Survival among cancer patients undergoing opioid rotation to methadone as compared to other opioids.
183 Background: Recent studies have reported that methadone has antineoplastic activity. Other studies have associated methadone with lower overall survival in patients with chronic pain. Methadone is the most frequent opioid chosen for purpose of opioid rotation (OR) in cancer patients experiencing refractory pain or opioid induced neurotoxicity. There is no data available on the association of methadone with overall survival in cancer patients. Our aim was to compare the characteristics and overall survival in cancer patients in methadone group with other strong opioid group. Methods: In this ad hoc analysis, we reviewed 2471 consecutive patient visits to the supportive care center of a tertiary cancer center in 2008 for ORs from strong opioids to methadone or other strong opioids with a follow-up visit within 6 weeks. Information regarding demographics, Edmonton Symptom Assessment Scale (ESAS), and morphine equivalent daily dose (MEDD) were collected. Successful pain response was defined as 2-point or 30% reduction in pain score. Kaplan-Meier curves were used to evaluate survival. Results: Of the 102 eligible patients, 54 underwent OR to methadone and 48 to other strong opioids. The median age was 56 years, 56% were male, and 81% had advanced cancer. There were no significant differences between the methadone group and the other opioid group in patient characteristics, performance status, MEDD, and ESAS scores. Although both the groups showed significant pain response, methadone group (72%) had a significantly higher pain response as compared to the other opioid group (65%; P = 0.04). The Kaplan-Meier curves revealed no significant difference in overall survival (OS) between the methadone group and the other opioid group [median OS: 5.2 months (95% CI 3.64-7.41) vs. 5.9 months (95% CI 2.6-9.2); P = 0.89]. Conclusions: We observed no significant difference in overall survival in cancer patients in methadone group as compared to other opioids. Further validation studies in a larger sample are warranted.