Changing trends in incidence of ovarian cancer - the Indian scenario

Ovarian cancer has emerged as one of the most common malignancies affecting women in India. The present communication reports the trends in the incidence rate of ovarian cancer for Indian women. The data published in Cancer Incidence in Five Continents for various Indian registries for different periods and / or publication by the individual registries served as the source material. Mean annual percentage change (MAPC) in rates was computed using relative differences between two time periods. During the period 2001-06, the age-standardized incidence rates (ASR) for ovarian cancer varied from 0.9 to 8.4 per 100,000 person years amongst various registries. The highest incidence was noted in Pune and Delhi registries. The Age Specific Incidence Rate (ASIR) for ovarian cancer revealed that the disease increases from 35 years of age and reaches a peak between the ages 55-64. The trend analysis by period showed an increasing trend in the incidence rate of ovarian cancer in most of the registries, with a mean annual percentage increase in ASR ranged from 0.7% to 2.4 %. Analysis of data by ASIR revealed that the mean annual percentage increase was higher for women in the middle and older age groups in most of the registries. Estimation of annual percent change (EAPC) in ovarian cancer by Poisson regression model through Maximum Likelihood Estimation (MLE) for the data of 3 population-based cancer registries vs. Mumbai, Chennai and Bangalore for the period 1983-2002 revealed that linear regression was found to be satisfactory fit between period and incidence rate. Statistically significant increase in EAPC was noted with the crude rate (CR,) ASR, and ASIR for several age-groups. Efforts should be made to detect ovarian cancer at an early stage by educating population about the risk factors. Most of the ovarian cancers are environmental in origin and consequently, at least in principle avoidable.