Incidence of positive exfoliative peritoneal lavage before and after tumor resection for colorectal cancer.

Background Colorectal cancer (CRC) represents the seventh commonest cancer in Egypt. Early detection of peritoneal metastasis is a major challenge in CRC management. The aim of this study was to assess the incidence of positive malignant cells in peritoneal lavage before and after resection of CRC. Patients and methods This prospective study was conducted from May 2020 to June 2022 and included 50 patients who underwent colorectal tumor resection. Intraoperative peritoneal lavage before and after tumor resection was done to detect intraperitoneal free cancer cells by conventional cytology. Results Preresection cytology was positive in four (8%) patients and negative in 46 (92%) patients. Postresection cytology was positive in five (10%) patients and negative in 45 (90%) patients. Positive preresection cytology was significantly prevalent in cases with mucinous carcinoma (P<0.031) and in cases with positive lymph node metastases (P<0.008). Positive postresection cytology in originally negative preresection one was significantly prevalent in the younger age group (P=0.046). There was more incidence of change of negative preresection cytology to positive postresection cytology whenever the tumor was located in the rectum than in cases of left or right tumor location. Conclusions Positive intraperitoneal free cancer cells are a prognostic factor of recurrence for patients treated for CRC, and it may be used as a criterion for selecting patients for further management. [ABSTRACT FROM AUTHOR]