The American Society for Radiation Oncology (ASTRO) has issued a new clinical guideline for the management of oropharyngeal cancer. The guideline, “Radiation therapy for oropharyngeal squamous cell carcinoma: An ASTRO Evidence-based Clinical Practice Guideline,” was published by Sher et al in Practical Radiation Oncology.
Drawing on data from clinical trials and other prospective studies, recommendations address the use of radiotherapy to treat tumors of the oropharynx in a variety of scenarios. The new clinical practice guideline covers optimal radiation dose and fractionation schedules, the integration of chemotherapy with radiotherapy, and the role of induction chemotherapy.
Oropharyngeal Squamous Cell Cancer
Oropharyngeal squamous cell cancer is rapidly becoming the most commonly diagnosed head and neck malignancy. The demand for radiation oncologists to treat head and neck cancer is projected to increase nearly 20% by 2020 over 2010 rates, according to an analysis by Smith et al in the Journal of Clinical Oncology.
The profile of the typical patient with oropharyngeal squamous cell cancer has changed in the past several decades. From 1988 to 2004, the rates of human papillomavirus (HPV)-associated oropharyngeal squamous cell cancer rose more than 200%, while the rates of HPV-negative disease dropped by half, according to research published by Chaturvedi et al in the Journal of Clinical Oncology. The estimated risk of death for HPV-positive oropharyngeal squamous cell cancer patients is 50% lower than for those with HPV-negative disease, in large part due to the more favorable biology of HPV-driven disease, but also because these patients tend to be younger and healthier when they are diagnosed, according to Gillison et al’s findings in the Journal of the National Cancer Institute.
“Advances in treatment planning and technology, as well as a shift in the ‘typical’ oropharyngeal cancer patient over the past several decades, have led to a significant improvement in treatment outcomes for these patients,” said David J. Sher, MD, MPH, Co-Chair of the Task Force that authored the guideline and a radiation oncologist at the University of Texas Southwestern in Dallas. “Despite these advances, however, treatment in this sensitive and complex region of the head and neck often leads to short-term, long-term, and potentially lifelong side effects—which become even more salient as this patient population trends younger.”
“Radiation therapy is the most commonly used curative option for the primary treatment of oropharynx tumors,” said Avraham Eisbruch, MD, also Co-Chair of the Task Force and a radiation oncologist at the University of Michigan in Ann Arbor, Michigan. “We developed the current guideline to address critical topics facing radiation oncologists who treat oropharyngeal cancer, including when to use chemotherapy, as well as appropriate dose and fractionation schedules for definitive and postsurgical radiotherapy settings.”
Guideline Recommendations
The guideline first addresses the addition of chemotherapy to curative radiotherapy for oropharyngeal cancer, recommending concurrent chemoradiation for patients with stage IV disease or stage III disease with large-volume tumors, but not for patients with stage I to II disease. Recommendations by disease stage are as follows:
The guideline also provides guidance for the use of radiation and chemoradiation following primary surgery for oropharyngeal squamous cell cancer. Adjuvant radiotherapy is recommended for patients who show pathologic risk factors for disease recurrence, such as positive surgical margins or positive lymph nodes following surgery, although concurrent chemoradiation is strongly recommended only for high-risk patients. Recommendations by treatment type and risk level are as follows:
The guideline also outlines optimal dosing and fractionation schedules based on treatment approach, disease profile, and risk of recurrence. Recommendations by treatment setting are as follows:
The guideline also addresses the role of induction chemotherapy in treating oropharyngeal squamous cell cancer, examining the three existing published randomized trials examining induction chemotherapy followed by chemoradiation for the disease. Because none of these trials found an improvement in overall survival yet all found increased toxicity following induction chemotherapy, the guideline strongly recommends that induction chemotherapy should not be delivered routinely to patients with oropharyngeal squamous cell cancer.
The guideline was based on a systematic literature review of studies published from January 1990 through December 2014. A total of 2,615 abstracts were retrieved from PubMed, and the 119 articles that met inclusion criteria were abstracted into evidence tables and evaluated by a 16-member task force of experts in oropharyngeal cancer, including radiation oncologists, medical oncologists, otolaryngologists, and a patient representative. The Clinical Practice Statement was approved by ASTRO’s Board of Directors following a 6-week period of public comment. The guideline has been endorsed by the European Society for Radiotherapy & Oncology (ESTRO) and ASCO.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.