Wall Street Journal
Researchers presented new findings Saturday at a breast-cancer symposium here suggesting that the risks associated with anthracyclines, a class of chemotherapy drugs widely used to treat the disease, outweighed their benefits in some patients.
The findings renewed a debate over whether anthracyclines, which have been around since the 1960s, should remain the standard of care in treating breast cancer, or whether newer drugs should be used more frequently instead.
The findings renewed a debate over whether anthracyclines, which have been around since the 1960s, should remain the standard of care in treating breast cancer, or whether newer drugs should be used more frequently instead.
Anthracyclines are effective but can damage the heart, particularly when used in combination with Roche Holding AG's Herceptin, a highly effective medication used to treat women with HER2-positive cancer.
The researchers, from the Breast Cancer International Research Group, evaluated the efficacy and safety of two separate regimens to treat breast cancer, one comprised of Herceptin and anthracyclines and another comprised of Herceptin and non-anthracycline drugs. The researchers compared the two treatment regimens to a control group receiving anthracyclines, but not Herceptin.
The 10-year study, which includes 3,222 women with Her2-positive breast cancer, is sponsored by French pharmaceutical company Sanofi-Aventis SA and supported by Genentech, a subsidiary of Roche. The data presented Saturday was collected at the study's halfway point.
The data showed that, after five years, women in both Herceptin groups were significantly more likely to remain alive than those in the control group, and there wasn't a statistically significant difference in overall survival between those who received anthracyclines and those who got non-anthracyclines, according to Dennis Slamon, one of the study investigators and director of the women's cancer research program at the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles.
But, women receiving the combination of Herceptin and anthracyclines had significantly more heart damage, including cases of congestive heart failure, than those getting Herceptin and non-anthracyclines. They also had more cases of leukemia, a secondary consequence of the chemotherapy. "The damage we're doing to the heart is not transient," said Dr. Slamon.
The results are consistent with an earlier analysis of less comprehensive data in 2005, which provoked considerable debate in the field. One group of oncologists, including Dr. Slamon, believes that doctors should move away from using anthracyclines as a uniform treatment for all cases of breast cancer and instead use it only in subgroups of patients, such as those who express both the Her2 gene and another one called the Topo gene.
"I don't know why we keep pushing the anthracycline agenda," said Dr. Slamon, who called these latest results a "direct assault" on these drugs.
However, other experts disagree, saying the data aren't convincing enough to change the standard of care.
"What the data show is that there's certainly no superiority" of the non-anthracycline treatment, said Eric Winer, director of the Breast Oncology Center at the Dana-Farber Cancer Institute in Boston. But because the two treatment groups aren't significantly different on efficacy, "I'm just not of the view that [non-anthracycline therapy] is the preferred regimen," said Dr. Winer. "We have to be cautious before adapting new standards."
Dr. Winer also pointed out that, even though there wasn't a statistically significant difference in survival between the two Herceptin groups, there were a greater number of deaths among the patients who got Herceptin and non-anthracyclines than among those who got Herceptin and anthracyclines. The difference was 214 deaths to 185.
Gary Lyman, a professor of medicine at Duke University's Comprehensive Cancer Center, said he didn't think the results would change much the use of anthracyclines. His patients want the best treatment for the cancer they are facing at the moment and are less concerned about the potential future safety concerns. "When I go back home, they are not going to want to compromise the most effective treatment for cancer" because of concerns over heart damage or leukemia, he said.
However, "patients should be warned; they should be informed about these issues," said Dr Lyman.
The researchers, from the Breast Cancer International Research Group, evaluated the efficacy and safety of two separate regimens to treat breast cancer, one comprised of Herceptin and anthracyclines and another comprised of Herceptin and non-anthracycline drugs. The researchers compared the two treatment regimens to a control group receiving anthracyclines, but not Herceptin.
The 10-year study, which includes 3,222 women with Her2-positive breast cancer, is sponsored by French pharmaceutical company Sanofi-Aventis SA and supported by Genentech, a subsidiary of Roche. The data presented Saturday was collected at the study's halfway point.
The data showed that, after five years, women in both Herceptin groups were significantly more likely to remain alive than those in the control group, and there wasn't a statistically significant difference in overall survival between those who received anthracyclines and those who got non-anthracyclines, according to Dennis Slamon, one of the study investigators and director of the women's cancer research program at the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles.
But, women receiving the combination of Herceptin and anthracyclines had significantly more heart damage, including cases of congestive heart failure, than those getting Herceptin and non-anthracyclines. They also had more cases of leukemia, a secondary consequence of the chemotherapy. "The damage we're doing to the heart is not transient," said Dr. Slamon.
The results are consistent with an earlier analysis of less comprehensive data in 2005, which provoked considerable debate in the field. One group of oncologists, including Dr. Slamon, believes that doctors should move away from using anthracyclines as a uniform treatment for all cases of breast cancer and instead use it only in subgroups of patients, such as those who express both the Her2 gene and another one called the Topo gene.
"I don't know why we keep pushing the anthracycline agenda," said Dr. Slamon, who called these latest results a "direct assault" on these drugs.
However, other experts disagree, saying the data aren't convincing enough to change the standard of care.
"What the data show is that there's certainly no superiority" of the non-anthracycline treatment, said Eric Winer, director of the Breast Oncology Center at the Dana-Farber Cancer Institute in Boston. But because the two treatment groups aren't significantly different on efficacy, "I'm just not of the view that [non-anthracycline therapy] is the preferred regimen," said Dr. Winer. "We have to be cautious before adapting new standards."
Dr. Winer also pointed out that, even though there wasn't a statistically significant difference in survival between the two Herceptin groups, there were a greater number of deaths among the patients who got Herceptin and non-anthracyclines than among those who got Herceptin and anthracyclines. The difference was 214 deaths to 185.
Gary Lyman, a professor of medicine at Duke University's Comprehensive Cancer Center, said he didn't think the results would change much the use of anthracyclines. His patients want the best treatment for the cancer they are facing at the moment and are less concerned about the potential future safety concerns. "When I go back home, they are not going to want to compromise the most effective treatment for cancer" because of concerns over heart damage or leukemia, he said.
However, "patients should be warned; they should be informed about these issues," said Dr Lyman.
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