The Correlation of the Grading of Chemotherapy-Induced Peripheral Neurotoxicity (CIPN) Using the Total Neuropathy Score-Reduced and Various Electrophysiological Parameters in Breast Cancer Patients

ABSTRACT

BACKGROUND: The accurate grading of chemotherapy-induced peripheral neuropathy (CIPN) represents an unsolved issue. This study evaluated usefulness of the reduced version of Total Neuropathy Score TNS (TNSr) and the correlation of this scale with various electrophysiological parameters. METHODS: Neuropathic symptoms and quality of life were assessed using the neuropathy symptom scale and the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group Neurotoxicity (FACT/GOG-NTX) scale. A detailed neurologic examination, nerve conduction study (NCS), and the current perception threshold (CPT) were also performed. The TNSr score was calculated by a single examiner. We divided the patients with small fiber neuropathy and large fiber neuropathy and compared each variable between groups. Also, we analyzed correlations of the TNSr score with various parameters (NCS data, CPT score, and neuropathy symptom scales). RESULTS: Of 30 recruited patients, 16 (53%) had large fiber neuropathy, and the other 14 (47%) had small fiber neuropathy. Patients with large fiber neuropathy had a lower sural sensory nerve action potential (SNAP) (p=0.000), lower peroneal compound muscle action potential (CMAP) (p=0.002), higher National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE, NTC) sensory grade (p=0.029) and higher TNSr score (p=0.000). There were no differences in any domain of the FACT/G, neuropathy symptom scale, or FACT/GOG-NTX between the two groups. The TNSr score was most significantly correlated with the sural SNAP (p=0.000), NTC-sensory grade (p=0.000), neuropathy symptom scale (p=0.001), FACT/GOG-NTX score (p=0.009), and pin score (p=0.002). CONCLUSIONS: The TNSr score is correlated with sensory peripheral neurotoxicity and also present the symptom severity in CIPN.