Predictive Factors for Peritoneal Metastases in Colorectal Cancer: A Retrospective Study Conducted at a Tertiary Care Center in Riyadh, Saudi Arabia.

Background The incidence of colorectal cancer (CRC) is increasing nationally, emphasizing the importance of early detection. Late-stage diagnosis, particularly with peritoneal metastasis (PM), is associated with poor outcomes despite advancements in treatment. PM poses a challenge owing to the lack of standardized treatment, although cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) shows promise in improving survival rates. This study aimed to document the incidence and risk factors for patients presenting with PM following CRC. Materials and methods This retrospective chart review study was conducted at King Abdulaziz Medical City in Saudi Arabia. Patients of all ages and genders who underwent surgical resection for CRC from January 2016 to December 2021 were included. Patients with PM at primary index surgery, distant organ metastasis to the lung or liver, or other types of cancer were excluded. The data was analyzed via SPSS Statistics version 27.0 (IBM Corp. Released 2020. IBM SPSS Statistics for Windows, Version 27.0. Armonk, NY: IBM Corp.), t-test, Wilcoxon rank-sum test, chi-square test, and Fisher's exact tests. Results Among 565 patients with CRC, 65 patients (11.5%) developed PM. Tumor characteristics such as T4 stage, mucinous tumors, elevated CEA, and the presence of ovarian metastasis at primary resection were independent factors for peritoneal recurrence. However, in univariate and multivariate associations, the presence of ovarian metastasis, mucinous tumors, postoperative CEA levels exceeding 5 ng/ml, and perforation are significant risk factors for PM development post-surgery, with hazard ratios of 6.457 (CI 2.481-16.801) and 4.057 (2.029-8.115), respectively. Conclusion Mucinous tumors and ovarian metastasis are significant risk factors for PM development, emphasizing the importance of early identification for tailored treatment strategies such as CRS and HIPEC.