Study shows experimental treatment not superior to standard therapy for head and neck cancer

University Health Network (UHN)Dec 9 2016

Results of the largest Canadian clinical trial to date comparing standard treatment for locally advanced squamous cell head and neck cancer with an experimental treatment, did not show the new treatment is superior.

The findings, published online today in JAMA Oncology, mean that for now the standard of care for these patients remains combined chemotherapy and radiotherapy.(DOI: 10.1001/jamaoncol.2016.4510)

Nevertheless, the research provides invaluable clinical and quality of life data, including biospecimens from 320 patients, to inform future studies, say co-principal investigators Drs. Lillian Siu and John Waldron at the Princess Margaret Cancer Centre, University Health Network.

Dr. Siu, medical oncologist and Professor of Medicine, and Dr. Waldron, radiation oncologist and Associate Professor of Radiation Oncology, are both at University of Toronto. The study was sponsored and conducted by the Canadian Cancer Trials Group, whose core funder is the Canadian Cancer Society.

Seventeen Canadian cancer centres participated in the Phase III randomized clinical trial from December 2008 to November 2011 that analyzed progression-free survival as its primary end point. Half the patients received the current standard of care; the other half received the new treatment - a targeted, biological agent that inhibits cancer growth, plus accelerated radiation ("bioradiotherapy"). In the end, there was no statistically significant difference between the two treatment arms.

Dr. Waldron says: "Our intention was to look at the effect of this new class of compounds. We used the drug panitumumab which is a member of a specific class of drug known as EGFR inhibitors. In a previous randomized study, combination of a different EGFR inhibitor with radiotherapy compared to radiotherapy alone has been shown to improve outcomes.

"So we thought if traditional treatment is radiation and cytotoxic chemotherapy (cisplatin), can we change the standard of care by dropping cisplatin and adding in the new agent, which may have fewer side effects and can be used with a wider range of patients."

When the study was designed, less was known about the role of the human papilloma virus (HPV) in driving the increasing incidence of head and neck cancer. Now it is known that HPV-positive patients can respond better to treatment and so the researchers are retrospectively analyzing the biospecimens from the study to add to the growing canon of HPV knowledge.

For the researchers, the potential use of bioradiotherapy as a new treatment strategy is far from determined. Says Dr. Siu: "A larger study of 900+ participants has been completed by another group in the U.S. and we anticipate those results in the near future to help us understand whether bioradiotherapy can replace the current standard of care for patients with locally advanced head and neck cancer."

Drs. Siu and Waldron say that their study offered a valuable opportunity to standardize specialized radiation techniques which were delivered with extremely high levels of quality across the participating sites and now represent the standard of care for head and neck cancer patients.

They conclude: "It also provided a platform for detailed assessment of quality of life, swallowing symptoms and physiologic swallowing function for these patients, which will be an invaluable source of data to characterize the impact of disease and treatment from the patient perspective."

Dr. Waldron adds: "One of the main benefits of the study was to rally the Canadian head and neck oncology community in terms of support. It was the first Canadian Cancer Trials Group led randomized study of head and neck cancer and it provided patients with consistent, standardized care."

The ability to test new therapies in tumours such as head and neck cancer requires collaboration between patients and health care providers, says Dr. Wendy Parulekar, Senior Investigator who supervised this study at Queen's University. 'This study represents a major accomplishment for the Canadian research community and we are committed to building on this success."