The long awaited clinical trial to determine the best use of Herceptin has some good news for women with invasive HER2+ breast cancer. When Herceptin is used with chemotherapy, instead of after, the regime offers a 25 percent reduction in the risk of recurrence of cancer, or death, and should be the new standard of care says a Mayo Clinic researcher who led the key research.
Dr. Edith Perez, M.D., chair, North Center Cancer treatment Group (NCCTG) Breast Committee and a breast cancer researcher at the Mayo Clinic campus in Jacksonville, Fla., presented the findings at the Cancer Therapy and Research Center –American Association for Cancer Research (CTRC-AACR) 2009 San Antonio Breast Cancer symposium.
These findings may have global implications for women being treated for HER2+ breast cancer, which makes up 20 percent to 25 percent of all cases, Dr. Perez said.
Herceptin is the brand name for the monoclonal antibody Trastuzumab, the first humanized antibody approved in 1998 by the Food and Drug Administration for the treatment of HER2-positive metastatic breast cancer. Herceptin is designed to target and block the function of HER2 protein overexpression, according to its manufacturer, Genentech.
Research has shown that HER2-positive breast cancer is a more aggressive disease with a greater likelihood of recurrence, a poorer prognosis, and a decreased chance of survival compared with HER2-negative breast cancer.
In the United States, Herceptin is already approved for use on either a sequential or concurrent treatment schedule with adjuvant chemotherapy. In much of the rest of the world, Herceptin is used sequentially, Dr. Perez said.
The term adjuvant has a special meaning in oncology. Adjuvant therapy refers to additional treatment, usually given after surgery where all detectable disease has been removed, but where there remains a statistical risk of relapse due to occult disease.
“The results of this trial have been eagerly awaited in the U.S. and in many nations as this is the only trial developed to define the optimal way to incorporate Herceptin in the context of adjuvant chemotherapy,,” Dr. Perez says. “The goal was to decrease the risk of cancer recurrence, and we have shown that concurrent use is the best way to achieve that.”
Dr. Perez says the results show as many as 10,000 women around the world may have a better outcome each year if the drug is used in combination with chemotherapy. “Given that, I believe this study will lead to a global evaluation of how Herceptin is used,” she said.
Some of the study data—the (NCCTG) clinical trial N9831—have been released before, such as in 2005 in the New England Journal of Medicine. But this is the first time that mature outcome information on patients given sequential vs. concurrent treatment is available. The trial enrolled women who had surgery to treat Stage I-III invasive HER2+ breast cancer.
The study is the only phase III randomized clinical trial to assess chemotherapy alone versus either sequential or concurrent incorporation of Herceptin in patients. Chemotherapy used in the study was doxorubicin and cyclophosphamide, then paclitaxel, and was administered for approximately six months. Herceptin was given for 52 weeks.
“The study demonstrated that adding Herceptin clearly improves disease-free survival, with improvement if given after chemotherapy, but even more improvement if started concurrent with taxane-based chemotherapy,” Dr. Perez said.
Lynette Summerill, is an award-winning journalist who lives in Scottsdale, Arizona. In addition to writing about cancer-related issues, she writes a blog, Nonsmoking Nation, which follows global tobacco news and events.