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.