Large fiber contribution to symptoms in chemotherapy-induced peripheral neuropathy in cancer survivors.

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) is associated with a large amount of interindividual variability in signs and symptoms. The purposes were to use latent profile analysis to identify subgroups of survivors with distinct lower extremity (LE) loss-of-function CIPN profiles; evaluate for differences in demographic, clinical, and pain characteristics between the profiles and characteristics associated with membership in the more severe profile; and examine relationships between the profiles and measures of large fiber loss and C-tactile fiber function.

METHODS

LE loss-of-function CIPN profiles were created using measures of worst pain, loss of light touch sensation, loss of cold sensation, loss of pain sensation, vibration threshold, and two balance measures.

RESULTS

Of the 405 survivors evaluated, two distinct profiles were identified: less severe loss of LE function (76.5%) and more severe loss of LE function (23.5%). Risk factors for membership in the more severe profile included being older, male, and having lower functional status. In terms of the loss of large fiber function, survivors in the more severe class had four more sites on average that lost light touch sensation; their vibration thresholds were 1.5 times higher; and their ratings of numbness were significantly higher. For C-tactile fiber function, significant between-group differences were found in survivors' ratings of the severity of sensitive skin and unpleasantness.

CONCLUSIONS

Findings suggest that distinct "CIPN phenotypes" can be identified in cancer survivors. Detailed phenotyping and molecular characterization of various CIPN phenotypes will lead to the development and testing of targeted and personalized interventions.