Anthracyclines in Adjuvant Br... Video Transcript

Participants

Cathy Conley , Hyman B. Muss MD, Kathleen I. Pritchard MD, Carol L. Kornmehl MD, FACRO

Summary

Anthracyclines are becoming an increasingly important part of adjuvant therapy for breast cancer, with new data demonstrating its significant survival benefits.

Webcast Transcript

CATHY CONLEY: Hi, I'm Cathy Conley. I'm here at the Annual San Antonio Breast Cancer Symposium, where professionals have gathered to discuss the latest in breast cancer treatment. One approach on the table is the use of anthracycline-based adjuvant therapy.

Dr. Pritchard, what is adjuvant therapy, and why is it necessary?

KATHLEEN PRITCHARD, MD: Adjuvant therapy really means therapy that's given in addition to the primary therapy. For breast cancer, after diagnosis, the primary therapy is to remove the breast cancer, perhaps remove axillary lymph nodes and radiate the breast. Adjuvant therapy is hormonal therapy or chemotherapy that's given in addition to that in order to reduce the risk of recurrence of the breast cancer.

CATHY CONLEY: Doctor, it's now widely accepted that adjuvant chemotherapy containing an anthracycline is better than the historical treatment known as CMF. Why is that?

HYMAN B. MUSS, MD: There's a very wonderful thing that we've all participated in clinical trials called the Worldwide Overview, and they have data on about 190,000 women from all over the world, many American women, Canadian women who have been put in randomized trials comparing one drug with another by a coin flip, and in their trials, they've looked at the anthracyclines versus more traditional therapies like CMF, which are among the original adjuvant therapies that were so successful in improving survival. In the overview, the use of anthracyclines has further added to the benefits of CMF by about 10 to 15 percent. In those overviews, which are pretty convincing overall, I think it's pushed many physicians to consider anthracycline use. But again, in older women -- for instance, in their 70s -- and people with heart disease and others, their use is of great concern.

CATHY CONLEY: Doctor, what are the side effects of anthracyclines, and is there a difference between the two agents?

HYMAN B. MUSS, MD: Well, anthracyclines' major side effect is lowering blood counts. Both epirubicin and doxorubicin can be very damaging to the marrow. It's a transient effect in most patients, lower counts. When you have low blood counts, especially low white cell counts, you're at higher risk of infection, and that is the most dangerous side effect of chemotherapy.

Other side effects, like nausea and vomiting, we're actually very good with these days. Thinks like mouth sores, which can be very rough to have, are probably similar among the agents, and then, as we talked about with cardiac toxicity, the heart damage, probably in the doses they're given, it's probably not a major problem for either anthracycline if a patient is closely monitored. When you get to high doses, there might be some advantage for epirubicin.

CATHY CONLEY: Dr. Pritchard, is there anything you'd like to add?

KATHLEEN PRITCHARD, MD: Either adriamycin, the older anthracycline, or epirubicin, the newer anthracycline, both have cardiac effects, but you can give almost twice as much epirubicin as adriamycin before seeing the same cardiac effects, and the two drugs appear to be almost equivalent or barely different in terms of their antitumor effect. So you have a window where you can give more epirubicin with more effect on the tumor and less risk of cardiac effect.

There have been many head-to-head trials comparing doxorubicin and epirubicin in combinations and as single agents in metastatic disease, and in that setting it looks as though, milligram for milligram, epirubicin and doxorubicin are very similar in their effect against tumors.