Tumor immune profiling of gingivo-buccal oral cancer patients reveals two groups with significant differences in prognosis and immune contextures

Interactions between cancer and immune cells determine the formation and progression of a tumor. Variability of immune contextures in tumor and margins among patients with oral squamous cell carcinoma of the gingivobuccal region (OSCC-GB) – the most prevalent subtype of oral cancer in India and southeast Asia – and the relationship of these contextures with prognosis are largely unknown. Treatment naïve, HPV negative, OSCC-GB patients (n=46) were recruited, treated, followed-up for two years and recurrence/death noted. Immune contextures of tumor and negative margins were studied using RNA-sequencing and immunohistochemistry (n=43; margin tissues were unavailable from three patients). Expressions of 544 immune related genes (IRGs) revealed a subgroup of patients (28%) with poor prognosis (high recurrence and death). The compositions of immune cell-types of normal and negative margin tissues were similar among patients irrespective of prognoses; differences were observed only in tumor. Immune contextures of tumor and negative margins were studied using RNA-sequencing