Determining the optimal surgical margin using whole scene pathology and molecular surgical margin analysis in colorectal cancer radical surgery-a cross-sectional study.

Background: An inadequate surgical margin is the major reason for disease recurrence; however, tumor recurrence sometimes even occurs in patients with pathologically negative surgical margins. The aim of this study is to determine the ideal surgical margin in radical colorectal cancer (CRC) surgery using panoramic pathology coupled with a molecular surgical margin (MSM) analysis.

Methods: The surgical specimens and clinical data of 194 CRC patients at the Guangxi Medical University Cancer Hospital from January 2016 to December 2019 were collected. Specifically, whole pathological sections of intact primary lesions of CRC were collected. Carcinoembryonic antigen (CEA) and methylation detection were used to analyze the molecular changes and protein expression patterns of different regions.

Results: A total of 194 patients with high-quality sections and complete clinical data were included in this study. Different tumor cells and different regions of the primary focus of CRC had different protein expression patterns, and some cells expressed multiple proteins. The submucosal interstitial space of the tumor margin (i.e., the extension area) and the submucosal space near the cancer area was obvious. The positive rate of CEA in the normal mucosal tissues of distant cancer was 19.15%.

Conclusions: A tumor is a disease caused by molecular regulation failure and internal environment disorder at the high molecular level of the body. "Cell-cell" interactions may play an important role. In tumor surgery, the cutting edge may not always need to be as extensive as possible, especially when function preservation is important, which affects the quality of life of patients and ultimately affects the actual treatment outcomes. Further high-powered randomized trials need to be conducted to confirm the results of this study.