Not that long ago, cancer treatments were focused on only one goal: immediate survival. As technology evolved, physicians have been able to focus attention on a patient's quality of life as well, said Dr. Andrew Zelenetz at an American Medical Association media briefing in New York.
"We've moved away from the treatments that are simply blunt tools. They can defeat cancer, but have both good and bad side effects," said Zelenetz, chief of the Lymphoma Service at Memorial Sloan-Kettering Cancer Center in New York. "Now, not only have we defined better and modified traditional tools, but we've also discovered new therapies that can prolong life and prevent the serious side effects that can create problems for the patient years down the road."
A major advancement in cancer treatment was a better understanding of tumor and cancer cell biology, Zelenetz said. This has enabled oncologists to target specific molecules and processes within cancer cells.
In lung cancer treatment, researchers have focused their attention on targeting the epidermal growth factor receptor, or EGFR, said Dr. Bruce Johnson, director of the Lowe Center for Thoracic Oncology at the Dana-Farber Cancer Institute in Boston.
"Activation of EGFR triggers reactions inside lung cancer cells that make them multiply and spread," Johnson said. "With inhibition therapy, we can block EGFR from activating its downstream activity and causing tumor growth."
However, only 10 percent to 20 percent of patients have a positive response to the EGFR inhibition therapy. Johnson and his colleagues studied the tumor cells from patients with the greatest treatment response and discovered a somatic, or genetic, mutation that specifically activates EGFR. The mutation is three times more likely in women, nonsmokers and people of Eastern Asian descent.
This finding has caused a fundamental change in the way oncologists approach treatment planning for patients with lung cancer, he said. "Today, when a patient presents in our office with a lung cancer diagnosis, we can genetically type the tumor and know that if they have a specific mutation, they'll respond to specific therapies 80 to 90 percent of the time."
Researchers are in the process of characterizing genetic changes occurring in other populations, as well as in other cancers, and believe new findings will offer insight into how these new therapies can be used in a more targeted fashion and make treatment more successful.
Log on to www.ama-assn.org for more information. - NU |
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