JAMA logoNovel treatments and discoveries help physicians treat various ailments. So here is an investigation that may benefit doctors in treating breast cancer patients. A latest study claims that women displaying higher risk scores that were dependent on having breast cancer related genetic variants were at a greater risk for developing the disease. It was mentioned that the scores also enabled experts to figure out which women would be suffering from estrogen receptor-positive disease.

The experts aimed to examine 14 individual single-nucleotide polymorphisms (SNPs;) and a polygenic which is known to be linked with an inheritable character regulated by various genes at once risk score. This investigation possibly empowered them to predict women facing a higher risk for breast cancer.

For conducting the study, Gillian K. Reeves, Ph.D., of the Cancer Epidemiology Unit, University of Oxford, U.K., and colleagues enrolled 10,306 women with breast cancer whose average age at diagnosis was 58 years. The investigation was included 10,393 women without breast cancer. These women had given blood samples for genotyping in 2005-2008. It was assumed that the per-allele odds ratio (OR) for individual SNPs and the aggregate incidence of breast cancer to age 70 years correlated to a polygenic risk score based on the 4, 7, or 10 SNPs most strongly linked with risk.

The investigators elucidate, “Findings from genome-wide association studies (GWAS), together with analyses of specific candidate polymorphisms [gene variations], have identified a number of variants that are definitely or probably associated with breast cancer risk. There is also increasing evidence that some genetic factors have different effects on different subtypes of breast cancer.”

In the course of the study, it was ascertained that odd ratios for breast cancer were greatest for the SNPs FGFR2-rs2981582 and TNRC9-rs3803662. These 2 SNPs appeared to be greatly higher for estrogen receptor (ER)-positive as compared for ER-negative disease. A strong relation between 2q-rs13387042 was also suggested wherein the per-allele OR was strongly linked to bilateral disease in comparison to unilateral. The association was seemingly greater for lobular than ductal tumors.

A variation in women in the highest and the lowest fifth of polygenic risk score was observed. After thorough inspections the scientists revealed some acquired risk factors for breast cancer to consist of identical or greater effects on breast cancer incidence than the dissimilarities monitored. It was suggested that the cumulative incidence of breast cancer to age 70 years in women in the top fifth for polygenic risk score which was 8.8 percent.

This score was very much alike for women in developed countries with one first-degree relative with breast cancer that was 9.1 percent. However, it seems to be lower than that for women with 2 affected first-degree relatives which was 15.4 percent. Effects of the examined genes and other risk factors for breast cancer did not appear to share any communication.

The scientists shared, “When the effects of the 7 SNPs most strongly associated with overall breast cancer risk in these data were combined using a polygenic risk score, the cumulative risk of breast cancer to age 70 years among women in the top fifth was twice that in the bottom fifth (8.8 percent vs. 4.4 percent). Both the relative and, particularly, the absolute difference was much greater for ER-positive disease (7.4 percent vs. 3.4 percent) than for ER-negative disease (1.4 percent vs. 1.0 percent).”

Therefore, segregating women on the basis of their polygenic risk may not be beneficial for population-based breast cancer screening programs. Grouping women seems to be useful for determining the exact mechanisms of the disease.

The study is published in the July 28 issue of JAMA.