Outcomes of advanced stage endometrial cancer by residual disease and MMR status.

Abstract

e17638 Background: Mortality rates are rising in the United States from endometrial cancer with low survival in advanced stages. The RUBY and NRG GY018 trials demonstrated adding immunotherapy to chemotherapy improves survival in patients with advanced endometrial cancer. Benefits to survival were seen in patients with mismatch repair deficient (dMMR) and proficient (pMMR) tumors, although more significant for dMMR. Most patients had measurable disease. Current NCCN guidelines recommend immunotherapy with chemotherapy for stage III-IV patients. Benefits of immunotherapy for patients without measurable disease remains unclear. This objective of this study is to examine the survival of advanced endometrial cancer based on residual disease and MMR status after surgery. Methods: A retrospective chart review of FIGO 2009 Stage III and IV endometrial cancer cases seen at a single academic institution between 2005 – 2022 was conducted. Demographic information, histology, residual disease, MMR status, and adjuvant treatment were collected. Uterine sarcomas, secondary malignancies, or prior immunotherapy/radiation treatment were excluded. PFS and OS were examined by stage, histology, residual disease status, MMR status, and adjuvant therapy. Results were assessed using Kaplan Meier curves and log-rank tests. Results: A total of 231 patients were identified in this timeframe. Patients with stage III disease had a significantly prolonged PFS and OS compared to those with stage IV disease (p < 0.0001). PFS and OS was statistically better in patients without residual disease than those with residual disease (p < 0.001). Patients who had adjuvant chemotherapy and radiation had significantly improved PFS and OS than those with chemotherapy alone (p < 0.0001). MMR status did not statistically impact PFS (p=0.22) and OS (p=0.18) (Table 1). Conclusions: Patients with Stage III endometrial cancer, no residual disease, and underwent both adjuvant chemotherapy and radiation had improved PFS and OS. The benefit of adding immunotherapy in these groups with better survival is unclear. More research is needed to truly understand which patients should be receiving immunotherapy with chemotherapy in the adjuvant setting. Characteristic Median Progression Free Survival (months) p-value 1 Median Overall Survival (months) p-value 1 Stage <0.001 <0.001  III 116 297  IV 10 36 Histology <0.001 <0.001  Low grade NR NR  High grade 15 69 Adjuvant Therapy <0.001 <0.001  Chemotherapy and Radiation 151 180  Chemotherapy alone 13 117 MMR Status 0.2 0.2  dMMR NR NR  pMMR 25 78 Residual Disease <0.001 <0.001  No 114 180  Yes 9.7 36 MMR Status & Residual Disease <0.001 <0.001  dMMR, No Residual NR NR  dMMR, Residual 8.2 11  pMMR, No Residual 54 93  pMMR, Residual 10 58 1 Log-rank test. NR (not reached).