The method, called Caspase Independent Cell Death (CICD), completely removed tumours in experimental models. Current treatments like chemotherapy, radiation and immunotherapy kill cancer cells through a process called apoptosis, which activates proteins called caspases.
However, these treatments carry the risk of side effects and often fail to kill all cancer cells, leading to disease recurrence.
Dr Stephen Tait, who led the University of Glasgow research into CICD, said the new method "often led to complete tumour regression" and "may be a more effective way to treat cancer" than apoptosis.
He added: "In essence, this mechanism has the potential to dramatically improve the effectiveness of anti-cancer therapy and reduce unwanted toxicity.
"Taking into consideration our findings, we propose that engaging CICD as a means of anti-cancer therapy warrants further investigation."
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When cancer cells are killed through CICD, they alert the immune system through the release of inflammatory proteins.
The immune system can then attack tumour cells that were not killed during the initial treatment.
While colorectal cancer cells were used by researchers, the benefits of CICD may also apply to a wide-range of cancer types.
Cancer Research UK, which part-funded the research, said scientists should further research the method and develop ways to trigger it in humans.
"Although many cancer treatments work by triggering apoptosis, that method sometimes fails to finish the job and instead may lead to the tumour becoming harder to treat," spokesperson Dr Justine Alford said.
"This new research suggests there could be a better way to kill cancer cells which, as an added bonus, also activates the immune system."