Prostate Cancer Risk Reduced by Physical Activity Even Among Men With Prolonged Sitting Time: A Study From Vietnam

Cancer Etiology and Prevention Principle: "1 + X"

Cancer was previously thought to be an inevitable aspect of human health with no effective treatments. However, the results of in-depth cancer research suggest that most types of cancer may be preventable. Therefore, a comprehensive understanding of the disparities in cancer burden caused by different risk factors is essential to inform and improve cancer prevention and control. Here, we propose the cancer etiology and prevention principle "1 + X," where 1 denotes the primary risk factor for a cancer and X represents the secondary contributing risk factors for the cancer. We elaborate upon the "1 + X" principle with respect to risk factors for several different cancer types. The "1 + X" principle can be used for precise prevention of cancer by eliminating the main cause of a cancer and minimizing the contributing factors at the same time.

Attributable Causes of Cancer in Vietnam

PURPOSE

Vietnam is undergoing rapid socio-economic transition with an increasing cancer burden. The contribution of modifiable risk factors to cancers in Vietnam has not been studied. Therefore, we sought to evaluate the attributable causes of cancer in Vietnam.

METHODS

We reviewed the data on burden of cancer in Vietnam from 2 cancer registries in Hanoi and Ho Chi Minh City between 1995 and 2012. Next, we calculated the fractions of cancers occurring in 2018 attributable to established modifiable risk factors whose impact could be quantified. Data on exposure prevalence were obtained for the period from 2000 to 2010 from national sources wherever possible.

RESULTS

Cancer incidence in Vietnam has decreased slightly in both sexes. Cancer related to infectious agents decreased sharply, whereas cancer related to nutrition and metabolism has increased. In 2018, established carcinogens included in the analysis explained 47.0% of cancer burden in Vietnam. Chronic infections accounted for 29.1% of cancers (34.7% in men and 22.1% in women), tobacco smoking for 13.5% (23.9% in men and 0.8% in women), and alcohol drinking for 10.3%. Passive smoking was responsible for 8.8% of cancers in women. Other risk factors, including overweight or obesity, nulliparity, and low vegetable and fruit intake, accounted for < 1% of all cancers each.

CONCLUSION

Cancer incidence is slowly decreasing in Vietnam, and the causes of more than half of cancers remain unexplained. This result underlines the need for further epidemiologic and fundamental research. Our findings confirm the notion that controlling oncogenic infections and decreasing tobacco smoking are the most effective approaches to reduce the burden of cancer in Vietnam, but other risk factors, including alcohol drinking and diet, should not be neglected.