Breastcancer.org
Dr. Marissa Weiss and her colleagues have an excellent article posted on breastcancer.org detailing some of the new developments in breast cancer prevention, including a breast cancer vaccine.
Breast cancer vaccine may reduce risk of death
What breastcancer.org says about this article
The very small study reviewed here looked at an experimental treatment for HER2-positive breast cancers. This experimental treatment, a vaccine, isn't available yet. Still, the results do seem promising as a way to treat HER2-positive breast cancer in the future.
The experimental vaccine is called NeuVax. Researchers gave the vaccine to 163 women who had been diagnosed with HER2-positive breast cancer. About 2.5 years after receiving the vaccine, the number of women who died from breast cancer was 50% lower compared to a group of women diagnosed with HER2-positive breast cancer who didn't receive the vaccine. The vaccine is given once a month as an injection under the skin.
HER2-positive breast cancers make too much of the HER2 gene or HER2 protein. HER2-positive cancers:
tend to grow faster
are harder to treat
are more likely to come back
compared to breast cancers that are HER2-negative. About 25% to 30% of all breast cancers are HER2-positive. Herceptin (chemical name: trastuzumab) and Tykerb (chemical name: lapatinib) are targeted therapy medicines that treat HER2-positive advanced breast cancers. Herceptin also is used to treat HER2-positive early-stage breast cancer after surgery to reduce the risk of the cancer coming back.
Your immune system helps keep you healthy by preventing and fighting infections. Your immune system also plays a role in preventing and fighting cancer. In a sense, vaccines rev up your immune system so it's better at protecting you against disease. The NeuVax vaccine tells the immune system to target breast cancer cells with HER2 protein.
Because the NeuVax vaccine targets the HER2 protein, the researchers thought that cancers that made a lot of HER2 protein would be most affected by the vaccine. (Cancers classified as HER2-positive can have a range of HER2 protein levels, but all are higher than cancers classified as HER2-negative.) But the results showed that even HER2-positive cancers with lower HER2 protein levels were affected by the vaccine, which is good news. None of the women diagnosed with HER2-positive breast cancers with lower HER2 protein levels who received the NeuVax vaccine died during the 2.5 years after receiving the vaccine. The women diagnosed with HER2-positive breast cancers with lower HER2 protein levels who received the NeuVax vaccine also had lower rates of the cancer coming back.
Because this study was so small, none of the results were statistically significant, which means they could have happened by chance. So we don't know if the NeuVax vaccine will really be an effective treatment for HER2-positive breast cancer. The results are very promising, but much more research is needed before doctors will know whether they can confidently and safely use this treatment.
If you've been diagnosed with breast cancer and think you might be interested in participating in a clinical research trial on a new treatment approach, such as NeuVax, talk to your doctor about whether any studies make sense for your unique situation.
And stay tuned to breastcancer.org for the latest updates on research that may lead to more effective ways to treat breast cancer.
Last Updated: 2008-04-14 11:19:39 -0400 (Reuters Health)
By Deena Beasley
SAN DIEGO (Reuters) - A small trial of an experimental vaccine designed to trigger the immune system to fight breast cancer suggests that it may reduce the risk of death for most patients, U.S. military researchers said on Sunday.
The vaccine, designed to treat women with tumors that generate a protein called HER-2, has been licensed to Scottsdale, Arizona-based Apthera Inc under the brand name NeuVax.
If results from this 163-patient study are validated in a larger trial, the vaccine may offer a new therapy for the largest subset of breast cancer patients, said Linda Benavides, a resident in general surgery at Brooke Army Medical Center in San Antonio, Texas, and the study's lead researcher.
About 25 percent to 30 percent of women with breast cancer have tumors that express high levels of HER-2. Their tumors tend to grow faster and are more likely to recur than tumors that do not carry the protein.
Most of these women are currently treated with Herceptin, also known as trastuzumab, an expensive antibody-based drug made by Genentech Inc.
Researchers at Brooke Army Medical Center in San Antonio, Texas tested NeuVax in women whose tumors generated low levels of HER-2 as well as women with high levels of the protein.
At 30 months follow-up, the injected vaccine was shown to cut the risk of death for all patients by half, and in the group of patients with low-expressing HER-2 tumors, no deaths were reported. Due to the small size of the study, the survival results were not statistically significant.
The study, presented here at a meeting of the American Association for Cancer Research (AACR), also showed that cancer recurred in 10.7 percent of vaccinated low-expressors, compared with 18.2 percent of the control group.
Benavides said that a planned Phase III trial of NeuVax in more than 700 patients will test the vaccine solely in women with tumors that generate low levels of HER-2 -- a group for which immune-targeting therapy is currently unavailable.
But these breast cancer patients already have a better prognosis than women with high levels of the protein, leading to questions about whether the results can be duplicated in a larger trial.
"The surprising result is that it was the low-expressing patients who had the better outcomes ... that makes it difficult to interpret the data," said Dr. William Hait, AACR president and head of oncology research at Johnson & Johnson's Ortho Biotech unit.
Benavides said the experimental vaccine offers a "very simplistic approach," toward targeting HER-2, adding that it would be "very cheap to mass produce."
The wholesale price for Herceptin, which had U.S. sales of $1.3 billion last year, is around $40,000 a year.