Evidence that endometriosis behaves in a malignant manner

It is well known that certain aspects of endometriosis are similar to those of malignant disease. For example, like cancer, endometriosis can be both locally and distantly metastatic; it attaches to other tissues, invades, an d damages them. Endometriosis is a common disease that does not create a ca chectic or catabolic state, and is ra rely fatal. There are, however, numer ous reported cases of malignancy arising from endometriotic deposits and su bstantial histologic evidence that endometriosis is associated with endomet rioid carcinoma and clear cell carcinoma of the ovary. A large review artic le by Mostoufizadeh and Scully investigated the association between endomet riosis and endometrioid carcinoma, noting that women who had both diseases tended to be younger [1]. They found no association between endometriosis a nd serous or mucinous carcinoma of the ovary, and reported that malignant t ransformation of endometriosis was rare and associated with the use of exog enous estrogens. An epidemiological study of Swedish women reported a highe r incidence of breast and ovarian cancer and non-Hodgkin's lymphoma in wome n with endometriosis compared with controls [2]. Vercellini and colleagues also reported a higher incidence of endometrioid and clear cell carcinoma i n women with endometriosis compared with controls [3]. Mutations in genes a ssociated with galactose metabolism have been identified as one possible me chanism for this association. These mutations are more common in ovarian ca ncer and have been reported to be more common in women with endometriosis. We compared 78 women with endometriosis with 248 controls and were unable t o demonstrate an increased frequency of these mutations in any of these gro ups. Copyright (C) 2000 S.Karger AG, Basel.