Results of the study of factors predicting the risk of the development of grade III radiation-induced mucositis during radiation or chemoradiation therapy in patients with oral cavity and oropharynx cancer.

Abstract

Background: Today, a number of methods and ways of prevention and treatment of radiation- -induced mucositis of the oral cavity and oropharynx have been developed, but the represented approaches are still not effective enough. Therefore, to increase the effectiveness of the prevention and treatment of radiation-induced mucositis, it is necessary to approach this problem comprehensively and individually, and to evaluate the factors affecting the development of mucositis.

Materials and methods: In this single-center prospective controlled non-randomized clinical trial, the results of clinical observation of the development of complications of radiation and chemoradiation therapy in 105 patients with a newly diagnosed squamous cell cancer of the oral cavity and oropharynx were analyzed. Factors affecting the risk of the development of grade III radiation-induced mucositis including the age, gender of the patients, their general condition before the treatment according to World Health Organisation scales, type of the treatment and its doses, additional use of immunotherapy with alpha/beta defensins, characteristic signs of the tumor process and all indices of the immune status of the patients before the treatment have been analyzed.

Results: The method of construction and analysis of one-factor logistic regression models, where 24 indices were analyzed as factorial features, showed that the reduction of the risk of the development of grade III radiation-induced mucositis is predicted by several factors: immunotherapy, gender, serum concentrations of IgG and IgA. A decrease (P < 0.001) in the risk of the development of grade III radiation-induced mucositis was revealed if immunotherapy with alpha/beta defensins (with a total dose of 40 mg) was included into the treatment scheme (relative odds (RO) 0.05; 95% reference interval (RI) 0.02-0.18), in comparison with patients of the groups where it was not present or this immune agent was used in a total dose of 60 mg (P = 0.001, RO 0.06; 95% RI 0.01-0.30). The next factorial sign was gender, namely the risk of the development of grade III radiation-induced mucositis was lower for men (P = 0.003; RO 0.15; 95% RI 0.04-0.53) compared to women. An increase (P = 0.024) in the risk of the development of grade III radiation-induced mucositis with an increase in the initial level of IgG serum concentration was revealed, (RO 1.08; 95% RI 1.01-1.16) for each 1 mg/mL, as well as an increase (P = 0.044) in the possibility of the appearance of grade III radiation-induced mucositis with an increase in the serum concentration of IgA (RO 1.23; 95% RI 1.01-1.50) for every 1 mg/mL also before the beginning of the treatment. Multifactorial analysis has also confirmed that the risk of the development of grade III radiation-induced mucositis increases (P = 0.008) with a high serum IgG concentration before the treatment or with an increase in this index during therapy (RO 1.13; 95% RI 1.03-1.09) for every 1 mg/mL (when standardized by other risk factors). It was determined that when standardizing according to other factors (gender, IgG level), the risk of the development of grade III radiation-induced mucositis in the use of the immune agent alpha/beta defensins in a total dose of 40 mg per course decreases (P < 0.001; RO 0.08; 95% RI 0.02-0.27) compared to patients with oral cavity and oropharynx cancer who were not treated with immunotherapy. The risk of the development of grade III radiation-induced mucositis also decreases (P = 0.001) in the use of immunotherapy in a higher dose, i.e. 60 mg per course (RO 0.03; 95% RI 0.004-0.24 compared to patients whose treatment did not include immunotherapy (when standardized by other factors).

Conclusion: As a result of this controlled clinical study, some factors were determined in addition to the radiation as those affecting the risk of the development of grade III radiation-induced mucositis in patients with oral cavity and oropharynx cancer during special treatment. These factors comprise the inclusion of immunotherapy with alpha/beta defensins into the specific treatment; gender, and baseline levels of serum IgG and IgA concentrations suggest a pattern in which the higher the serum IgG and IgA concentrations are before the start of the treatment, the greater is the likelihood of severe radiation-induced mucositis degree during special therapy. The results of the study of humoral state of the immune system in patients with oral cavity and oropharynx cancer before the beginning of chemoradiation therapy can be used as prognostic risk factors for the development of severe gamma-irradiation-induced mucositis of the oropharyngeal area, as well as an indication for the use of immunotherapeutic agents (in particular, alpha/beta defensins) that are able to polarize the immune response towards type 1 T-helpers through their immunomodulatory action.