Gleason score / Grade Group

The limit of what a prostate scan can be asked to do. It is a good triage test for whether to biopsy and a poor map of where every tumour is, which matters for anyone being offered treatment to part of the gland or follow-up by imaging alone.

The clearest evidence that radical treatment of localised prostate cancer saves lives when the cancer was found clinically rather than by a blood test, and the clearest single statement of what grade does: a Gleason score above 7 carried ten times the risk of death of a score of 6 or lower in the same trial.

It gives a cheap way to find the rare men who could benefit from checkpoint blockade: an immunohistochemical stain on the highest-grade primary tumours, where the yield is twenty times higher than average. It also shows the loss is clonal and early, so the diagnostic block is an adequate place to look.

The evidence that put a scan in front of the biopsy. It reduces the number of men who are biopsied at all, reduces the number of harmless cancers found, and increases the number of dangerous ones, which is the only combination that improves a screening pathway on both sides at once.

The reference classification of prostate cancer as it presents, and the source of the two numbers that drive most molecular treatment decisions in the disease: a quarter with a PI3K or MAPK lesion, which is the rationale for capivasertib in PTEN-deficient disease, and a fifth with DNA repair inactivation, which is the rationale for PARP inhibitors.

The honest state of the overdiagnosis question. Prostate cancer is common in the prostates of men who die of something else, screening finds a proportion of it, and how much of that is harm depends on what is done next. The fix is not a better estimate but fewer treatments for the cancers that do not need them.

It established that an inherited BRCA2 mutation changes the disease and not only the treatment options, which is why a carrier's localised disease is generally treated more intensively and watched more closely rather than put on surveillance.

The origin of the idea that a prostate tumour's copy-number pattern carries prognostic information the pathologist's grade does not. That idea became Decipher and the other genomic classifiers, which are now used in some systems to decide whether a man needs radiotherapy after surgery.