These findings, from the largest randomised trial of IMRT in head and neck cancer so far, will improve the function and quality of life for thousands of patients with squamous-cell carcinoma of the head and neck (HNSCC), the most common type of head and neck cancer worldwide.
Conventional radiotherapy for head and neck cancers damages the parotid salivary glands which secrete saliva, and dry mouth is the most frequently reported late side-effect. A lack of saliva prevents patients from eating solid food and speaking normally, and can accelerate development of tooth decay.
In contrast, IMRT can deliver precise radiation to tumours while minimising exposure to healthy surrounding tissues. Small phase 2 studies have shown better saliva function in patients given IMRT compared with conventional radiotherapy.
The PARSPORT randomised phase 3 trial was funded by Cancer Research UK and designed to confirm whether IMRT reduces the incidence of severe dry mouth compared with conventional radiotherapy. Between January 2003 and December 2007, 94 patients with HNSCC were enrolled from six radiotherapy centres across the UK and randomly assigned to IMRT (47 patients) or conventional radiotherapy (47).
Saliva flow was measured before treatment and at regular intervals after radiotherapy, and side-effects assessed using the Late Effects of Normal Tissue (LENT SOMA) scale. Quality of life was evaluated using self-reported questionnaires completed at regular intervals after treatment for up to 2 years.
Overall, patients treated with IMRT experienced significantly less dry mouth than those given conventional radiotherapy, had significantly better recovery of saliva flow, and a consistently higher quality of life score.
At 12 months, grade 2 or worse dry mouth was reported by 74% of patients receiving conventional radiotherapy compared with 39% given IMRT, and at 24 months in 83% of patients versus 29%.
At 1 year, unstimulated saliva flow was recorded in nearly half of patients in the IMRT group compared with none in the conventional radiotherapy group.
Fatigue during treatment was the only grade 2 or worse adverse event that was significantly greater in patients treated with IMRT (74%) than those given conventional radiotherapy (41%).
The authors suggest that these results are likely to be applicable to all head and neck tumours for which conventional radiotherapy is used.
They conclude: “Sparing the parotid glands with IMRT significantly reduces the incidence of xerostomia and leads to recovery of saliva secretion and improvements in associated quality of life, and thus strongly supports a role for IMRT in squamous-cell carcinoma of the head and neck.”
The PARSPORT trial was co-ordinated by The Institute of Cancer Research Clinical Trials and Statistics Unit in Sutton, Surrey.
For media enquiries, please contact Dr Elizabeth Rapley on + 44 (0) 207 153 5380 or after hours +44 (0) 7721 747 900.
About Cancer Research UK
- Cancer Research UK is the world’s leading cancer charity dedicated to saving lives through research.
- The charity’s groundbreaking work into the prevention, diagnosis and treatment of cancer has helped save millions of lives. This work is funded entirely by the public.
- Cancer Research UK has been at the heart of the progress that has already seen survival rates double in the last forty years.
- Cancer Research UK supports research into all aspects of cancer through the work of over 4,000 scientists, doctors and nurses.
- Together with its partners and supporters, Cancer Research UK’s vision is to beat cancer.
For further information about Cancer Research UK’s work or to find out how to support the charity, please call 020 7121 6699 or visit www.cancerresearchuk.org
The Institute of Cancer Research (ICR)
- The ICR is Europe’s leading cancer research centre.
- The ICR has been ranked the UK’s top academic research centre, based on the results of the Higher Education Funding Council’s Research Assessment Exercise.
- The ICR works closely with partner The Royal Marsden NHS Foundation Trust to ensure patients immediately benefit from new research. Together the two organisations form the largest comprehensive cancer centre in Europe.
- The ICR has charitable status and relies on voluntary income, spending 90 pence in every pound of total income directly on research.
- As a college of the University of London, the ICR also provides postgraduate higher education of international distinction.
- Over its 100-year history, the ICR’s achievements include identifying the potential link between smoking and lung cancer which was subsequently confirmed, discovering that DNA damage is the basic cause of cancer and isolating more cancer-related genes than any other organisation in the world.
For more information visit www.icr.ac.uk