~ Chemotherapy helps improve breast cancer survival in post-menopausal women, adding to a long-standing debate about how best to treat these women. A gene-based test called Oncotype DX made by Genomic Health Inc may help identify a small group of women who are not likely to benefit from chemotherapy, a second study found. The main study proves that adding chemotherapy to treatment with the estrogen-blocking drug tamoxifen can help prevent cancer from coming back in women with estrogen-receptor positive breast cancers, the most common kind in which a hormone is driving the cancer. “We have a survival benefit that lasts for a very long time … for women who got both modalities of treatment versus women who just got tamoxifen,” said Dr. Kathy Albain of Loyola University Health System in Maywood, Illinois. “It is considered a landmark study in the clinical trials literature because it is the only one really demonstrating the survival advantage of chemotherapy added to tamoxifen,” Albain said in a telephone interview. “Up until this trial, studies adding common chemotherapy drugs to tamoxifen or tamoxifen alone were essentially negative.”
For the study, the team followed nearly 1,500 post-menopausal women with estrogen-receptor positive breast cancers that had spread to at least one lymph node. Some of the women got both tamoxifen and a chemotherapy drug known as anthracycline, and some got tamoxifen alone. The team found that the women who got the chemotherapy were 24 percent less likely to have their cancer come back. They were also 17 percent less likely to die during the 10-year study period, but this finding was just shy of meeting statistical significance. The team also found that giving tamoxifen after chemotherapy ended instead of during chemotherapy improved a woman’s survival chances.
In a second study led by Albain, published in the journal Lancet Oncology, the team evaluated whether the Oncotype DX test can predict which women would benefit from chemotherapy. The test examines 21 genes from a tumor sample to see how active they are, and produces a score that predicts chemotherapy benefit. It is most commonly used in women with estrogen-fed tumors whose cancer has not spread to a lymph node. But Albain’s study suggests it may also be useful in identifying women whose tumors had spread that would not benefit from chemotherapy. –Reuters
~ Some women with very advanced breast cancer may have a new treatment option. A combination of two drugs that more precisely target tumors significantly extended the lives of women who had stopped responding to other medicines, doctors reported Friday.It was the first big test of combining Herceptin and Tykerb. In a study of 300 patients, women receiving both drugs lived nearly five months longer than those given Tykerb alone. Doctors hope for an even bigger benefit in women with less advanced disease, and were elated at this much improvement for very sick women who were facing certain death.
“We don’t see a lot that works in patients who have seen six prior therapies as they did in this trial, so that alone is exciting,” said Dr. Jennifer Litton, a breast cancer specialist at the University of Texas M. D. Anderson Cancer Center. The good results are in stark contrast to two other studies that found no survival advantage from Avastin, a $30,000-a-month drug whose approval for breast cancer patients was very controversial.
Considering Avastin’s potential side effects — blood clots in the lungs, poor wound healing, kidney problems — a survival benefit “would have made the cost of the drug less painful to take,” Litton said.
Herceptin and Tykerb aim at a protein called HER-2 that is made in abnormally large quantities in about one-fourth of all breast cancers. Herceptin blocks the protein on the cell’s surface; Tykerb does it inside the cell.
“It’s kind of like having a double brake on your tumor. If the first one fails, the second one does the job,” said the Dr. Kimberly Blackwell of Duke University. She led the combo treatment study and has consulted for its sponsor, British-based GlaxoSmithKline PLC, which makes Tykerb, and for Genentech, which makes Herceptin and Avastin.
Women in the study had already received Herceptin alone or with various chemotherapy drugs and still were getting worse. They were randomly assigned to receive only Tykerb or both drugs, to see whether the combo might help Herceptin regain its effectiveness.
Median survival was analyzed after about three-fourths of the women had died — roughly two years after the study began. It was 61 weeks in the combo group versus 41 for those taking only Tykerb. That likely underestimates the combo’s true benefit because women on Tykerb alone were allowed to add Herceptin partway through the study if they continued to worsen, and many of them did, Blackwell said.
One woman on the combo in the study suffered a fatal blood clot. The only other common, serious side effect was diarrhea, which plagued 7 to 8 percent of each group. Herceptin costs about $10,000 a month; Tykerb, $5,000 to $6,000.
Dr. Eric Winer, breast cancer chief at the Dana-Farber Cancer Center in Boston, said several studies now show that Herceptin still helps women even when their cancers seem to be getting worse. “Herceptin is like a big roadblock on a superhighway. Eventually the cancer finds a way around it by taking an off ramp. But it’s much less efficient to take that off ramp, so Herceptin is still having some influence on that cancer,” said Winer, who, like Litton, has no financial ties to any drugmakers. Not so for Avastin, which works by crimping a tumor’s blood supply. The federal Food and Drug Administration approved its use in women whose cancers had spread beyond the breast over the objections of FDA advisers who wanted more evidence of benefit for these patients. – AP