Wang, M.

270 Background: Neuropathy is a common and potentially enduring and disabling complication of adjuvant taxane therapy. Recent studies have identified candidate host single nucleotide polymorphisms (SNPs) associated with taxane-induced neuropathy (Schneider et al. ASCO 2011, abstr. 1000). We therefore sought to determine whether neuropathy was associated with breast cancer recurrence. Methods: This study included 4,950 eligible women with axillary lymph node positive or high-risk node-negative breast cancer who received up to 4 cycles of AC (doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2) every 3 weeks, followed by either: (1) paclitaxel 175 mg/m2 every 3 weeks x 4 (P3), (2) paclitaxel 80 mg/m2 weekly x 12 (P1), (3) docetaxel 100 mg/m2 every 3 weeks x 4 (D3), or (4) docetaxel 35 mg/m2 weekly x 12 (D1). Chemotherapy doses were based on actual body weight. Cox proportional hazards model were used to determine the relationship between neuropathy and disease free survival (DFS) and overall survival (OS) treating neuropathy status as a time dependent covariate and using a landmark analysis. Results: Of 4,702 patients who received at least 1 taxane dose, grade 2-4 neuropathy developed in 20%, 27%, 16%, and 16% in the P3, P1, D3, and D1 arms, respectively. In a model including age, tumor size, nodal status, treatment arm, neuropathy, and the neuropathy- treatment interaction, there was no relationship between neuropathy and DFS and OS in the entire population, for any of the individual treatment arms, or for any breast cancer subtypes, whether analyzed as a time-dependent covariate or using a landmark analysis. Baseline covariates associated with an increase rate of neuropathy included black race (25% vs. 19% grade 2-4, p=0.02) and obesity (21% vs. 19%, p=0.04), but not age. Conclusions: There was no association between taxane-induced neuropathy and DFS or OS in patients treated with contemporary AC-taxane therapy, including weekly paclitaxel. These findings show that taxane-induced neuropathy is not associated with outcome, thus suggesting that validation of SNPs predictive of neuropathy may be useful in identifying patients at higher risk for neuropathy but not taxane benefit and thereby improve therapeutic individualization.