US Pharm. 2007;32(4):HS48-HS50.

New Drug to Treat Advanced Breast Cancer
The FDA has approved lapatinib (Tykerb, GlaxoSmithKline), a new molecular entity to be used in combination with capectabine (Xeloda, Roche Laboratories), for patients with advanced, metastatic breast cancer that is HER2 positive. The combination treatment is indicated for women who have received prior therapy with other cancer drugs, including an anthracycline, a taxane, and trastuzumab (Herceptin, Genentech).

Tykerb is a kinase inhibitor working through multiple pathways to deprive tumor cells of signals needed to grow. Tykerb is a small molecule that enters the cell and blocks the function of this and other proteins, unlike Herceptin, a monoclonal antibody that targets the part of the HER2 protein on the outside of the cell. Tykerb's unique mechanism of action works in some HER2-positive breast cancers that have been treated with Herceptin and are no longer benefiting.

It is estimated that 8,000 to 10,000 women die from metastatic HER2-positive breast cancer each year.

Protection Against Prostate Cancer with Soy Has Mixed Results
A study of 43,509 Japanese men finds that while diets rich in soy may protect against some types of prostate cancer, in some patients it may also raise the risk for advanced prostate cancer. The data, the results of a study done by the National Cancer Center of Japan and published in Cancer Epidemiology, Biomarkers & Prevention, suggests that for some of the test subjects, soy isoflavones in the diet decreased the risk of localized prostate cancer, but at the same time soy containing miso soup increased the risk of advanced prostate cancer. According to lead investigator Norie Kurahashi, MD, there is no clear understanding of "when or how localized cancer will develop to aggressive cancer, and the related effect of isoflavones."

The researchers hypothesized that soy in general, and isoflavones genistein and daizden in particular, may attenuate but not prevent the progression of latent prostate cancer. Soy isoflavones are estrogen mimics and strong antioxidants in vitro, and appear to be protective against cancer in animal models.

Vitamin D May Reduce Risk of Breast and Colorectal Cancer
Researchers who conducted two meta-analyses of published studies reported that high levels of vitamin D can significantly reduce the relative risks of breast and colorectal cancer.

One published study showed that a daily dose of 2,000 IUs of vitamin D3 would reduce the relative risk of both forms of cancer by at least 50%.

HIV Vaccine Trial in South Africa
A large-scale phase IIb clinical trial of a candidate HIV vaccine has begun in South Africa. This vaccine has shown promise in smaller U.S. studies. The trial involves 3,000 HIV-negative men and women, making it the largest African HIV vaccine trial to date. The study vaccine is provided by Merck & Co., Inc. and contains copies of only three HIV genes, not the entire virus, so it is impossible for trial volunteers to become infected from the vaccine.

The South African trial is called Phambili (HVTN 503), which literally means "moving forward." It is designed to provide preliminary information on vaccine efficacy and thus enable researchers to decide whether or not to conduct a larger phase III efficacy trial that could lead to licensure. In smaller trials, the vaccine was found to be safe and to stimulate cellular immune responses against HIV in more than half of the volunteers. The primary objectives of HVTN 503 are to determine whether the candidate vaccine can prevent HIV infection or, in those who do become infected, lower the level of HIV early on.

Risk of Breast Cancer Possibly Related to Fatty Diets
According to a study published in the Journal of the National Cancer Institute, diets heavy in fat may increase the risk of breast cancer for postmenopausal women by approximately 15%. The elevated risk was similar across all types of fat--saturated, monounsaturated, and polyunsaturated--and was particularly strong for women who used hormone replacement therapy.

The researchers found that the modest risk association between fat-filled diets and breast cancer is outweighed by "robust evidence" for a strong link between body fat and postmenopausal breast cancer. 

Women in the highest fat intake quintile (with 40.1% energy from fat) had an 11% higher incidence of invasive breast cancer than women in the lowest quintile (20.3% energy from total fat). It should be noted that the associations were not modified by family history of breast cancer, history of breast biopsy, body mass index, smoking history, and alcohol consumption. However, it was discovered that women not using hormone replacement therapy at baseline had a lower hazard ratio for invasive breast cancer in every fat quintile compared with women who were using menopausal hormone therapy.

Marijuana Reduces HIV Neuropathy
While the debate and controversy over legalizing medical marijuana continues across the country, a study published in the journal Neurology reports that smoking marijuana significantly reduces nerve pain associated with HIV infection. According to Donald Abrams, MD, and his colleagues at the University of California, San Francisco, the pain reductions are comparable with those seen with oral drugs used to treat peripheral HIV-associated neuropathy. "There is a measurable medical benefit to smoking cannabis for these patients," said Dr. Abrams.

Over the course of the study, those subjects who smoked cannabis reduced daily pain by 34% versus 17% with placebo.   The first cannabis cigarette reduced chronic pain by 72% on average, compared to 15% for placebo. No serious adverse effects were reported.

Task Force Nixes NSAIDs for Colon Cancer Prevention
The U.S. Preventive Services Task Force is recommending that aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) not be used to prevent colorectal cancer because the risks of gastrointestinal side effects outweigh the possible benefits.

The task force made its recommendations based on two systematic risk–benefit analyses carried out by Catherine Dubé, MD, and her colleagues at the University of Calgary in Alberta, Canada. The review results appeared in the Annals of Internal Medicine. "Cyclo-oxygenase-2 inhibitors and NSAIDs reduce the incidence of colonic adenomas," said the Canadian researchers. "Non-steroidal anti-inflammatory drugs also reduce the incidence of colorectal cancer. However, these agents are associated with important cardiovascular events and gastrointestinal harm. The balance of benefits to risk does not favor chemoprevention in average risk individuals."

Black Male Patients Have Higher Risk of Dying from Breast Cancer
While the rate of male breast cancer is miniscule (<1%) compared to other cancers in men, a small study conducted by a team of researchers at Columbia University, New York, NY, uncovered that men with breast cancer show the same racial disparities in survival as do women with the disease. The study demonstrated that Medicare-age black men with breast cancer were three times more likely to die from the disease than white men, according to investigator Dr. Dawn L. Hershman, MD, MS, and her colleagues. According to an article published in the Journal of Clinical Oncology, their findings parallel those of previous studies among women, which have shown higher breast cancer mortality rates for black women at all ages.

Smoke in Workplace Linked to Increased Lung Cancer Risk
A study published in the online edition of the American Journal of Public Health underscores the likelihood that nonsmokers who are exposed to second-hand smoke in the workplace are at a greater risk of developing lung cancer.

According to epidemiologist Leslie Stayner, PhD, University of Illinois at Chicago and colleagues, exposed nonsmoking workers were 24% more likely to develop lung cancer than if they were smoke-free.

The researchers conducted a meta-analysis of 22 studies from the U.S., Europe, and Asia. And while there was a strong correlation of second-hand smoke to developing lung cancer in factories, offices, restaurants and bars, the strongest smoking–lung-cancer connection came from studies of nonsmokers exposed to a smoking spouse.

Despite the alarming data extracted from the studies, the investigators estimate that smoking remains permissible in approximately 30% of workplaces in the U.S.

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