Multi-center assessment of the Total Neuropathy Score for chemotherapy-induced peripheral neurotoxicity

The aim of this multi-center study was to assess with reduced versions of the Total Neuropathy Score (TNS), the severity of chemotherapy-induced peripheral neurotoxicity (CIPN), and to compare the results with those obtained with common toxicity scales. An unselected population of 428 cancer patients was evaluated at 11 different centers using a composite (clinical + neurophysiological, TNSr) or clinical (TNSc) examination and with the National Cancer Institute - Common Toxicity Criteria (NCI-CTC) 2.0 and Eastern Cooperative Oncology Group (ECOG) scores. A highly significant correlation was demonstrated between the TNSr and the NCI-CTC 2.0 and ECOG scores; but the TNSr evaluation was more accurate in view of the more extended score range. Also, the simpler and faster TNSc (based only on the clinical neurological examination) allowed to grade accurately CIPN and correlated with the common toxicity scores. The correlation tended to be closer when the sensory items were considered, but also the TNSr motor items, which were not specifically investigated in any other previous study, significantly correlated with the results of the common toxicity scales. In conclusion, this study suggests that the TNSr is a reliable tool for accurately grading and reporting CIPN, with the additional and so far unique support of a formal comparison with known and widely used common toxicity scales. The TNSc is a valid alternative if neurophysiological examination is not feasible. The longer time needed to calculate the TNSr and TNSc in comparison to the ECOG or the NCI-CTC 2.0 scales is offset by the more detailed knowledge of the CIPN characteristics.