A genomic testing method called Prosigna could spare millions of women with breast cancer from unnecessary chemotherapy - without sacrificing the outcome of treatment. That is the conclusion of the international OPTIMA study, led by University College London, which followed more than 4,000 patients across six countries.

The headline finding is clear: among the patients the test showed to be low risk for recurrence, those who skipped chemotherapy had 94 percent survival; those who did receive chemotherapy had 95 percent. A single percentage point of difference - "no significant additional benefit", as the researchers conclude. The real-world translation: half the women going through chemotherapy after surgery today may not need it.

The test analyses 50 genes in the tumour tissue to calculate the 10-year risk of recurrence. That gives an individual risk profile for each patient, instead of a one-size-fits-all standard protocol. Those who do not need chemotherapy - do not receive it. Those who do - carry on. A simple idea. But to become usable, it had to come through a decade-long study.

For patients that means freedom from the harshest side effects of chemotherapy: hair loss, nausea, cognitive damage, infertility. For health systems, it means enormous savings - and less load on oncology centres. For Balkan clinics - already strained by shortages of oncology drugs and limited access to advanced tests - it means something mixed: a remedy that exists, but whether it becomes available will depend on how state insurance funds integrate it into the standard protocols.

The study's lead investigator sums it up: "Many patients can safely avoid chemotherapy without fear that it will compromise the outcome of their treatment." For people in medicine, that is a plain sentence. For people receiving a diagnosis - it is the difference between six months of hellish therapy and six months of a normal life after surgery.