La endometriosis atípica como lesión precursora del cáncer de ovario asociado a endometriosis, un estudio prospectivo

Resum

In this thesis we have studied the possible malignant transformation of endometriosis in endometriosis-associated ovarian cancer (EAOC). Our hypothesis is based on the potential role played by "atypical endometriosis" in the pathogenesis of EAOC, mainly in histotypes, clear cell adenocarcinoma (CCAc) and endometrioid adenocarcinoma (EAc). We have explored the possibility that it represents an evolutionary stage between "typical" endometriosis and EAOC. In addition, we have considered whether cellular atypia (ECA) and architectural atypia or hyperplasia (EAA), the two histological findings globally referred to as atypical endometriosis (AE), have a different meaning in the etiopathogenesis of EAOC. OBJETIVES Main objetive: To establish the prevalence of AE and its histological subtypes: ECA and EAA in patients with Endometriosis and EAOC. Other objetives: Objetive 1.- To establish differences in prevalence of histological subtypes CCAc and EAc between patients with EAOC and ovarian cáncer (OC). Objetive 2.- To compare the clinical and epidemiological characteristics, risk factors and prognoses of the study groups: patients with postoperative diagnosis of Endometriosis, EAOC and OC. MATERIAL AND METHOD: Prospective observational study of case series from January 2014 to April 2017 in patients assisted in the Gynecology and Obstetrics Service of the Virgen de la Arrixaca Clinical Universitary Hospital, with the diagnosis of endometriosis and / or OC undergoing surgery. An anatomopathological and immunohistochemical analysis of the surgical pieces of the different groups (Endometriosis, OC and EAOC) was performed. RESULTADOS: 266 patients were included. Endometriosis was confirmed in 185 patients, of whom 159 had isolated endometriosis and 26 had EAOC. Of the total of 107 registered ovarian cancers (TOC), 26 (24.3%) were EAOC and 81 (75.7%) ovarian cancer without associated endometriosis (OC). The 53.1% of the OC were serous carcinomas, compared to the 15.4% seen in the EAOC. Likewise, 23.1% of the EAOC were CCAc and 42.3% were EAc, versus 6.2% and 14.8% respectively of those found in OC (p<0.001). There were 23 cases (12.43%) with characteristics of AE in the 185 patients with endometriosis. An analysis of the 23 cases of atypical endometriosis found that 11 (47.8%) patients had ECA and 12 (52.2%) had EAA. In addition, we observed that 10 of 11 patients with ECA had atypical endometriosis without neoplasm, and 8 of 12 patients with EAA had EAOC (p = 0.009) From the immunohistochemical studies, we found association (p= 0.004) between high Ki-67 and EAA. There are no significant differences for COX-2 or BAF250a. Regarding the differences between the histological types of the OC and EAOC, the serous carcinomas were associated with the OC group, and the CCAc and EAc with EAOC (p<0.001). According to EAOC staging, 76.9% patients of EAOC cases and 44.45% of non-EAOC were stage I (p< 0.001). CONCLUSIONS: 1. There is a significant association between Atypical Endometriosis and Endometriosis-associated Ovarian Cancer. 2. The histological types of Ovarian Cancer significantly associated with Endometriosis were Clear Cell Adenocarcinoma and Endometrioid Adenocarcinoma, both included in type I of the Kurman and Shild model. 3. Our data suggest that ovarian cancer associated with endometriosis could present a better prognosis in ovarian cancer. 4. There is a significant association between Atypical Architectural Endometriosis and Endometriosis-associated Ovarian Cancer. 5. Our data support the hypothesis that Hiperplasia or Atypical Architectural Endometriosis could constitute a precursor lesion in the pathogenesis of Endometriosis-Associated Ovarian Cancer.