Validación del escore de severidad de enfermedad de superficie peritoneal (PSDSS) tras la citorreducción y quimioterapia intraperitoneal hipertérmica en carcinomatosis ovárica peritoneal

Abstract

INTRODUCTION Epithelial ovarian cancer (EOC) is the second gynecological neoplasm in order of incidence and the first one in mortality. More than 75% of ovarian cancers are diagnosed in advanced stages, frequently presenting peritoneal carcinomatosis. The most established treatment for advanced ovarian cancer is cytoreductive surgery associated with platinum-based systemic chemotherapy. The addition of HIPEC (Hyperthermic IntraPeritoneal Chemotherapy) to this treatment increase survival rates in patients with EOC. The morbimortality associated with the above procedures makes an adequate selection of those patients who can benefit from them. The development of different scores such as the PSDSS (Peritoneal Surface Disease Severity Score) allows a better classification of patients according to their prognosis, making it possible to apply an individualized therapeutic algorithm to them. HYPOTHESIS AND OBJECTIVES The hypothesis was that the preoperative application of the PSDSS alone or in combination with other scales, to patients operated for EOC allowed the establishment of subgroups of patients with different disease-free survival (DFS). The main objective was to evaluate the applicability of this score to patients with EOC undergoing cytoreduction surgery and HIPEC in the establishment of groups with different DFS. Secondary objectives were to establish the relationship between PSDSS and the achievement of complete cytoreduction in this subgroup of patients and to determine the applicability of using PSDSS in combination with other validated prognostic scales for the establishment of prognostic subgroups in patients with recurrence of EOC. MATERIAL AND METHOD A retrospective study was performed with prospectively collected data from 179 patients with EOC (115 primary and 64 recurrences) undergoing cytoreduction and HIPEC procedures between January 2008 and December 2016. All patients were operated on by the Peritoneal Carcinomatosis Unit of the General Surgery Service of the Hospital Universitario Virgen de la Arrixaca. Variables collected included those necessary for the calculation of the PSDSS, AGO and Tian score. RESULTS During the follow-up, 58.1% of the patients presented recurrence of the disease. The median DFS was 23 months (95% CI: 17.4 - 28.6 months) with a rate of 70.3%, 40.0% and 30.6% at 1, 3 and 5 years, respectively. After multivariate analysis, the variables independently associated with DFS in patients in the series were radiological PCI (PCI 10-20: HR 1.928, 95% CI 1.222-3.043, p=0.005; PCI >20: HR 3.314, 95% CI 1.750-6.276, p <0.001), histological type (Type B: HR 1.469, 95% CI 1.205-2.385, p=0.019), neoadjuvant chemotherapy (HR 2.519, 95% CI 1.287-4.930, p=0.007) and PSDSS score (PSDSS III,IV: HR 2.989, 95% CI 1.742-5.128, p <0.001); in patients with primary tumor, it was radiological PCI and PSDSS; in patients with disease recurrence, only PSDSS and the "very low risk" subgroup, resulting from the combination of patients with PSDSS I - II and low-risk Tian, were related. In all cases, the variable with the greatest influence on prognosis was PSDSS (divided into two risk stages). Among the variables included in the PSDSS, symptomatology and radiological detection of lymph node involvement were not related to the risk of recurrence. Those patients with low PSDSS presented more frequently a complete cytoreduction. CONCLUSIONS The application of PSDSS to patients with advanced and recurrent ovarian cancer undergoing cytoreduction and HIPEC procedures allows us to establish groups with different DFS and probability of complete cytoreduction. On the other hand, the combination of low PSDSS and low-risk Tian makes it possible to detect a subgroup of patients with a particularly good prognosis