New research has indicated that exposing tumors to oxygen can radically increase the effectiveness of radiotherapy.
Scientists at Oxford University found slightly increasing the supply strengthened blood vessels in cancer cells, making chemotherapy more effective.
The new way of destroying cancer was heralded as a "very exciting" breakthrough by scientists. They said it would allow drugs to "prime and soften up" potentially deadly tumors before they are targeted with intensive treatment, reports The Daily Express.
Research was carried out on breast, head and neck cancers as well as carcinomas that line the surface of the skin and organs.
The research has been published in the journal Cancer Research, and was carried out by scientists from the Cancer Research UK-MRC Gray Institute for Radiation Oncology and Biology at the University of Oxford.
In the study, boffins treated mice with certain drugs that improved the stability of blood vessels in the tumors.
Professor Gillies McKenna, director of the Institute, said: "We have discovered a new way of overcoming the major reason most cancers become resistant to treatment with radiation or chemotherapy.
"Early results from a trial in patients with advanced pancreatic cancer suggest that this method can greatly improve the outcome in this disease, which is very difficult to treat.
"Clinicians in Oxford are pressing on to expand their trials to include patients with lung, cervical and rectal cancer, and they hope to begin adding patients to new trials later this year.
"If successful, these methods could bring new hope to patients with some of the most difficult to treat cancers."
McKenna added: "We are very excited to have uncovered this brand new approach to cancer treatment, where the drugs prime the cancer cells for radiotherapy."