Cancer survival in Bhopal, India, 1991-1995.

The Bhopal population-based cancer registry was established in 1986 under the national cancer registry programme to investigate the after-effect of a gas leak in 1984. Cancer registration is done entirely by active methods. The registry is contributing data on survival for 16 cancer sites or types registered during 1991-1995. Follow-up of cases was done by active methods with median follow-up time ranging between 8-44 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged between 61-100%; death certificates only (DCOs) comprised 0-2%; 50-92% of total registered cases were included for survival analysis. The 5-year age-standardized relative survival rates for common cancers were mouth (34%), cervix (31%), breast (25%), tongue (12%), oesophagus (3%) and lung (1%). The 5-year relative survival by age group showed that survival was the highest in the youngest age group (45 years and below) for a majority of cancers. A decreasing survival with increasing clinical extent of disease was noted for most cancers studied.