Hereditary cancer syndromes in patients with second primary breast cancer

Abstract

Objective: The objective of this study was to evaluate the presence of hereditary cancer syndromes (HCS) in patients with
a diagnosis of two primary breast carcinomas and analyze the frequency of pathogenic variants in high- and moderatepenetrance genes. Methodology: This is a retrospective unicentric cohort study on patients with a diagnosis of two primary breast cancers, diagnosed between January 2000 to December 2020, at A.C. Camargo Cancer Center, Brazil. The association between categorical variables was analyzed by the chi-square test or Fisher’s exact test. For survival curves, the
Kaplan-Meier method and log-rank test were used to describe the survival curve differences. Results: Medical records of
breast cancer patients were reviewed from 2000 to 2020, and a frequency of 600 patients with two primary breast tumors
(metachronous or synchronous) was observed. In total, 190 (31.7%) patients performed genetic testing and 35 (5.8%)
patients presented a pathogenic or likely-pathogenic germline variant in cancer predisposing genes. Conclusion: Our
results revealed a low rate of genetic testing among patients with two primary breast cancers in a cancer center and a
frequency of carrier patients lower than expected.