RESUMO
PURPOSE: Although diabetes mellitus (DM) is recognized as a risk factor for chemotherapy-induced neurotoxicity, its true impact on intensity and time course of peripheral neuropathy is still unclear. The goal was to analyze the relevance of preexisting DM to weekly paclitaxel-induced peripheral neuropathy (PIPN). METHODS: We performed a retrospective case-control study (1:2) including a total of 129 patients with breast cancer (43 with DM and 86 controls) treated with single-agent weekly paclitaxel (wP). RESULTS: Compared with controls, patients with DM treated with wP experienced PIPN more frequently (74.4% vs 58.4%; P=.016) and with higher severity (grade 2-3: 51.2% vs 27.7%; P=.014). A significant delay in PIPN resolution was observed in women with DM (P=.001) and, in a multivariate analysis, DM was the only independent predictor for delayed recovery (hazard ratio [HR], 0.16; 95% CI, 0.05-0.55; P=.003). After 2 years, 68.7% of patients with DM (vs 29.2% of women without DM) still experienced PIPN, which was functionally significant (grade 2-3) in 18.2%. CONCLUSIONS: Significantly more dose delays and reductions because of PIPN occurred in patients with DM. Preexisting DM associates with long-lasting significant PIPN in patients treated with wP. Benefits and risks of long-term significant PIPN should be carefully balanced in patients with DM before starting wP chemotherapy.