Time-dependent discrepancies between physician-assessed and patient-reported oxaliplatin-induced peripheral neuropathy in patients with metastatic colorectal cancer who received mFOLFOX6 plus bevacizumab: a post hoc analysis (WJOG4407GSS2).

PURPOSE

Cumulative sensory neurotoxicity induced by oxaliplatin impairs patients' quality of life and treatment continuation. This study investigated the relationship between physician-assessed and patient-reported oxaliplatin-induced peripheral neuropathy (OIPN) during treatment of metastatic colorectal cancer (mCRC) over time.

METHODS

A post hoc analysis was conducted for 191 patients with mCRC who received mFOLFOX6 plus bevacizumab in the WJOG4407G trial. Physician-assessed OIPN was graded by CTCAE every 2 weeks. Patient-reported OIPN was assessed with the FACT/GOG-Ntx (11 items, best score 44) at baseline and at 3, 6, and 9 months. Physician underestimation was defined as when the highest scores of the NTX1-4 sensory subscale/CTCAE grade were 2/0, 3/0-1, or 4/0-1, and overestimation as 0/2-3, 1/2-3, or 2/3.

RESULTS

The median total dose (range) of oxaliplatin was 762 (85-5950) mg/m. Overall, the least squares mean of FACT/GOG-Ntx scores (standard error), estimated by a linear mixed model, were 36 (0.8), 34 (0.9), 29 (1.0), and 27 (1.1) for CTCAE grades 0, 1, 2, and 3, respectively. FACT/GOG-Ntx scores were weakly-to-moderately correlated with CTCAE grade (Spearman's r = - 0.24 [p = 0.0026], - 0.46 [p < 0.0001], and - 0.56 [p < 0.0001] at 3, 6, and 9 months, respectively). OIPN was underestimated in 85/159 (54%), 43/109 (39%), and 18/69 (26%) patients at 3, 6, and 9 months, respectively. In contrast, OIPN was overestimated in less than 5% of the patients at any time.

CONCLUSION

During early treatment, physician underestimation of OIPN in patients with mCRC is likely.