with BC in a first-degree relative (FDR) versus 25,366 BC women without such a family history.

Results: Familial BC cases were not diagnosed at earlier stages compared to sporadic cases. There was no difference in survival of familial BC patients who were diagnosed at high TNM staging (T2-T4, N1-N3, M1) compared to sporadic cases diagnosed at the same late stage. Young BC patients (age<40) in early stages (T0-T1, N0, M0, Stage 0-I) had the worst survival when their FDR were diagnosed with single (HR: 2-3.7) or multiple (HR: 2.4-7.1) BC at any age.

Conclusion: Young BC patients (age<40), diagnosed at early stages (T0-T1, N0, M0, stage 0-I), whose FDR were diagnosed with BC at any age had the higher risk of mortality compared to sporadic cases at the same stages. Our results offer novel information for personalized genetic counseling and treatment modalities and urge the need for identifying the underling genetic component for such a difference in survival of familial breast cancer.

Citation Format: Elham Kharazmi, Asta Försti, Kristina Sundquist, Kari Hemminki. Survival in familial breast cancer: Novel findings based on a nationwide prospective cohort study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1290. doi:10.1158/1538-7445.AM2014-1290