Intravasation and circulating tumour cells

When patients who agreed in advance die of cancer, sampling every tumour within hours reveals how the disease evolved and escaped every drug. Few hospitals can do this today.

After surgery or curative treatment, everyone gets regular blood tests for leftover cancer DNA, and the pooled results power forecasts of who will relapse and trials of acting early.

Some people have only a few sites of spread and can be treated at each one; others have further deposits not yet visible, and counting lesions cannot tell them apart. A signature built from tumour DNA levels, microRNA classifiers and clonal diversity across lesions would define the biology and spare futile ablation.

Rather than giving the same dose until the cancer grows, measure tumour DNA in blood every few weeks and let a validated algorithm raise, lower, pause or switch drugs to keep the cancer suppressed for longer.

Most stage II patients never relapse, yet all are offered a year of immunotherapy. Use a blood test to treat only those with detectable residual disease.

Track FGFR2 resistance mutations in blood and switch to the next-generation inhibitor that still covers them, before the scan shows progression.

If a blood test reliably shows whether cancer will come back after surgery, trials could use it instead of waiting years for relapse. Regulators have a process to bless such a test; oncology should use it.

When a treatment stops working, the tumour is rarely re-sampled, so nobody learns why. Paying for a biopsy at that moment would build the missing map of resistance.

Because cervical tumours carry viral DNA that normal cells do not, a blood test for HPV DNA is a near-perfect tumour marker for tracking response and relapse.

Instead of trying to kill every hidden cancer cell after surgery, keep them dormant for life with low-toxicity drugs, the way extended hormone therapy already does in breast cancer.

Blood tests can now find leftover cancer months before scans, but most patients who test positive have nothing to enrol in. One standing trial per country would fix that.

Use a blood test after surgery to decide who gets chemotherapy: spare the negatives, and find something that actually works for the positives.

Blood tests can already detect tumour DNA. Reporting which sub-populations of the tumour are growing or shrinking, cycle by cycle, would turn the test into an evolution monitor.

Almost all cancer deaths are caused by spread, yet metastatic tissue is rarely studied because rapid autopsy programmes exist at only a handful of centres. A funded 20-site network with one protocol, one consent framework and open sample access would collect donated tissue within hours of death.

Between diagnosis and surgery there are usually a few weeks. Giving a new drug in that window and comparing the tumour before and after surgery shows whether it hits its target in real people, quickly and cheaply.

Most cancer drugs cannot cross into the brain. Combine ultrasound that briefly opens the barrier with drugs engineered to be carried across, and make this a standard platform for every brain tumour and brain metastasis.

Once a year, send the same blinded blood samples to every company selling a tumour-DNA test and publish how each performed.

Trials often measure a stand-in for survival, such as time until the cancer grows on scans. An independent body would test, for each cancer and treatment type, whether the stand-in actually predicts survival, and publish the answer.

Sleeping cancer cells survive by recycling their own contents. An old malaria drug blocks that recycling and is being tested in people with no visible cancer but detectable residual cells.

Dozens of companies sell blood tests for tumour DNA and they report different results on the same sample. Government-issued reference samples with known amounts of tumour DNA would expose the differences.