Surgery- vs Radiation-Based Therapy for p16+/HPV-Related Oropharyngeal Cancers

[HPV-related oropharyngeal squamous cell carcinoma-Incidence steadily rising]

The incidence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is steadily increasing worldwide and has already exceeded cervical cancer rates in the USA. Due to their tumor biology, HPV-positive tumors of the oropharynx, which have been included in the eighth edition of the AJCC/UICC (American Joint Committee on Cancer/Union Internationale Contre le Cancer) Staging Manual since 2018, represent a separate entity. Following biopsy, diagnostic confirmation is performed by immunohistochemical detection of p16 expression, with p16 acting as a surrogate marker. Therapeutically, surgical and radiotherapeutic approaches are considered equivalent in terms of efficacy. With a 5-year overall survival of up to 80%, patients with HPV-positive OPSCC have a better prognosis compared to patients with HPV-negative OPSCC, where survival rates are between 40 and 50%.

Quality assurance of radiotherapy in the ongoing EORTC 1420 "Best of" trial for early stage oropharyngeal, supraglottic and hypopharyngeal carcinoma: results of the benchmark case procedure

INTRODUCTION

The current phase III EORTC 1420 Best-of trial (NCT02984410) compares the swallowing function after transoral surgery versus intensity modulated radiotherapy (RT) in patients with early-stage carcinoma of the oropharynx, supraglottis and hypopharynx. We report the analysis of the Benchmark Case (BC) procedures before patient recruitment with special attention to dysphagia/aspiration related structures (DARS).

MATERIALS AND METHODS

Submitted RT volumes and plans from participating centers were analyzed and compared against the gold-standard expert delineations and dose distributions. Descriptive analysis of protocol deviations was conducted. Mean Sorensen-Dice similarity index (mDSI) and Hausdorff distance (mHD) were applied to evaluate the inter-observer variability (IOV).

RESULTS

65% (23/35) of the institutions needed more than one submission to achieve Quality assurance (RTQA) clearance. OAR volume delineations were the cause for rejection in 53% (40/76) of cases. IOV could be improved in 5 out of 12 OARs by more than 10 mm after resubmission (mHD). Despite this, final IOV for critical OARs in delineation remained significant among DARS by choosing an aleatory threshold of 0.7 (mDSI) and 15 mm (mHD).

CONCLUSIONS

This is to our knowledge the largest BC analysis among Head and neck RTQA programs performed in the framework of a prospective trial. Benchmarking identified non-common OARs and target delineations errors as the main source of deviations and IOV could be reduced in a significant number of cases after this process. Due to the substantial resources involved with benchmarking, future benchmark analyses should assess fully the impact on patients' clinical outcome.

HPV/p16-positive oropharyngeal cancer treated with transoral robotic surgery: The roles of margins, extra-nodal extension and adjuvant treatment

PURPOSE

Human papilloma virus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) treatment outcomes are re-defining management. Traditional margins, the role of extranodal extension (ENE) and adjuvant treatment intensity continue to be debated. This study aimed to determine the impact of margins, ENE and adjuvant therapy on survival following transoral robotic surgery (TORS).

METHODS

Patients treated with TORS at an academic center were retrospectively identified (2013-2019). Survival outcomes were evaluated using Kaplan-Meier curves.

RESULTS

48 patients were included. 40 (83%) were male. Mean age was 61.2 years. 43 (90%) were stage I. 22 (45.8%) had ENE. 31 (65%) had margins >1 mm. 38 (79%) had indications for radiation therapy; 9 (24%) refused. Chemotherapy was recommended in 36 (75%) patients; 24 (67%) refused. Locoregional control was 98%, metastasis-free survival was 96%, and disease-specific survival was 100% at 5-years. Overall survival was 95%.

CONCLUSIONS

Given the high survival rate seen after TORS, it is likely that margins, ENE and adjuvant treatment may not significantly contribute to outcomes.