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ASTRO 2015: Reduced-Intensity Chemoradiotherapy May Be as Effective as Current Standard for Patients With HPV-Related Oropharynx Cancer

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Key Points

  • Radiation therapy was reduced by 16%, to a 6-week course of 60 Gy, and the chemotherapy dose was reduced by 60% overall, with low doses (30 mg/m2) of cisplatin delivered concurrently for 6 weeks.
  • After patients completed chemoradiotherapy, the tumor site was biopsied and any lymph node regions that were originally cancer-positive were removed in order to determine the treatment’s efficacy. Of the 43 patients studied, 37 of them (86%) had no residual invasive tumor and no residual lymph node metastasis.
  • Early findings suggest that reduced-intensity chemoradiotherapy resulted in less acute toxicity and a decrease in side effects of mucositis, nausea, vomiting, swallowing difficulty, and dryness of the mouth.

For some patients with human papillomavirus (HPV)-related cancer of the tonsils and tongue, reduced-intensity radiation therapy and chemotherapy may be as effective as standard-dose radiation and chemotherapy, and result in fewer acute side effects, according to research presented by Chera et al (Abstract 3) October 18, 2015, at the American Society for Radiation Oncology’s (ASTRO’s) 57th Annual Meeting in San Antonio, Texas.

The incidence of cancer at the base of the tongue and tonsil is rapidly increasing and thought to be caused by HPV infection. The standard treatment for patients with HPV-related squamous cell carcinoma of the oropharynx is a 7-week course of 70 Gy of radiation therapy, in conjunction with a high-dose (100 mg/m2) of the chemotherapy drug cisplatin for three cycles. Although this standard chemoradiotherapy protocol results in excellent cancer control and survival among patients, it produces substantial adverse side effects—like acute difficulties in talking or swallowing, which may require a feeding tube; dry mouth; painful inflammation of the mucous membranes and/or digestive tract; tooth decay; and necrosis of the jawbone.

Study Details

This prospective, multi-institutional, phase II study assessed the use of reduced-intensity chemoradiotherapy among 43 patients with favorable-risk HPV-associated oropharyngeal squamous cell carcinoma who had a minimal history of smoking. Radiation therapy was reduced by 16%, to a 6-week course of 60 Gy, and the chemotherapy dose was reduced by 60% overall, with low doses (30 mg/m2) of cisplatin delivered concurrently for 6 weeks.

After patients completed chemoradiotherapy, the tumor site was biopsied and any lymph node regions that were originally cancer-positive were removed in order to determine the treatment’s efficacy.

Study Findings

Of the 43 patients studied, 37 of them (86%) had no residual invasive tumor and no residual lymph node metastasis. The cancer remaining in the other six patients was microscopic. Follow-up was conducted for 6 to 36 months, with an average follow-up of 20.7 months, during which all patients were alive and had no evidence of cancer recurrence.

Symptoms and quality of life were evaluated using two patient-reported questionnaires—the National Cancer Institute’s Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). Modified barium swallow studies assessed swallowing outcomes.

Early findings suggest that reduced-intensity chemoradiotherapy resulted in less acute toxicity and a decrease in side effects of mucositis, nausea, vomiting, swallowing difficulty, and dryness of the mouth. Standard chemoradiotherapy regimens have reported feeding tube rates of up to 80%, approximately 10% of which were permanent. On the contrary, only 39% of patients in this study needed a feeding tube, none of which were permanent.

Patients also reported that their swallowing function returned to almost normal, compared to pretreatment patient reports, and this was verified by the objective modified barium swallow studies, whereby patients’ swallowing difficulty is assessed using a fluoroscopic x-ray while they swallow various consistencies of food and liquids.

“Our study provides strong preliminary evidence that reduced-intensity chemoradiotherapy may be as effective as standard-dose chemoradiotherapy,” said Bhishamjit Chera, MD, Associate Professor of Radiation Oncology at University of North Carolina School of Medicine. “With further study, this regimen may become the new standard of care for carefully selected patients with HPV-associated squamous cell carcinoma of the oropharynx. The results so far are certainly encouraging, and with longer follow-ups, we hope to confirm [the development of fewer] long-term side effects, as well.”

Additional data are needed, so at this time reduced-intensity treatment should only be given if patients are enrolled in carefully controlled clinical trials, concluded Dr. Chera. He and his team are currently conducting a follow-up study among certain patients, in which biopsies and lymph node removal are done only if a 12-week postchemoradiotherapy positron-emission tomography (PET) scan is suspicious for persistent cancer.

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®.


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