Letrozole is the generic name for a medication typically prescribed to combat breast cancer in post-menopausal women, and less frequently to treat other types of cancer or as a pre-treatment for pregnancy termination.

There are a variety of circumstances in which Letrozole may be prescribed to women battling breast cancer:

• The cancer has not responded to other treatments
• It is unknown if the cancer is hormone receptor positive
• To inhibit metastasization (spreading) of cancer
• The cancer has worsened with antiestrogen therapy
• To enhance effectiveness of other cancer treatments
• As a preventative measure in women at high risk of developing breast cancer

Letrozole may be used at any stage of cancer growth, before or after surgery, and is often prescribed in conjunction with other cancer treatment therapies. Depending on the individual patient, therapy may begin immediately after surgery or chemotherapy, or years later.

This product is also sold under the brand name Femara.

Letrozole Therapy for Breast Cancer:

Many breast cancers thrive on the hormone estrogen; this is called hormone receptor positive breast cancer. With this type of cancer the presence of estrogen in the body encourages cancer to grow and spread. Conversely, the less estrogen present, the slower the growth and spread of the cancer.

In pre-menopausal women most estrogen is produced by the ovaries. In post-menopausal women, estrogen is primarily produced by the adrenal glands.

Letrozole works by inhibiting estrogen production in the adrenal glands, which in turn inhibits the spread and growth of hormone receptor positive cancer. In certain high-risk women it may also be used as a preventative therapy.

Because it does not inhibit estrogen production in the ovaries, Letrozole is generally not very effective as a treatment for hormone receptor positive cancer in pre-menopausal women. There are rare occasions, however, in which it does prove useful and may be prescribed.

Taking Letrozole:

Letrozole comes as a tablet, taken once daily with fluids and with or without food. For best results it should be taken at the same time each day. Missed doses should be taken as soon as remembered.

Dosage strength will vary depending on a number of factors, including patient response to treatment and other medications being taken. Dosage may be adjusted periodically during Letrozole therapy.

Treatment with this medication may span years, and is often recommended after similar medications, namely tamoxifen, has already been taken for several years.

Patients treating estrogen responsive cancer should take care to avoid products containing estrogen. Some common examples include:

• Lotions or facial cremes containing estrogen
• Certain foods, particularly soy products and flax seeds
• Birth control pills
• Hormone replacement therapies
• Certain health supplements

Side Effects:

Most side effects associated with Letrozole are mild and disappear entirely as the body adjusts to the medication. A physician should be consulted if adverse effects persist or worsen over time:

• Frequent or worsening headaches
• Night sweats or hot flashes
• Edema (swelling of hands or feet)
• Persistent nausea or stomach pain
• Rapid weight loss or gain
• Extreme fatigue
• Rash, hives, itchiness or swelling of the face (allergic reaction)
  

Women taking Letrozole or similar drugs over time are at increased risk of developing osteoporosis. Bone density may be monitored during treatment, and risk of fractures or breaks is increased. Osteoporosis medications may be prescribed in conjunction with Letrozole.

This medication is harmful to nursing infants and may cause miscarriage or birth defects in unborn babies. Use during pregnancy should be avoided.

Certain medications will interact with Letrozole and may reduce its effectiveness or cause dangerous side effects. Consult a doctor or pharmacist before mixing medications.

This is not a complete list of possible adverse effects. Please read the documentation included with the medication for more detailed information prior to use.