Millions of breast cancer patients could safely avoid chemotherapy, study suggests

A DNA test called Prosigna can identify who will (and won't) benefit from chemotherapy — in an international trial two-thirds of patients scored low and safely avoided chemo, with similar five‑year survival (93.7% vs 94.9%).
That could spare many people the harsh side effects of chemotherapy (hair loss, nausea, fatigue, fertility impact) by letting them use hormone therapy instead.
The study of 4,000+ patients is being called “practice‑changing” — UCL estimates it could let over 5,000 NHS patients a year skip chemo; results presented at the ASCO conference.