COMPARATIVE STUDY BETWEEN CYTOREDUCTIVE SURGERY ALONE VERSUS CYTOREDUCTIVE SURGERY AND HYPERTHERMIC INTRA-PERITONEAL CHEMOTHERAPY IN IRAQI PATIENT WITH DIFFUSE INTRAPERITONEAL CARCINOMATOSIS

Background: Peritoneal Carcinomatosis (PC) remains a major therapeutic challenge. Cytoreductive surgery (CRS) combined with Hyperthermic Intraperitoneal chemotherapy (HIPEC) is increasingly adopted, but local evidence from low- and middle-income settings is limited. We evaluated outcomes of CRS alone versus CRS+HIPEC in an Iraqi cohort. Methods: We performed a prospective cohort study of 100 consecutive PC patients(2021–2025) treated with CRS alone (n=50) from total (217 cases) or CRS+HIPEC (n=50)from total (71 cases). Baseline variables included age, sex, primary tumor type, Peritoneal Cancer Index (PCI), and neoadjuvant therapy. Primary endpoints were overall survival (OS) and peritoneal relapse-free survival (PRFS). Secondary endpoint was postoperative performance status. Group comparisons used Welch’s t-test when variances were unequal and Student’s t-test otherwise; categorical variables were compared with chi-square tests. Results: Groups were balanced at baseline: mean age 58.86±7.48 (CRS) vs. 58.46±8.13 years (CRS+HIPEC); PCI 11.00±3.12 vs 10.88±3.44 (both p>0.05). Females comprised 86% in each arm; primaries were ovarian (68%), colonic (12%), gastric (12%), and appendiceal (8%); neoadjuvant therapy was used in 74% per group. CRS+HIPEC achieved longer OS (37.90±16.03 vs 19.42±8.45 months; mean difference 18.48 months; 95% CI 3.38–13.58; p=0.001, Welch’s) and longer PRFS (28.34±13.32 vs 15.36±5.58 months; mean difference 12.98 months; 95% CI 8.90–17.06; p<0.001, Welch’s). Performance status was better (lower score) after CRS+HIPEC (8.58±2.60 vs 11.06±2.94; mean difference 2.48; 95% CI 1.38–3.58; p<0.001). Conclusion: In this single-center Iraqi cohort, adding HIPEC to complete Cytoreductive surgery was associated with clinically meaningful improvements in survival and postoperative function compared with CRS alone, with balanced baseline characteristics. These findings support adopting CRS+HIPEC for carefully selected patients within standardized pathways; prospective multicenter evaluation with time-to-event methods and comprehensive toxicity reporting is warranted.