Outcomes of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion in Patients with High-Grade, High-Volume Disseminated Mucinous Appendiceal Neoplasms.

BACKGROUND: High-grade (HG) mucinous appendiceal neoplasms (MAN) have a worse prognosis than low-grade histology. Our objective was to assess the safety and efficacy of cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) in patients with high-grade, high-volume (HG-HV) peritoneal metastases in whom the utility of this aggressive approach is controversial. METHODS: Prospectively collected perioperative data were compared between patients with peritoneal metastases from HG-HV MAN, defined as simplified peritoneal cancer index (SPCI) ≥12, and those with high-grade, low-volume (HG-LV; SPCI <12) disease. Kaplan-Meier curves and multivariate Cox regression models identified prognostic factors affecting oncologic outcomes. RESULTS: Overall, 54 patients with HG-HV and 43 with HG-LV peritoneal metastases underwent CRS/HIPEC. The HG-HV group had longer operative time, increased blood loss/transfusion, and increased intensive care unit length of stay (p < 0.05). Incomplete macroscopic cytoreduction (CC-1/2/3) was higher in the HG-HV group compared with the HG-LV group (68.5 vs. 32.6 %; p = 0.005). Patients with HG-HV disease demonstrated worse survival than those with HG-LV disease (overall survival [OS] 17 vs. 42 m, p = 0.009; time to progression (TTP) 10 vs. 14 m, p = 0.024). However, when complete macroscopic resection (CC-0) was achieved, the OS and progression-free survival of patients with HG-HV disease were comparable with HG-LV disease (OS 56 vs. 52 m, p = 0.728; TTP 20 vs. 19 m, p = 0.393). In a multivariate Cox proportional hazard regression model, CC-0 resection was the only significant predictor of improved survival for patients with HG-HV disease. CONCLUSIONS: Although patients with HG-HV peritoneal metastases from MAN have worse prognosis compared with patients with HG-LV disease, their survival is comparable when complete macroscopic cytoreduction is achieved.

Institutional learning curve of cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion for peritoneal malignancies.

BACKGROUND: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemoperfusion (HIPEC) is routinely used to treat certain peritoneal carcinomatoses (PC), but it can be associated with relatively high complication rates, prolonged hospital length of stay, and potential mortality. Our objective was to determine the learning curve (LC) of CRS/HIPEC in our high-volume institution. METHODS: A total of 370 patients with PC from mucinous appendiceal neoplasms (MAN = 282), malignant peritoneal mesothelioma (MPM = 60), and gastric cancer (GC = 24) were studied. Outcomes analyzed included incomplete cytoreduction (IC), severe morbidity (SM), 60-day mortality, progression-free survival (PFS), and overall survival (OS). Risk-adjusted sequential probability ratio test (RA-SPRT) was employed to assess the LC of CRS/HIPEC for IC and SM using prespecified odds ratio (OR) boundaries derived from previously published data. Risk adjusted-cumulative average probability (RA-CAP) was used to analyze 1-year PFS and 2-year OS. RESULTS: Complete cytoreduction, severe morbidity, and 60-day mortality were 84.2, 30, and 1.9 % respectively. Higher simplified peritoneal cancer index was the major independent risk factor for IC, whereas high-grade histology, IC, and diagnosis of MPM and GC (compared with MAN) were predictors of SM after CRS/HIPEC (p < 0.05). RA-SPRT showed that approximately 180 cases are needed to achieve the lowest risk of IC and SM. Ninety cases were needed to achieve a steady 1-year PFS and 2-year OS in RA-CAP plots. CONCLUSIONS: The completeness of cytoreduction, morbidity, and mortality rates for CRS/HIPEC at our institution are comparable to previously reported data. Approximately 180 and 90 procedures are required to improve operative and oncologic outcomes respectively.