External multicentre validation of pseudomyxoma peritonei PSOGI-Ki67 classification.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare malignant disease. Adding of the Ki67 proliferation index to the PSOGI PMP classification provided two different subcategories of the extensive HG-PMP group (HG-PMP ≤15% and HG-PMP >15%) with different survival in a previous unicentric study. This study aims to carry out an external and multicentre validation of this new proposed classification. METHOD: It was a prospective analysis of samples from a historical and international cohort of patients. A representative area with higher cellular density was used to determine the Ki67%. The Ki67 proliferation index (%) was determined in all the HG-PMP patients. A Cox proportional hazard models and multivariable COX models were used. The Kaplan-Meier method and the two-tailed log-rank test were used to analyse the effect of different PSOGI-Ki67 categories on OS and DFS. Its predictive accuracy was analysed using Harrel's C-index and the ROC curve. The calibration was performed using the calibration plots matching. RESULTS: After exclusions, 349 patients were available for analysis. The 5-years OS were 86% for LG-PMP, 59% for HG-PMP≤15, 38% for HG-PMP>15 and 42% for SRC-PMP (p = 0.0001). The 5-years DFS were 49% for LG-PMP, 35% for HG-PMP≤15, 16% for HG-PMP>15 and 18% SRC-PMP (p = 0.0001). The discrimination capability of PSOGI-Ki67 was validated. CONCLUSION: the PSOGI-Ki67 classification discriminates and predicts the OS and DFS in patients with PMP dividing the HG-PMP category into two well-defined sub-categories. The Ki67 proliferation index should be incorporated routinely in the pathology report for these patients.

The use of cisplatin plus doxorubicin or paclitaxel in hyperthermic intraperitoneal chemotherapy (HIPEC) for stage IIIC or IV epithelial ovarian cancer: a comparative study.

PURPOSE: Our main aim is to analyze the survival results in women operated on for advanced ovarian cancer with two different HIPEC regimens (cisplatin plus doxorubicin versus paclitaxel). PATIENTS AND METHODS: A prospective cohort of patients with stage IIIC or IV epithelial ovarian cancer operated on with cytoreductive surgery and HIPEC, from October-2008 to February-2016, was retrospectively analyzed. The two drugs used, cisplatin/doxorubicin (Group A) and paclitaxel (Group B), were compared. RESULTS: Forty-one patients were treated with cytoreductive surgery and HIPEC; 19 patients (46%) were in Group A and 22 (54%) were in Group B. The extent of peritoneal disease was comparable between groups (Peritoneal Cancer Index of 10 in Group A versus PCI of 12.5 in Group B). There were no differences in morbidity between groups, with a severe morbidity (Dindo-Clavien III or IV) of 36.8% versus 27.3%, respectively. There was no postoperative mortality. Median follow-up was 39 months. Median overall survival was 79 months. Overall survival at 3 years in Group A was 66% versus 82.9% in Group B (p = 0.248). Incomplete cytoreduction (macroscopic residual tumour after surgery) was identified as the only independent factor that influenced overall survival (HR 12.30, 95% CI 1.28-118.33, p = 0.03). The cytostatic used in HIPEC had no influence in overall survival. CONCLUSION: The cytostatic used in HIPEC did not have a negative effect in the prognosis of patients with advanced ovarian cancer.