One in five breast cancer patients could benefit from existing treatment, genetic study reveals

Researchers have discovered that a greater number of breast cancers are genetically similar to rarer cases with faulty BRCA1 or BRCA2 genes. The results open up the possibility of up to 20 percent of women being treated with PARP inhibitors, a class of drug previously only thought to be effective for women with an inherited BRCA1 or BRCA2 mutation.