Tamoxifen, anti-estrogen used for many years in the treatment of breast cancer, has now been approved by the FDA for reducing the incidence of breast cancer in women at increased risk of developing the disease.

Use of a selective serotonin reuptake inhibitor (SSRI) is common in women taking tamoxifen (Nolvadex, and others) for breast cancer, both to treat depression and to decrease hot flashes. However, tamoxifen must be metabolized by CYP2D6 to become pharmacologically fully active (MJ Higgins et al. J Natl Compr Canc Netw 2009; 7:203), and the SSRIs fluoxetine (Prozac, and others) and paroxetine (Paxil, and others) are strong inhibitors of CYP2D6. Sertraline (Zoloft, and others) inhibits CYP2D6 to a lesser extent. Citalopram (Celexa, and others) and escitalopram (Lexapro), the 2 other SSRIs...

Anastrozole (Arimidex - AstraZeneca, Medical Letter 1996; 38:61), an aromatase inhibitor, has received accelerated approval from the FDA for adjuvant treatment of postmenopausal women with early hormone-receptor-positive breast cancer. The drug was approved for treatment of postmenopausal women with metastatic breast cancer in 1996.

Adjuvant hormone therapy with anti-estrogen drugs has been shown to reduce disease recurrence and mortality in postmenopausal women with estrogen receptor (ER)-positive breast cancer. In recent years, aromatase inhibitors (AI) have become the preferred first-line hormonal treatment over tamoxifen for such patients.1,2

Preliminary results from a new study, unpublished but reported in a press release from the National Cancer Institute and widely disseminated in the public press, suggest that raloxifene (Evista) might be a better choice than tamoxifen (Nolvadex, and others) for prevention of breast cancer in high-risk postmenopausal women.

In addition to surgery and radiation therapy, a variety of drugs are used both singly and in combination to treat breast cancer. This article summarizes the principles of adjuvant therapy and treatment for metastatic disease. A summary of individual drugs and their adverse effects begins on page 3.

The antiestrogen toremifene (Fareston - Schering) and the selective aromatase inhibitor letrozole (Femara - Novartis) have been approved by the FDA for treatment of advanced breast cancer in postmenopausal women.

The most important prognostic variable in early breast cancer is axillary lymph node involvement. Based on past experience, after 10 years about 70% of node-negative patients will be alive and apparently free of disease; about 30% will have relapsed or died. Patients with positive nodes may have a 30% to 60% relapse rate, depending on the number of positive nodes and other prognostic factors, such as the presence of estrogen receptors (IC Henderson et al, in VT DeVita, Jr et al, eds, Cancer: Principles and Practice of Oncology, 3rd ed, Philadelphia:Lippincott, 1989, p 1197). Which of...

Interim results of a double-blind, placebo-controlled trial suggest that off-label use of the anticholinergic drug oxybutynin may reduce the frequency and severity of hot flashes in women with breast cancer. Extended-release oral oxybutynin (Ditropan XL, and generics) has been shown to reduce the frequency and severity of hot flashes in healthy menopausal women.

Fulvestrant (Faslodex -- AstraZeneca), an estrogen receptor antagonist given intramuscularly (IM) once a month, was recently approved by the FDA for treatment of hormone-receptor-positive metastatic breast cancer in postmenopausal women with disease progession on tamoxifen (Nolvadex, and others) or another antiestrogen.