How Common Is Use of Off-Label Drugs in Breast Cancer?

Cancer Newsline - July 2009

Many Patients Receive Legal But Non-Approved Drugs

More than one-third of breast cancer patients receive chemotherapy drugs that, while approved by the U.S. Food and Drug Administration (FDA), have not been vetted specifically to treat the disease.

The use of drugs for conditions other than those for which they were approved is legal, and, according to a study by M. D. Anderson researchers, prevalent in breast cancer treatment. The study was presented at the American Society of Clinical Oncology's (ASCO) annual meeting in May.

Significance of study

After rigorous clinical trials for safety and efficacy, drugs are approved by the FDA for use in a specific condition by a specific population — as a frontline therapy for metastatic breast cancer patients, for example. However, once a drug is approved, physicians can prescribe it as they deem appropriate.

While the off-label use of chemotherapies is known to be common practice in the management of breast and other cancers, there's been little research on its prevalence or impact, says the study’s senior author, Sharon Giordano, M.D., associate professor in M. D. Anderson's Department of Breast Medical Oncology.

"Off-label drug use runs a dramatic spectrum,” she says. “Sometimes there's strong evidence that the use of a particular drug in a specific setting is effective, but perhaps the drug company has not gone through the regulatory process of getting approval. In contrast, some off-label uses of drugs are completely inappropriate and may put patients at risk."

Adding to the controversy is the fact that off-label uses often are not approved by Medicare, Medicaid or insurance companies, even when they’ve shown to be effective in clinical trials.

Background

This is the first known study of the prevalence and impact of off-label therapies in breast cancer.

It has been nearly 20 years since the U.S. General Accounting Office conducted a study that evaluated off-label drug use in all types of cancer.

Research methods

Giordano and colleagues used the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) database, the premier population-based cancer registry representing 26% of the country's population.

They identified 2,082 women with metastatic breast cancer.

The women were:

Over 65 years old
Diagnosed between 1991 and 2002

Primary results

Of the 36 chemotherapy agents used to treat these patients, 22% were FDA-approved for use in breast cancer.

Almost 35% of the women were treated with off-label chemotherapy drugs.

Of these patients:

16% received Navelbine® (vinorelbine), which is approved for lung cancer
8% received Gemzar® (gemcitabine), which is approved for pancreatic cancer
7% received drugs considered medically inappropriate

Both vinorelbine and gemcitabine have been shown to be effective in the treatment of metastatic breast cancer, Giordano says. Gemcitabine has been approved for breast cancer when given in combination with Taxol® (paclitaxel).

Additional results

Since physicians tend to be more conservative in treating older patients, Giordano says the findings may underestimate the use of off-label drugs in breast cancer treatment.

What’s next?

Off-label drugs are an even greater issue in rare cancers, Giordano says. As a follow-up to this study, she plans to look at off-label use across a variety of tumor types and stages of cancer. She also intends to review their use in younger breast cancer patients.

"I think our study represents a very difficult and relevant policy issue that will soon need to be addressed,” she says.

This article was adapted by Dawn Dorsey from an M. D. Anderson news release.

M. D. Anderson Study First to Evaluate Prevalence, Impact of Off Label Chemotherapy in Breast Cancer