Intratumoral Fibrotic Features Are Associated With Lymph Node Metastasis and Recurrence in Patients With Advanced Colon Cancer

Abstract

Fibrosis is a significant pathological feature of advanced colon adenocarcinomas. However, objective and systematic assessments of fibrosis signatures in colon cancer remain underexplored. This study evaluated the phenotypic histologic features of fibrosis within the tumor, which reflect lymph node (LN) metastasis and predict recurrence, to identify fibrosis signatures in patients with advanced colon adenocarcinoma. Of 499 patients who underwent surgical resection for colorectal cancer, 38 patients with stage T3 colon adenocarcinoma were selected by propensity score matching. Paraffin-embedded tissues were stained with Azan-Mallory and converted to digital pathological images. The histologic phenotypes of fibrosis were quantified based on collagen content and structure in primary tumors using the FibroNest quantitative digital pathology platform. Quantitative fibrosis traits, describing most of the variability between consecutive groups, were integrated into a phenotypic fibrosis composite score (Ph-FCS). Overall, Ph-FCS, which encompasses collagen content, fiber morphology, and fiber structure, differed significantly between the T3 colon cancer with LN metastasis and nonmetastasis groups, distinguishing between the metastasis and nonmetastasis groups with 89.5% sensitivity and 89.5% specificity (area under the curve, 0.95). Among all the parameters, kurtosis, a texture analysis component indicating the concentration of histogram data, was the most significantly different individual factor between the 2 groups. Furthermore, among the 19 patients with LN metastasis, Ph-FCS could distinguish between the recurrence and nonrecurrence groups after chemotherapy with 71.4% sensitivity and 100% specificity (area under the curve, 0.88). Detailed analysis revealed that the number of fiber branches was significantly higher in the recurrence group compared with the nonrecurrence group. In conclusion, among patients with advanced colon cancer who underwent colon surgery, the fibrotic histologic phenotype differed significantly between those with and without LN metastasis, as well as between patients with and without recurrence following chemotherapy. Phenotypic analysis of collagen in nontumor lesions may be an effective method for predicting outcomes.