An epidemiological assessment of increasing incidence and trends in breast cancer in Mumbai and other sites in India, during the last two decades.

A great deal is known on the epidemiology of breast cancer. In this paper an attempt has been made to discuss the epidemiology and trends in incidence of breast cancer in various populations of India with special reference to the data available at Mumbai Cancer Registry. For discussing descriptive epidemiology of breast cancer the data collected for most recent year, 1999, by Mumbai Cancer Registry has been utilized. For studying time trends in breast cancer the data collected for the Mumbai Cancer Registry for the years 1982-99 and for Bangalore and Chennai 1982-96 and for Barshi, Bhopal and Delhi for the years 1988-96 has been employed. A linear regression model based on the logarithms of the various incidence rates, a method frequently used for studying time trends, was applied to the entire dataset. Age specific incidence rates for breast cancer for most of the urban population in India were found to show steep increase till menopause years, after which the curves plateau. Most of the registries data indicate that Christians in India have the greatest risk of breast risk and Muslims have the lowest rate. In all the populations breast cancer was found to be less prevalent at the lower education level and the incidence increased with the education level. The trends for increase in breast cancer incidence over time for most of the populations in India were found to be statistically significant.