The Year in Breast Cancer

SAN ANTONIO -- Among the major breast cancer events of 2006, there was a report of a dramatic drop in the annual incidence, evidence that an osteoporosis drug may prevent invasive disease, and encouraging reports about an investigational therapy.

The last month of the year brought the news that the annual incidence of breast cancer had fallen by 7%. During the year women learned that a drug that keeps bones healthy was comparable to tamoxifen for preventing invasive disease in high-risk women and encouraging reports about a new drug.

The following summary reviews some of the highlights of the year in breast cancer. For fuller accounts, links to the individual articles published in MedPage Today have been provided.

Breast Cancer Incidence Declined
The 7% decline in annual incidence from 2002 to 2003, was reported by Peter M. Ravdin, M.D., Ph.D., of the M.D. Anderson Cancer Center in Houston, and colleagues. This represented an absolute reduction of about 14,000 cases from one year to the next.

The reason for the dramatic drop is still unclear, but one possible explanation was abrupt decline in the use of hormone replacement therapy beginning in July 2002 when data from the Women's Health Initiative linked use of Prempro (estrogen/progestin) to increased risk of breast cancer.

• SABCS: Breast Cancer Incidence Falls Along with Hormone Replacement Decline

Estrogen: No Easy Answers
Hormone replacement is not a simple issue as was amply illustrated in a series of reports during the year.

For example, a new analysis of data from the estrogen-only arm of the Women's Health Initiative found that women who took the hormone alone for more than seven years not only didn't have an increased risk of breast cancer, they also had fewer breast cancers than women randomized to placebo.

• Estrogen Alone Does Not Increase Risk of Breast Cancer

That analysis, which was published in the Journal of the American Medical Association, was released a month before Harvard researchers reported in Archives of Internal Medicine that the use of estrogen alone for 10 years or longer increased the risk of breast cancer in postmenopausal women.

• Long-Term Use Estrogen Alone Increases Breast Cancer Risk

Another study found that black women who used hormone replacement therapy for 10 years or longer increased their risk of developing breast cancer by 50% compared with same-age black women who didn't take hormones. Those data were published in Archives of Internal Medicine.

• HRT-Breast Cancer Link Holds True for Black Women

Evista for Breast Cancer Prevention
Investigators with the National Surgical Adjuvant Breast and Bowel Project reported that Evista (raloxifene), a drug used to prevent and treat osteoporosis, was as good as tamoxifen for preventing invasive breast cancer in high risk women. In the STAR trial of almost 20,000 high-risk women there were 163 invasive breast cancers in 9,726 women randomized to tamoxifen and 167 among the 9,745 women who took Evista.

Moreover, the researchers said Evista was safer than tamoxifen, which made it "the real winner" in the STAR trial.

• Evista Prevents Invasive Breast Cancer in High Risk Post-Menopausal Women

Results of the STAR trial continued to create a buzz in June at the annual meeting of the American Society of Clinical Oncologists, but not everyone was calling Evista a winner.

Data reported at ASCO suggested that a number of factors play into the choice of Evista versus tamoxifen. For example, women who are sexually active complained of pain and vaginal dryness with Evista, but for women with a uterus, Evista appeared to be a better choice than tamoxifen because it was associated with a lower rate of uterine cancer.

• ASCO: Evista or Tamoxifen? The Trade-Offs in Preventing Breast Cancer

Later, a report in the New England Journal of Medicine said that Evista reduced invasive breast cancer by 44%, but the flip side of that benefit was a 49% increase in risk of fatal stroke.

• Evista Prevents Breast Cancer but Increases Risk of Fatal Strokes

Tykerb (lapatinib) Findings Emerge
Another big story at both ASCO and the San Antonio Breast Cancer Symposium was Tykerb (lapatinib), an investigational drug on the FDA's accelerated review list that demonstrated impressive efficacy in combination with Xeloda (capecitabine) in women with HER2-positive breast cancer.

