Breast cancer patients can receive radiotherapy in fewer but higher doses with the same beneficial effect, say the authors of 10-year long trials.
Fewer overall doses can still beat cancer, is the conclusion of the START A and B trials (UK Standardisation of Breast Radiotherapy Trial) funded by Cancer Research UK, the Medical Research Council and Department of Health.
The trials involving around 4,500 women with early breast cancer have shown that a lower total dose of radiotherapy but delivered in fewer and larger doses is just as effective as current practices which give a higher total dose over a longer time.
The new pattern of administering the treatment gives similar tumour control and fewer adverse side effects, says the research published in The Lancet and The Lancet Oncology.
Professor John Yarnold, Institute of Cancer Research and Royal Marsden Hospital, Professor Judith Bliss, clinical trials and statistics unit of the Institute of Cancer Research, and colleagues from the START trials collaborative group, comprising researchers from 35 UK cancer centres, carried out both START trials to test this hypothesis.
Under the trials, around half of the women were given the international standard radiotherapy of 25 treatments, being treated five times a week over five weeks.
The remainder of the participants received a lower total dose given in fewer, larger treatments in either three or five weeks.
The researchers compared the rate of cancer recurrence in the treated breast along with the effects of the treatment on surrounding healthy breast tissues.
After an average follow-up of five to six years, the rate of recurrence in the breast remained low for the women in each of the treatment groups studied.
The rate of side-effects were low overall, and no higher in women receiving the revised treatment than those receiving the international standard of 25 treatments.
The authors conclude: “A lower total dose in a smaller number of fractions could offer similar rates of tumour control and normal tissue damage as the international standard fractionation schedule.”
In an accompanying comment, Dr Harry Bartelink, Netherlands Cancer Institute, Amsterdam, and Dr Rodrigo Arriagada, Institut Gustave Roussy, Villejuif, France, said: “We realise that hypo fractionation is convenient for patients, because it reduces the number of visits to radiotherapy departments and waiting lists in several cancer centres.
“Nevertheless we have to wait for data on longer follow-up before final conclusions can be drawn from the START trials.”
(Picture: Wellcome Images)