Healthy lifestyle factors such as low body mass index, abstinence from smoking, and drinking and exercise are related to decreased cancer incidence, even in individuals with a high genetic risk. The new research was carried and was published in Cancer Research, a journal of the American Association for Cancer Research. The lead author of the research is Guangfu Jin, Ph.D., a professor at Nanjing Medical University.
As genetic research continues to uncover areas in DNA or loci with specific changes that influence cancer risk. Researchers can personalize estimates of people’s cancer risk, define polygenic risk scores (PRS) based on a patient’s unique combination of these changes. Rather than for overall cancer risk most PRS are generated for a specific cancer type. According to Jin, “A PRS indicating risk of a certain cancer is important but not enough. “We tried to create an indicator—the cancer polygenic risk score (CPRS)—to measure the genetic risk of cancer as a whole.”
Individual PRS Jin and colleagues calculated for 18 cancers in women and 16 cancers in men, using available data from genome-wide association studies. Then statistical methods were used to combine these scores into a single measure of cancer risk based on the relative proportion of each cancer type in the general population. Separate CPRS were generated for women and men.
The researchers to validate their CPRS utilized genotype information from 239,659 women and 202,842 men from the UK Biobank, a group of general-population participants recruited from Wales, Scotland, and England between 2006 and 2009, and calculated a CPRS for each individual.
Upon enrollment, the UK Biobank participants were surveyed for various lifestyle factors, including alcohol consumption and smoking, typical diet, exercise habits, body mass index. Based on these factors, Jin and colleagues classified each patient as having an unfavorable, favorable, or intermediate overall lifestyle.
Patients with the highest quintile CPRS were nearly 1.6 times as likely for women and nearly twice as likely for men by their most recent follow-up, in 2015 or 2016, to have a cancer diagnosis. 97% of patients in the study had a high genetic risk of at least one cancer type. As per Jin, “This suggests that almost everyone is susceptible to at least one type of cancer. It further indicates the importance of adherence to a healthy lifestyle for everyone.”
Patients with the highest quintile genetic risk and an unfavorable lifestyle were 2.38 times in women and 2.99 times in men more likely to develop cancer than those with the lowest quintile of genetic risk and a favorable lifestyle. Among patients with high genetic risk, the five-year cancer incidence was 5.77% in women and 7.23% in men with an unfavorable lifestyle, compared with 3.69% in women and 5.51 in men with a favorable lifestyle.
According to Jin, “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. We hope our CPRS could be useful to improve a person’s awareness of their inherited susceptibility of cancer as a whole and facilitate them to participate in healthy activities.”
