What is the incidence of severe late toxic effects after modern definitive image-guided intensity-modulated radiotherapy (IG-IMRT) in the era of human papillomavirus-associated oropharynx cancer?
In this review of 156 patients with stage I-IVB squamous cell carcinoma of the oropharynx, the cumulative incidence of severe late dysphagia after narrow-margin IG-IMRT for oropharynx cancer is reported to be very low at 2 years.
This finding has implications for informed consent discussion, patient selection for deintensification protocols, and for future clinical trial design.
Late toxic effects are common after definitive radiotherapy and chemoradiotherapy for oropharynx cancer and are considered a significant contributor to decreased quality of life for survivors. The incidence of severe late toxic effects may be reduced by modern narrow-margin image-guided intensity-modulated radiotherapy (IG-IMRT), current supportive care improvements, and the changing epidemiology of oropharynx cancer.
Assess the incidence of severe late toxic effects after modern definitive non-operative treatment for oropharynx cancer.
Design, Setting, and Participants
For this single-institution retrospective review, 156 patients with stage I-IVB squamous cell carcinoma of the oropharynx treated between April 2009 and February 2015 at a tertiary-referral academic multidisciplinary head and neck practice were recruited.
Definitive narrow-margin IG-IMRT to a dose of 66 Gy (to convert milligray to rad, multiply by 0.1) or higher with or without concurrent cisplatin.
Main Outcomes and Measures
The primary outcome was the prospectively collected 2-year cumulative incidence of severe late toxic effects (Common Terminology Criteria for Adverse Events grade 3 or higher) occurring 3 months or more after radiotherapy. Toxic effect end points investigated included esophageal stricture requiring dilation, aspiration pneumonia hospitalization, vocal dysfunction, delayed feeding tube insertions, and osteoradionecrosis. Feeding tube dependence at 1 year was also considered a severe late toxic effect. Secondary outcomes collected include physician-reported grade 2 or higher neck fibrosis and xerostomia. The competing risks of recurrence and death were accounted for using the Gray method.
One-hundred fifty-six patients (median [range] age, 58 [37-96] years) were identified; 130 patients (83%) were HPV positive. Concurrent cisplatin was delivered in 131 patients (84%) and 5 patients (3%) underwent an adjuvant neck dissection. The median (range) follow-up for survivors was 22 (4-73) months from diagnosis. The projected 2-year locoregional control was 93% (95% CI, 88.4%-97.6%) and overall survival was 88% (95% CI, 82.2%-94.0%). Thirty-eight patients (23%) required a feeding tube during treatment. The cumulative incidence of severe late toxic effects adjusted for competing risks at 2-year posttreatment was 2.3% (95% CI, 0%-5.6%). One patient required free-flap reconstruction for grade 3 osteoradionecrosis at 47 months. At 1 year, 2 patients (1%) experienced grade 2 neck fibrosis and 38 patients (23%) experienced grade 2 xerostomia.
Conclusions and Relevance
These results suggest that severe late toxic effects after modern definitive IG-IMRT, with or without cisplatin, for oropharynx cancer is likely uncommon. The importance of late toxic effect reduction in current and future investigational strategies, including clinical trials, should be considered.
Ward MC, Ross RB, Koyfman SA, Lorenz R, Lamarre ED, Scharpf J, Burkey BB, Joshi NP, Woody NM, Prendes B, Houston N, Reddy CA, Greskovich JF, Adelstein DJ. Modern Image-Guided Intensity-Modulated Radiotherapy for Oropharynx Cancer and Severe Late Toxic EffectsImplications for Clinical Trial Design. JAMA Otolaryngol Head Neck Surg. 2016;142(12):1164-1170. doi:10.1001/jamaoto.2016.1876