Healthy Lifestyle May Dial Down High Genetic Cancer Risk

By Megan Brooks

August 04, 2021

NEW YORK (Reuters Health) - A healthy lifestyle may reduce the risk of cancer in people at high genetic risk, new research suggests.

"Our findings indicate that everyone should have a healthy lifestyle to decrease overall cancer risk. This is particularly important for individuals with a high genetic risk of cancer," Dr. Guangfu Jin of Nanjing Medical University in China said in a news release.

Using data from genome-wide association studies, Dr. Jin and colleagues calculated individual cancer polygenic risk scores (CPRSs) for 16 cancers in men and 18 cancers in women. They combined these scores into a single measure of cancer risk, based on the relative proportion of each cancer type in the general population.

To test their CPRSs, they used genotype information from more than 440,000 men and women from the UK Biobank between 2006 and 2009.

There was a significant increase in incident cancer risk from quintile 1 (lowest) to quintile 5 (highest) of CPRSs, the team reports in Cancer Research.

Individuals with the highest CPRS were nearly twice as likely (for men) and 1.6 times as likely (for women) to have be diagnosed with cancer by their most recent follow-up in 2015 or 2016.

Notably, 97% of patients in the study were in the top quintile of genetic risk for at least one type of cancer.

"This suggests that almost everyone is susceptible to at least one type of cancer (and) further indicates the importance of adherence to a healthy lifestyle for everyone," Dr. Jin said in the news release.

Individuals with both an unfavorable lifestyle and the highest genetic risk were 2.99 times (in men) and 2.38 times (in women) more likely to develop cancer than those with a favorable lifestyle and the lowest genetic risk.

Among individuals with high genetic risk, the five-year cancer incidence was 7.23% in men and 5.77% in women with an unfavorable lifestyle, compared with 5.51% in men and 3.69% in women with a favorable lifestyle.

"CPRS may act like an indicator for genetic testing now," Dr. Jin told Reuters Health by email. "Therefore, in clinical practice, cancer patients and their relatives are suggested to have a CPRS test to evaluate if there are at high genetic risk for overall cancer or site-specific cancer, although it is still challenging to develop a standard testing protocol and to interpret the test results."

"A healthy lifestyle and earlier cancer screening should be helpful in reducing cancer risk for individuals at high genetic risk. However, it is unclear whether CPRS impacts patients' therapy and prognosis," Dr. Jin added.

The study did not have commercial funding, and the authors declare no conflicts of interest.

SOURCE: Cancer Research, online July 28, 2021.