Analysis of therapeutic effect of cell reduction combined with intraperitoneal thermoperfusion chemotherapy in treatment of peritoneal pseudomyxoma.

Background: Pseudomyxoma peritonei is a rare tumor that can produce a biological behavior similar to that of a malignant tumor. Surgical resection combined with chemotherapy is the traditional treatment method, but the effect is not good. Cell reduction (CRS) combined with intraperitoneal thermoperfusion chemotherapy (HIPEC) has become a new method for the treatment of peritoneal pseudomyxoma (PMP).

Aim: To find out if CRS and HIPEC can be used safely and effectively to treat PMP.

Methods: This is an observational study. Clinical data of PMP patients treated with CRS + HIPEC at our hospital from January 2013 to June 2023 was collated and analyzed. The main outcome measures were overall survival (OS), and the secondary outcome measures were the incidence of surgical complications and serious adverse events. Complications were graded according to common adverse event evaluation criteria. Peritoneal tumor staging was performed using the peritoneal tumor index (PCI) scoring system, and a cell reduction degree (CCR) score was performed after CRS. CCR-0 and CCR-1 were considered satisfactory CRS.

Results: A total of 186 patients with PMP were included, with a median age of 56 (48-64) years, 65 (34.9%) years in males, and 121 (65.1%) years in females. The median PCI score was 28 (20-34) points. The median operative time was 300 (211-430) minutes, and no significant complications occurred. 91.4% (170/186) were from the appendix, 53.2% (99/186) were from the low grade, and 30.6% (57/186) were from the high grade. CCR scores showed that 55 patients (29.6%) achieved satisfactory CRS, and 113 patients (60.8%) did not achieve satisfactory CRS. The fatality rate at 30 days after surgery was 2.7% (5/186), 1.6% (3/186) needed a second operation, and the fatality rate at 90 days was 4.3% (8/186). The total incidence of III-IV complications was 43.0% (80/186), among which the higher incidence was mainly anemia (27.4%, 51/186), electrolyte disturbance (11.6%, 21/181), and albumin decrease (7.5%, 14/186). The main complications associated with abdominal surgery were gastrointestinal anastomotic leakage (2.2%, 4/186), abdominal hemorrhage (2.2%, 4/186), and abdominal infection (4.3%, 8/186). The median follow-up was 38.1 (95%CI: 31.2-45.1) months. The 5-year OS of PMP patients treated with CRS + HIPEC was 50.3% (95%CI: 40.7%-59.9%), and the median survival time was 66.1 (95%CI: 43.1-89.1) months. The results of the survival analysis showed that patients with a low pathological grade, a low PCI, and a satisfactory CCR score had a higher survival rate (all < 0.05). 5-year OS was 88.9% (95%CI: 68.3%-100.0%) in CCR-0 patients, 77.6% (95%CI: 62.7%-92.5%) in CCR-1 patients, and 42.0% (95%CI: 29.5%-54.5%) in CCR-2/3 patients.

Conclusion: The application of CRS + HIPEC in PMP is safe and feasible, and the survival benefit is high, especially in those who achieve satisfactory CRS, which can significantly extend the OS.