Factors affecting outcome for young women with early stage invasive breast cancer treated with breast-conserving therapy

Background Young women have worse outcome following breast-conserving therapy (BCT) than do older patients in many studies. We examined how clinical, pathological, and treatment factors affect these results. Method Between 1993 and 1999, 130 patients age 40 years or younger with stage I or II breast cancer were treated with BCT. The median radiation dose to the tumor bed was 61 Gy; 80% of patients received chemotherapy; and 29% of 72 patients with estrogen-receptor positive tumors received tamoxifen. Median follow-up was 93 months. Results Fifteen patients (12%) developed an ipsilateral breast tumor recurrence (IBTR), with or without other simultaneous failure sites. The Kaplan-Meier 5- and 8-year actuarial rates were 8% and 14%, respectively. The 74 patients with grade 3 tumors had a higher IBTR rate (8-year actuarial rate, 18%) than the 54 patients with grade 1-2 lesions (7%) (P = 0.09). Six patients developed contralateral breast cancers, and 17 developed distant metastases (DM). The 8-year actuarial rates for freedom-from-DM, relapse-free survival, and overall survival were 85%, 72% and 96%, respectively. Conclusions This represents one of the largest series of young women treated with BCT, using an approach similar to current practice. The IBTR rate was substantially lower than in many past studies, but still higher than would be expected for older women. This appeared largely due to the increased rate of IBTR in patients with grade 3 tumors. If this observation is confirmed, further analysis of this subgroup may lead to ways of reducing the risk of IBTR.