Cancer epidemiology in South Asia - past, present and future.

Pakistan, India, Sri Lanka, Bangladesh, Nepal and Bhutan, with their total population of more than 1,500 million, make up the subcontinent of South Asia. Despite massive diversity across the region, there are sufficient similarities to warrant a collective approach to chronic disease control, including development of cancer control programs. Cancer is already a major problem and there are general similarities in the prevalence patterns. In males, oral and lung cancer are either number one or two, depending on the registry, with the exceptions of Quetta in the far north, Larkana and Chennai. Moderately high numbers of pharyngeal and/or laryngeal cancer are also consistently observed, with prostate cancer now becoming visible in the more developed cities. Breast and cervical cancer share first and second place except in Muslim Pakistan, where oral cancer generally follows breast. The ovary is often included in the five most prevalent types. Markedly increasing rates for breast cancer and distribution shifts in other cancers suggest that, despite improvement in cervical and oral rates, the overall burden will only become heavier over time, especially with increasing obesity and aging of what are still youthful populations. Coordination of activities within South Asia is a high priority for cancer control in the region.