In 2002, there were over 270,000 new cases of mouth cancer and around 145,500 deaths worldwide, two-thirds of which occurred in developing countries. Mouth cancer is the commonest form of cancer and cancer death in men in India. The high-risk in the Indian subcontinent is related to the high prevalence of pan-tobacco (a combination of betel leaf, lime, areca nut and sun cured tobacco) chewing in the population.
Rengaswamy Sankaranarayanan (International Agency for Research on Cancer, Lyon, France), Kunnambath Ramadas (Regional Cancer Centre, Trivandrum, India) and colleagues randomly selected 13 population clusters in the Trivandrum district of Kerala, India, for inclusion in the study. 7 of the clusters were randomised to receive 3 rounds of oral visual screening by trained health workers at 3-year intervals and 6 clusters were assigned to receive usual care. Those eligible for the study were healthy individuals aged 35 years and above with no past history of oral cancer. The health workers referred anyone with one or more mouth lesions to a dentist or oncologist for clinical confirmation of mouth cancer. Over 87,600 people were screened at least once, over 53,300 twice, and over 29,100 three times. Of 5145 positive screens, 3218 complied with referral. Among these, 835 had benign lesions, 2,252 were diagnosed with oral pre-cancers, and 131 with invasive oral cancer. Follow-up revealed that 5-year survival was substantially increased in the intervention group (50%) compared with control (34%). The researchers also found that mortality among tobacco/alcohol users was reduced by 34% in the screening group compared with similar controls, 9-years after the initiation of screening.