WS10-2 - A Pilot Randomized Trial Comparing Standard Pain Control with or without Gabapentin for the Treatment of Pain Related to Radiation-Induced Mucositis in Head and Neck Cancer

Abstract

ABSTRACT Background Radiation-induced mucositis (RIM) in chemoradiation (CRT) for head and neck cancer (HNC) causes severe pain and worsens CRT compliance and outcome. Following retrospective reports that gabapentin might improve RIM-associated pain during CRT, we conducted a randomized phase II trial to analyze the safety and efficacy of gabapentin for RIM-associated pain. Methods HNC patients (pts) receiving CRT were randomized to receive standard pain control (SPC) or SPC plus gabapentin (SPC + G). Pts in the SPC arm received acetaminophen and opioids as analgesic, while those in the SPC + G arm received gabapentin in addition to SPC. Gabapentin maintained at dose of 900 mg/day till 4 weeks after CRT. The prescribed RT dose was 66-70 Gy/33-35Fr. Concurrent chemotherapy consisted of a three-week cycle of cisplatin. Primary endpoint was maximum VAS score during CRT. Secondary endpoints were total dose of opioids, change in QOL (EORTC QLQ-C30 and EORTC QLQ-HN 35) from base line to 4 weeks after CRT, and adverse events. Results From Apr 2010 to Oct 2011, 22 eligible pts were randomly assigned to receive SPC (n = 11) or SPC + G (n = 11). All pts were Stage III or IV. Twelve were treated in a locally advanced setting and 10 in a postoperative setting. No statistically significant differences were seen in median maximum VAS scores between arms (47 in SPC vs. 74 in SPC + G; p = 0.517). Median total dose of opioids at maximum VAS and total dose of opioids at 4 weeks after CRT did not statistically differ but appeared higher in the SPC + G arm (215 mg vs. 745.3 mg; p = 0.880, 1260 mg vs. 1537.5 mg; p = 0.9438). QOL analysis showed significantly worse scores in the SPC + G arm for weight gain (p = 0.005). Adverse events related to gabapentin were manageable. One-year survival rate in both arms was equivalent. Conclusions This is the first prospective randomized trial to analyze the safety and efficacy of gabapentin for RIM-associated pain. While survival data was equivalent in both arms, gabapentin may have detrimental effects for RIM and further investigation is warranted. Disclosure N. Kiyota: an advisory board member on proper usage of cetuximab for head and neck cancer in Japan (Merck Serono) All other authors have declared no conflicts of interest.