Dilatation and curettage is more accurate than endometrial aspiration biopsy in early-stage endometrial cancer patients treated with high dose oral progestin and levonorgestrel intrauterine system

OBJECTIVE To determine whether less invasive endometrial (EM) aspiration biopsy is adequately accurate for evaluating treatment outcomes compared to the dilatation and curettage (D&C) biopsy in early-stage endometrial cancer (EC) patients treated with high dose oral progestin and levonorgestrel intrauterine system (LNG-IUS). METHODS We conducted a prospective observational study with patients younger than 40 years who were diagnosed with clinical stage IA, The International Federation of Gynecology and Obstetrics grade 1 or 2 endometrioid adenocarcinoma and sought to maintain their fertility. The patients were treated with medroxyprogesterone acetate 500 mg/day and LNG-IUS. Treatment responses were evaluated every 3 months. EM aspiration biopsy was conducted after LNG-IUS removal followed D&C. The tissue samples were histologically compared. The diagnostic concordance rate of the two tests was examined with κ statistics. RESULTS Twenty-eight pairs of EM samples were obtained from five patients. The diagnostic concordance rate of D&C and EM aspiration biopsy was 39.3% (κ value=0.26). Of the seven samples diagnosed as normal with D&C, three (42.8%) were diagnosed as normal by using EM aspiration biopsy. Of the eight samples diagnosed with endometrioid adenocarcinoma by using D&C, three (37.5%) were diagnosed with endometrioid adenocarcinoma by using EM aspiration biopsy. Of the 13 complex EM hyperplasia samples diagnosed with the D&C, five (38.5%) were diagnosed with EM hyperplasia by using EM aspiration biopsy. Of the samples obtained through EM aspiration, 46.4% were insufficient for histological evaluation. CONCLUSION To evaluate the treatment responses of patients with early-stage EC treated with high dose oral progestin and LNG-IUS, D&C should be conducted after LNG-IUS removal.