Ovarian suppression is a medical treatment that uses medication to temporarily stop the ovaries from producing hormones, primarily estrogen. These drugs lower the body’s circulating estrogen levels, inducing a state similar to menopause. The treatment is a temporary measure designed to manage specific health conditions.
Medical Applications of Ovarian Suppression
Ovarian suppression is used to manage several health conditions that are sensitive to hormones. Its primary applications include:
- Hormone-receptor-positive breast cancer: For premenopausal women, stopping the ovaries from making estrogen helps slow or stop cancer growth. It is often used in combination with other hormone therapies to reduce the risk of the cancer returning.
- Endometriosis: Suppressing estrogen production helps reduce the growth of tissue similar to the uterine lining that grows outside the uterus, which alleviates pain and other symptoms.
- Uterine fibroids: Reducing estrogen levels can shrink these noncancerous growths of the uterus. This can lessen symptoms like heavy menstrual bleeding and pelvic pressure and is often used before surgery to remove the fibroids.
- Fertility preservation: For women undergoing chemotherapy that can damage the ovaries, suppressing ovarian function during treatment may help protect them.
- Severe PMS or PMDD: In severe cases of premenstrual syndrome (PMS) or premenstrual dysphoric disorder (PMDD), halting the hormonal cycle may be considered to control symptoms.
Mechanism of Action
Ovarian suppression is managed by regulating a hormonal pathway that begins in the brain. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which signals the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones then travel to the ovaries and instruct them to produce estrogen; ovarian suppression drugs interrupt this pathway.
One class of these drugs is GnRH agonists. These medications work by first overstimulating the GnRH receptors in the pituitary gland. This causes a temporary surge in LH, FSH, and estrogen, a phenomenon called a “tumor flare.” With continued exposure, the pituitary receptors become desensitized and stop responding, leading to a drop in hormone production.
A different class, GnRH antagonists, functions more directly. Instead of first stimulating the pathway, these drugs immediately block the GnRH receptors on the pituitary gland. This direct blockade prevents the release of LH and FSH from the start, resulting in a rapid decrease in estrogen without the initial hormonal surge.
Types of Ovarian Suppression Drugs
The medications for ovarian suppression fall into two primary categories. The first category includes GnRH agonists, which are commonly administered as injections or as small implants placed under the skin. Examples of generic drug names in this class are leuprolide and goserelin.
The second category consists of GnRH antagonists. Unlike agonists that are primarily injectable, some antagonists are available as oral pills, offering a different method of administration. Elagolix and relugolix are examples of drugs in this class.
Managing Treatment-Related Side Effects
The side effects of ovarian suppression drugs are a consequence of low estrogen levels, mirroring the symptoms of menopause. Common effects include hot flashes, changes in mood, fatigue, and vaginal dryness. It is important to report any spotting or bleeding, as this could indicate that ovarian suppression is not complete.
A significant consideration during treatment is the potential for loss of bone density, as reduced estrogen can affect bone health over time. To manage menopausal-like side effects, a strategy known as “add-back” therapy may be used. This involves giving a small amount of hormone back to the body to lessen symptoms like hot flashes without interfering with the treatment’s primary goal. Lifestyle adjustments, including adequate intake of calcium and vitamin D, are also recommended to support bone health.
Reversibility and Post-Treatment Considerations
The effects of ovarian suppression through medication are temporary. Once drug therapy is discontinued, the hormonal system begins to function again, and the ovaries are expected to resume their normal production of estrogen. The return of menstrual cycles is a primary indicator that the ovaries are active again.
The timeframe for the hormonal system to fully recover and for periods to resume can differ from person to person. Individuals should discuss any long-term fertility goals or concerns with their healthcare provider after the treatment course is complete.