Chemotherapy-induced neurological disorders (CIND) represent a serious side effect of cancer treatment. They can exist long after treatment ends and significantly impair functional independence and daily life. While this toxicity is well known in oncology, its epidemiological and cost burden features among various cohorts remain understudied. To better understand the current gap, we conducted a retrospective cohort study using de-identified administrative claims data from the IBM MarketScan research database. Our study included 258,410 adult patients undergoing chemotherapy and 4.7 million adult patients without chemotherapy. The chemotherapy group was stratified by cancer behaviors and treatment routes to examine CIND patterns and healthcare utilization.

Survival analysis and Cox proportional hazards models showed that approximately one-quarter to over one-third of cancer patients receiving chemotherapy developed CIND. All malignant cohorts showed higher CIND probability than their benign counterparts across all treatment routes, with the highest rates observed in patients receiving both intravenous and oral chemotherapy. Cox modeling adjusted for demographic characteristics, comorbidities, and baseline medications showed that chemotherapy increased the risk of neuropathy by approximately 40% compared to cancer patients not exposed to chemotherapy, with female and older age as critical risk factors. A healthcare burden analysis showed that patients with CIND had significantly higher opioid use, CIND-specific medication use, and rehabilitation service needs compared to the general population, resulting in about 2 times higher healthcare costs per patient. These results indicate that CIND influences a considerable proportion of cancer patients experiencing chemotherapy, with chemotherapy administration route being a key determinant of risk. Our findings emphasize the clinical importance of comprehensive neurotoxicity monitoring and highlight the significant economic burden that CIND places on the healthcare system.