Early thermal quantitative sensory testing to measure acute oxaliplatin neurotoxicity and predict chronic neuropathy in gastrointestinal malignancies.

Abstract

425 Background: Acute oxaliplatin neurotoxicity has been shown to be predictive of chronic oxaliplatin neuropathy. A recent study by Attal et al showed that tQST (thermal quantitative sensory testing) at cycle 4 provides a noninvasive method for predicting chronic neuropathy. A high risk population defined as those experiencing pain with a ≥ 20 degree cold stimulus had an OR of 39 for developing a severe chronic neuropathy at 1 year. Our study was designed to test the utility of tQST at earlier time points for predicting chronic neuropathy. Methods: Gastrointestinal cancer patients receiving FOLFOX were evaluated over a 1 year period for the development of acute and chronic oxaliplatin neurotoxicity: before starting FOLFOX, 1 hour into oxaliplatin infusion, before cycles 2, 4 and 12, and 1 year after start of treatment. Patients underwent a series of QSTs to measure thermal and mechanical sensitivities, fine motor skills, vibration detection, validated questionnaires, and presence of hyperalgesia. Results: Preliminary analysis of 13 patients using cycle 4 data as a surrogate for chronic neuropathy shows that cold pain (the temperature at which subjects report pain) prior to starting FOLFOX and at cycle 2 is predictive of cold pain at cycle 4, rs = 0.67 (p=.01) and 0.49 (p=0.09), respectively. There is a significant difference in cold pain across all time points between high and low risk populations(p=0.02 at baseline, p=0.04 during cycle 1, p=0.08 at cycle 2, and p=0.03 at cycle 4). Correlation between cycles 1 and 4 is seen for changes in cold sensitivity from baseline, rs = 0.52 (p=0.07). Conclusions: Baseline tQST correlates to cycle 4 measurements and may be an early predictor of patients at the highest risk for chronic neuropathy. These preliminary data indicate an inherent, pre-existing sensitivity to oxaliplatin induced chronic neuropathy for high risk patients which can be detected with tQST. Early identification of these patients can allow for preventive measures to decrease the incidence of this debilitating chronic adverse effect of oxaliplatin. A larger biomarker validation study is planned using tQST to stratify patients into high and low risk.