A Prediction Model Intended for Exploratory Laparoscopy Risk Stratification in Colorectal Cancer Patients With Potential Occult Peritoneal Metastasis

Abstract

BackgroundThe early diagnosis of occult peritoneal metastasis (PM) remains a challenge due to the low sensitivity on computed tomography (CT) images. Exploratory laparoscopy is the gold standard to confirm PM but should only be proposed in selected patients due to its invasiveness, high cost, and port-site metastasis risk. In this study, we aimed to develop an individualized prediction model to identify occult PM status and determine optimal candidates for exploratory laparoscopy.MethodA total of 622 colorectal cancer (CRC) patients from 2 centers were divided into training and external validation cohorts. All patients’ PM status was first detected as negative on CT imaging but later confirmed by exploratory laparoscopy. Multivariate analysis was used to identify independent predictors, which were used to build a prediction model for identifying occult PM in CRC. The concordance index (C-index), calibration plot and decision curve analysis were used to evaluate its predictive accuracy and clinical utility.ResultsThe C-indices of the model in the development and validation groups were 0.850 (95% CI 0.815-0.885) and 0.794 (95% CI, 0.690-0.899), respectively. The calibration curve showed consistency between the observed and predicted probabilities. The decision curve analysis indicated that the prediction model has a great clinical value between thresholds of 0.10 and 0.72. At a risk threshold of 30%, a total of 40% of exploratory laparoscopies could have been prevented, while still identifying 76.7% of clinically occult PM cases. A dynamic online platform was also developed to facilitate the usage of the proposed model.ConclusionsOur individualized risk model could reduce the number of unnecessary exploratory laparoscopies while maintaining a high rate of diagnosis of clinically occult PM. These results warrant further validation in prospective studies.Clinical Trial Registrationhttps://www.isrctn.com, identifier ISRCTN76852032

A prediction model to refine the timing of an early second‐look laparoscopic exploration in patients with colon cancer at high risk of early peritoneal metastasis recurrence

“…Peritoneal metastasis (PM) is an insidious disease likely to be at an advanced stage when clinical symptoms appear. During the last two decades, many clinical studies have tried to predict the risk of PM recurrence in colon cancer (CC), 1,2 including using a computerbased score calculating the recurrence risk at 1, 2, and 3 years. 3 Metachronous PM often occurs in high-risk clinical situations, [4][5][6] which are likely to promote peritoneal invasion, such as obstructed or perforated tumors operated emergently and the presence of synchronous localized PM and/or ovarian metastasis.…”