CHICAGOThe role of endocrine therapy in breast cancer is still evolving, with about half a dozen agents contending as players in the metastatic, adjuvant, and chemoprevention settings. At the Lynn Sage Breast Cancer Conference, William J. Gradishar, MD, summarized recent clinical trials and put the current agents into a clinical context for oncologists.
Dr. Gradishar is director of Breast Medical Oncology at the Robert H. Lurie Comprehensive Cancer Center and associate professor of medicine at Northwestern University.
Clinical trials have shown a wide range of response to various endocrine therapies, largely because of heterogeneity and variability in subjects and trial design. Generally, however, about one third of patients will respond to endocrine therapies, he said.
Candidates for Therapy
Dr. Gradishar summed up the general suitability of patients for endocrine therapies as "patients who are hormone-receptor (HR)-positive, have a long disease-free interval between their initial diagnosis of breast cancer and metastatic disease, and generally have nonvisceral disease. Although visceral disease will also respond, it is probably more suitable for chemotherapy initially."
The idea that premenopausal patients do not respond to endocrine therapy is probably a misconception, he said, "but the frequency of HR-positive disease is clearly greater in older patients."
Patients who respond to one endocrine therapy have an increased likelihood of responding to subsequent endocrine maneuvers. "While response rates generally diminish with each succeeding therapy, there are patients who can go on to second-, third-, fourth-, and even fifth-line therapy. The fundamental question we grapple with as newer agents go forward is the sequence with which to use these agents," he said.