Chemotherapy-induced peripheral neurotoxicity can be misdiagnosed by the National Cancer Institute Common Toxicity scale

The assessment of chemotherapy-induced peripheral neurotoxicity (CIPN) is still uncertain as several of the most frequently used scales do not rely on a formal neurological evaluation and depend on patients' reports and examiners' interpretations. The aim of this study was to compare the assessment of CIPN using the National Cancer Institute Common Toxicity Criteria (NCI-CTC) scale and a formal neurological assessment scored with the Total Neuropathy Score (TNS, i.e., a composite scale designed to grade the impairment in neuropathy patients) to identify possible discrepancies in the diagnosis. In this prospective study, 155 patients treated with cisplatin/carboplatin or with paclitaxel/docetaxel and CIPN were examined in a collaborative oncological/neurological multi-center trial using the NCI-CTC scale and the TNS; the results were then extensively compared. We evidenced that the TNS allows possible misdiagnosed neuropathies to be revealed. In fact, the NCI-CTC evaluation performed by experienced examiners overestimated the occurrence of motor neuropathy, possibly because of the presence of confounding factors (e.g., fatigue, depression, cachexia), which might be difficult to be ruled out without a formal neurological examination. This study strongly indicates that a more formal neurological assessment of patients with CIPN than that achievable with the common toxicity scales (e.g., NCI-CTC) is advisable.