Yuganov Konstantin/Shutterstock.com Breast cancer treatment has come a long way, but one of the hardest questions has always been: who really needs chemotherapy, and who can safely do without it? Chemotherapy saves lives, but it also comes with serious side-effects and long‑term risks. A new study, presented at the American Society of Clinical Oncology’s annual meeting in Chicago, shows that a DNA‑based test of the tumour can help two‑thirds of certain breast cancer patients safely avoid chemot