A study undertaken by a group of doctors under the leadership of Dr Swaminathan of the Cancer Institute of Adyar in Chennai revealed that fewer people in India were surviving cancer than currently acknowledged. The objective of their study was to assess the bias in absolute cancer survival estimates in the absence of active follow-up of cancer patients in developing countries.

According to doctors associated with the research, the findings imply that national prevention, diagnosis and treatment drives may not be as effective as previously thought. But the data collected could help pinpoint what action is needed to improve survival rates, and therefore highlight the need for more such studies to be undertaken in cancer registries across the country.

The methods of the study were all incident cases of the 10 most common cancers and corresponding sub-types with all tobacco-related cancers not ranked among the top 10 that were registered in the population-based cancer registry in Chennai.

The research papers were published in the bulletin of the World Health Organisation recently, which show that relying on methods used in the West to track cancer survival rates resulted in a bias in favour of survival. The results show that in countries such as India, where mortality registration systems are deficient and the identity particulars of deceased individuals are often inaccurate, these "active follow up" methods would give a truer picture.

"If we know survival rates we can better predict the future cancer burden, which is useful for public health planning", Dr Swaminathan said.

Since the radiation treatment is available in four government hospitals in Chennai, the data on the survival rate of breast cancer patients beyond 5 years is as low as 44 per cent, compared with 54 per cent of those with cervix cancer. Whereas the breast cancer treatment is prolonged, uses various methods and may be managed by multiple people. Matching the figures for both cancers with Western survival rates that range from 70-80 per cent highlighted the need to invest in early screening, he said.

The doctors findings prove that under the conditions that prevail in India and other developing countries, active follow-up of cancer patients yields the most reliable estimates of cancer survival rates. Passive case follow-up alone or applying standard methods to estimate survival are likely to result in an upward bias.