Parity confers better prognosis in older women with early-stage breast cancer treated with breast-conserving therapy.

A comparison was made of pretreatment characteristics and outcomes of patients with stage I/II breast cancer treated with breast-conserving therapy who had a history of parity with those who were nulliparous. From 1979 to 1996, 1358 women with stage I/II (T1/2 N0/1 M0) breast cancer underwent lumpectomy, axillary dissection, and radiation therapy with or without systemic therapy. Of the total population, 1162 patients (86%) were parous and 196 patients (14%) were nulliparous. The median follow-up was 87 months. The 2 groups were compared for clinical, pathologic, and treatment-related factors. Multivariate analysis was used to determine independent predictors of outcome. Outcome was also evaluated for patterns of failure including distant metastases (DM), cause-specific survival (CSS), and overall survival (OS). Significant differences between the 2 groups were observed for age > 60 years and median age. Multivariate analysis demonstrated that nulliparous status was an independent predictor of DM, CSS, and OS after adjusting for age. Multivariate analysis for DM, CSS, and OS for patients > 60 years of age demonstrated that parity was the most highly significant independent predictor of decreased DM and improved OS. Parity can be considered a prognostic factor in elderly patients with early-stage breast cancer, and therefore may be used as a tool for identifying patients who may benefit from a more aggressive treatment approach.