In head and neck cancers, the number of intra-tumoral lymphocytes associates with improved survival. The impact of the exact cellular composition and localization of these lymphocytes, however, is less well studied. In the current study, we assessed the prognostic values of density, localization and cellular networks of defined lymphocyte populations in early-stage oral tongue cancer.
Patient with T1-T2, primary oral tongue squamous cell carcinoma and treated with surgical resections and without any peri-operative (chemo) radiotherapy were included in a discovery cohort (n = 47). Multiplexed in-situ immunofluorescent staining was performed using FFPE sections for CD4, CD8, CD20, pan-cytokeratin and cellular nuclei (DAPI); and spatial distributions of 3 lymphocyte populations were assessed in the tumour and stromal compartments, both at the invasive margin (IM) and the center of tumours (CT). Using algorithm-based pathology and nearest neighbor analysis (NNA), we have computed cellular densities and networks for lymphocytes and related these immune parameters to overall survival (OS). Findings were validated using another cohort of patients with identical clinical characteristics (n = 91).
In our discovery cohort, we observed a high stromal density of CD20-positive B cells at IM but not CT, which correlated with OS (p = 0.005, HR 0.225). NNA demonstrated that survival benefit particularly related to the number of CD20 cells in the vicinity of CD4 cells and the frequency of B cells touching each other. The prognostic value of B cell-rich areas was validated in a second cohort, but only for those patients with low stromal densities of CD4 T cells (in accordance to discovery cohort, p = 0.007, HR = 0.275).
Our study highlights the prognosis of B cell-rich areas in early-stage oral-tongue cancer patients, particularly in the context of low intra-tumoral CD4 T cell densities.
The authors.
Erasmus MC, Rotterdam, the Netherlands and HRH Princess Chulabhorn College of Medical Science, Bangkok, Thailand.
All authors have declared no conflicts of interest.