Trials and papersColon cancer (adenocarcinoma of the colon)

For colon cancer survivors, a prescribed, supported exercise programme is now an evidence-based treatment with a survival benefit comparable to many drugs. Health systems will need to fund exercise consultants as they fund chemotherapy. The trial does not tell us whether unsupervised advice achieves the same.

The blood test stratifies risk far better than stage or pathology. It supports treating ctDNA-positive patients and suggests ctDNA-negative patients gain little from chemotherapy, but because treatment was not randomised the de-escalation claim needs the randomised trials that are now under way.

A UK-led trial that moved part of colon cancer chemotherapy in front of the operation, and showed that tumour regression grade after six weeks predicts recurrence, which is the basis for using the response itself to choose what follows.

For stage II colon cancer, where most patients are cured by surgery alone, a blood test can identify the minority who benefit from chemotherapy and spare everyone else its side effects. It does not yet prove that treating ctDNA-positive patients improves survival compared with not treating them.

People with Lynch syndrome should be offered daily aspirin, which roughly halves bowel cancer risk with a delayed and durable effect. Whether a lower dose (as tested in CAPP3) is as effective, and whether the finding extends to the general population, are separate questions.

The European rulebook for what happens after a colon cancer operation, and the reason a patient with a T3 N1 tumour is now offered three months of chemotherapy rather than six.

The largest de-escalation exercise in adjuvant oncology, and the reason a patient with a T3 N1 colon cancer is now offered four cycles of CAPOX rather than twelve of FOLFOX, with a fraction of the neuropathy.

Minimal residual disease became measurable in solid tumours, and the DYNAMIC and CIRCULATE trials that followed turned the measurement into a treatment decision.