Histopathological Prognostic Factors of Surgically Treated HPV-Associated Oropharyngeal Squamous Cell Carcinoma: A Systematic Review and Meta-analysis.

Background: Human papilloma virus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is rising in prevalence and is associated with better survival than HPV-negative OPSCC. In surgically treated HPV-negative OPSCCs, adverse pathologic features such as positive surgical margins, extra-nodal extension (ENE) and perineural invasion are well described to portend worse clinical outcomes. These adverse pathological features, however, are not validated prognostic markers among surgically treated HPV-positive OPSCCs. To that end, we pooled all available evidence to address the prognostic significance of these histologic features.

Patients and methods: This meta-analysis was performed according to PRISMA guidelines. PubMed, Web of Science and Embase databases were systematically searched for articles evaluating 13 known adverse histopathological prognostic factors of surgically treated HPV-associated OPSCC. Data analysis was done using R v4.0.5.

Results: A total of 32 studies (n = 31,535) fulfilled the inclusion criteria. ENE and advanced pT stage were associated with poorer overall survival (OS) [hazard ratio (HR):1.80, 95% confidence interval (CI) [1.59-2.03], p < 0.0001, HR: 3.28, 95% CI [2.20-4.87], p = 0.0025]; disease-specific survival (DSS) (HR: 3.14, 95% CI [1.20-8.26], p = 0.0327, HR: 3.49, 95% CI [2.45-4.96], p = 0.0043) and disease-free survival (DFS) (HR: 2.03, 95% CI [1.05-3.94], p = 0.0397, HR: 3.66, 95% CI [2.81-4.77], p = 0.0001) respectively. The presence of lymphovascular invasion (HR: 1.46, 95% CI [1.22-1.75], p = 0.0018) and positive margins (HR: 1.50, 95% CI [1.185-1.899], p = 0.0069) significantly worsen OS.

Conclusion: ENE, advanced pT stage, positive margins and lymphovascular invasion were adverse histologic prognostic marker among surgically treated HPV-positive OPSCC. The presence of these factors should be carefully evaluated in order to select the optimal patients for surgical treatment.