NCI-CTC vs TNS: which tool is better for grading the severity of chemotherapy-induced peripheral neuropathy?
- Hughes, Richard
SYNOPSIS
BACKGROUND
Chemotherapy-induced peripheral neuropathy (CIPN) is usually graded with common toxicity scales such as the National Cancer Institute-Common Toxicity Criteria (NCI-CTC), but these scales rarely provide detailed information on clinical and pathological aspects of peripheral neuropathy. Clinicians have, therefore, begun to use measures of peripheral nerve function such as the Total Neuropathy Score (TNS), which involves the evaluation of motor, sensory and autonomic signs and symptoms, determination of the vibration perception threshold, and electrophysiological examination of one motor and one sensory nerve in the leg.
OBJECTIVE
To compare the usefulness of the NCI-CTC for the detection of changes in CIPN severity with that of the TNS and the TNSc (a reduced version of the TNS that is exclusively based on the clinical assessment of patients).
DESIGN AND INTERVENTION
Two series of patients were analyzed. Study 1 included 122 patients (age range 32-74 years; all female) who received a platinum-taxane combination, and study 2 included 51 patients (age range 32-72 years; 24 female) who received a platinum-taxane combination or thalidomide. Patients with pre-existing causes of peripheral neuropathy were excluded. At baseline and at frequent time points during treatment, patients in study 1 were evaluated with the NCI-CTC version 2.0 (range of scores 0-4) and the TNS (range of scores 0-40). Patients in study 2 were evaluated with the NCI-CTC 2.0 and the TNSc (range of scores 0-28); these patients were examined at baseline and at each chemotherapy course. The investigators analyzed pairs of examinations for which the NCI-CTC indicated either no change or a change of 1 point between each examination (150 pairs of examinations in study 1 and 97 pairs of examinations in study 2).
OUTCOME MEASURES
The main outcome parameter was the change in CIPN severity observed with the various grading scales.
RESULTS
A preliminary analysis confirmed that the TNS and the TNSc were significantly correlated with the NCI-CTC in scoring CIPN severity. In study 1, the TNS detected a change in the range of 1-5 points in 71% of patients who were scored as unchanged with the NCI-CTC. All patients with a 1-point change on the NCI-CTC scale had a ≥1-point difference in the TNS (94% with a change of ≥2 points). In the entire study 1 population, a change in the TNS of ≥1 occurred in 81% of patients, 67% had a change of ≥2, and 34% had a change of ≥3; the NCI-CTC detected a 1-point change in only 34% of patients. In study 2, the TNSc detected a change of 1-3 points in 50% of patients who were scored as unchanged with the NCI-CTC. In this study, all patients with a 1-point change on the NCI-CTC scale had a ≥1-point change on the TNSc; 77% had a change of ≥2 points. In the entire study 2 population, 67% had a score of ≥1 on the TNSc, 39% had a change of ≥2, and 28% had a change of ≥3; only 36% had a 1-point change on the NCI-CTC.
CONCLUSION
Both the TNS and the TNSc showed a higher sensitivity to changes in CIPN severity than did the NCI-CTC.