Advances & Insights: Cancer
February 2, 2006
What the news means for you
Edward Romond, MD
Study changes standard of breast cancer care
This NCI study has changed the practice of breast cancer medicine quicker than almost anything we've seen in a long time. The treatment has been adopted very quickly by doctors who treat women with breast cancer and I think it's because the results are so strikingly beneficial. Women who face HER-2 positive breast cancer are benefiting from these results almost immediately.
"[It] is the biggest improvement in outcomes for women with breast cancer in 25 years."
HER-2 positive breast cancer
About 25 percent of breast cancers are HER-2 positive, which means they're more likely than other kinds to spread to other organs and to recur despite chemotherapy. This study has changed the outcome from one of the most worrisome kinds of cancer to one that has a much better prognosis.
Breast cancer is still the most commonly diagnosed cancer in women and the second leading cause of cancer-related death in women in this country. More than 211,000 women are diagnosed with the disease annually and approximately 40,000 of that number will die, accounting for about 15 percent of all cancer-related deaths in women in the nation.
Breast cancer risk factors
Despite decades of research, we still haven't pinpointed the precise cause of breast cancer, as we have with lung cancer for example. We do know there are risk factors-for example just being a woman, growing older or having a family history of breast cancer puts a person at risk.
Other factors have been identified as inherited genetic mutations, but those account for only about one in 20 cases. There's also some increased risk among women who've taken hormone replacement therapy long past menopause and those who regularly consume three or four alcoholic beverages daily.
Detecting breast cancer
One of the most important things a woman can do to protect herself is to begin breast self-examination in her 20s so she is familiar with her own breast tissue and able to identify any changes later on. Annual mammograms should begin at age 40, or earlier if the woman's mother or sister had breast cancer before age 50. In addition, an annual exam by a primary care physician or nurse practitioner is important since not all breast cancers show on mammograms.
In the last two decades the level of breast cancer research and support has increased substantially. The number of deaths and recurrences has been going down because we're finding cancers earlier through mammograms and the treatment is much better. For example, tamoxifen, which was introduced in the 1980s, has proven to be a very powerful drug in stopping the spread of hormone-receptor positive cancers and reducing the risk of recurrence. New hormone therapies are improving the benefits already achieved with tamoxifen.
Treating breast cancer
It's important to recognize that breast cancer is not a single disease. New research is separating breast cancer into at least four different diseases based on the genetic make-up of the cancer cells. A pathology report will usually contain a description of cell type and grade. Other useful information derived from the pathology laboratory includes estrogen receptor and progesterone receptor status as well as HER-2 status. This information can help to guide treatment.
It's too early to say that Herceptin is a cure. We can say there was a 52 percent reduction in recurrence among the women in the NCI studies who took Herceptin along with chemotherapy. In addition, three or four years after surgery, 90 percent who had that treatment have no evidence of cancer in other parts of their body. That is the biggest improvement in outcomes for women with breast cancer in 25 years.
Like many other cancer treatments, Herceptin has its risks. A small number of women taking the drug suffer heart failure. Herceptin is also quite expensive. A year's worth of therapy can cost up to $50,000, but most insurance providers will likely pay for it. Given the fact that we're saving lives and significantly reducing recurrence, it is well worth the risk and expense. Additionally, there are programs for women who don't have the resources to pay for the treatment.
What lies ahead?
We have a lot more questions to answer now: Which patients get the most benefit from taking Herceptin? Why do some patients experience recurrence of breast cancer in spite of taking Herceptin? What other targeted therapies can we use along with Herceptin that would improve the results over what we have now?
Basic research done in breast cancer is finding a number of targets that could be approached, and new medications are being developed to target these other proteins that occur in cancer.
Dr. Romond is a professor of medicine at the University of Kentucky College of Medicine and UK Markey Cancer Center. In addition, he serves as the protocol chair for the NCI-sponsored study and chairs the National Surgical Adjuvant Breast and Bowel Project Herceptin Study.
Study shows effectiveness of drug in early breast cancer
The cancer drug Herceptin® has been used successfully for several years in treating women with a particularly virulent form of breast cancer that has spread to other organs. But could it work as effectively in earlier-stage disease to prevent metastasis (spread of cancer to other organs)? Medical researchers set out to answer this question in clinical trials involving of 3,351 women, and the results turned out to be stunning.
The trials were sponsored by the National Cancer Institute and conducted by a network of researchers led by National Surgical Adjuvant Breast and Bowel Project and the North Central Cancer Treatment Group, in collaboration with the Cancer and Leukemia Group B, the Eastern Cooperative Oncology Group and the Southwest Oncology Group. Genentech Inc., which manufactures trastuzumab under the brand Herceptin, provided the drug. More than 500 testing sites throughout the U.S. and Canada were involved. Results were published in the New England Journal of Medicine on Oct. 20, 2005.
Benefits of Herceptin were so clear. . . that the clinical trials were stopped in April 2005 and patients in the control group were offered the drug.
Patients with early, operable HER-2 positive breast cancers that had not yet spread to other organs but were present in at least one lymph node were enrolled in these studies conducted between February 2000 and April 2005. HER-2 is a growth-promoting protein present in small amounts on the surface of normal breast cells and in most breast cancers. Approximately 25 percent of breast cancers, however, have very high amounts of this protein and tend to grow and spread more aggressively.
Herceptin administered in addition to chemotherapy
Herceptin is an example of targeted antibody therapy directed against a specific change in the cancer cell. It was approved by the FDA for treatment of advanced HER-2 positive breast cancer in 1998.
The recently reported studies looked at the effectiveness of Herceptin along with traditional chemotherapy given to the women immediately after surgery. Participants received either:
- Chemotherapy drugs doxorubicin and cyclophosphamide followed by paclitaxel, or
- The same chemotherapy regimen with the addition of Herceptin. Herceptin was administered intravenously once a week for three months during chemotherapy, then weekly for nine months.
The women who took Herceptin in addition to chemotherapy experienced a 52 percent reduction in recurrence in their cancer, as compared to patients who received chemotherapy alone.
After a follow-up of approximately two years, researchers found the mortality rate was reduced by one-third in the Herceptin group. Even though women in the control group were given Herceptin when they experienced recurrences, they still did not do as well as those who received the therapy up front. Other factors influencing survival included the patient's age, hormone receptor status, tumor size and number of positive nodes.
Herceptin therapy not for all
Researchers emphasized that Herceptin therapy isn't for everyone and it does involve risks. The primary concern is an increased risk of cardiac dysfunction. In the NCI studies, there was about a 3 percent increase in congestive heart failure among the women taking Herceptin. Further research is being done to see whether the heart problems are reversible and to determine how to administer Herceptin with chemotherapy to minimize risks.
However, the benefits of Herceptin were so clear for women with early HER-2 positive breast cancer that the clinical trials were stopped in April 2005 and patients in the control group were offered the drug. The FDA is currently reviewing Herceptin for use with women in the earlier stages of breast cancer.
UK HealthCare Cancer Services - Markey Cancer Center
For more information, or to make an appointment with a UK HealthCare physician, please call UK Health Connection at (800) 333-8874.