Abstract P4-10-02: Young Age Is Associated with Increased Risk of Local Recurrence Following Breast Conservation Surgery

Abstract

Abstract Background Local recurrence after breast conservation surgery (BCS) varies with clinical risk factors. The aim of this study was to evaluate how local recurrence rates vary by patient age at time of BCS. Methods With IRB approval, all patients undergoing BCS for primary breast cancer between 1988 and 2001 at Mayo Clinic, Rochester were identified. Patients receiving neoadjuvant chemotherapy were excluded. Local recurrence-free survival rates were estimated using the Kaplan-Meier method. Associations with local recurrence-free survival were evaluated using log-rank tests and Cox proportional hazards regression models. Results 3,075 patients underwent 3,143 BCS between 1988 and 2001. Mean age at BCS was 61 years (range 21-98). There were 177 (5.6%) patients aged <40, 496 (15.8%) 40-49, 763 (24.3%) 50-59, 803 (25.6%) 60-69, and 904 (28.8%) who were 70+ years old at time of surgery. At last follow-up, 214 patients (6.9%) experienced a local recurrence at a median of 3.4 years following BCS (range 0.1-14.4). Median follow-up for patients who did not experience a local recurrence was 8.7 years (range 0.0-20.2). The 5-year local recurrence-free survival rate was 95.0%. The frequency of local recurrences by age group were as follows: age <40 — 11.9%; age 40-49 — 5.9%; age 50-59 — 5.9%; age 60-69 — 7.6%; age 70 and older — 6.4%. The 5-year local recurrence-free survival rates for these age groups were 90.0%, 95.4%, 95.6%, 95.4%, and 94.7%, respectively (p=0.041; log-rank test). On univariate analysis, patients <40 years old were nearly twice as likely to experience a local recurrence following BCS compared with patients DCIS was associated with an increased risk of local recurrence compared with T1, T2, T3, or T4 disease (HR 2.25; P<0.001). Factors associated with a decreased risk of local recurrence on univariate analysis included ER positivity (HR 0.46; P<0.001), PR positivity (HR 0.60; p=0.001), adjuvant radiation (HR 0.48; p=0.007) and endocrine therapy (HR 0.65; p=0.012). Multivariate analysis of patients with complete data (n=2126) demonstrated that age <40 and node positivity were associated with an increased risk of local recurrence, while ER positivity, adjuvant radiation and endocrine therapy were associated with a decreased risk of local recurrence. Multivariable analysis of local recurrence after BCS Conclusion Risk factors for local recurrence after BCS include young age, node positivity, ER and PR negativity and absence of adjuvant radiation and endocrine therapy. Patients under age 40 are at increased risk of local recurrence following BCS for breast cancer. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-10-02.