Impact of Screening and Risk Factors for Local Recurrence and Survival After Conservative Surgery and Radiotherapy for Early Breast Cancer: Results From a Large Series With Long-Term Follow-Up

Abstract

To investigate conventional prognostic factors for ipsilateral breast tumor recurrence (IBTR), distant metastasis (DM), and survival after breast-conserving therapy (BCT) in screen-detected and symptomatic cases on surveillance up to 25 years. A total of 1812 consecutive patients in three cohorts (1981-1989, 1990-1992, and 1993-1998) with T12N01M0 invasive breast cancer were treated with BCT (median follow-up, 14 years). Tumor type and grade were reviewed by a single pathologist. Hormone receptor status was measured by immunohistochemistry on tissue microarrays. A Cox proportional hazards model was used to assess independent prognostic variables for relapse and survival. A total of 205 IBTR occurred, with 5-, 10-, 15-, and 20-year actuarial relapse rates of 4.5% (95% confidence interval [CI] 3.35-5.5%), 8.4% (95% CI 7.1-9.8%), 14.1% (95% CI 12.0-16%), and 17.4% (95% CI 14.5-20.2%). Number of nodes, young age, pathologic tumor size, and multifocality were significant factors for IBTR. Three hundred seventy-eight patients developed DM. The actuarial metastatic rate was 12% at 5 years and 17.9% at 10 years. Young age, number of positive nodes, pathologic tumor size, and tumor grade were significant factors for DM relapse. When conventional prognostic indices were taken into account screen-detected cancers showed no improvement in overall relapse or survival rate compared with symptomatic cases but did show a reduced risk of DM after IBTR. After 10 years IBTR relapse continued at a constant rate of 0.87% per annum. The Edinburgh BCT series has shown that screen-detected invasive breast cancers do not have significantly different clinical outcomes compared with symptomatic cases when pathologic risk factors are taken into account. This suggests that these patients be managed in a similar way.