[A retrospective study of oral adverse events with colorectal cancer chemotherapy using bevacizumab]

We encountered serious oral mucositis in some patients undergoing colorectal chemotherapy with bevacizumab. We retrospectively investigated the role bevacizumab plays in the occurrence of oral mucositis.

Between January 2008 and December 2009, we encountered 11 patients for whom chemotherapy with bevacizumab had resulted in oral mucositis. The patients included 5 men and 6 women, with a mean age of 67. 9 years(range, 62-76 years). Among the patients, 5 had grade 1 oral mucositis, 3 had grade 2, and 3 had grade 3. We analyzed the risk factors, grades, symptoms, and treatments of oral mucositis in these patients.

In 6 patients, bevacizumab was administered in combination with mFOLFOX6, and in 5 patients, bevacizumab was administered in combination with FOLFIRI. Seven patients had undergone prior treatment without the occurrence of serious oral mucositis. With respect to oral health, 8 patients had periodontal disease, 7 had dental caries, 3 wore dentures, 3 exhibited poor oral self-care, and 2 had diabetes; in addition, 2 patients were smokers. Symptoms of oral mucositis included mucosal reddening in 11 patients, oral mucosal erosion or ulcer in 7, fungus infection in 6, aphtha in 7, pseudomembrane formation in 3, and poor oral intake in 2. All the patients had oral mucositis at the occlusal line of the buccal mucosa. The treatment for oral mucositis included polaprezinc.

Because many factors influence the development of oral mucositis, determining the specific cause of oral mucositis is difficult. Bevacizumabmay possibly decrease the VEGF levels in saliva and delay wound healing in oral mucositis. Therefore, oral mucositis may be caused not only by diabetes and poor oral self-care but by bevacizumab.