Differences in risk factors for local and distant recurrence after breast-conserving therapy or mastectomy for stage I and II breast cancer: Pooled results of two large European randomized trials

Purpose: Risk factors for local and distant recurrence after breast-conserv ing therapy and mastectomy were compared to define guidelines for the decis ion making between both treatments. Patients and Methods: The data of two randomized clinical trials for stage I and II breast cancer patients were pooled. The total number of patients i n the study was 1,772, of whom 879 underwent breast conservation, and 893, modified radical mastectomy. Representative slides of the primary tumor wer e available for histopathologic review in 1,610 cases (91%). Results: There were 79 patients with local recurrence after breast-conserva tion and 80 after mastectomy, the 10-year rates being 10% (95% confidence i nterval [CI], 8% to 13%) and 9% (95% CI, 7% to 12%), respectively. Age no m ore than 35 years (compared with age >60: hazard ratio [HR], 9.24; 95% CI, 3.74 to 22.81) and an extensive intraductal component (HR, 2.52; 95% CI, 1. 26 to 5.00) were significantly associated with an increased risk of local r ecurrence after breast-conserving therapy. Vascular invasion was predictive of the risk of local recurrence, irrespective of the type of primary treat ment (P <.01). Tumor size, nodal status, high histologic grade, and vascula r invasion were all highly significant predictors of distant disease after breast-conserving therapy and mastectomy (P <.01). Age no more than 35 year s and microscopic involvement of the excision margin were additional indepe ndent predictors of distant disease after breast-conserving therapy (P <.01 ). Conclusion: Age no more than 35 years and the presence of an extensive intr aductal component are associated with an increased risk of local recurrence after breast-conserving therapy. Vascular invasion causes a higher risk of local recurrence after mastectomy as well as after breast conserving thera py and should therefore not be used for deciding between the two treatments . <(c)> 2001 by American Society of Clinical Oncology.