Reduced radiation exposure may improve the long term health of patients being treated for human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC), according to a study published in the Journal of Clinical Oncology.1

HPV-associated OPSCC is increasingly common in the United States, and though it is often curable, significant treatment-related toxicity can impair a number of normal functions. For this phase 2 trial (ClinicalTrials.gov Identifier: NCT01084083), researchers evaluated whether reducing the radiation dosage and substituting cetuximab for cisplatin would improve treatment-related toxicity in this patient population.

Ninety patients with stage III or IV resectable OPSCC were enrolled, of whom 80 were evaluable. All enrolled patients were p16 immunohistochemistry (IHC)-positive and/or had a HPV16-positive tumor.

Of the 56 patients who achieved a complete response after induction chemotherapy, 51 received the reduced radiation dose of 54 Gy, though 2 patients discontinued treatment. Two-year progression-free survival for these patients was 80%; 2-year overall survival was 94%.

Risk factors such as smoking and high tumor volume predicted a worse clinical outcome.

After one year, patients treated with reduced radiotherapy had less difficulty swallowing solids and had an improved nutrition status in contrast with those who receive standard treatment doses.

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Reducing radiation intensity, according to this study’s authors, may be effective for reducing toxicities associated with the standard treatments for HPV-associated OPSCC. Further trials are recommended, and should take risk factors such as smoking and tumor volume into account.

Reference

  1. Marur S, Li S, Cmelak AJ, et al. E1308: phase II trial of induction chemotherapy followed by reduced-dose radiation and weekly cetuximab in patients with HPV-associated resectable squamous cell carcinoma of the oropharynx—ECOG-ACRIN Cancer Research Group. J Clin Oncol. 2016 Dec 27. doi: 10.1200/JCO.2016.68.3300 [Epub ahead of print]