(RxWiki News) More than a quarter of women diagnosed with breast cancer have high levels of HER2, a protein that makes the cancer grow faster and more likely to return. New research has discovered one treatment method that’s been used may no longer be necessary.
A new study found that Herceptin (trastuzumab) — a medication that targets the HER2 molecule — may not need to be given at the same time as chemotherapy.
While effective in shrinking the tumor before surgery, this combination is not warranted, the researchers concluded.
So the preferred method, according to this phase lll clinical trial, is to give the treatments in a sequential fashion.
"Ask your oncologist about the medications being used for your chemotherapy."
Aman Buzdar, MD, professor and vice president of clinical research at The University of Texas MD Anderson Cancer Center, and colleagues in the Alliance for Clinical Trials in Oncology looked at the timing of neoadjuvant (before surgery) therapies.
The goal of this neoadjuvant therapy is to reduce the size of or eliminate the tumor and whatever cancer is present in the regional lymph nodes to make surgery easier. This approach can possibly allow for breast conserving surgery, in which only the tumor and surrounding tissue is removed, instead of mastectomy, which removes the entire breast.
Herceptin can produce what doctors call a “complete pathological response” in 30 to 65 percent of patients, the authors noted in the study introduction. A complete pathological response means there is no evidence of disease.
The researchers in this study evaluated the timing of giving Herceptin and chemotherapy, either at the same time (concurrent) or one after another (sequential).
The phase lll trial enrolled 280 women with operable HER2-positive invasive breast cancer at 36 centers across the United States from September 2007 through December 2011.
These women were randomly assigned to receive either concurrent or sequential therapy.
In the concurrent group, 142 patients were treated with paclitaxel and trastuzumab weekly for 12 weeks. This was followed by fluorouracil, epirubicin and cyclophosphamide on day one of a 21-day cycle with trastuzumab on days one, eight and 15 of the 21-day cycle for four cycles.
In the sequential group, 138 participants received fluorouracil, epirubicin and cyclophosphamide on day one of a 21-day cycle for four cycles followed by paclitaxel plus trastuzumab weekly for 12 weeks.
Both groups achieved similar results: 56.5 percent of patients in the sequential group had complete pathological remission in the breast, as did 54.2 percent of participants in the concurrent group.
Remission rates for both the breast and the axillary (armpit) lymph nodes were also similar: 48.3 percent in the sequential group and 46.7 percent in the concurrent group.
Cardiac (heart) toxicity was about the same in both groups, with participants who received both therapies at the same time slightly more likely to have high blood pressure and heart pumping problems than the patients who received therapy sequentially.
Based on these findings, the researchers concluded, “Concurrent administration of trastuzumab with anthracyclines offers no additional benefit and is not warranted.”
Kelly Hunt, MD, professor of surgical oncology at MD Anderson and co-principal investigator of this trial, said in a statement, “If we can identify the patients most likely to have pathologic complete response with therapy, we can reduce or potentially eliminate surgery for these patients in the future.”
dailyRx News spoke with Contributing Expert Adam M. Brufsky, MD, PhD, professor of medicine at the University of Pittsburgh School of Medicine.
Dr. Brufsky said that he treats women with HER2-positive breast cancer with the latest evidence-based protocol. “At this point, many of us are treating women with TCHP and trastuzumab and not with anthracyclines based on the most current data,” he said.
The TCHP regimen consists of Taxotere (docetaxel), Carboplatin (tradename Paraplatin), Herceptin (trastuzumab) and Perjeta (pertuzumab).
Anthracycline chemotherapy agents include Adriamycin (doxorubicin) and Ellence (epirubicin).
This study was published November 13 in The Lancet Oncology.
The National Cancer Institute supported this research.
One author reported a financial relationship with Roche, and all other authors declared no conflicts of interest.