Posttreatment imaging at 3 months and physical examinations during the 6 months following treatment can detect most recurrences in patients treated with definitive radiation therapy for oropharyngeal cancer caused by human papillomavirus (HPV).1 This research was presented at the 2016 Multidisciplinary Head and Neck Cancer Symposium.
A dramatic increase in oropharyngeal squamous cell carcinoma (OPSCC) cases associated with HPV has been reported by the American Cancer Society. Survival rates after definitive radiation therapy have also increased. This has led to the need to determine general time to recurrence and the most effective modes of recurrence detection, to guide standards for optimal follow-up care by oncology teams.
This study examined 246 cases of HPV-positive or p16-positive non-metastatic OPSCC treated with definitive radiation therapy at a single, large-volume cancer center between 2006 and 2014.
Follow-up care included a PET/CT scan 3 months after completing treatment and physical examinations every 3 months in the first year following treatment, every 4 months in the second year and every 6 months in years 3 through 5. Median follow-up care length for all patients was 36 months. Patient outcomes, including recurrence and survival rates, were calculated using the Kaplan-Meier method from the end of radiation therapy.
Most recurrences were detected either by persistent disease appearing on 3-month posttreatment imaging or by patients presenting with symptoms at follow-up examinations.
Disease characteristics that increase the likelihood of recurrence include presenting with 5 or more nodes or having level 4 lymph nodes (P < .05). Distant metastases were a greater risk in patients with a lymph node larger than 6 cm or with bilateral lymphadenopathy (P < .05).
“For most patients with HPV-associated oropharynx cancer, after a negative 3-month PET scan, physical exams with history and direct visualization are sufficient to find recurrences,” said Jessica M. Frakes, MD, an assistant member of the department of radiation oncology at the H. Lee Moffitt Cancer Center in Tampa, Florida, and lead author in the study. “Minimizing the number of unnecessary tests may alleviate the financial and emotional burden on these patients, including overall health care costs, time spent away from work and family, and the anxiety of waiting for scan results.”
This study also supports the effectiveness of specialist teams in treating HPV-positive OPSCC with definitive radiotherapy (RT). Within 3 years, local control was achieved in 97.8% of all patients in the study; regional control in 95.3%; locoregional control in 94%; and freedom from distant metastases in 91.4%. The 3-year overall survival rate was 91%.
“We were pleasantly surprised by the high cure rates and the low permanent side effect rates for these patients,” said Frakes. “These findings demonstrate that individuals with HPV-associated oropharyngeal cancer who are treated with definitive RT and cared for by multidisciplinary specialists have excellent outcomes.”
1. Frakes JM, Naghavi AO, Strom T, et al. Detection of recurrence in HPV associated oropharynx squamous cell carcinoma. Presented at 2016 Multidisciplinary Head and Neck Cancer Symposium; Scottsdale, AZ; February 18, 2016. Abstract 6.