Public release date: 3-Oct-2007
Drugs called anthracyclines are a breast cancer chemo staple despite a well-known risk: They weaken some women’s hearts. What’s new is research suggesting the drugs work no better than safer alternatives for most women.
It’s a controversy born of success: Treatment advances are enabling more women than ever before to beat breast cancer, and some 2.4 million survivors are alive today. Now a move is underway to determine just how many women are vulnerable to heart disease because of their cancer battle, and how to help them.
Dr. Dennis Slamon of UCLA’s Jonsson Cancer Center cites nine studies, here and abroad, that conclude that only the 20% of patients whose tumors have an overactive gene called Her2 are specifically sensitive to anthracyclines
Chemo is only one cardiac culprit. Other factors play a role, too: Chest radiation, the weight gain that plagues many survivors, physical inactivity during treatment and stress.
Then Slamon’s closer inspection found that not all Her2 patients are alike — and only those who have a second overactive gene, called TopoII, derive special benefit from anthracyclines. That’s about 8% of breast cancer patients.
The powerful Her2-targeting drug Herceptin — key for women with Her2-positive tumors — also comes with a heart-damage warning. But adding it to anthracyclines increases the heart risk fivefold, with no extra benefit, Slamon found
And in this month’s Journal of Clinical Oncology, researchers tracked breast cancer survivors ages 66 to 70 who had undergone chemo 10 years earlier. Those who had received an anthracycline were 26% more likely to have developed heart failure in the following decade than those on different chemo.
“It’s almost like the perfect storm,” Slamon says of all the research. “We’re adding no incremental benefit with plenty of incremental toxicity.”
But many oncologists aren’t convinced, and want more evidence that other chemos work as well.
Ralph’s Note – At least 80% to 92% of breast cancer patients don’t respond to this Chemo; However, it may increase the risk of heart failure 5 fold; forgetting about other possible side effects. Hmmm.