Descriptive Epidemiology of Female Breast Cancer in Delhi, India.

Background: Breast cancer is the most frequently diagnosed cancer in females worldwide. The Population Based Cancer Registry data of Delhi were here used to describe the epidemiology and trends in breast cancer incidence in Delhi. Methods: Crude rate, age-standardized incidence rates (ASR) and age-specific incidence rates were calculated using the data collected by Delhi PBCR for the year 2012. The time trend of breast cancer incidence was evaluated by joinpoint regression using the PBCR data from 1988-2012. Results: A total of 19,746 cancer cases were registered in 2012, 10,148 in males and 9,598 in females. Breast cancer was the leading site of cancer in females accounting for 2,744 (28.6%) of cases with a median age of 50 years. The crude and age standardized incidence rates for breast cancer were 34.8 and 41.0 per 100,000 females, respectively. Age specific incidence rates increased with age and attained a peak in the 70-74 years age group..A statistically significant increase in ASR with an annual percentage change (APC) of 1.44% was observed. Conclusions: The breast, which was the second most common cancer site in Delhi in 1988, has now surpassed cancer of cervix to become the leading site over the years. A similar trend has also been noted for other metropolitan cities viz. Bangalore, Bhopal and Chennai. Though the ASRs in these are comparable, they are still low compared to Western countries. Changing life styles in metropolitan cities like delayed marriage, late age at first child birth, lower parity and higher socio-economic status, may be some of the probable primary cause for higher incidences of breast cancer in urban as opposed to rural areas.