As genetic research continues to uncover loci, or areas in DNA, with specific changes that influence cancer risk, researchers can relay this type of scores.
‘The cancer polygenic risk score (CPRS) is an indicator of genetic risk of cancer as a whole.’
“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”, said lead author Guangfu Jin, PhD, a professor at Nanjing Medical University.
Researchers calculated individual PRS for 16 cancers in men and 18 cancers in women, using available data from genome-wide association studies. Then they used statistical methods to combine these scores into a single measure of cancer risk, based on the relative proportion of each cancer type in the general population.
To validate their CPRS, the researchers utilized genotype information from 202,842 men and 239,659 women from the UK Biobank, a cohort of general-population participants recruited from England, Scotland, and Wales between 2006 and 2009, and calculated a CPRS for each individual.
UK Biobank participants were surveyed upon enrolment for various lifestyle factors, including smoking and alcohol consumption, body mass index, exercise habits, and typical diet.
Based on these factors, researchers classified each patient as having an unfavorable (zero to one healthy factor), intermediate (two to three healthy factors), or favorable (four to five healthy factors) overall lifestyle.
The results of the study show that patients with the highest quintile CPRS were nearly twice as likely (for men) and 1.6 times as likely (for women) to have a cancer diagnosis by their most recent follow-up, in 2015 or 2016.
Patients with an unfavorable lifestyle and the highest quintile 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 quintile of genetic risk.
Among patients with high genetic risk, the five-year cancer incidence was 7.23 per cent in men and 5.77 per cent in women with an unfavorable lifestyle, compared with 5.51 per cent in men and 3.69 per cent in women with a favorable lifestyle.These findings suggest that patients can benefit from a healthy lifestyle regardless of genetic risk.
Limitations of this study include the fact that only the strongest genetic risk loci were included in the individual PRS, which disregards the influence of loci with weaker effects.
Researchers also noted an imbalance in the number of loci included between different cancer types, which can potentially skew their individual impact.
Source: Medindia
