Local Recurrence after Breast-Conserving Surgery: Multivariable Analysis of Risk Factors and the Impact of Young Age

Background. Local recurrence (LR) after breast conservation surgery (BCS) varies with risk factors. This study was designed to evaluate the impact of young age on LR. Methods. All patients (excluding those who received neoadjuvant chemotherapy) who underwent BCS from 1988-2001 at our institution were identified and evaluated for risk factors of LR. Results. A total of 3,064 patients underwent 3,131 BCS. Mean age at surgery was 61 (range, 21-98) years: 175 (5.6%) patients were aged <40 years; 492 (15.7%) were 40-49 years; 761 (24.3%) were 50-59 years; 801 (25.6%) were 60-69 years; and 902 (28.8%) were age 70 + years. A total of 212 patients (6.8%) developed LR at a mean of 4.5 (range, 0.1-14.4) years after BCS. Mean follow-up was 8.9 (range, 0-20.2) years. The 5-year LR-free survival rate was 94.9%. The frequencies of LR by age group were: <40 years-11.4%; 40-49 years-5.7%; 50-59 years-6.2%; 60-69 years-7.6%; 70 years and older-6.2%. The 5-year LR-free survival rates for these age groups were 90.5%, 95.4%, 95.5%, 95.4%, and 94.7%, respectively (P = 0.09, log-rank test). On univariable analysis, patients aged <40 years were nearly twice as likely to experience LR (hazards ratio (HR), 1.81; P = 0.012). Multivariable analysis of patients with complete data (n = 2,122) demonstrated that age <40 years and node positivity were associated with increased risk of LR, whereas ER positivity and radiation therapy were associated with decreased risk. Conclusions. Risk factors for LR after BCS include age <40 years, node positivity, ER negativity, and absence of adjuvant radiation therapy. Patients younger than age 40 years are at increased risk of LR after BCS.