Clinico-pathologic characteristics and prognostic factors of ovarian carcinoma with different histologic subtypes - A benchmark analysis of 482 cases

Ovarian carcinomas (OCX) have traditionally been thought to arise from the ovarian surface epithelium. However, recent (immuno-) histopathological and molecular analyses suggest that OCX consist of morphological subtypes with different epidemiologic features and a varying prognosis.The data of 482 OCX from the Clinical Cancer Registry of Leipzig who were surgically treated between 2000 and 2019 and were evaluated regarding incidence, clinico-pathologic characteristics and prognostic factors. Cases were separated into high-grade and non-high-grade serous tumors. Both groups were analyzed regarding the tumor stage, lymph node involvement, site of origin and prognosis.The overall incidence for OCX was 17.9. The most common histological subtype was high-grade serous OCX (57.9%; 279/482). Patients with high-grade were significantly older than those with a non-high-grade serous OCX (63.9 versus 58.5 years; p 0.001), more frequently diagnosed at an advanced stagepT3 (78.5% (219/279) versus 42.8% (87/203); p 0.001) and showed a 2.4-fold higher frequency of lymph node metastases (53.4% vs. 21.2%; p 0.02) with a 4.6-fold higher rate of 1 cm metastatic deposits (pN1b) within the lymph nodes (14.8% vs. 4.6%; p 0.02). Irrespective of tumor stage and morphological subtype, the 1- and 5-year overall survival (OAS) was 72.9% and 40.8%, respectively. Patients with high-grade serous OCX showed a shorter 5-year OAS compared to non-high-grade serous OCX (34.1% vs. 57.0%; p 0.001). This association was reproducible in patients with an advanced tumor stage irrespective of the histopathologic tumor type serous OCX (pT3: 32.4% vs. pT1: 75.1%; p 0.001) as well as within high-grade (pT3: 28.7% vs. pT1: 55.5%; p = 0.003) and non-high-grade serous OCX (pT3: 43.0% vs. 80.0%; p 0.001). There were no differences in OAS depending on the site of origin (fallopian tube, ovary, peritoneum) within the two histologic subgroups.OCX cases from a single institution with uniform surgical treatment and a standardized histopathological workup were evaluated. The poor prognostic outcome of patients with high-grade serous compared non-high-grade serous OCX as well as an advanced stage of the disease was confirmed. This study demonstrates for the first time that the histopathological distinction into high-grade serous and non-high-grade serous tumors may be much more prognostically relevant than the site of origin.