Abstract

The purpose of this study was to quantify and describe nonmammary neoplasms (n-MN), particularly gynecological neoplasms, in a patient population previously diagnosed with breast cancer. Data were collected prospectively in our institutional review board–approved registry for patients diagnosed with infiltrating breast cancer or ductal carcinoma in situ. Patients who developed a second, n-MN were identified; neoplastic site, time to development after breast cancer, and clinical outcomes were recorded. FIGO stage was recorded for patients who developed a gynecological neoplasm. Synchronous bilateral breast cancer was defined as a second, contralateral diagnosis made within 12 months of the first and, similarly, synchronous n-MN were defined as those identified within 1 year of a breast cancer diagnosis. Outcome curves were generated using the method of Kaplan and Meier, and compared using the log-rank test. Of 4126 patients diagnosed with breast cancer, 3% developed a n-MN, the majority of which were nongynecological and asynchronous to the initial breast cancer diagnosis. Three percent of patients diagnosed with breast cancer were diagnosed with a second, n-MN. Among patients who developed a n-MN, most developed a nongynecological cancer more than 1 year after the initial breast cancer diagnosis, and their outcomes were significantly worse than those patients who did not develop a n-MN.