Attributable fraction of tobacco smoking on cancer using population-based nationwide cancer incidence and mortality data in Korea

Abstract

Background: Smoking is by far the most important cause of cancer that can be modified at the individual level. Cancer incidence and mortality rates in Korea are the highest among all Asian countries, and smoking prevalence in Korean men is one of the highest in developed countries. The purpose of the current study was to perform a systematic review and provide an evidence-based assessment of the burden of tobacco smoking-related cancers in the Korean population.

Methods: Sex- and cancer-specific population-attributable fractions (PAF) were estimated using the prevalence of ever-smoking and second-hand smoking in 1989 among Korean adults, respectively, and the relative risks were estimated from the meta-analysis of studies performed in the Korean population for ever-smoking and in the Asian population for passive smoking. National cancer incidence data from the Korea Central Cancer Registry and national cancer mortality data from Statistics Korea for the year 2009 were used to estimate the cancer cases and deaths attributable to tobacco smoking.

Results: Tobacco smoking was responsible for 20,239 (20.9%) cancer incident cases and 14,377 (32.9%) cancer deaths among adult men and 1,930 (2.1%) cancer incident cases and 1,351 (5.2%) cancer deaths among adult women in 2009 in Korea. In men, 71% of lung cancer deaths, 55%-72% of upper aerodigestive tract (oral cavity, pharynx, esophagus and larynx) cancer deaths, 23% of liver, 32% of stomach, 27% of pancreas, 7% of kidney and 45% of bladder cancer deaths were attributable to tobacco smoking. In women the proportion of ever-smoking-attributable lung cancer was 8.1%, while that attributable to second-hand smoking among non-smoking women was 20.5%.

Conclusions: Approximately one in three cancer deaths would be potentially preventable through appropriate control of tobacco smoking in Korean men at the population level and individual level. For Korean women, more lung cancer cases and deaths were attributable to second-hand than ever-smoking. Effective control programs against tobacco smoking should be further developed and implemented in Korea to reduce the smoking-related cancer burden.

Figure 1

Number of cancer incident cases attributable to tobacco smoking in Korean men, 2009*. * A) Proportion of cancer incident cases attributable to tobacco smoking; B) Number of cancer incident cases attributable to tobacco smoking by cancer sites.

Figure 2

Number of cancer incident cases attributable to tobacco smoking in Korean women, 2009*. * A) Proportion of cancer incident cases attributable to tobacco smoking; B) Number of cancer incident cases attributable to tobacco smoking by cancer sites.

Figure 3

Sensitivity analysis of the PAF for tobacco smoking using the lower and upper limits of 95% confidence interval for relative risks. Note: the length of shaded bars represent the estimated PAF values when RRs in Table 1 were used and the intervals represent the PAF estimated using the lower and upper limits of 95% confidence interval for RRs.