Adding Tykerb to Xeloda doubled the median time to progression, according to Charles E. Geyer, Jr., M.D., of Allegheny General Hospital in Pittsburgh, and colleagues, who said the drug "should be considered a new standard of care."

• ASCO: Tykerb Seen as Next Best Thing After Herceptin for Breast Cancer

Six months later at SABCS a team of investigators from M.D. Anderson Cancer Center reported that Tykerb plus Taxol (paclitaxel) demonstrated efficacy as a neoadjuvant chemotherapy regimen for treatment of inflammatory breast cancer.

• SABCS: Tykerb Plus Taxol Effective Against Inflammatory Breast Cancer

And in late December, the New England Journal of Medicine published complete results from the trial reported by Dr. Geyer at ASCO, which confirmed Tykerb's ability to slow progression of advanced breast cancer. But the journal report also found that there was no survival benefit associated with Tykerb, which, given the high cost of Tykerb therapy, may dampen enthusiasm for the compound.

• Tykerb Plus Chemotherapy Slows Advance of Metastatic Breast Cancer

Downside of Aromatase Inhibitors
Aromatase inhibitors such as Arimidex (anastrozole) are both effective and well tolerated for preventing breast cancer recurrence in high-risk women, and these drugs are often promoted as more patient friendly than tamoxifen. But a report at ASCO found that five years of breast cancer adjuvant therapy with Arimidex could lead to a 6% to 7% loss of bone mineral density, a trigger for osteoporosis for women who are borderline osteopenic when they begin treatment.

For women with normal bone density at baseline, however, five years of Arimidex was unlikely to cause osteoporosis, said investigators with ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial.

• ASCO: Five Years of Arimidex Causes Bone Loss

Aggressive Cancers Target Blacks
African American women often have worse outcomes with breast cancer, a finding that has often been linked to socioeconomic factors including poor access to health care services. But a study from M.D. Anderson Cancer Center in Houston suggested that the real culprit may be unfavorable tumor cell biology. In a review of more than 2,100 breast cancer patients, African Americans were found to be more likely to have aggressive cancers.

• Breast Tumors More Aggressive in African-American Women

Red Meat Risk

Red meat, already recognized as a usual suspect in coronary artery disease, may also increase the risk of breast cancer, according Harvard researchers. They said a study of more than 90,600 nurses followed for 12 years found that women who regularly consumed red meat increased their risk of developing hormone receptor positive breast cancer. There was no increased risk for hormone receptor negative breast cancers, they reported in Archives of Internal Medicine.

• Red Meat Linked to Hormone Receptor-Positive Breast Cancer

No Help From Fish or Statins
And while eating fish can decrease the risk of heart disease, the same cannot be said for breast cancer. Catherine H. MacLean, M.D, Ph.D. and colleagues of Rand Health reported in the Journal of the American Medical Association that women who consumed diets rich in fish and other sources of omega-3 fatty acids were no less likely to reduce their risk of cancer than those who pass on fish.

• Omega-3 Flounders as Cancer Protection

Likewise, lipid-lowering statins, regularly touted for their ability to prevent heart attacks and stroke, flopped at preventing cancer, according to researchers at the University of Connecticut School of Pharmacy, who reported their findings in the Journal of the American Medical Association.

• Meta-Analysis Rules Out Statin Cancer Prevention

Ginseng a Winner
But a popular "natural" cure-ginseng-may improve survival and enhance the quality of life for women with breast cancer, according to a report from researchers at Vanderbilt-Ingram Cancer Center. They said that disease-specific mortality was 30% lower in women taking ginseng compared with women who never used the traditional Chinese herb.

• Ginseng Appears to Help Breast Cancer Patients

Pump It Up
And finally, researchers at the University of Pennsylvania and the University of Minnesota said that women who lift weights after breast cancer surgery improve their quality of life and gain a better sense of well being.

Writing in the journal Cancer the researchers said women who pumped iron after surgery also increased lean muscle mass and upper body strength.

• Pumping Iron Raises Quality of Life After Breast Cancer Surgery