Endometriosis, in vitro fertilisation and the risk of gynaecological malignancies, including ovarian and breast cancer

• Published in: Best practice & research. Clinical obstetrics & gynaecology 2010-02, Vol.24 (1), p.39-50
• Main Authors: Vlahos, Nikos F., MD, Economopoulos, Konstantinos P., MD, Fotiou, Stylianos, MD
• Format: Article
• Language: English
• Subjects: bcl-2-Associated X Protein - genetics; Biomarkers, Tumor - genetics; breast cancer; Breast Neoplasms - etiology; cervical cancer; Clomiphene - administration & dosage; Clomiphene - adverse effects; endometrial cancer; endometriosis; Endometriosis - complications; Estrogens - administration & dosage; Estrogens - adverse effects; Female; Fertility Agents, Female - administration & dosage; Fertility Agents, Female - adverse effects; Fertilization in Vitro - adverse effects; Fertilization in Vitro - methods; Genes, bcl-2 - genetics; Genes, p53 - genetics; Genital Neoplasms, Female - epidemiology; Genital Neoplasms, Female - etiology; Genital Neoplasms, Female - genetics; Greece - epidemiology; gynaecological cancer; Humans; in vitro fertilisation; Obstetrics and Gynecology; ovarian cancer; Ovarian Neoplasms - etiology; Risk; Uterine Neoplasms - etiology
• ISSN: 1521-6934; 1532-1932
• DOI: 10.1016/j.bpobgyn.2009.08.004

There is evidence that endometriosis as well as drugs used in the process of in vitro fertilisation appear to associate with increased risk for gynaecological cancer. In this review, we attempt to describe this relationship according to the most recent epidemiologic data and to present the possible mechanisms on the molecular level that could potentially explain this correlation. There are data to support that ovarian endometriosis could have the potential for malignant transformation. Epidemiologic and genetic studies support this notion. It seems that endometriosis is associated with specific types of ovarian cancer (endometrioid and clear cell). There is no clear association between endometriosis and breast or endometrial cancer. More studies are needed to establish the risk factors that may lead to malignant transformation of this condition and to identify predisposed individuals who may require closer surveillance. Currently, there is no proven relationship between any type of gynaecological cancer and drugs used for infertility treatment. In principle, infertile women have increased risk for gynaecologic malignancies. Nulligravidas who received treatment are at increased risk for malignancy compared with women who had conceived after treatment. There is limited evidence that clomiphene citrate use for more than six cycles or 900 mg or treatment of women over the age of 40 could increase their risk for ovarian and breast cancer. More studies with the appropriate statistical power and follow-up time are required to evaluate accurately the long-term effects of these drugs and procedures.