Does Bulky Adenopathy in Human Papilloma Virus-Positive Oropharyngeal Squamous Cell Carcinoma Require a Planned Post-Treatment Neck Dissection for Occult Residual Disease?

Abstract

A planned neck dissection was traditionally considered for a large nodal disease after definitive chemoradiation, yet controversy exists for the human papilloma virus-positive oropharyngeal squamous cell carcinoma (HPV OPSCC). We aimed to measure the frequency of persistent occult neck disease in planned neck dissection for HPV OPSCC presenting with a large (≥3.0cm) nodal burden. We designed a retrospective cohort study at a single tertiary referral institution. The study population was sampled from 2006 to 2018 and subjects with HPV OPSCC and adenopathy ≥3.0cm. Inclusion criteria encompassed subjects who completed primary chemoradiation therapy (CRT) or primary radiation therapy (RT), and subsequently underwent a planned neck dissection. We excluded subjects who did not complete therapy or had less than 1-year follow-up. Our primary predictor variable was the size of cervical adenopathy on presentation (3.0-3.9cm, 4.0-4.9cm, 5.0-5.9cm, and ≥6.0cm). Our primary outcome of interest was the presence of disease based on the histopathology review. Other variables included the demographics, primary treatment with CRT or RT, and post-treatment clinical or radiographic evidence of disease. Chi-square testing was used to compare rates of persistent disease, with varying sizes of cervical adenopathy on presentation. The alpha level for statistical significance was set at 0.05. A total of 86 subjects were analyzed, with forty-one females and forty-five males, ranging from 36 to 77years (mean 54.6years). From the total study sample, 35% showed persistent disease, and 67% of those subjects had occult disease at the time of planned neck dissection. Greater than 20% of subjects had persistent disease when the nodal burden was ≥3.0cm at presentation. Furthermore, there was a statistically significant difference in the rates of persistent microscopic disease among subjects with nodal burden of different sizes based on chi-square testing (P=.01, χ2=10.66). Our data suggest that subjects with HPV OPSCC presenting with a nodal burden ≥3.0cm are likely to have 23% chance of persistent occult neck disease after primary CRT or RT. These findings may support the routine treatment of these subjects with a planned neck dissection after initial therapy to confirm or surgically complete disease eradication.