Standard of Care

Visual Inspection of Oral Cavity for Precancers and Cancer

Participants were invited for 3 rounds of oral cavity cancer screening, conducted 3-years apart. Screening was conducted by health workers trained to perform visual inspection of the oral mucosa and identify potential precancerous lesions or oral cancer. Lesions found were referred to a weekly clinic for further evaluation by dentists and oncologists with experience in the diagnosis of oral lesions. Oral precancerous lesions were surgically excised whenever possible and those with confirmed oral cancer were referred for appropriate treatment with surgery, radiotherapy, and/or chemotherapy.

Information on all deaths were collected from the municipal and district death registers, hospital medical records, death records of churches and mosques, hospital visits by the population cancer registry staff and by project health workers. Cancer cases were coded by the ICD-O 3rd edition codes and cause of death was coded using ICD-10 by the registry and project staff blinded to study group allocation. Deaths were attributed to oral cancer if the patient had histologically or clinically confirmed oral cancer, lymph nodes or distant metastasis at the time of death or had died due to complications of oral cancer treatment.

Information on incident oral cancer cases were obtained from the Trivandrum population-based cancer registry, hospital cancer registry of the RCC and medical records departments of other hospitals treating oral cancer patients. Collection of information was blinded to study group assignment of cases. The staging of oral cancers was done according to the UICC TNM staging system.