Ulcerative colitis in a patient with non-small-cell lung cancer receiving bevacizumab

Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor, is anticipated to prolong survival with inhibition of angiogenesis in patients with non-small-cell lung cancer. Rare life-threatening adverse events affecting the digestive tract have been reported, such as gastrointestinal hemorrhage and bowel perforation. A 62-year-old Japanese woman who was diagnosed as having stage IIIB (cT4N2M0) lung adenocarcinoma received chemotherapy with bevacizumab, pemetrexed and carboplatin every 3 weeks for four cycles, which resulted in a partial response, and then continued with maintenance bevacizumab monotherapy. Fourteen days after completion of the seventh cycle of bevacizumab maintenance therapy, the patient developed sudden abdominal pain with more than 10 episodes of hematochezia per day. On the basis of colonoscopic and pathological findings, ulcerative colitis (UC) with severe pancolitis was diagnosed. This case was unresponsive to medical treatment and required subtotal colectomy for management of the ulcerative colitis. This is the first reported case of ulcerative colitis occurring during bevacizumab therapy. The anti-angiogenesis activity of bevacizumab may have been involved in the development and exacerbation of UC in this patient.