[A Case of Multiple Bevacizumab-Related Colonic Perforations during Opioid Use].

We present the case ofa 54-year-old man who had been treated with bevacizumab-containing chemotherapy for a postoperative recurrence of lung cancer for 5 months; he had used opioids for cancer pain in his right lateral chest for 2 months. He was admitted to the hospital because his chest pain had worsened 5 days earlier and he was experiencing a dull pain in his lower abdomen. His condition was recognized as an aggravation of the cancer pain and his opioid dose was increased. He presented with intense abdominal pain 6 days after admission, and we diagnosed gastrointestinal perforations from an abdominal CT scan. Therefore, we undertook an emergency operation. Multiple perforations were seen on the transverse and descending colon; an extensive colectomy and a colostomy were performed. Histopathological findings showed that multiple ulcer perforations and normal mucosa coexisted throughout the resected specimen. Bevacizumab-induced ischemic changes were the suspected cause. When pain control becomes variable during opioid use, conditions such as bevacizumab-related gastrointestinal perforations should be considered, in addition to progression of the cancer pain itself, and the appropriate treatment should be administered.