Cell-in-Cell Structures in Colorectal Cancer: A Proposed Assessment Method and Correlation with Established Poor...

Area of Science:

• Oncology
• Histopathology
• Cancer Research

Background:

• Cell-in-cell (CIC) structures, where one cell is found inside another, are linked to poor prognosis and treatment resistance in colorectal cancer (CRC).
• Standardized methods for quantifying CIC structures are lacking, hindering their clinical application in CRC research.

Purpose of the Study:

• To develop and validate an adapted method for quantifying CIC structures in colorectal adenocarcinoma surgical specimens.
• To assess the correlation between CIC structures and established adverse prognostic factors in CRC.

Main Methods:

• Analysis of 250 histological slides from 58 colorectal adenocarcinoma patients (pT1-pT4).
• Immunohistochemistry (CK20) for cell identification and CIC visualization.
• Quantitative assessment of CIC structures on H&E stained digital slides using a ×40 objective.
• Correlation analysis with prognostic factors like tumor-stromal ratio, tumor buds, and tumor-infiltrating lymphocytes.

Main Results:

• Homotypic CIC structures (formed by cancer cells) predominated (95%) over heterotypic ones (5%).
• A significant increase in CIC structures was observed at the invasive front (16.7 ± 5.2) compared to the tumor center (1.2 ± 1.3).
• Weak but statistically significant correlations were found between CIC structures and tumor-stromal ratio, tumor buds, and tumor-infiltrating lymphocytes.

Conclusions:

• An adapted method for counting CIC structures in CRC surgical specimens has been established, with defined identification criteria.
• The study confirms a higher prevalence of CIC structures at the invasive front of colorectal tumors.
• Weak correlations suggest CIC structures may be an independent prognostic factor requiring further investigation in CRC.