Examination of the relationship between serum zinc levels and peripheral neuropathy induced by paclitaxel/carboplatin combination therapy in gynecological cancer patients.

Objectives: Chemotherapy-induced peripheral neuropathy (CIPN), a frequently occurring adverse event associated with paclitaxel/carboplatin (TC) combination therapy, causes limb pain and markedly reduces the patient's quality of life. Since zinc has been reported to be associated with neuropathic pain, we investigated the relationship between CIPN due to TC therapy and serum zinc levels. Methods: The study included 13 patients with gynecological cancer whose serum zinc levels were measured before and during TC therapy. CIPN was classified into severity grades based on the Common Terminology Criteria for Adverse Events v5.0. A retrospective analysis was conducted on the relationship between the serum zinc level before TC therapy (PreZn), the minimum serum zinc level measured during TC therapy (MinZn), the MinZn/PreZn ratio, the number of TC treatment cycles, and the maximum grade of CIPN (MaxG) using Pearson's correlation coefficient. Moreover, an analysis was also conducted on clinical factors influencing MaxG, as well as fluctuations in serum zinc levels and CIPN grades for each cycle of TC therapy. Results: A negative correlation was observed between the MinZn/PreZn ratio and MaxG (r=-0.557, p=0.048). The clinical factors influencing CIPN remained unclear, and the decrease in serum zinc levels and the aggravation of CIPN plateaued after the third cycle. Conclusions: If a decrease in serum zinc levels during TC therapy is smaller than before therapy, it may imply the existence of a causal relationship that suppresses the aggravation of CIPN.