Her2 Trial Results

Herceptin and Chemo Before Surgery Better Than Chemo Alone
A. U. Buzdar et al.

American Society of Clinical Oncology annual meeting June 2004 Abstract #520

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August 2004 Research News
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Herceptin and Chemo Before Surgery Better Than Chemo Alone

Many Women in the U.S. Do Not Get Regular Mammograms

Male Breast Cancer on the Rise

Background and importance of the study: Herceptin (chemical name: trastuzumab) works only against breast cancers that make too much of a special protein called HER2/neu or HER2. These cancers are called HER2-positive. About one of every four breast cancers is HER2-positive.

As of July 2004 Herceptin has been approved by the U.S. Food and Drug Administration (FDA) only for women with advanced (metastatic stage IV) HER2-positive breast cancer. But many women with earlier stages of HER2-positive breast cancer are wondering whether they should take Herceptin to lower their risk of the cancer coming back.

Words on this page

• trastuzumab
• metastatic
• neoadjuvant therapy
• lumpectomy
• mastectomy

Large clinical trials are looking at Herceptin for women with stage II and III HER2-positive disease. Many important questions may be answered when the results of these studies are released. Until then most doctors will only use Herceptin for women with stage II or III breast cancer as part of a clinical trial.

Meanwhile many of you are asking your doctors some of the very questions that remain unanswered. Will the potential benefits of Herceptin outweigh the possible side effects for women with stage II and III disease? How long will the potential benefits and side effects of Herceptin last? How long can or should women take Herceptin to lower the risk of recurrence? We need to wait for the results of ongoing clinical trials to answer these questions.

Another question that comes up is: Can Herceptin before surgery help shrink a medium-to-large cancer to make it more likely that you can have breast-conserving therapy instead of mastectomy?

Giving a treatment before surgery is called neoadjuvant therapy. The study reviewed here looked at giving neoadjuvant Herceptin along with chemotherapy.

Study design: The study included 42 women with stage II or III HER2-positive breast cancer. About half of the women received only chemotherapy. The drugs included Taxol (chemical name: paclitaxel) plus the FEC combination (5-fluorouracil epirubicin and cyclophosphamide). The other women received the same chemotherapies plus Herceptin. Both groups received the treatments before surgery.

The researchers looked at how much the women's cancers shrank in the two groups. And they looked carefully at the results of each woman's surgery as described in her pathology report.

Results: Twelve of the 18 women (65%) who got chemotherapy and Herceptin had a "pathological complete response" to the therapy compared to 4 of the 16 women (25%) who got only chemotherapy. A pathological complete response means that no cancer was present in the breast tissue that was removed after the women had received neoadjuvant treatment.

The researchers had originally planned to include 164 women in their study. But after fewer than 50 women had completed therapy the committee that was monitoring the study stopped it. They did this because the results with chemotherapy plus Herceptin were so much better than with chemotherapy alone.

When the results of a study strongly suggest that there is a 95% or higher chance that patients will do better with one type of therapy over the other the trial is stopped to give everyone the benefit of the better treatment.

None of the women in either group had serious heart problems—an uncommon but serious side effect of Herceptin.

Take-home message: This study was very small (only 42 women) but it suggests that adding Herceptin to chemotherapy before surgery can significantly reduce the size of the cancer for women with stage II or III HER2-positive disease without serious side effects.

This means that if you have stage II or III HER2-positive breast cancer taking Herceptin with chemotherapy before surgery may allow you to have breast preservation therapy (lumpectomy plus radiation) rather than mastectomy.

Still this small study can provide only limited information. Larger studies are needed to confirm the results.

And even in this study Herceptin didn't work for everyone. As with any other treatment you have to carefully consider the potential benefits and drawbacks for YOU.

Herceptin does have potential side effects including possible damage to the heart. In this study there was no increase in serious heart problems with Herceptin. But again larger studies are needed to support this result.