Patients with breast cancer who have vitamin D insufficiency have a 45% increased likelihood to develop grade 3 or higher chemotherapy-induced peripheral neuropathy (CIPN) with paclitaxel, researchers reported in the Journal of the National Comprehensive Cancer Network. The findings identify a racial disparity because the increased risk was more common among Black patients (who are more likely to have vitamin D insufficiency), where it more often linked to sensory CIPN.

Researchers conducted prospective-retrospective analysis of 1,191 patients participating in SWOG S0221, a phase III trial comparing dosing schedules of a chemotherapy regimen (doxorubicin, cyclophosphamide, and paclitaxel) for early-stage breast cancer. They compared pretreatment serum vitamin D levels to reports of grade 3 or higher sensory or motor CIPN.

They found that 20.7% of patients with vitamin D deficiency and 14.2% of patients who had sufficient levels of vitamin D experienced CIPN and the risk increased as paclitaxel dosages did. Additionally, compared with White patients, Black patients had a higher prevalence of vitamin D insufficiency incidence of sensory CIPN, although the association was not statistically significant.

The researchers said that more clinical trials are needed to understand the role and effects of vitamin D deficiency in CIPN and the potential benefit of supplementation. “Vitamin D insufficiency may be a clinically useful biomarker to inform personalized supplementation to reduce CIPN occurrence, improve long-term quality of life, and perhaps enable patients to remain on effective paclitaxel treatment and improve survival,” they concluded.

ONS’s Peripheral Neuropathy Symptom Interventions and GuidelinesTM offer evidence-based recommendations for nursing management strategies for CIPN.