Relationship Between Tramadol Response and Cancer Cachexia: A Retrospective Cohort Study

It was reported that the administration of tramadol in patients with cancer pain who have a higher interleukin 6 (IL-6) serum level led to insufficient pain relief. Cytokines produced by tumors, including IL-6, are associated with cancer cachexia. However, whether nonresponse to tramadol is related to cancer cachexia is unknown. The purpose of this study was to examine the relationship between tramadol response and cancer cachexia in patients with cancer pain.

We conducted a retrospective cohort study of patients with cancer who received tramadol treatment for mild to moderate pain from January 2016 to June 2019. Patients who experienced <20% pain reduction based on the numeric rating scale from baseline to day 7 after treatment with tramadol were defined as nonresponders. Univariate and multivariate logistic regression analyses were conducted to examine the relationships between tramadol response and various patient characteristics, including cancer cachexia.

Of 115 patients, 79 were included in the analysis. A total of 24 patients experienced cancer cachexia, and 22 patients were nonresponders. In the univariate logistic analysis, cancer cachexia (odds ratio [OR]: 6.04, 95% confidence interval [CI]: 2.06-17.7), higher white blood cell counts (× 10³/μL; OR: 1.28, 95% CI: 1.04-1.61), and lower body mass index (OR: 0.79, 95% CI: 0.66-0.96) were significantly associated with nonresponse to tramadol. The multivariate logistic analysis revealed that cancer cachexia (OR: 5.27, 95% CI: 1.75-15.9) was the only significant factor associated with nonresponse to tramadol.

Cancer cachexia in patients with cancer pain can be associated with nonresponse to tramadol.