Efficacy of 1 384 cases of peritoneal carcinomatosis underwent cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy

Objective: Peritoneal carcinomatosis refers to a group of heterogeneous (primary or secondary) malignancies in the surface of the peritoneum. Cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is a comprehensive treatment strategy aiming at peritoneal carcinomatosis. This study analyzed the efficacy and safety of CRS+HIPEC in patients with peritoneal carcinomatosis, and explored prognostic factors. Methods: In this descriptive case-series study, the clinicopathological data of 1384 consecutive patients with peritoneal carcinomatosis treated in Zhongnan Hospital of Wuhan University (330 patients) and Shijitan Hospital of Capital Medical University (1054 patients) from January 2004 to January 2020 were collected retrospectively. Treatment patterns of CRS+HIPEC characteristics (operative time, number of resected organs, number of stripped peritoneum, number of anastomosis, and HIPEC regimens), safety [blood loss volume, postoperative severe adverse event (SAE) and treatment outcome], survival time and prognostic factors influencing survival were analyzed. The SAE was defined as grade III-IV adverse event according to the Peritoneal Surface Oncology Group International Textbook. Perioperative period was defined from the day of CRS+HIPEC to postoperative 30th day. OS was calculated from the day of CRS+HIPEC to the date of death or the last follow-up. Kaplan-Meier method was used for survival analysis, and log-rank test was used for comparison between groups. Cox regression model was used to identify the prognostic factors. Results: Among 1384 peritoneal carcinomatosis patients, 529 (38.2%) were male; median age was 55 (10-87) years old; median body mass index (BMI) was 22.6 kg/m(2); peritoneal carcinomatosis of 164 (11.8%) patients were from gastric cancer, 287 (20.7%) from colorectal cancer, 356 (25.7%) from pseudomyxoma peritonei, 90 (6.5%) from malignant peritoneal mesothelioma, 300 (21.7%) from gynecological cancer or primary peritoneal carcinoma, and 187 (13.5%) from retroperitoneal sarcoma, lung cancer, breast cancer, and other rare tumors. The median duration of CRS+HIPEC was 595 (90-1170) minutes, median number of resected organs was 2 (0-10), median number of resected peritoneal area were 4 (0-9), median peritoneal cancer index (PCI) was 21(1-39). Completeness of cytoreduction (CC) score of 0-1 was observed in 857 cases (61.9%). Regarding HIPEC regimens, there were 917 cases (66.3%) with cisplatin plus docetaxel, 183 cases (13.2%) with cisplatin plus mitomycin, 43 cases (3.1%) with adriamycin plus ifosfamide, and the other 240 cases (17.3%) with modified regimens. Perioperative SAE developed in 331 peritoneal carcinomatosis patients (23.9%) with 500 cases, of whom 21 patients (1.5%) died during the perioperative period due to ineffective treatment, while the others recovered after active treatment. During median follow-up time of 8.6 (0.3-82.7) months, there were 414 deaths (29.9%). The median OS was 38.2 months (95% CI: 30.6-45.8), and the 1-, 3-, 5-year survival rate was 73.5%, 50.4% and 39.3%, respectively. The median OS of peritoneal carcinomatosis patients from gastric cancer, colorectal cancer, pseudomyxoma peritonei, malignant peritoneal mesothelioma and female genital cancer or primary peritoneal carcinomatosis was 11.3 months (95% CI: 8.9-13.8), 18.1 months (95% CI: 13.5-22.6), 59.7 months (95% CI: 48.0-71.4), 19.5 months (95% CI: 6.0-33.0) and 51.7 months (95% CI: 14.6-88.8), respectively, and the difference among groups was statistically significant (P<0.001). Univariate and multivariate analyses revealed that the primary gastric cancer (HR=4.639, 95% CI: 1.692-12.724), primary colorectal cancer (HR=4.292, 95% CI: 1.957-9.420), primary malignant peritoneal mesothelioma (HR=2.741, 95% CI: 1.162-6.466), Karnofsky performance status (KPS) score of 60 (HR=4.606, 95% CI: 2.144-9.895), KPS score of 70 (HR=3.434, 95% CI: 1.977-5.965), CC score of 1 (HR=2.683, 95% CI: 1.440~4.999), CC score of 2-3 (HR=3.661,95% CI: 1.956-6.852) and perioperative SAE (HR=2.588, 95% CI: 1.846-3.629) were independent prognostic factors influencing survival with statistically significant differences (all P<0.05). Conclusions: CRS+HIPEC is an effective integrated treatment strategy for patients with peritoneal carcinomatosis, which can prolong survival with acceptable safety. Preoperative evaluation of patients' general condition is necessary and CRS+HIPEC should be carefully considered to perform for patients with preoperative KPS score <80. During the operation, the optimal CRS should be achieved on condition that safety is granted. In addition, it is necessary to prevent perioperative SAE to reduce the risk of death in peritoneal carcinomatosis patients.