The multidirectional effects of some comorbid disorders on the malignant process and tumor-bearing organism in the experiment.

Abstract

e15616 Background: The question of the effects of comorbid diseases on oncogenesis has been little studied else. The increase in the frequency of dorsopathies and arthritis with age determines the important of the question about their influence on malignant process. The aim of the research was to study the features of the tumor growth and animal's condition under chronic neurogenic and inflammatory pain. Methods: In experiments on 54 white unbred male rats of 280-390 g, with transplantable Guerin's carcinoma (сG), two experimental models of chronic pain were used - unilateral sciatic nerve ligation (SNL) according to G.J. Bennet (neurogenic pain) and injections of formalin (Fm) into the ankle joint of the back paw (inflammatory pain). Formalin injection is known to be used to form both acute and chronic pain. The dynamics of tumors size, level of motor activity (MAL) in open field test, hematological parameters (by the blood analyzer «Exigo EOS vet», Sweden), adaptation status (AS) by Selye-Garkavi-Kvakina and also the lifespan of the animals (LS) were evaluated. Results: Unlike the unidirectional negative influence of chronic pain known in tumor-bearing animals in the cases of bilateral SNL, two opposite effects were observed with unilateral SNL and the formalin injection. Along with accelerated tumor growth in some animals (up to 62%), increase of LS of more than a third of the rats of the main groups by 3-30% in comparative with maximal LS in the control group was noted. In these cases, often the death of animals occurred with the larger tumors than in the control groups. In the cases of unilateral SNL, a relation between changes in the characteristics of the AS and the LS was noted. In the cases of Fm injections, animals with diverse LS differed in the features of the inflammatory reaction and the dynamics of the MAL. The prognostic value of shifts of the MAL in chronic inflammatory pain and tumor growth is assumed. Conclusions: A nonlinear relationship between the processes caused by chronic pain, oncogenesis, and individual characteristics of systemic regulation was shown. The question about the mechanisms of adaptation to the malignant process, promoting the body's viability in large tumors in conditions of chronic neurogenic and inflammatory pain is of interest.