Inflammation has historically been a cornerstone of clinical recognition and therapeutic approaches to malignant disease, presumably influencing tumor onset, staging, and progression. Systemic inflammatory responses, in particular, frequently become heightened before a cancer manifests and persist throughout its evolution. In cancer detection and surveillance, systemic inflammatory activity is quantified using indices such as the systemic inflammatory response index (SIRI), plasma-to-lymphocyte ratio (PLR), systemic immune inflammation index (SII), and neutrophil-to-lymphocyte ratio (NLR). Our objective was to ascertain the connection between pre- and post-treatment concentrations of these inflammatory metrics and the prognosis and clinical outcomes of oropharyngeal cancer (OPC). A retrospective review of medical records was undertaken for 172 individuals diagnosed with OPC who received therapeutic intervention at University Medical Center in Lubbock, TX, from May 2013 through May 2023. Primary tumor locations were extracted from clinical documentation. The HPV infection status and degree of tumor differentiation were documented for each subject. Therapeutic strategies were divided into surgery, radiotherapy, chemotherapy, or a combination of concurrent chemotherapy and radiation. Clinical outcomes were stratified by disease recurrence and mortality attributable to the malignancy. Associations between treatment outcomes and the aforementioned inflammatory indices were analyzed. Given the extensive array of variables, suitable parametric statistical tests were employed. Pre-treatment values of SIRI and albumin showed a positive predictive relationship with locoregional recurrence (P = 0.031 and P = 0.039). Measurements of NLR, SII, and SIRI obtained at the three-month post-treatment mark likewise demonstrated positive predictive values for locoregional recurrence (P = 0.005, P < 0.0005, and P = 0.007, respectively). SIRI readings collected at six months after treatment were also positively predictive of locoregional recurrence (P = 0.008). SII levels at the six-month post-treatment interval were positively predictive of overall survival (P = 0.027). The findings of this investigation suggest that post-treatment concentrations of several inflammatory indices, particularly SIRI, NLR, and SII, may be useful for predicting long-term prognosis and recurrence risk in head and neck cancer following therapy.
