(Reuters) – AstraZeneca said on Monday two of its existing therapies were recommended for treating patients with some forms of high-risk breast cancers in the European Union, in a boost to the company’s oncology portfolio. Lynparza, a cancer drug developed jointly with U.S.-based Merck, was backed for standalone use or in combination with endocrine therapy in adults with a form of genetically mutated early-stage breast cancer. The drug, which has received a similar recommendation in the United States in March, is a key asset for AstraZeneca. It was recommended in patients with low-to-normal le…