Dexamethasone dose-dependently attenuates docetaxel-induced peripheral neuropathy in breast cancer treatment.

Purpose: Peripheral neuropathy is one of the most problematic adverse effects of docetaxel. We previously reported that dexamethasone (DEX) prevents taxane-associated acute pain syndrome (T-APS) in a dose-dependent manner, which might be a partial manifestation of chemotherapy-induced peripheral neuropathy (CIPN), in breast cancer treatment. Therefore, this study examined the dose-dependent prophylactic efficacy of DEX against CIPN.

Methods: Female patients with breast cancer receiving docetaxel-containing treatments (75 mg/m²) were divided into two groups according to DEX dosage on days 2-4; an 8 mg group (n = 56) and a 4 mg group (n = 28) and retrospectively evaluated. The primary endpoint in this study was defined as the development of grade ≥ 2 CIPN during 4 cycles of the treatment.

Results: The incidence of grade ≥ 2 CIPN was 32.1% in the 4 mg group and 10.7% in the 8 mg group and was significantly lower in the 8 mg group (P = 0.03). The incidence of all-grade CIPN was lower in the 8 mg group than in the control group, although the difference was not statistically significant (P = 0.06). Onset time of all-grade and grade ≥ 2 CIPN in the 8 mg group was significantly delayed compared to that in the 4 mg group (P = 0.003 and 0.01, respectively). Additionally, 8 mg/day of DEX was identified as a preventive factor for all-grade CIPN, although the evaluation of grade ≥ 2 symptoms was not possible.

Conclusion: Our study found that DEX attenuated docetaxel-induced CIPN in a dose-dependent manner during real-world breast cancer treatment. Further studies are needed to develop better CIPN management strategies.