BMI, lifestyle factors and taxane-induced neuropathy in breast cancer patients: The pathways study

Background: Lifestyle factors may be associated with chemotherapy-induced peripheral neuropathy (CIPN). We examined associations between body mass index (BMI) and lifestyle factors with CIPN in the Pathways Study, a prospective cohort of women with invasive breast cancer. Methods: Analyses included 1237 women who received taxane treatment and provided data on neurotoxicity symptoms. Baseline interviews assessed BMI (normal: <25 kg/m²; overweight: 25-29.9kg/m²; obese: ≥30 kg/m²), moderate-to-vigorous physical activity (MVPA) (low: <2.5; medium: 2.5-5; high: >5 hours/week) and fruit/vegetable intake (low: <35 servings/week; high: ≥35 servings/week). Baseline and six-month interviews assessed antioxidant supplement use (nonuser, discontinued, continued user, initiator). CIPN was assessed at baseline, six months, and 24 months using the Functional Assessment of Cancer Therapy-Taxane Neurotoxicity (FACT-NTX); a 10% decrease was considered clinically meaningful. Results: At baseline, 65.6% of patients in the sample were overweight or obese, 29.9% had low MVPA, 57.5% had low fruit/ vegetable intake, and 9.5% reported antioxidant supplement use during treatment. In multivariable analyses, increased CIPN was more likely to occur in overweight (odds ratio [OR] = 2.37, 95% confidence interval [CI] = 1.19 to 4.88) and obese patients (OR=3.21, 95% CI=1.52 to 7.02) compared with normal weight patients at 24 months and less likely to occur in patients with high MVPA compared with those with low MVPA at six (OR=0.56, 95% CI=0.34 to 0.94) and 24 months (OR=0.43, 95% CI=0.21 to 0.87). Compared with nonusers, patients who initiated antioxidant use during treatment were more likely to report increased CIPN at six months (OR=3.81, 95% CI=1.82 to 8.04). Conclusions: Obesity and low MVPA were associated with CIPN in breast cancer patients who received taxane treatment.