The American Society for Radiation Oncology (ASTRO) issued a new clinical guideline on April 17 for the management of oropharyngeal cancer. The guideline, “Radiation therapy for oropharyngeal squamous cell carcinoma: An ASTRO Evidence-based Clinical Practice Guideline,” is available as a free access article in Practical Radiation Oncology, ASTRO’s clinical practice journal.
Drawing on data from clinical trials and other prospective studies, recommendations address the use of radiation therapy (RT), also known as 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 RT and the role of induction chemotherapy.
Oropharyngeal squamous cell cancer (OPSCC) 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 percent by 2020 over 2010 rates.1 The profile of the typical OPSCC patient has changed in the past several decades. From 1988 to 2004, the rates of human papillomavirus (HPV)-associated OPSCC rose more than 200 percent, while the rates of HPV-negative disease dropped by half.2 The estimated risk of death for HPV-positive OPSCC patients is 50 percent 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.3
“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 post-surgical RT settings.”
The guideline first addresses the addition of chemotherapy to curative RT 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-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 OPSCC. Post-operative, or adjuvant, RT 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 (IC) in treating OPSCC, examining the three existing published randomized trials examining IC followed by CRT for the disease. Because none of these trials found an improvement in overall survival yet all found increased toxicity following IC, the guideline strongly recommends that IC should not be delivered routinely to patients with OPSCC.
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 six-week period of public comment. The guideline has been endorsed by the European Society for Radiotherapy & Oncology (ESTRO) and the American Society of Clinical Oncology (ASCO).
Additional information on oropharyngeal cancer and radiation therapy:
1. Smith BD, Haffty BG, Wilson LD et al. Smith BD, Haffty BG, Wilson LD et al. The future of radiation oncology in the United States from 2010 to 2020: will supply keep pace with demand? J Clin Oncol. 2010 Dec 10; 28(35): 5160-5.
2. Chaturvedi AK, Engels EA, Pfeiffer RM, et al. Human papillomavirus and rising oropharyngeal cancer incidence in the United States. J Clin Oncol. Nov 10 2011;29(32):4294-4301.
3. Gillison ML, D'Souza G, Westra W, et al. Distinct risk factor profiles for human papillomavirus type 16-positive and human papillomavirus type 16-negative head and neck cancers. J Natl Cancer Inst. Mar 19 2008;100(6):407-420.Back To Top
New ASTRO guideline establishes standard of care for curative treatment of oropharyngeal cancer with radiation therapy. Appl Rad Oncol.