Best Friends Forever

Best Friends Forever

I have three important messages today for all women who are concerned about the prevention and treatment of breast cancer – in other words: all women.

The big question

Message One: If your doctor prescribes chemotherapy, this is the question that must be asked: Is the cancer estrogen driven?

In women who have not yet reached menopause, gene damage is usually the cause of breast cancer. In these cases, chemo is one of the standard treatments. But most women are still not aware that about 75 percent of breast cancer tumors in postmenopausal women are estrogen driven. For these estrogen receptor-positive tumors, chemo has little or no effect, while treatment with tamoxifen (a synthetic hormone-like drug that prevents estrogen from binding to breast cancer cells) has been shown to be far more effective than chemo, even if the cancer has spread to lymph nodes.

As I reported to you in a 2005 e-Alert, a test called Oncotype DX has been developed to reveal which patients will most likely respond to chemo or tamoxifen. And although the test is expensive (more than $3,000), insurance companies may choose to offer coverage on the chance of deferring costly chemo treatments.

Preventive use

Message Two: If you take tamoxifen to prevent breast cancer, there’s good news and bad news.

We’ll start with the good news: The beneficial effects of tamoxifen may be more far-reaching than previously thought, according to a new study published this month in the Journal of the National Cancer Institute.

STUDY PROFILE

• Results from the International Breast Cancer Intervention Study (IBIS) showed that risk of estrogen receptor-positive tumors were reduced by 31 percent in 3,579 women at high risk for breast cancer who took 20 mg of tamoxifen per day for five years (3,575 women were given a placebo)
• IBIS researchers conducted a follow up to assess rates of estrogen receptor-positive tumors and side effects in the eight years after discontinuing tamoxifen use
• Women who took tamoxifen during the initial study were found to have 27 percent lower risk of developing estrogen receptor-positive tumors, compared to the placebo group
• Tamoxifen side effects dropped off after tamoxifen use was discontinued

And this brings us to the bad news: Although side effects dropped off, they didn’t disappear altogether. This is a concern because the list of tamoxifen side effects looks exactly like a list of menopausal symptoms: hot flashes, nausea, vomiting, weight gain, mood swings, depression, and loss of energy. More serious side effects include two life-threatening conditions: deep-vein thrombosis and pulmonary embolism.

During the initial IBIS trial, 52 women who took tamoxifen suffered either deep-vein thrombosis or pulmonary embolism, while 23 cases occurred in the placebo group. In the eight-year follow up, 16 cases were reported in the tamoxifen group, and 14 in the placebo group.

Supplemental support

Message Three: If you take tamoxifen, certain supplements may promote a positive outcome.

Researchers at the University of Madras recently reported on a study in which 84 breast cancer patients received either 20 mg of tamoxifen daily or a placebo for one year. During the trial period, tamoxifen subjects who also took 100 mg of CoQ10, 50 mg of niacin, and 10 mg of riboflavin for 45 or 90 days had significantly reduced levels of two key markers that are usually elevated prior to relapse.

In addition, a 2005 animal study suggested that CoQ10 might boost the effectiveness of tamoxifen.

Women who are taking tamoxifen should talk with their doctors before adding these supplements to their daily regimen.