Comparison of dilatation & curettage and endometrial aspiration biopsy accuracy in patients treated with high-dose oral progestin plus levonorgestrel intrauterine system for early-stage endometrial cancer

Objective To compare the diagnostic accuracy of dilatation & curettage (D&C) vs. endometrial aspiration biopsy in follow-up evaluation of patients treated with high-dose oral progestin plus levonorgestrel intrauterine system (LNG-IUS) for early-stage endometrial cancer (EC). Method A prospective observational study was conducted with 11 patients with FIGO grade 1 or 2, clinical stage IA endometrioid adenocarcinoma. Patients were aged up to 40 years wishing to preserve fertility treated with high-dose oral progestin plus LNG-IUS. Treatment response assessment was done at three month intervals. Endometrial tissues were obtained via endometrial aspiration biopsy with LNG-IUS in place and D&C after removal of LNG-IUS. We identified 28 cases; the histologic results were compared. Kappa statistics were used to assess the agreement of two methods. Results Diagnostic concordance between examinations was assessed for 9 out of 28 cases examined (32.1%). These consisted of three cases with both examination results of normal, 3 cases with endometrioid adenocarcinoma, 1 case with complex endometrial hyperplasia, 2 cases with material insufficient for diagnosis. Endometrioid adenocarcinoma on D&C was diagnosed in 9 out of 28 cases, but from endometrial aspiration biopsy, only 3 of these 9 cases were diagnosed with endometrioid adenocarcinoma, giving the diagnostic concordance at 33% (kappa value = 0.27). From endometrial aspiration biopsy, 17 out of 28 cases (60.7%) had material insufficiency for diagnosis. Conclusion In patients treated with high-dose oral progestin plus LNG-IUS for early-stage EC, endometrial aspiration biopsy with LNG-IUS in place may be not reliable as a follow-up evaluation method.