Ovarian cancer in endometriosis

TO REVIEW ARTICLE Int J Clin Oncol (2009) 14:377 © The Japan Society of Clinical Oncology 2009 DOI 10.1007/s10147-009-0930-3 I. Konishi (*) Department of Gynecology and Obstetrics, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan Tel. +81-75-751-3267; Fax +81-75-761-3967 e-mail: [email protected] Ikuo Konishi Ovarian cancer in endometriosis (Yamaguchi et al.)3 has disclosed that a high-iron microen- vironment exists in ovarian endometriotic cysts, and that this may be related to clear cell carcinogenesis that is char- acterized by the expression of specifi c genes. Against this background, this review covers recent progress in the important area of ovarian cancer and endometriosis.

1. Nezhat F, Datta S, Hanson V , et al. (2008) The relationship of endometriosis and ovarian malignancy. Fertil Steril 90:1559– 1570 2. Kobayashi H, Sumimoto K, Moniaw N, et al. (2007) Risk of devel- oping ovarian cancer among women with ovarian endometrioma: a cohort study in Shizuoka, Japan. Int J Gynecol Cancer 17:37–43 3. Yamaguchi K, Mandai M, Toyokuni S, et al. (2008) Contents of endometriotic cysts, especially the high concentration of free iron, are a possible cause of carcinogenesis in the cysts through the iron- induced persistent oxidative stress. Clin Cancer Res 14:32–40 Received: August 17, 2009 Endometriosis is a unique disease entity in which ectopic endometrial-like tissues exist in the ovary, pelvic perito- neum, and various other sites in young women; this entity produces severe symptoms and effects such as dysmenor- rhea, dyspareunia, pelvic pain, and infertility. Recently, endometriosis has also received much attention as an impor- tant origin of cancer. 1 Although among various histological types of ovarian carcinoma, clear cell and endometrioid adenocarcinomas are known to arise frequently in ovarian endometriotic cysts, little was known about the incidence, molecular mechanisms, natural clinical course, possibility of early detection, or treatment strategy for these two types of ovarian carcinoma. Recently, however, there has been prominent progress in this fi eld. Kobayashi’s group 2 has reported that the possible incidence of malignant transfor- mation of ovarian endometriotic cysts is 0.7%, based on the prospective follow-up of cohorts in the ovarian cancer screening program of Shizuoka Prefecture, Japan. In regard to the molecular basis of malignant change, Mandai’s group