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Guest column

Drug helpful if cancer returns

By V. UPENDER RAO
Published July 11, 2005

About 8 to 9 percent of women will develop breast cancer. This year, there will be an estimated 211,240 new cases and 40,110 deaths from breast cancer in the United States. Approximately 1-million women are diagnosed with breast cancer each year in the world.

About 20 to 30 percent of all breast cancer patients will have more than the normal number of copies of a gene known as Her2. This causes an overexpression of this gene's protein product, which in turn stimulates the growth of cancer cells and confers a poor prognosis.

Herceptin is a drug designed to nullify the adverse action of the overexpressed Her2 oncogene. It is approved and extensively used for Her2 positive breast cancer patients if the disease recurs. Because of its effectiveness in recurrent cancer, researchers tested the addition of Herceptin to the standard adjuvant chemotherapy after mastectomy in clinical trials and found a dramatic decrease, more than 50 percent, in the cancer recurrence rate.

At the annual convention of the American Society of Clinical Oncology, the results of the two American trials conducted by the National Surgical Adjuvant Breast and Bowel Project and the North Central Oncology Group and a European trial, HERA, were presented. In the American trials, Herceptin was given either with Taxol or after the completion of Taxol. In the European study, Herceptin was allowed to be administered up to six months from the completion of chemotherapy. Each of these trials revealed a substantial benefit for Her2 positive breast cancer patients with the addition of Herceptin to adjuvant chemotherapy.

Congestive heart failure was a notable side effect seen to a variable extent depending upon the timing of the administration of Herceptin. Up to 4 percent of patients who received Herceptin with Taxol developed congestive heart failure; a lesser percentage of heart failure was noted among those who received Herceptin after completion of Taxol. An unpublished study is under way, examining alternate chemotherapy drugs that are not known to cause heart failure. If found to be equally effective, Herceptin could be combined with these other agents without the risk of heart failure.

The practical "take home points" for oncologists and breast cancer patients from these trials are:

--Adding Herceptin to chemotherapy after mastectomy decreases the risk of recurrence by at least 50 percent.

--Congestive heart failure can occur in up to 4 percent of patients who receive Herceptin at the same as Taxol.

--Incidence of heart failure is less if Herceptin is administered after the completion of Taxol, but the efficacy is also lesser.

--Patients who completed adjuvant chemotherapy within the past six months could still benefit from receiving Herceptin.

--The duration of Herceptin therapy in these trials varied from one year to two years. Whether less or more is better is unknown at this time. Further clinical trials could address this issue.

--Oncologists should evaluate the status of the heart before and after the adjuvant chemotherapy and periodically during the administration of Herceptin. For symptomatic patients, cardiology referrals might be beneficial.

--If the studies under way that examine non-cardio-toxic chemotherapy prove to be effective, heart failure will no longer be an issue.

Because this information is very recent, the third-party payers, including Medicare, will probably need time to approve Herceptin for adjuvant therapy of breast cancer.

Several leaders in breast cancer treatment feel that the addition of Herceptin to adjuvant chemotherapy for Her2 positive breast cancer patients will become the new standard of care. Those experts include George Sledge Jr., MD, co-director of the breast cancer program at Indiana University in Indianapolis; Edward Raymond, MD, from the University of Kentucky in Lexington;, William M. Hryniuk, MD, editor of HEM/ONC today ; and Edith Perez, MD, professor of medicine at the Mayo Clinic in Jacksonville and author of one of the studies mentioned above.

--V. Upender Rao, MD, FACP, practices at the Cancer and Blood Disease Center in Lecanto.

[Last modified July 11, 2005, 01:00:09]