The study, led by researchers from City St George’s, University of London, suggests that doctors may improve treatment outcomes by switching between different therapies while tumors are still responding, rather than waiting until the disease returns.

The findings, published in the journal Genetics, are based on mathematical models that examine how cancer cells evolve during treatment. Researchers say cancer behaves similarly to other evolving systems, where cells that develop survival advantages can eventually dominate when exposed to pressure from medicines.

Dr. Robert Noble, a researcher from the Department of Mathematics at City St George’s, explained that cancer often returns because some cells survive the first round of treatment and develop resistance.

“Although tumors may at first shrink under therapy, in many cases they eventually regrow. These relapses stem from a small number of cancer cells that have gained mutations making the cells resistant to the treatment,” he said.

The researchers compared the current approach, where doctors usually continue treatment until the cancer stops responding, with a new strategy that involves switching treatments while the tumor is weakened.

They described the approach as “kicking it while it’s down,” meaning doctors could attack cancer at a stage when it is already vulnerable before resistant cells become strong enough to cause another relapse.

Using computer simulations, the team found that planned changes between different treatments could be more effective than waiting for resistance to appear. The models showed that a combination of three or more therapies used in a carefully timed sequence could have greater potential, especially when treating larger tumors.

“Our models predict that this new approach will generally outperform the standard of care. A sequence of two treatments, even if optimally timed, is likely to succeed only in relatively small tumors. But we have reason to hope that switching between three or more treatments, following the same principle, could eliminate larger tumors,” Dr. Noble said.

The researchers explained that the strategy is based on evolutionary principles, which have already been used in other areas such as managing antibiotic resistance and improving predictions of seasonal influenza strains.

However, scientists cautioned that the findings are still at an early stage. The study was based on mathematical modelling and computer simulations, meaning the approach must undergo further laboratory studies and clinical trials before it can become part of routine cancer treatment.

Several early-stage clinical trials are already investigating similar ideas in cancers including soft tissue cancer, prostate cancer, and breast cancer. Researchers hope that continued studies could lead to treatments that stay ahead of cancer’s ability to evolve.

If successful, the approach could help doctors extend the effectiveness of existing cancer medicines, delay disease relapse, and improve outcomes for patients without relying only on the development of new drugs.