Chemotherapy-induced peripheral neuropathy after neoadjuvant or adjuvant treatment of breast cancer: a prospective cohort study

Susana Pereira, Filipa Fontes, Teresa Sonin, Teresa Dias, Maria Fragoso, José M. Castro-Lopes, Nuno Lunet

The purposes of this study were to estimate the incidence of chemotherapy-induced peripheral neuropathy (CIPN) and to identify its main determinants and impact in patient-reported outcomes. We performed a prospective cohort study including 296 patients with incident breast cancer submitted to chemotherapy, followed for 1 year. Patients with incident CIPN were reevaluated 6 months after this diagnosis. Relative risks (RR) with 95 % confidence intervals (95 % CI) were computed to quantify the relation between different clinical characteristics and the occurrence of CIPN, using Poisson regression. The variation of patient-reported outcomes between baseline and 1-year follow-up assessments was compared between patients with and without CIPN. The cumulative incidence of CIPN in the first year after diagnosis was 28.7 % (95 % CI 23.8-34.1), and more than 80 % of the patients were still symptomatic after 6 months. Among the latter, there was a significant decrease in the median total neuropathy score, clinical version (7 versus 4) between the two periods. In multivariable analysis, the risk of CIPN was higher for treatment with docetaxel (cumulative doses ≤300 mg/m(2), RR = 6.96, 95 % CI 2.53-19.10; >300 mg/m(2), RR = 13.32; 95 % CI 4.11-43.14). Alcohol consumption and diabetes were not significantly associated with CIPN. There were no significant differences in the variation of patient-reported outcomes between the baseline and 1-year follow-up evaluations. CIPN was frequent in this contemporary cohort of early-stage breast cancer patients and was strongly associated with docetaxel-based regimens. Symptoms persisted for at least 6 months in most patients, but severity was low and CIPN had no impact on patient-reported outcomes.