Serum CA-125 as a Predictor of Radiologic Evidence of Metastatic Disease in Type 2 Endometrial Cancer
Pham T, Kole M, Tang X, Elshaikh M, and Dimitrova I. Serum CA-125 as a Predictor of Radiologic Evidence of Metastatic Disease in Type 2 Endometrial Cancer. Gynecologic Oncology 2020; 158(1):e14-e15.
Objectives: For high grade endometrial carcinoma, current NCCN guidelines recommend consideration of chest, abdomen and pelvis CT to evaluate for metastatic disease. The objective of this study is to evaluate the utility of serum CA-125 as a preoperative tool to identify patients with type 2 endometrial cancer who preoperative imaging will have very little or no value in detecting metastatic disease.
Methods: Institutional Review Board approval was obtained for this retrospective chart review. Data was obtained from patients treated at Henry Ford Health System in Detroit, Michigan. The inclusion criteria included women age 18 and older with a diagnosis of Type 2 endometrial cancer diagnosed between 2000-2019 who had a preoperative computed tomography scan of the chest, abdomen, and pelvis and preoperative serum CA-125. A Youden’s index was used to calculate the optimal CA-125 cutoff. The sensitivity and specificity of CA-125 to determine the likelihood of metastasis on CT scans was then calculated using the predetermined CA-125 cutoff.
Results: 2168 patients were identified as having endometrial (Type 1 and Type 2) from 2000-2019. 1703 charts were excluded because they were patients with Type 1 endometrial cancer. Upon review, 236 charts had a preoperative CT scan and preoperative CA-125. A receiver operating characteristic (ROC) curve was used to generate Youden’s index which identified the optimal CA-125 cut-off to be 22.5 U/mL. Using this cut-off, we determined the specificity of this cut-off to be 72.9% and sensitivity to be 68.3.%. The positive predictive value was 51% and negative predictive value of 92.8%.
Conclusions: Type 2 endometrial cancers encompass histologic variants that are aggressive and have a higher incidence of extrauterine disease at presentation. The NCCN guidelines and Society of Gynecologic Oncology state that if extrauterine disease is suspected, imaging studies are recommended if clinically indicated and CA-125 testing can be considered. Serum CA-125 is helpful in monitoring clinical response; however, it is unclear whether it should be used as a screening tool to select which patients require further radiologic evaluation and there is limited data in the literature regarding this topic. Our study shows that by using a serum CA-125 cutoff of 22.5 U/mL, we can triage patients with high grade disease to determine who would necessitate advanced radiologic testing to assist in surgical planning.