Outcome of undifferentiated/dedifferentiated endometrial carcinoma in a single institution

• Published in: Gynecologic oncology Vol. 162; pp. S222 - S223
• Main Authors: Khalique, Saira, Alvarez, Edwin, Rabban, Joseph, Butler, Blythe
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.08.2021
• Subjects: Hematology, Oncology, and Palliative Medicine; Obstetrics and Gynecology
• ISSN: 0090-8258
• DOI: 10.1016/S0090-8258(21)01074-X

Undifferentiated endometrial carcinoma (UEC) and dedifferentiated endometrial carcinoma (DDEC) are rare tumors with aggressive behavior. Most outcome literature is based on pathology consultation cohorts-and thus subject to referral bias– with limited information regarding treatment, this study was designed as a single institutional review of clinicopathologic prognostic features in women with UEC/DDEC. We undertook a retrospective analysis of our pathology database to identify patients with UEC or DDEC who underwent a hysterectomy in our institution between 2000 and 2020. The pathologic diagnosis of UEC/DDEC was confirmed by a gynecologic pathologist. Corresponding cancer registry data (censored at 05/20/20) and electronic medical records were examined. Survival outcomes were described using Kaplan-Meier method and log-rank testing, using Prism version 8.31. Thirty-one women were identified, five patients (16%) with UEC and 26 (84%) with DDEC. Median age was 59 years (range 36-88 years). All patients presented with vaginal bleeding. The FIGO stage was III or IV in 5/5 UEC and 17/26 DDEC. Mismatch repair deficiency (MMRd)/microsatellite instability (MSI) was detected in 18/25 patients. Two patients had Lynch syndrome. Nodal metastases were detected in 41% of those examined (11/27). Only 4 patients (13%) had evidence of residual disease at the end of surgery. Management recommendations included surgery, external beam radiotherapy (±vaginal boost), vaginal brachytherapy, chemotherapy, anti-angiogenic therapy, chemoradiotherapy, hormonal treatment and immunotherapy. Treatment was given in neo-adjuvant, adjuvant and palliative settings. Three patients had surgery only, with 90% of patients having multi-modality treatment. Recurrence occurred in 30% of cases, often local recurrence in the pelvis or vagina. Chemotherapy was mainly platinum and taxane based with one patient receiving 3rd line topotecan. Two patients received pembrolizumab and one patient received bevacizumab. At censorship, 17 patients (55%) were dead and 14 patients remained alive. Median overall survival (OS) for all patients was 67.2 months, with Figure 1 showing early stage (FIGO I and II) disease survival at 73.2 months and advanced stage 36.6 months (p=0.019). DDEC median OS was 26.6 months and not reached for UEC (p=0.0002). This was likely due to one outlier patient who remains alive at censorship (79.4 months post diagnosis), OS ranged between 0.8-35.2 months in other UEC patients. Analysis of mismatch repair status showed that MMRd/MSI patients had a median OS of 36.6 months, not yet reached in MMR proficient/microsatellite stable patients, (p=0.0027). [Display omitted] UEC and DDEC patients often present at advanced stages. Outcomes in our institution were encouraging and this may be due to surgical technique combined with multi-modality treatment. MMRd/MSI was prevalent and assessment may increase future therapeutic options to improve outcomes.