(S007) Intensity of Follow-Up After Radiotherapy for HPV-Positive Oropharyngeal Cancer

Jessica M. Frakes, MD, Stephanie Demetriou, BS, Tobin Strom, MD, Jeffrey Russell, MD, PhD, Julie A. Kish, MD, Judith McCaffrey, MD, Kristen Otto, Tapan Padhya, MD, Andy Trotti, MD, Jimmy J. Caudell, MD, PhD; Moffitt Cancer Center; Florida Atlantic University

PURPOSE AND OBJECTIVES: According to the American Cancer Society, human papilloma virus-positive (HPV+) oropharynx cancer is an epidemic. Fortunately, outcomes for these patients with radiotherapy +/− chemotherapy are excellent. We reviewed our institutional experience with HPV+ oropharynx cancer to determine the time to recurrence or to grade ≥ 3 toxicities to better define an optimal follow-up schedule.

MATERIALS AND METHODS: An institutional database of patients with head and neck cancer seen between 2006–2014 was queried, and 232 patients with a biopsy-proven diagnosis of nonmetastatic HPV+ oropharynx squamous cell carcinoma were identified with at least 6 months of follow-up. Charts were reviewed to capture patients’ tumor, treatment, toxicity, and outcome information. Recommended follow-up was every 3 months in the first year, every 4 months in Year 2, and every 6 months in Years 3–5. Locoregional control (LRC), distant control (DC), and overall survival (OS) were calculated according to the Kaplan-Meier (KM) method from the end of treatment.

RESULTS: Median follow-up of all patients was 33 months (range: 6–99 mo). Based on Radiation Therapy Oncology Group [RTOG] 0129 risk stratification, 162 patients (70%) were low-risk and 70 (30%) were intermediate-risk. Concurrent systemic therapy was utilized in 85% of patients (n = 196). Three-year LRC, DC, and OS rates were 94%, 91%, and 91%, respectively. Late grade ≥ 3 toxicity occurred in 9% (n = 21) of patients. There were a total of 19 grade 3 toxicities (most commonly feeding tube) and 2 grade 4 toxicities (tracheostomy), with resolution in 15 patients and 1 patient, respectively, at time of last follow-up. Overall, local, regional, or distant relapse or grade ≥ 3 toxicity occurred in 27 patients (68% of all events) within the first 6 months. Subsequently, there were very few events at each time point over 48 months (< 2% at each time point). As expected, recurrence or toxicity events were more common in the intermediate-risk group, while the time to an event was most likely to occur within the first 6 months after therapy.

CONCLUSIONS: Following radiotherapy +/− chemotherapy for HPV+ oropharynx cancer, there is a low risk of disease recurrence or late grade ≥ 3 toxicity. As most events occur within 6 months of treatment completion, it may be reasonable to reduce the intensity of follow-up appointments to an every-6-month basis beyond this window.

Proceedings of the 97th Annual Meeting of the American Radium Society - americanradiumsociety.org