Lung cancer mortality in Sub-Saharan Africa

Valid data on mortality is a very important part of vital statistics for health policy. Worldwide, lung cancer (LC) is the most frequent cancer death among men with an estimated age-adjusted mortality (ASR) of 31.2 per 100,000 in the year 2002. Tobacco smoking causes more than 90% of all LC cases in developed countries, though, WHO reports the lowest LC mortality is seen in Sub-Saharan Africa (SSA). There are two possible explanations for this observation: (i) a considerably low smoking prevalence and (ii) errors in cancer diagnosis. However, in 1995, the estimated prevalence of smoking was high in males (28%) and low in females (8%) in SSA. More recent data on smoking prevalence confirm relatively high percentages in males. We developed and validated a method to estimate LC burden in countries where reliable cancer registration is lacking. Our model is based on smoking prevalence, estimates on LC in non-smokers, and relative risk estimates for tobacco smoking. We use recent smoking prevalence data from the WHO Report on the Global Tobacco Epidemic 2009 to estimate country-specific ASR and absolute numbers of LC deaths and compare the results to different available data sources as e.g. GLOBOCAN (published by IARC) and Cancer in Africa. First results show the LC mortality is underestimated for most SSA countries except for Zimbabwe and South Africa. Based on recent population figures (UN 2008) we estimate about 40,000 LC deaths for SSA per year. For 2002 GLOBOCAN estimated only 11,503 deaths. Even by assuming a non-smoking population in SSA we still estimate about 24,000 LC deaths. Our findings strongly suggest that the WHO largely underestimates the burden of LC in SSA. We consider a similar underestimation for other tobacco-related diseases as likely. Given the increasing life expectancy in developing countries, the public health impact of smoking prevention will also increase.