Patterns of spread and genetic mutations of primary endometrioid carcinomas of the ovary (168)

Abstract

<b>Objectives:</b> Primary endometrioid carcinoma of the ovary is rare and comprises approximately ten percent of all primary ovarian carcinomas. Less is known about their pattern of spread and genetic alterations. Thus, the objective of this study was to characterize patterns of spread, rate of recurrence, and genetic mutations in a cohort of patients with primary endometrioid ovarian carcinoma. <b>Methods:</b> After obtaining institutional review board approval, all patients diagnosed with primary endometrioid adenocarcinoma of the ovary between January 1, 2012, and May 11, 2021, we re identified from an institutional pathology database. All tissue diagnoses were subject to expert pathologic review to confirm accuracy. Patients with co-existing neoplasms were excluded. Demographic and disease-related data were collected from pathology reports and clinical records, and time to recurrence and death were calculated if applicable. Statistical analyses were performed using SAS statistical software version 9.4. <b>Results:</b> Sixty-three patients were identified for analysis. Median age at diagnosis was 60 years (range: 22-90) and the median CA-125 at presentation was 133 U/mL (mean: 1140 U/mL, range: 7-21,545 U/mL). Assigned FIGO stage after surgery included IA in 17 (27%), IC in 24 (38%), II in 17 (27%), III in four patients (6%), and assigned histologic grades were: grade 1 in 32%, grade 2 in 43%, and grade 3 in 25% of patients. The mean ovarian tumor size was 12.7cm (range: 4.1-22cm). At either primary or re-staging surgery, 41 (65%) patients had pelvic lymph node sampling, and 33 (52%) had para-aortic lymph node sampling. The median number of pelvic lymph nodes removed was 12 (mean: 13.1; range: 1-46), and the median number of paraaortic lymph nodes removed was six (mean: 8.7; range: 1-46). All assessed lymph nodes were negative for metastases. Twenty-eight patients had germline mutational status documented. Only two patients had pathologic mutations identified - one in <i>BRCA1</i> and one in <i>BRCA2</i>. One additional patient was found to have two variants of unknown significance (VUS) in the <i>BRCA2</i> gene. Two further patients were negative for germline <i>BRCA</i> mutations but had a positive HRD score on tumor analysis. Median follow-up for patients alive at the time of data cutoff was 42 months (range: 4-70). The median progression-free survival (PFS) and overall survival (OS) for the cohort of patients who completed primary therapy were 42 and 44 months, respectively. Ten out of 63 patients (16%) experienced recurrence(s) with a median time to recurrence of 25 months. Four patients died of disease with a median OS of 31 months. <b>Conclusions:</b> No nodal metastases were identified in a cohort of comprehensively surgically staged patients with primary endometrioid ovarian carcinoma. Surgeons may consider omitting re-staging operations in patients with partially-staged but completely resected endometrioid carcinoma, regardless of grade. Germline <i>BRCA1</i> and <i>BRCA2</i> mutations were seen less frequently compared to high-grade serous carcinomas.