Secondary primary cancers in male breast cancer survivors.

Abstract

129 Background: Male Breast Cancer (MBC) survivors have an increased risk of developing secondary contralateral breast cancer. However, the risk of developing other solid tumors and hematological malignancies is not well understood. Methods: The Surveillance Epidemiology and End Results (SEER) database was used to detect MBC cases diagnosed up to 12/31/2011. The Standardized Incidence Ratio (SIR) was calculated as the ratio of observed to expected cases of second primary malignancy based on incidence data in the general United States population. The latency exclusion period from the date of diagnosis was 5 years. We also investigated for any modifying effects such as radiation therapy, age at diagnosis, and latency period after initial diagnosis (5-10 years and >10 years) that may have increased the risk for secondary cancer. Results: A total of 1,239 men with an initial diagnosis of primary breast cancer were included in our analysis. Overall, there was an increased SIR of secondary solid tumors of the pharynx (SIR: 8.39, P<0.05), hypopharynx (SIR: 15.77, P<0.05), and brain (SIR: 4.40, p<0.05), and Non-Hodgkin Lymphoma (NHL) (SIR: 2.49, P<0.05), that was also seen in MBC cases that received radiation (24.1%), (SIR: 4.51, P<0.05). For MBC diagnoses in patients >40 years, there was an increased incidence for these malignancies and for “all solid tumors” (SIR: 1.30, P<0.05) as well. In the period ranging from 5-10 years after initial breast cancer diagnosis increased incidence for tumors of the pharynx (SIR: 8.95, P<0.05) and hypopharynx (SIR: 16.70, P<0.05) were seen. In contrast, there was no significant increased incidence of secondary cancers >10 years after initial diagnosis. Conclusions: MBC survivors are at increased risk for secondary malignancies of the pharynx, hypopharynx, brain, and NHL. Older age at diagnosis and radiation treatment appear to be risk factors. Risk of secondary tumors of the pharynx and hypopharynx is greatest 5-10 years after initial breast cancer diagnosis but optimal surveillance for MBC survivors requires further clarification.