The American Society for Radiation Oncology (ASTRO) has issued new clinical guidelines for the management of oropharyngeal cancer. The guidelines, “Radiation Therapy for Oropharyngeal Squamous Cell Carcinoma: An ASTRO Evidence-Based Clinical Practice Guideline,” are available for free from Practical Radiation Oncology, ASTRO’s clinical practice journal.
Drawing on data from clinical trials and other prospective studies, the recommendations address the use of radiation therapy (RT), also known as radiotherapy, to treat tumors of the oropharynx in a variety of scenarios. The guidelines cover 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, reports ASTRO, which also notes that the demand for radiation oncologists to treat head and neck cancer will increase nearly 20% by 2020 compared to 2010.
Also, the profile of the typical OPSCC patient has changed. From 1988 to 2004, the rates of OPSCC related to human papillomavirus (HPV) rose more than 200% while the rates of HPV-negative disease dropped by half, according to ASTRO. Meanwhile, the estimated risk of death for HPV-positive OPSCC patients is 50% lower than for those with HPV-negative disease, largely due to the more favorable biology of HPV-driven disease and because those patients tend to be younger and healthier when diagnosed.
“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 wrote the guidelines 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,” said Sher.
“Radiation therapy is the most commonly used curative option for the primary treatment of oropharynx tumors,” said Avraham Eisburch, MD, co-chair of the task force and a radiation oncologist at the University of Michigan in Ann Arbor. “We developed the current guidelines 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 RT settings.”
The guidelines first address the addition of chemotherapy to curative RT for oropharyngeal cancer, recommending concurrent chemoradiation for patients with stages III or IV disease with large-volume tumors, but not for patients with stages I or II disease. They also provide guidance for the use of radiation and chemoradiation following primary surgery for OPSCC. And, they outline optimal dosing and fractionation schedules based on treatment approach, disease profile, and risk of recurrence.
Furthermore, the guidelines address the role of induction chemotherapy (IC) in treating OPSCC, examining the 3 existing published randomized trials examining IC followed by chemoradiation for the disease. None of these trials found an improvement in overall survival, yet all found increased toxicity following IC, so the guidelines strongly recommend 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 to December 2014. 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. The Clinical Practice Statement was approved by ASTRO’s board of directors following a 6-week period of public comment. It has been endorsed by the European Society for Radiotherapy and Oncology and the American Society of Clinical Oncology.