A new study suggests that the timing of cancer treatments could be just as important as the treatments themselves, according to a study published in the journal Genetics. Striking with a second therapy while a tumour is already weakened by the first could significantly improve the chances of a cure.
The research, led by Dr Robert Noble, Senior Lecturer at the Department of Mathematics, City, St George’s, University of London, tackles one of the most persistent problems in cancer care: relapse.
When a patient receives cancer treatment, their tumour may shrink at first but in many cases it eventually comes back. This happens because a small number of cancer cells carry genetic mutations that make them resistant to the treatment. Once those cells survive and multiply, the cancer returns, often harder to treat than before.
The standard approach is to wait and see if the tumour regrows, and only then try a different treatment. But by that point, the surviving cancer cells may already have developed resistance to the second therapy too, causing that to fail as well.
Dr Noble and his team propose a different strategy, inspired by evolutionary theory. Rather than waiting for the cancer to bounce back, they suggest switching to a second treatment while the tumour is still responding to the first.
“Although tumours may at first shrink under therapy, in many cases they eventually regrow,” said Dr Noble. “These relapses stem from a small number of cancer cells that have gained mutations making the cells resistant to the treatment.”
The idea draws on the same scientific thinking used to tackle antibiotic resistance and predict which flu vaccines will work each season. “Evolutionary approaches have been very successful in other contexts, such as combatting antibiotic resistance, or predicting what vaccines we should use in a particular flu season. There is every reason to suppose that similar approaches should work in tumours,” said Dr Noble.
To test the concept, the researchers adapted mathematical models normally used to study how plants and animals evolve in response to environmental pressures such as climate change, applying them to the behaviour of tumours under treatment.
The results were encouraging. “Our models predict that this new approach will generally outperform the standard of care,” said Dr Noble. “A sequence of two treatments, even if optimally timed, is likely to succeed only in relatively small tumours. But we have reason to hope that switching between three or more treatments, following the same principle, could eliminate larger tumours.”
The researchers say their findings justify further testing, and three small clinical trials are already underway in soft-tissue cancer, prostate cancer and breast cancer, with more in development.
Srishti Patil, Armaan Ahmed, Yannick Viossat, Robert Noble, Preventing evolutionary rescue in cancer using two-strike therapy, Genetics, Volume 232, Issue 2, February 2026, iyaf255, https://doi.org/10.1093/genetics/iyaf255