This is the first study to investigate the clustering patterns of six lifestyle risk factors for stomach cancer (ever smoking, heavy drinking, physical inactivity, overweight/obesity, high red/processed meat intake, and high salted food intake) and the relationship between the clusters and adherence to stomach cancer screening in Korea using nationally representative survey data. Among all six lifestyle risk factors, physical inactivity was the most frequent risk factor in both sexes, followed by smoking in males and high salted food intake in females. More males tended to exhibit clustering of multiple lifestyle risk factors than females. Specifically, 58.5% of males and 36.8% of females had a cluster of at least two risk factors. Regardless of sex, more lifestyle risk factors were associated with a lower likelihood of adherence to stomach cancer screening. Our study provides significant empirical evidence to guide prevention strategies and cancer screening programs to reduce the burden of stomach cancer.
Previous studies have demonstrated the prevalence of lifestyle risk factors among Korean adults; however, comparisons should be made with caution due to differences in target populations and variations in the investigation and measurement of risk factors. In the present study, physical inactivity was the most frequent risk factor. This finding is consistent with a study that examined five lifestyle risk factors (i.e., smoking status, heavy drinking, obesity, physical inactivity, and unintentional weight loss) in 9,945 Koreans aged 45 years and older32. This consistent evidence is particularly alarming as insufficient physical activity is a strong risk factor for other types of cancer and non-communicable diseases33,34.
In our study, most female participants had one risk factor, whereas clusters of two to three risk factors were more common among males. This finding is consistent with studies performed in other countries35,36. The higher prevalence of clustering of risk factors could partially explain why stomach cancer is more common in males3,37,38.
We observed a close relationship between the presence of multiple lifestyle risk factors and stomach cancer screening. Compared with those with no risk factors, those with three or more combined risk factors were less likely to adhere to stomach cancer screening guidelines, with an aOR of 0.35 (95% CI: 0.23–0.53) in males and 0.32 (95% CI: 0.21–0.48) in females. Because this is the first study to assess the association between combined risk factors and stomach cancer screening, we cannot directly compare our results with others. However, a recent study has highlighted the link between composite behavioral risk factors and a lower rate of non-uptake preventive health services, including blood pressure and cholesterol testing, cytology, and mammography39. These findings indicate that screening services are provided inequitably, as people with a higher number of lifestyle risk factors are less likely to get screened. There are several possible explanations for this trend. First, people with lifestyle risk factors often take less care of themselves and participate less in screening programs40. Second, inadequate knowledge about cancer risk factors and early detection may provide a barrier to adherence to screening guidelines41. Finally, the lack of recommendations from health professionals could result in a decrease in participation in screening. Therefore, efforts to increase the use of cancer screening and prevent delays in diagnostic evaluation should address these specific barriers.
For a correct interpretation of our results, some methodological comments are needed. First, the study utilized cross-sectional data, which limits the ability to establish causation. The relationship could thus be bidirectional, i.e., the uptake of stomach cancer screening might influence lifestyle changes or vice versa. Second, behavioral risk factors and the screening data were self-reported and may reflect either over- or under-reporting and recall biases. Lastly, several lifestyle risk factors could not be assessed due to the availability of the data. For example, low fruit consumption9, one of the most critical risk factors for stomach cancer development, could not be evaluated.
In conclusion, our results indicate a disparity in stomach cancer screening, in which those who have a more significant number of risk factors are less likely to get screened. Increasing public awareness of lifestyle risk factors and regular cancer screening, providing counseling at the time of screening, and targeting high-risk populations (those with multiple risk factors) for screening interventions are critical to promote cancer screening adherence and motivate health behavior changes.