Chronic pain after rectal cancer surgery-development and validation of a scoring system.

Aim The aim was to develop and validate a scoring system for the assessment of chronic pain on quality of life (QoL) following surgical treatment of rectal cancer (RC). Method Patients diagnosed with RC between 2001 and 2014 in Denmark were evaluated for inclusion. Eligible patients were mailed questionnaires concerning pain and QoL. Questionnaire items were associated with QoL by odds ratio using regression analyses. The patients were randomized into a development group and a validation group. The most significant items were each assigned a score value based on multivariate-adjusted odds ratio. Validity was tested in the validation group using receiver operating characteristic curves and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 (EORTC QLQ-30). Results A total of 1928 eligible patients completed the questionnaire; 1072 were randomized to the development group and 856 to the validation group. The calculated scores included the six most important questionnaire items giving a score range of 0-45 which identified three groups: no significant pain, minor pain syndrome and major pain syndrome. Our results suggest a significant correlation between QoL assessment and the presence of major pain. Conclusion We have developed and validated a reliable, QoL-based scoring system for chronic post-surgical pain following RC.