Survival of First and Second Primary Breast Cancer

Background: A second primary tumor (SPT) in the breast is the most common one seen in clinical practice. There are conflicting reports regarding the incidence and survival of patients with SPT in the breast.

Methods: To elucidate this, data on 139,932 patients with primary breast cancer, reported to the Surveillance, Epidemiology, and End Results Program between 1973 and 1986, were analyzed. Of these, 3431 patients had a contralateral metachronous breast cancer (interval, > 6 months).

Results: Survival from the date of diagnosis of the metachronous breast tumors was compared with that of patients with single breast tumors, controlling for age at diagnosis, stage, race, and treatment. In the multivariate analysis, age and stage at diagnosis of first and second tumors were the only variables that significantly influenced survival. The survival of patients with localized SPT was similar to that of patients with a localized single breast tumor. Patients with regionally advanced SPT lived for a shorter time than did corresponding patients with only one tumor.

Conclusions: Patients with single breast cancer were at increased risk of having a SPT in the breast. As a result, efforts for early detection by physical examination and mammography of survivors of single breast cancer are advocated because the survival of patients with a localized SPT in the breast is as good as that of those with a single localized tumor.