Blood test for many cancers could potentially thwart progression to late stage in up to half of cases

The study, led by Professor Peter Sasieni from Queen Mary University of London, aimed to find out if a multi-cancer early detection (MCED) test either once a year or once every two years could detect cancer early and improve outcomes for patients. The results, published today in BMJ Open, showed that MCED tests have the potential to intercept 31–49% of cancers at stage I-II that would otherwise present at stage III-IV.

Currently, only a few cancers can be reliably screened for—those of the breast, bowel, cervix (neck of the womb), and lung for those at high risk. While effective at lowering death rates from these diseases, these screens can also result in false positive results and overdiagnosis.

The researchers drew on a previously published disease progression model for many different cancers. They used this to predict the impact of regular screening with an MCED test on the time of cancer diagnosis and patient death for different screening schedules.

Cancer types included were those of the anus; bladder; breast; cervix; bowel/rectum; food pipe (oesophagus); gallbladder; head and neck; kidney; liver/ bile-duct; lung; ovary; pancreas; prostate; sarcoma (soft tissues/bone); stomach; thyroid; urothelial tract, and uterus, as well as leukaemia, lymphoma, melanoma, blood cancers (myeloid neoplasm, immune cell cancers (plasma cell neoplasm).

The researchers’ models found that all MCED screening intervals had more favourable early-stage diagnostic rates than usual care alone. There was a larger impact on stage shift for tumours with ‘fast’ growth (where tumours remain at stage I for between 2 and 4 years before progressing) than for tumours with ‘fast aggressive’ (where tumours remain at stage 1 for between 1 and 2 years, with decreasing periods of time for progression to successive stages) growth. Annual MCED screening was found to increase diagnoses and prevent more deaths within 5 years than screening every two years. It also picked up more cancers for each completed test.

From the modelling scenario, in which 392 people are diagnosed each year with an aggressive cancer that would kill them within 5 years, earlier diagnosis through biennial MCED screening could have averted 54 (14%) of these deaths, but annual MCED screening could have avoided 84 (21%) deaths.

Professor Peter Sasieni, Professor of Cancer Epidemiology, Centre Co-Lead for the Centre for Cancer Screening, Prevention and Early Diagnosis, at Queen Mary said: “When choosing how often to offer different type of cancer screening there is a balance to be made between preventing more cancer deaths and obtaining the greatest benefit for the costs and inconvenience of screening. Generally, the faster the cancer develops the more frequently one needs to screen. We modelled what might be appropriate for a screening test that can detect all types of cancer. If screening works, even screening once every three years would prevent a substantial proportion of advanced stage cancers, but more frequent screening is needed to maximise the potential benefit. Depending on pricing, it seems likely that annual testing might deemed the most appropriate for blood-based multi-cancer screening.”