LAUSR

e12054Background: Late sequelae of breast cancer therapies potentially impact morbidity and mortality with increasing numbers of survivors. Radiation exposure has been linked to increased incidence of second primary cancers (SPC). However, to date, there is limited literature describing incidence of head and neck (HN) and esophageal cancers in patients with an index breast cancer (BC). This study aimed to describe the incidence of esophageal and HN cancers following breast cancer diagnosis. Methods: Standardized incidence ratios (SIRs) were calculated using the Surveillance, Epidemiology, and End Results (SEER) 9 database for BC patients diagnosed from 1973-2013. SIRs compared incidence of HN and esophageal cancer after an initial BC diagnosis to the general population. HN included oral cavity, pharynx, and larynx. BC patients were grouped into those who received radiotherapy for their breast cancer (n = 216,045) and those who did not (n = 289,596). SIRs were calculated in 5-year intervals. SEER does not ...