Preliminary study results on a new type of hormone therapy, currently known as SERM LY353381, indicate that this new agent may be an additional treatment option for women with advanced or recurrent endometrial cancer. Further investigation of SERM LY353381 is ongoing, according to researchers at the recent American Society of Clinical Oncology meeting in New Orleans.

Cancer of the endometrium is characterized by the presence of cancer cells in the lining of the uterus, or womb. Treatment options for endometrial cancer depend on many factors, including the stage (extent of disease at diagnosis) of disease. When the stage of endometrial cancer is such that it has spread outside the area of the uterus to other parts of the body, the disease is sometimes referred to as advanced or metastatic. When the cancer has been treated (usually with surgery, with or without radiation therapy) and it comes back, the disease is referred to as recurrent. Women who have advanced or recurrent endometrial cancer commonly receive either hormone therapy or chemotherapy to help relieve the symptoms of disease and prolong survival time.

The uterus is an organ that is highly sensitive to hormone levels, and thus the growth of endometrial cancer is often affected by hormones as well. Hormone therapy for endometrial cancer has long included the use of agents, called progestogens, which are synthetically produced derivatives of the natural hormone progesterone. Such progestogens include hydroxyprogesterone, medroxyprogesterone, and megestrol. Progestogen therapies are effective because endometrial cancer cells often have receptors for progesterone-like agents (referred to as progestogen-sensitive disease). Individually, these agents can produce response rates of 20 to 29%. However, the agent megestrol in particular has been shown to be more effective when combined with another hormone therapy called tamoxifen. Previous studies of this combination show response rates of up to 21%, with moderate side effects. Now, a new type of progestogen, thus far referred to only as SERM LY353381, is under study for the treatment of women with advanced or recurrent endometrial cancer.

Researchers treated 35 women who had progestogen-sensitive advanced or recurrent endometrial cancer with SERM LY353381. Most had previously undergone surgery and radiation therapy. The results showed a partial response to SERM LY353381 treatment in 22 patients. The main side effects were hot flushes, swelling, and sweating. Currently, this study is still in progress and survival information is not yet available.

These preliminary findings suggest that SERM LY353381 is active against advanced or recurrent progestogen-sensitive endometrial cancer, and may be an additional treatment option for women with this type of disease. Studies of this agent are ongoing. Persons who have advanced or recurrent progestogen-sensitive endometrial cancer may wish to talk with their doctor about the risks and benefits of participating in a clinical trial (research study) in which SERM LY353381 or another promising progestogen therapy is being studied. (Proceedings of the American Society of Clinical Oncology’s Thirty-Sixth Annual Meeting, Vol 19, Abstract 1527, p 386a, 2000).