QUESTIONS IN CANCER TREATMENT
Cancer research suggests changes in treatment maybe forthcoming
The American Association for Cancer Research held its annual meeting April 17-21 in Washington. Thousands of participants were able to consider more than 6,000 papers and short talks, and several hundred longer presentations. Some highlights follow.
Matching drug with tumor
Lung cancer patients given drugs such as Tarceva and Nexavar fare better when their tumors are first tested for certain genetic traits and then matched with the corresponding treatment, a study found.
The drugs, called targeted therapies because they home in on specific biological pathways involved in tumor growth, were studied by researchers at the University of Texas M.D. Anderson Cancer Center in Houston.
Most treatment decisions now are based on cancer type, said thoracic oncologist Edward Kim, the study's lead author. That is likely to change as more studies show the benefit of tailoring treatment to the individual, said Anil Potti, an associate professor of medicine at Duke University.
"A trial like this is unprecedented," Potti said. "It shows that getting biopsies and treating patients based on those biopsies is feasible in lung cancer today. It's a huge advance in lung cancer research and in the whole concept of personalized medicine."
In the study, patients who had been treated with chemotherapy in the past underwent another biopsy. Tumor samples were tested for cancer biomarkers, including mutations to a gene called KRAS and to EGFR, or epidermal growth factor receptor, a protein that causes cancer cells to grow and divide.
Patients were placed into five marker groups. A first subset was assigned to one of four drugs without regard to their biomarkers. Patients in a second wave were assigned to drugs based on their particular tumor biomarkers, taking into consideration how people in the first group with similar biomarkers were faring.
Overall disease control -- defined as "non-progression" of the cancer -- among all participants was 46 percent after eight weeks, Kim said. However, about 71 percent of patients with mutations involving EGFR who were given Tarceva, which is designed to inhibit EGFR, had disease control at eight weeks. Among those with KRAS gene mutations, 61 percent had non-progression of their cancer when given Nexavar, Kim said.
Calcium doesn't just build strong bones; it may also fight cancer.
Researchers at the Ponce School of Medicine in Puerto Rico reported that women who took calcium had a 40 percent lower risk of getting breast cancer, while those getting multivitamins showed a 30 percent reduction.