Cancer epidemiology and control in North-Western and Central Asia - past, present and future.

The North-Western and Central region of Asia stretches from Turkey through Armenia, Georgia and Azerbaijan, to Iran and Turkmenistan, Uzbekistan, Kazakhstan, Kyrgyzstan, Tadjikistan and Afghanistan. These countries in the main share Turkic, Iranian or Caucasus ethnicity and culture and can be considered as a regional entity for cooperation in control of cancer. The present review of cancer registry and other epidemiological data was undertaken to provide an evidence base for cancer control programs and pointers to possible research collaboration. The most prevalent cancer site in males is the lung in the Western part of the region and the stomach in most of Iran and Central Asia, followed by the oesophagus in the latter two. Bladder cancer is comparatively frequent throughout. In females breast cancer is number one, generally followed by gastric, oesophageal or cervical lesions. However, there are interesting differences between countries or regions, particularly regarding the stomach. General tendencies for increase in adenocarcinomas but decrease in squamous cell carcinomas and gastric cancer point to change in environmental influence over time. Variation in risk factors depends to some extent on the level of economic development but overall the countries of the region face similar challenges in achieving effective cancer control, underlying the necessity for cooperation.