Sympathetic Nervous Influences Are Negative Prognostic Factors in Stomach Cancer

(1) Background: The aim of our study was to assess the involvement of the sympathetic nervous system in the progression of patients with gastric carcinoma by analyzing the sympathetic neuronal fibers and beta 2 adrenoreceptors. (2) Methods: We performed a retrospective study in which we analyzed the clinical, biological, and histological data from a total of 104 patients diagnosed with stomach cancer. (3) Results: After analyzing the immunoreactivity of beta 2 adrenoreceptors, we observed increased values in patients with tumors larger than 5 cm in diameter (p = 0.0371), with a deeper degree of tumor invasion T3-4 (p = 0.0159), invasion in more than two lymph nodes (p = 0.0462), or a TNM stage III-IV. Regarding the survival analysis, better survival rates (65%) were observed for patients with a low value of beta 2 adrenoreceptors (B2A-), compared to B2A (+) patients, in which survival at 3 years of follow-up was only 43%. In addition, the analysis of intra-tumoral sympathetic fibers showed a better survival rate (83%) for patients with a low value of density compared to patients with increased density, in whom the survival rate was only 24%. (4) Conclusions: The findings of this study indicate that patients with stomach cancer have a more unfavorable prognosis when they have a higher density of sympathetic nerve fibers and an increased expression of beta 2 adrenergic receptors inside the tumor.