Introduction. Cigarette smoking along with alcohol consumption, infection with human papilloma (HPV) and the Epstein–Barr viruses, is one of the main risk factors for head and neck squamous cell carcinoma. It can also contribute to virus-associated carcinogenesis and affect the clinical and prognostic features of the tumor. Continued smoking at diagnosis of head and neck squamous cell carcinoma is a negative prognostic factor and contributes to reduced patient survival rates. Aim. To analyze the smoking status and the effect of etiopathogenesis on molecular and clinical features in patients with oropharyngeal squamous cell carcinoma (OpSCC). Materials and methods. In patients with OPSCC, the smoking status and the level of motivation to its cessation were clarified. Immunohistochemical analysis of tumor sections from paraffin blocks from the ThermoScentific immunohis-tosteiner was performed using monoclonal antibodies to estrogen receptors α (ERα), programmed death-ligand 1 (pD-L1), Bcl-2, p53 and p16. The percentage of tumor-infiltrating lymphocytes (TILs) in the stromal component of the tumor (hematoxylin and eosin staining) was also analyzed. Results. Of 113 patients with OpSCC, 80 % of patients were current smokers, including 75 % of patients with Hpv-positive tumor status. men with OpSCC were statistically significantly more likely to smoke than women (p = 0.001), as were men with Hpv-positive tumor (p = 0.015). Smoking patients were characterized by a larger size of the primary tumor (T3–4), including those with Hpv (p = 0.015). positive Hpv status of the tumor is associated with autoimmune diseases (autoimmune thyroiditis, psoriasis) (p ˂ 0.05). A high level of TILs is characteristic of smokers, including those with p16+-status (p ˂0.05), but not for all patients with this status. The positive expression of ERα is associated with p16+-status, and the latter is associated with the absence of p53 expression (p ˂0.05). During conservative therapy, tumor regression is associated with the primary tumor size T1–2, p16 + status, female sex, age less than 55 years, TILs level ≥ 57.5 %, pD-L1 expression levels on tumor cells ≥2.2 %, Bcl-2 ≥5 % and ERα ≥65 % (p ˂ 0.05). At the same time, quality of good predictive model for tumor regression showed a TILs level of ≥57.5 % (area under curve, AuC) 0.796; sensitivity 78.6 %; specificity 75 %) and ERα (AuC 0.725; sensitivity 65 %; specificity 83 %). The level of motivation to quit smoking ranged from 1 to 7 points according the 10-point motivation scale in 89 % of respondents. Only 10 patients were ready to quit smoking immediately (10 points on the motivation scale). Conclusion. Molecular heterogeneity of OPSCC was revealed, including in the group of p16+-tumors. Correlation of clinical and molecular parameters with response to conservative therapy can be used in planning of primary therapy and earlier use of surgical treatment. The level of motivation to quit smoking in patients with squamous cell carcinoma of the head and neck may be increased by drawing attention to the problem at each doctor’s appointment as well as by informing about how to quit smoking and therapeutic approaches. In unmotivated patients, the concept of reducing the harm of smoking can be used involving the replacement of cigarettes with electronic tobacco heating systems, eliminating the carcinogenic effect of its combustion products.
