Stage Ia endometrioid adenocarcinoma means that the cancerous tissue is confined to the body of the uterus without involving the cervix or invading the extra-pelvic tissues. Endometrioid adenocarcinoma is a malignant tumor of endometrial epithelial cells, which mostly occurs in menopausal or postmenopausal women, and can be classified into stage I, II, III and IV according to the extent of the cancerous tissues as well as the clinical stage. Stage I mainly involves the uterine body, stage II mainly involves the uterine cervix, stage III mainly spreads the cancerous tissue outside the uterus but does not invade the extra-pelvic tissues, and stage IV means that the cancerous tissues have gone beyond the pelvis and involved the rectum, bladder, rectal mucosa and other parts of the uterus. The 5-year survival rate after surgery for stage I is nearly 90%, while the 5-year survival rate for stage II can be reduced to 30%~50%. Since the survival rate after surgery decreases the more advanced the stage is, patients are advised to undergo timely treatment.