New DNA variants that raise breast, prostate and ovarian cancer risk identified

80 new regions of the genome associated with an increased vulnerability to developing breast, prostate and ovarian cancers have been identified by European Collaborative Oncological Gen-Environmental Study (COGS) by using mass sequencing techniques.

The findings are drawn from the collaborative work of more than 50 groups around the world, who carried out their genotyping in four different centres and whose work was coordinated by Javier Benitez, Director of the Human Cancer Genetics Programme at the Spanish National Cancer Research Centre (CNIO).

In order to identify those genetic ‘errors’ or genetic variants that may raise the risk of cancer, the researchers genotyped more than 200,000 SNPs—single- nucleotide polymorphisms or genome letter changes—selected from the genome of 100,000 breast, prostate and ovarian cancer patients, as well as from 100,000 control cases without cancer.

Among the genes identified, there are some that may help cancerous cells spread throughout the body, while others favour the uncontrolled growth of cells and still others may help by removing the brakes that stop cells from growing.

The authors of the study have also identified TERT as the gene susceptible to breast and ovarian cancer.

According to researchers, a big surprise to come out of the study was the identification of thousands of additional genes that to a lesser extent make someone more susceptible to cancer.

“These genes would explain why many families have these types of hereditary cancers without the presence of mutations in the BRCA genes,” Benitez said.

“Every tumour is born with its own distinct genetic history, so if we identify those individuals whose genetic characteristics confer them a greater probability of developing cancer, we will be able to provide them with more adequate follow-up and thus reduce the appearance of the disease or diagnose it in its initial phases,” he added.

The study has been published in Nature Genetics, Nature Communications, The American Journal of Human Genetics and PLOS Genetics.