Oral cancer screening saves lives

Oral cancer is the 8th most common cancer in men and ranks 14th among women worldwide. There were 274,300 new cases and 145,500 deaths worldwide in 2002. Two-thirds of this burden are borne by developing countries, and over 30% by India alone. A high rate of oral cancer has been recorded in the Indian subcontinent, central and eastern Europe, parts of France, southern Europe, South America, and Oceania.

The disease is largely preventable by avoidance of risk factors like tobacco, betel-quid chewing and alcohol. Betel quid and areca-nut chewing, a major risk factor, were evaluated by IARC as carcinogenic to humans in a 2003 Monograph evaluation. It now seems that oral visual screening can reduce mortality in high-risk individuals, because of the easily detectable precancerous lesions, early invasive cancers, and improved survival after treatment of early stage cancers, according to an article published in The Lancet on June 4, 2005 (Lancet 2005; 365: 1927-33).

Visual inspection of the oral cavity is a simple, socially acceptable, and accurate screening test for oral neoplasia. The main challenge was whether a visual inspection-based screening programme leads to a substantial reduction in oral cancer mortality.

The International Agency for Research on Cancer (IARC) and the Regional Cancer Centre (RCC) of Trivandrum, Kerala, India, undertook a trial in 1996 to assess the efficacy of visual screening to reduce oral cancer mortality in a high-risk population in Trivandrum district, Kerala, India. Of the 192,000 people involved in the study, half of them were allocated to screening by visual inspection by trained health workers, and the other half constituted the control group and were not screened.

After 3 rounds of screening at 3-years interval, a 34% reduction in the number of deaths from oral cancer among users of tobacco and/or alcohol was observed in the screened group as compared to the control group.

Dr Ramadas, who led the study from the RCC, said that "the results of this first-ever randomized intervention trial for oral cancer screening are very encouraging indeed." He was joined by Dr Rajan, Director of the RCC in Trivandrum who stressed that "it’s important to implement oral visual screening through the existing health services in India to reduce the large number of avoidable deaths in the subcontinent."

Summing up, Dr Sankaranarayanan, who was leading the effort from IARC, concluded: "Oral visual screening can reduce mortality in high-risk individuals and we projected that screening for early lesions of the oral cavity has the potential of preventing at least 37,000 oral cancer deaths worldwide."

"Increasingly cancer is becoming a disease of low- and medium-resource countries, and oral cancer is more common in countries such as India than in western countries. The results of this trial are highly encouraging, but the more favorable outcome of early detection of oral, precancerous lesions should not lead us, however, to underestimate the need for primary prevention and health education efforts in order to curb betel-quid chewing, tobacco smoking and alcohol use," said Dr Boyle, Director of IARC.