Genetic Findings Revolutionize Cancer Care
Treatment is becoming more targeted and individualized

(HealthDay News) -- The mapping of the human genome, along with the advent of more powerful tools for identifying mutant genes, has done wonders for cancer care.

Thanks to these advances, scientists have made some key discoveries that one day could lead to new and better cancer treatments. Recent highlights include:

• A team from Duke University Medical Center announced the development of the first-ever test to predict which people with early-stage lung cancer would benefit from chemotherapy to prevent a recurrence.
• Scientists at Johns Hopkins Kimmel Cancer Center completed the first draft of the genetic code for breast and colon cancer. The team identified close to 100 mutant genes for each cancer. Their work is part of the Cancer Genome Atlas, a joint project of the National Cancer Institute and the National Human Genome Research Institute to identify genomic changes involved in human cancer.
• Investigators at St. Jude Children's Research Hospital discovered mutations that contribute to the most common cancer in children, pediatric acute lymphoblastic leukemia.

"We are in the midst of both an evolution and a revolution in cancer care," Dr. J. Leonard Lichtenfeld, deputy chief medical officer for the national office of the American Cancer Society, told HealthDay .

Yet every discovery poses new challenges. "The more that we learn, the more complex it is going to get," he said.

Targeted cancer therapies, sometimes called "molecularly targeted drugs," block the growth and spread of cancer by interfering with specific molecules involved in the process of cancer cell growth and division, according to the National Cancer Institute.

Discoveries in cancer genomics already have resulted in several treatments that target cancer-related molecules, the Cancer Genome Atlas explains. One is Gleevec, the Novartis drug that targets specific proteins in cancer cells that cause cancer to grow and multiply. Gleevec is approved for treating chronic myelogenous leukemia and gastrointestinal stromal tumors.

Another is Herceptin, a drug given to treat an aggressive form of breast cancer caused by the overexpression of a gene called HER2 in tumor cells. About 25 percent of breast cancers are HER2-positive, according to studies cited by the drug's manufacturer, Genentech.

With the development of targeted cancer therapies, doctors will eventually be able to tailor cancer treatment based on the unique set of molecular targets produced by a specific patient's tumor, according to the Cancer Institute. Targeted cancer therapies also are expected to reduce side effects and improve quality of life by harming fewer normal cells.

For patients, a potential complication could be finding a qualified genetics counselor to help them understand the results of genetic tests and sort through treatment options.

"Most physicians simply aren't familiar with all the implications of assessing a woman's risk for breast cancer, for example, [or] of understanding all the genetic issues," Lichtenfeld said. "So I think that our theory right now is better than our practice. Our practice clearly needs to get better."

On the Web

To learn more about targeted cancer therapies, visit the National Cancer Institute online.

SOURCES: HealthDay News ; J. Leonard Lichtenfeld, M.D., deputy chief medical officer, American Cancer Society, Atlanta; Duke University Medical Center, Aug. 8, 2006, news release; Johns Hopkins Kimmel Cancer Center, Sept. 7, 2006, news release; St. Jude Children's Research Hospital, March 7, 2007, news release; Novartis (www.gleevec.com), Genentech (www.herceptin.com); National Cancer Institute (www.cancer.gov)
Author: Karen Pallarito
Publication Date: Sept. 30, 2008
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