Tumour-infiltrating lymphocytes do not predict survival in human papillomavirus-associated oropharyngeal squamous cell carcinoma: a single institution retrospective review

OBJECTIVE: Human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) exhibits a favourable prognosis compared to non-HPV OPCSCC. Tumour infiltrating lymphocytes (TILs) may predict better survival outcomes for patients with HPV+OPSCC. METHODS: A retrospective review of patients treated for HPV+OPSCC between 2003-2018. TIL density scores for each patient's tumour specimen were determined. Patients were categorised as TIL-Hi or TIL-Lo. Survival outcomes for the two TIL groups were compared. RESULTS: Fifty-seven patients, 33 in the TIL-Hi group, were included. 5-year overall survival was 81.8% in the TIL-Hi and 75% in the TIL-Lo groups. 5-year disease specific survival was 87.9% and 87.5%, respectively. There was no statistically significant difference in survival outcomes between TIL-Hi and TIL-Lo. CONCLUSION: TIL density in HPV+OPSCC has been reported to predict survival outcomes. This is not supported by the findings of this study. Further prospective evaluation with a standardised scoring technique may fully elicit the prognostic value of TILs in HPV+OPSCC.