Pre-treatment absolute lymphocyte count predicts for improved survival in human papillomavirus (HPV)-driven oropharyngeal squamous cell carcinoma

Background: The prognostic value of pretreatment complete blood count (CBC) data, including absolute lymphocyte count (ALC) and the neutrophil-to-lymphocyte ratio (NLR), has been reported for many diseases with decreased ALC and increased absolute neutrophil count (ANC) and NLR values correlating with worse outcomes. There is minimal data relating these hematologic parameters to oropharyngeal squamous cell carcinoma (OPSCC) prognosis. This study evaluates the prognostic value of pretreatment CBC data in OPSCC on overall survival (OS) and progression-free survival (PFS) in relation to HPV status. Methods: A single-institutional retrospective review of patients with pretreatment hematologic data who received radiation for OPSCC was performed. Univariate and multivariate (UVA/MVA) Cox proportional hazard regression analyses were performed to identify prognostic variables. Translational studies related outcomes to the degree of tumor-infiltrating lymphocytes (TILs) in histologic specimens. Results: From 2007 to 2018, 201 patients were treated for OPSCC. Median follow-up was 40 months. 3-year OS was 86.2% in the HPV-positive cohort, 46.3% for HPV-negative. Median NLR was 3.04. NLR ≥ 3 was associated with worse PFS (HR 1.67, p = 0.044. In the subset of 158 HPV + patients, MVA revealed increasing ALC to be associated with improved OS (HR 0.53; p = 0.040) and PFS (HR = 0.48; p = 0.0075). On UVA, high-TIL infiltration at diagnosis was associated with improved OS. Conclusion: In a cohort of HPV + OPSCC patients, increasing ALC is associated with improved OS and PFS. Our study is the first to identify pre-treatment ALC as an independent prognostic factor in HPV-associated OPSCC.