Hope on the Horizon for Advanced Breast Cancer
New Treatments Are Prolonging Survival and Improving Quality of Life
As with hormone therapy, cancer experts now have more chemotherapy drugs available to treat women with advanced breast cancer than ever before. Researchers are trying out both combinations of different chemotherapy drugs and approaches that use them one at a time in different sequences. While it may sound insignificant, tinkering with combinations and sequences of chemotherapy drugs has made a big difference for women with breast cancer. Dose density therapy, in which chemotherapy medications are taken more frequently than traditionally, has also been shown to be effective in women with advanced cancer, even after standard chemotherapy has failed.
Isaacs predicts that state-of-the-art care for advanced breast cancer in the future may also combine chemotherapy with newer types of drugs: immunotherapy, hormone therapy, and even vaccines.
"The big move is to look at novel agents given in conjunction with standard chemotherapy. That may be a way to really make a dent on prolonging survival," Isaacs says. Genentech, the company that developed Herceptin, is now testing an antibody that blocks a growth factor that's important to the formation of new blood vessels. Such an antibody could work in combination with chemotherapy to choke off the growth of cancerous cells.
In a one-two punch, Herceptin is also being combined with the chemotherapy drugs, Taxol and carboplatin (brand name Paraplatin), in a large clinical trial by the U.S. Oncology Group and McGill University. Other studies have shown potential in Gemzar -- a drug currently approved to treat other types of cancer -- especially for women with metastatic cancer.
The Promise of Vaccines
At the University of North Carolina's Lineberger Cancer Center, scientists are about to complete a early human study of a therapeutic vaccine to treat advanced breast cancer. This type of cancer vaccine doesn't work the way that vaccines for infections like measles do. Those are given to people to prevent disease. Therapeutic cancer vaccines are being studied to help the body's immune system "rev up" to fight the disease. Initially, at least, they would be used in women who have exhausted all other treatments.
In this case, the vaccine is customized for each individual woman. Doctors take a woman's dendritic cells -- a type of white blood cell that alerts the immune system to the presence of abnormal proteins present in breast cancer cells -- and engineer them to boost their response against a particular type of abnormal protein.