Oral Cancer and Oral Precancerous Lesions in Inflammatory Bowel Diseases: A Systematic Review

Oral cancer is historically linked to well-known behavioural risk factors such as tobacco smoking and alcohol consumption. Other risk factors include age over 40, male sex, several dietary factors, nutritional deficiencies, viruses, sexually transmitted infections, human papillomavirus, chronic irritation, and possibly genetic predisposition. Precancerous lesions in the oral cavity include leukoplakia, erythroplakia, and lichen planus. Histology of oral cancer varies widely but the great majority are squamous cell carcinomas. Epidemiological studies and cancer registries have shown a consistently increased risk of oral malignancies in kidney, bone marrow, heart, or liver transplantation, in graft vs host disease, and in patients with HIV infection. Because of the increasing use of immunosuppressive drugs in patients with inflammatory bowel disease, it is useful to more accurately delineate the consequences of chronic immunosuppression to the oral cavity. Oral cancer and precancerous oral lesions in patients with inflammatory bowel disease [IBD] have been scarcely reported and reviews on the topic are lacking. We conducted a literature search using the terms and variants of all cancerous and precancerous oral manifestations of inflammatory bowel diseases. By retrieving the existing literature, it is evident that patients with IBD belong to the high-risk group of developing these lesions, a phenomenon amplified by the increasing HPV prevalence. Education on modifiable risk behaviours in patients with oral cancer is the cornerstone of prevention. Oral screening should be performed for all IBD patients, especially those who are about to start an immunosuppressant or biological drug.