Features of the microstructure and metabolism of the colon mucosa at the resection border in patients with colorectal cancer

Abstract

BACKGROUND: In patients with colorectal cancer, the intestinal wall, which is not involved in the malignant process, despite histological signs of intactness, is characterized by impaired structure and metabolism. Modern optical bioimaging technologies make it possible to objectively assess these changes. AIM: To study metabolism and morphological structure features of the mucous membrane of the relatively normal colon in patients with colorectal cancer. MATERIAL AND METHODS: The object of study was the colon mucosa in patients with colorectal cancer stages I–IV. The study included 59 patients. There were 33 (56%) men, 26 (44%) women; median age — 67 [61; 74] years. In 10 cases, the tumor was localized in the right colon, in 9 — in the transverse colon, in 23 — in the sigmoid colon, in 17 — in the rectum. 7 samples were obtained from patients with stage I, 25 — with stage II, 21 — with stage III, 6 — with stage IV colorectal cancer. The metabolism of colon tissue from the mucosal side was studied using fluorescence-lifetime macroimaging, and the microstructure was studied using optical coherence tomography and histological examination. The results of calculating the weighted average fluorescence lifetime were presented as median values Me [Q1; Q3], comparison of this indicator between groups was carried out using the nonparametric Kruskal–Wallis test. RESULTS: According to histological examination, progression signs of structural changes with increasing stage of colorectal cancer were revealed: from the conventional norm in samples with stage I to the appearance of signs of chronic colitis, atrophy and erosion of the mucous membrane in samples with stages II, III and IV. Visual analysis of optical coherence tomograms obtained from colon samples showed a high degree of agreement with histological data: the Spearman correlation coefficient was r=0.96. According to fluorescence-lifetime macroimaging, statistically significant differences (p=0.027) in the weighted average fluorescence lifetime were detected between stages IV and II of colorectal cancer: the values were 1.6 [1.4; 1.8] ns and 1.3 [1.1; 1.4] ns, respectively, which indicated an intensification of the glycolysis process in the tissues of the colon mucosa in stage IV colorectal cancer. Presumably, the identified changes will become the pathophysiological and anatomical basis of postoperative complications. In clinical oncology, it is advisable to use the obtained data to optimize the volume of intestinal resection and postoperative therapy algorithms. CONCLUSION: Long-term tumor carriage and progression of colorectal cancer (invasion and metastasis) are associated with an increasing incidence of atrophy/erosion of the mucous membrane, the signs of which are determined both by optical coherence tomography and by histological examination.