Cancer incidence and mortality in Mongolia - National Registry Data.

Background: The National Cancer Registry of Mongolia began as a hospital-based registry in the early 1960s but then evolved to have a population-wide role. The Registry provides the only cancer data available from Mongolia for international comparison. The descriptive data presented in this report are the first to be submitted on cancer incidence in Mongolia to a peer-reviewed journal. The purpose was to describe cancer incidence and mortality for all invasive cancers collectively, individual primary sites, and particularly leading sites, and consider cancer control opportunities.

Methods: This study includes data on new cancer cases registered in Mongolia in 2003-2007. Incidence and mortality rates were calculated as mean annual numbers per 100,000 residents. Age-standardized incidence (ASR) and age-standardized mortality (ASMR) rates were calculated from age-specific rates by weighting directly to the World Population standard.

Results: Between 2003 and 2007, 17,271 new cases of invasive cancer were recorded (52.2% in males, 47.7% in females). The five leading primary sites in males were liver, stomach, lung, esophagus, and colon/rectum; whereas in females they were liver, cervix, stomach, esophagus and breast. ASRs were lower in females than males for cancers of the liver at 63.0 and 99.1 per 100,000 respectively; cancers of the stomach at 19.1 and 42.1 per 100,000 respectively; and cancers of the lung at 8.3 and 33.2 per 100,000 respectively. Liver cancer was the most common cause of death in each gender, the ASMR being lower for females than males at 60.6 compared with 94.8 per 100,000. In females the next most common sites of cancer death were the stomach and esophagus, whereas in males, they were the stomach and lung.

Discussion: Available data indicate that ASRs of all cancers collectively have increased over the last 20 years. Rates are highest for liver cancer, at about four times the world average. The most common cancers are those with a primary site of liver, stomach and esophagus, for which cases fatality rates are high in all populations. Emphasis is given in the National Cancer Control Program (NCCP) to limiting treatment for these and other high-fatality cancers to the small sub-set of potentially curable cases, while focusing on palliative care and patient support for the remainder. Meanwhile opportunities are being pursued to prevent liver cancer through hepatitis B vaccination and lung cancer through tobacco control, and to reduce cervical cancer mortality by finding lesions at a pre-malignant or early invasive stage.