Fertility-sparing treatment in young women with endometrial cancer or atypical complex hyperplasia: a prospective single-institution experience of 21 cases M Signorelli, a G Caspani, a C Bonazzi, a V Chiappa, a P Perego, b C Mangioni a a Department of Obstetrics and Gynecology and b Department of Pathology, San Gerardo Hospital, Monza, University of Milan-Bicocca, Milan, Italy Correspondence: Dr M Signorelli, Department of Obstetrics and Gynecology, San Gerardo Hospital, Via Solferino 16, Monza, Italy. Email maurosignorelli@inwind.it Accepted 7 October 2008. We conducted a prospective study of conservative treatment in 21 young nulliparous women with grade (G)1 endometrial cancer stage IA (11) or atypical complex hyperplasia (10). All were treated with a low-dose cyclic natural progestin therapy (200 mg/day from day 14–25) and encouraged to attempt pregnancy immediately. No adverse therapy-related effects were recorded. Overall response rate to progestin therapy was 57%. Nine women conceived (43%). There were 13 pregnancies, of which 13 were spontaneous and 8 were in women with persistent disease or partial response to hormonal treatment. Three additional complete responses were observed after delivery. Only women with known primary infertility or severe polycystic ovary syndrome showed inadequate pregnancy rate. Fifteen women underwent definitive surgery after enrolment (median 27 months, range 3–56 months). All 21 women are alive and disease free after a median follow up of 98 months. Keywords Atypical complex hyperplasia, childbearing age, conservative management, endometrial cancer. Please cite this paper as: Signorelli M, Caspani G, Bonazzi C, Chiappa V, Perego P, Mangioni C. Fertility-sparing treatment in young women with endometrial cancer or atypical complex hyperplasia: a prospective single-institution experience of 21 cases. BJOG 2009;116:114–118. Introduction Endometrial cancer is diagnosed in women less than 40 years in 3–14% of all cases. Polycystic ovary syndrome, obesity and nulliparity are well-known risk factors. When arising in young women, endometrial cancer usually presents with favourable prognostic features, that is, as a focal, well-differentiated lesion, with minimal or absent myometrial invasion. Tumour growth is supported by a hyperestrogenic background, which accounts for its sensitivity to progestin therapy. Progestins have been widely and successfully used since the early 1960s in the treatment of advanced and metastatic endo- metrial cancer. There are increasing evidences that hormonal therapy can be safe and effective as primary treatment in young, nulliparous women, who refuse standard surgical approach in order to preserve their reproductive potential. 1–4 Currently, there is no standard medical treatment for this subset of patients. Several compounds have been proved to be effective, and continuous high-dose medroxyprogesterone acetate seems to achieve the highest response rate. 2–4 The aim of this single-institution prospective study is to assess the feasibility and safety of a primary conservative treat- ment with cyclic low-dose natural progestin therapy in women with well-differentiated endometrial cancer (EC) and atypical complex hyperplasia (ACH) who strongly wish to preserve their childbearing potential. Methods Since 1992, all women less than 40 years of age with a diagno- sis of ACH or well-differentiated EC who desired childbearing were considered for a conservative management. The histology of the original diagnosis was reviewed by our senior consultant pathologist. ACH and well-differentiated adenocarcinomas were defined according to criteria stated by Kurman et al. 5 All patients referred to our institution underwent outpatient hysteroscopy with endometrial biopsy as soon as pos- sible, in order to confirm histopathological diagnosis, and to assess thoroughly the intrauterine extension of disease, focal myo- metrial invasion as well as cervical involvement. We performed 114 ª 2008 The Authors Journal compilation ª RCOG 2008 BJOG An International Journal of Obstetrics and Gynaecology DOI: 10.1111/j.1471-0528.2008.02024.x www.blackwellpublishing.com/bjog Short communication