Comparison of contemporary staging systems for oropharynx cancer in a surgically treated multi‐institutional cohort

Implications of updated staging system for p16+ oropharyngeal squamous cell carcinoma: Is valuable prognostic information being omitted?

BACKGROUND

This study characterized whether the updated AJCC 8th edition nodal staging system for p16+ oropharyngeal squamous cell carcinoma (OPSCC) resulted in the loss of prognostic value.

METHODS

The NCDB was queried for patients with node-positive p16+ OPSCC. The prognostic impact of nodal size, nodal quantity, nodal laterality, and extracapsular extension (ECE) on overall survival (OS) was assessed.

RESULTS

In the clinical cohort, inferior 5-year OS was observed in patients with more than one positive lymph node (p < 0.001; 82% vs. 86%), ECE (p < 0.001; 82% vs. 75%), or nodal size >6 cm (p < 0.001; 66% vs. 82%). In the pathologic cohort, inferior 5-year OS was observed in patients with > four positive lymph nodes (p < 0.001; 76% vs. 90%), ECE (p < 0.001; 83% vs. 92%), or largest nodal size >6 cm (p < 0.001; 81% vs. 89%).

CONCLUSIONS

Simplifications in the current p16+ OPSCC staging system led to loss of prognostic information in nodal staging.

HPV-associated oropharyngeal cancer: epidemiology, molecular biology and clinical management

Human papillomavirus (HPV)-positive (HPV⁺) oropharyngeal squamous cell carcinoma (OPSCC) has one of the most rapidly increasing incidences of any cancer in high-income countries. The most recent (8th) edition of the UICC/AJCC staging system separates HPV⁺ OPSCC from its HPV-negative (HPV⁻) counterpart to account for the improved prognosis seen in the former. Indeed, owing to its improved prognosis and greater prevalence in younger individuals, numerous ongoing trials are examining the potential for treatment de-intensification as a means to improve quality of life while maintaining acceptable survival outcomes. In addition, owing to the distinct biology of HPV⁺ OPSCCs, targeted therapies and immunotherapies have become an area of particular interest. Importantly, OPSCC is often detected at an advanced stage owing to a lack of symptoms in the early stages; therefore, a need exists to identify and validate possible diagnostic biomarkers to aid in earlier detection. In this Review, we provide a summary of the epidemiology, molecular biology and clinical management of HPV⁺ OPSCC in an effort to highlight important advances in the field. Ultimately, a need exists for improved understanding of the molecular basis and clinical course of this disease to guide efforts towards early detection and precision care, and to improve patient outcomes.

The incidence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is increasing rapidly in most developed countries. In this Review, the authors provide an overview of the epidemiology, molecular biology and treatment of HPV-positive OPSCC, including discussions of the role of treatment de-escalation and emerging novel therapies.

The incidence of human papillomavirus-associated oropharyngeal cancer (HPV⁺ OPSCC) is expected to continue to rise over the coming decades until the benefits of gender-neutral prophylactic HPV vaccination begin to become manifest.

The incidence of HPV⁺ OPSCC appears to be highest in high-income countries, although more epidemiological data are needed from low- and middle-income countries, in which HPV vaccination coverage remains low.

The substantially better prognosis of patients with HPV⁺ OPSCC compared to those with HPV^– OPSCC has been recognized in the American Joint Committee on Cancer TNM8 staging guidelines, which recommend stratification by HPV status to improve staging.

The molecular biology and genomic features of HPV⁺ OPSCC are similar to those of other HPV-associated malignancies, with HPV oncogenes (E6 and E7) acting as key drivers of pathogenesis.

Treatment de-intensification is being pursued in clinical trials, although identifying the ~15% of patients with HPV⁺ OPSCC who have recurrent disease, and who therefore require more intensive treatment, remains a key challenge.

Staging and treatment outcomes in oropharyngeal squamous cell carcinoma: a single-centre UK cohort

The 8^th edition of the UICC TNM (UICC 8) staging rules for oropharyngeal squamous cell carcinoma (OPSCC) acknowledges dichotomous disease biology based on the human papillomavirus (HPV) tumour status. This retrospective study was undertaken to validate those staging rules in a single UK treatment centre. Given a recent resurgence of interest in primary surgery for OPSCC, a secondary objective was to identify subsets of patients who might benefit. Patients presenting with OPSCC between 2010 and 2017 to the South Glasgow head and neck multidisciplinary team were identified from a prospective database. Only patients managed with curative intent were included (n=272). Stage group allocation according to the UICC 8 resulted in appropriate hazard discrimination, in contradistinction to the UICC 7 staging rules. Locally advanced (cT3-4) disease had a relatively poor prognosis irrespective of HPV status. No clear benefit for primary surgery in any subgroup was demonstrated. A dichotomous disease biology based on the HPV status of tumour is confirmed in this cohort. Patients with HPV-positive T1 and T2 primary tumours have an excellent prognosis when treated with non-surgical treatment regimens. The use of surgery as the primary management for categories of patients presenting with OPSCC should be in the context of clinical trials.