Role of Peritoneal Lavage Cytology and Prediction of Prognosis and Peritoneal Recurrence After Curative Surgery for Colorectal Cancer

Abstract

PurposeIn colorectal cancer, the role of detecting free malignant cells from peritoneal lavage is currently unclear. In this study, we investigated the positive rate of free malignant cells in peritoneal lavage fluid and their predictive value for prognosis and peritoneal recurrence after a curative resection.MethodsFrom October 2009 to December 2011, in a prospective manner, we performed cytologic examinations of peritoneal lavage fluid obtained just after the abdominal incision from 145 patients who underwent curative surgery for colorectal cancer. We used proportional hazard regression models to analyze the predictive role of positive cytology for peritoneal recurrence and survival.ResultsAmong total 145 patients, six patients (4.1%) showed positive cytology. During the median follow-up of 32 months (range, 8-49 months), 27 patients (18.6%) developed recurrence. Among them, 5 patients (3.4%) showed peritoneal carcinomatosis. In the multivariate analysis, positive cytology was an independent predictive factor for peritoneal recurrence (hazard ratio [HR], 136.5; 95% confidence interval [CI], 12.2-1,531.9; P < 0.0001) and an independent poor prognostic factor for overall survival (HR, 11.4; 95% CI, 1.8-72.0; P = 0.009) and for disease-free survival (HR, 11.1; 95% CI, 3.4-35.8; P < 0.0001).ConclusionPositive cytology of peritoneal fluid was significantly associated with peritoneal recurrence and worse survival in patients undergoing curative surgery for colorectal cancer. Peritoneal cytology might be a useful tool for selecting patients who need intraperitoneal or systemic chemotherapy.

Conventional peritoneal cytology lacks the prognostic significance of detecting local or peritoneal recurrence in colorectal cancer: An Egyptian experience

“…Multicenter studies reported that IPCCs are associated with peritoneal recurrence and worse survival 3,7 . However, other authors argue for the prognostic role of free IPCCs on survival and rejected its predictive significance for peritoneal recurrence after a curative resection 10,12 .…”

“…Despite the current debate of the actual significance of positive peritoneal fluid cytology, some authors still considered it evidence of the local aggressiveness of the disease during surgery. It may help in making the decision of whether to apply any of the previous treatment strategies immediately after resection of the tumor 7,17 . Either side of this argument should be supported by multi‐institutional studies to determine the prevalence of IPCC and to evaluate the real prognostic impact of peritoneal lavage cytology.…”

“…It helps with the decision of immediate application of intraperitoneal chemotherapy after curative resection. This reduces the incidence of peritoneal recurrence and avoids aggressive CRS and HIPEC, which have high mortality and morbidity 7,8 …”

“…Meta‐analysis studies argue for the controversial prognostic role of intraperitoneal free cancer cell (IPCC) detection in peritoneal recurrence and survival after curative resection 3,7,9–12 . Prospective validation is required to identify and compare sensitivities and specificities between the various diagnostic criteria for positive cytology in peritoneal lavage fluid to find the most optimal biomarkers for predicting outcome 3,7 …”

Intraoperative Peritoneal Lavage: Limitations of Current Evidence for Clinical Implementation

“…Among gastrointestinal malignancies, the significance of peritoneal cytology has been extensively studied in gastric cancer. The existence of free cancer cells at intraoperative peritoneal lavage has been reported to be one of the most accurate prognostic factors for gastric cancer and is now classified as Stage IV [ 3 , 4 ]. Besides gastric cancer, the examination of peritoneal free cancer cell is an important staging step in pancreatic, ovarian and endometrial cancer [ 5 ]…”