The research is published tomorrow (Saturday 20 September) in The Lancet medical journal and the results will also be presented next week at ECCO 12 - the European Cancer Conference, taking place in Copenhagen, Denmark.
Principal investigator Professor Jens Overgaard, from Aarhus University Hospital, Aarhus, Denmark, said that results from DAHANCA meant that the standard radiotherapy treatment for head and neck cancer had now changed.
In the trial, 1476 head and neck cancer patients were randomised to receive the same amount of radiotherapy per week, the only difference between the groups being the frequency with which they received it. One group had five treatments per week, and the other six. Overall, the results showed a benefit in tumour control of 60% in the 5 x week group, and 70% in the group receiving six treatments. The 6 x week group also showed better voice conservation in the patients with laryngeal cancer (80% as opposed to 68%). The patients were at different stages of the disease, from early to very advanced, but all were indicated for primary radiotherapy.
"Although all patients in the accelerated treatment arm did better," said Professor Overgaard, "some did better than others, and we are currently trying to identify those groups where the benefit is largest. It appears to be linked to two factors - a high degree of expression of epidermal growth factor receptor (EGFR) and a good differentiation of the tumour."
An unpublished meta-analysis of trials of modified fractionated radiotherapy in head and neck cancer, with about 8000 patients in all, also supports these findings, he said. "There are no shades of grey", said Professor Overgaard. These findings are unequivocal - accelerated treatment is definitely better in this cancer, both in terms of disease-specific survival and in quality of life."
Members of DAHANCA - the Danish head and neck cancer group - have been working together for 25 years. "What we have shown is that, with national collaboration and multidisciplinary, co-operative working, it is possible to run large-scale, but inexpensive, trials in small countries which can improve practice throughout the world," said Professor Overgaard.
 Five compared with six fractions per week of conventional radiotherapy of squamous-cell carcinoma of head and neck: DAHANCA 6&7 randomised controlled trial. The Lancet. Vol 362. September 20, 2003 pp 933-940.
 ECCO 12 abstract no: 1.065 (Thursday 25 September 09.30 hrs CET, FECS/EJC award presentations session)
 Abstract no: 678 (Wednesday 24 September 10.45 hrs CET, Head and neck cancer session)