Healthy Habits May Offset Genetic Cancer Risk

A genetic predisposition may increase a person’s risk of developing certain types of cancers but living a healthy lifestyle may help curb that risk, according to findings published in Cancer Research.

An individual’s estimated risk of developing a particular cancer is often defined by polygenic risk scores (PRS), which analyze DNA areas whose changes can impact the likelihood of getting one type of cancer. Now, researchers on this study took a broader approach and created the cancer polygenic risk score (CPRS), which does not look at one specific cancer type, but the genetic risk of any cancer.

“This study constructed an indicator (CPRS) to measure the genetic risk of overall cancer and provided convincing evidence that adherence to a healthy lifestyle could reduce overall cancer risk within and across different risk groups,” said study author Guangfu Jin, who holds a postdoctoral degree and is a professor at Nanjing Medical University in China, in an interview with CURE®. “Previous studies have proven that polygenic risk scores can predict risk of site-specific cancer, while this study is the first, to our knowledge, to provide convincing evidence that CPRSs can be used to assess the genetic risk of overall cancer.”

The researchers analyzed genotype information from 202,842 men and 239,659 women and calculated their CPRS. Data was pulled from the UK Biobank, which includes data from a general population living in England, Scotland and Wales between 2006 and 2009.

They also accounted for lifestyle factors, such as smoking, alcohol consumption, body mass index (BMI), exercise habits and diet. This information was used to classify people’s data into the following categories: unfavorable (zero to one healthy factors), intermediate (two to three healthy factors) or favorable (four to five healthy factors).

Within the lowest quintile of genetic risk, men with an unfavorable lifestyle were 2.99 times more likely to develop cancer than those in the favorable group. For women, those with unfavorable lifestyles were 2.38 times more likely to receive a cancer diagnosis.

In patients with a higher genetic risk for cancer, 7.23% of men and 5.77% of women with unfavorable lifestyle were diagnosed with cancer within five years, compared to 5.51% and 3.69% of women, respectively, with favorable lifestyles.

“In our opinion, the most important finding is that we proposed a new index to measure the genetic risk of overall cancer for each individual and found that the high genetic risk can be attenuated by adopting a healthy lifestyle,” Jin said.

Jin also explained that many people possess a genetic risk for at least one type of cancer, outlining the importance of everyone living more healthily.

“We hope that patients with cancer can realize that cancer is not a rare event for the public,” Jin highlighted. “According to our estimation, the absolute cumulative risk by age 75 was estimated to be as high as 38.2% in men and 29.1% in women in high genetic risk individuals on average. For their family members who have a genetic risk, we hope they can realize that the high genetic risk can be attenuated by adopting a healthy lifestyle, including not smoking, no alcohol consumption, regular physical activity, keeping a moderate BMI and a healthy diet plan.”

Looking forward, Jin said he hopes to see more studies analyzing the impact of a healthy lifestyle on genetic cancer risk.

“The findings of this study were mainly achieved in UK Biobank; therefore, the generalizability of our findings should be further assessed in more diverse populations when available,” he concluded.

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