A new observational study from Taiwan found that having one of eight chronic diseases, such as heart disease or diabetes, or their markers (e.g. high cholesterol levels as a marker for heart disease), also significantly raises the person's odds of developing cancer or dying from cancer. The study estimated that these diseases or markers accounted for about 20% of all new cancers and 39% of all cancer deaths. That's about the risk of 5 lifestyle factors combined (smoking, alcohol consumption, obesity, unhealthy diet, and lack of exercise) contributing to cancer development and death.
The eight chronic diseases and markers were: cardiovascular disease (markers for which include blood pressure, total cholesterol, and heart rate), diabetes, chronic kidney disease (markers for which include proteinuria and glomerular filtration rate), pulmonary disease, and gouty arthritis (for which uric acid is a marker). The higher the chronic disease and marker score, the higher the risk of developing cancer and cancer death (a dose-response). Chronic diseases and markers were associated with a shortened lifespan - about 13.3 years in men and 15.9 years in women.
But the good news is that regular physical exercise lowers the risk of developing cancer by about 48% and the risk of cancer death by 27%. That's huge! So physical exercise and activity could be viewed as "cancer prevention" strategies. The researchers pointed out that additional cancer prevention strategies are avoiding smoking (very important), avoiding excessive alcohol consumption, maintaining healthy weight, and a healthy diet. From Science Daily:
Several common chronic diseases together account for more than a fifth of new cancer cases and more than a third of cancer deaths, finds a study published by The BMJ today. The findings show that the cancer risks from common chronic diseases, such as heart disease and diabetes, are as important as those from five major lifestyle factors combined.
A team of researchers based in the US and Taiwan therefore set out to investigate the combined effect of eight common chronic diseases or disease markers (for example, high blood pressure as a marker of heart disease) on cancer risk compared with lifestyle factors. They also explored whether physical activity could reduce the cancer risk associated with chronic diseases and disease markers. The study involved 405,878 men and women in Taiwan with no history of cancer .... underwent a series of medical tests between 1996 and 2007. .... Participants were followed for an average of 8.7 years.
The researchers found that cardiovascular disease markers, diabetes, chronic kidney disease markers, pulmonary disease, and gouty arthritis marker were individually associated with risk of developing cancer or cancer death. Higher chronic disease risk scores based on these diseases or markers were linked with an increased risk of developing cancer and cancer death, with the highest level associated with a more than twofold increase in risk of developing cancer and a fourfold increase in risk of cancer death.
High chronic disease risk scores were also associated with substantial reduction in life span. The highest scores were associated with 13.3 years of life lost in men and 15.9 years of life lost in women. Together, these chronic diseases and markers accounted for more than one fifth of all new cancers and more than one third of all cancer deaths in this study population, which was similar to the contribution of five major lifestyle risk factors combined -- smoking, insufficient physical activity, insufficient fruit and vegetable intake, alcohol consumption, and obesity.
The researchers also found that physical activity was associated with a nearly 40% reduction in the excess risks of cancer and cancer death associated with chronic diseases and markers. [Original study.]