- Question from Photot: What, if anything, is available for those of us who are "triple negative"? Is there anything on the horizon for these types of cancers?
- Answers - Andrew D. Seidman, M.D. I think that is an excellent question and it begs clarification for those who are reading who might not be familiar with the term "triple negative." This refers to tumors that lack significant expression of estrogen receptor (ER), progesterone receptor (PR), as well as HER2. This is a clinical setting where we recognize the lack of expected benefit for hormonal therapies, as well as Herceptin, and thus we rely primarily on cytotoxic chemotherapy drugs to improve patient outcomes. Ongoing research is focusing on this group of patients to identify whether specific chemotherapeutic agents that currently exist may be more beneficial in triple-negative breast cancer, and also efforts are ongoing in the laboratory and the clinic to develop unique tailored strategies for this group of patients. There is some evidence in the laboratory that the platinum compounds and also the chemotherapeutic agent Camptosar (chemical name: irinotecan) may have particular promising activity in triple-negative breast cancers. Also, medications that target HER1 (also known as the epidermal growth factor receptor, or EGFR)—such as Erbitux (chemical name: cetuximab), Tarceva (chemical name: erlotinib), and Iressa (chemical name: gefitinib)—are currently being studied individually and together for these challenging tumors. I also want to point out that even the term "triple-negative breast cancer" is an oversimplification. Within those breast cancers that lack ER, PR, and HER2 are many sub-classes of tumors that have even further differences in gene and protein characteristics. It is likely that future breast cancer treatments will become even more tailored to specific genetic sub-types well beyond the simple classification by ER, PR, and HER2.
- Jennifer Armstrong, M.D. Thank you Dr. Seidman. That was an incredibly thorough and informative explanation. I also want to add that patients with triple-negative tumors are candidates for treatment with Avastin in the metastatic setting. I am not aware of whether Avastin is being studied in the adjuvant setting in breast cancer.
- Andrew D. Seidman, M.D. Because of the results of the randomized trial known as ECOG-2100, where the addition of Avastin to weekly Taxol (chemical name: paclitaxol) was of significant benefit in advanced breast cancer, clinical trials will soon begin that will randomize patients with early stage breast cancers to receive Avastin or not. Currently, smaller Phase 2 so-called "pilot studies" are going on that are more focused on addressing the safety of combining Avastin with chemotherapy as part of the adjuvant and indeed neo-adjuvant treatment of early stage breast cancer. I am not aware of any evidence to suggest that Avastin or other anti-angiogenic agents would be preferentially more or less effective as a function of estrogen receptor, progesterone receptor, or HER2 receptor status. There are some laboratory data to suggest that targeting the HER2 receptor in combination with an anti-angiogenic approach such as Avastin could make sense for patients. However, to date, we only have preliminary data from Dr. Mark Pegram and colleagues at UCLA. This practice should not be used outside of clinical trials.
- Jennifer Armstrong, M.D. Avastin now has compendial listing (in breast and lung cancer), which means that based on the studies that Dr. Seidman was just referring to, patients with advanced breast cancer can be considered for treatment with Avastin and will be able to receive it.
The Ask-the-Expert Online Conference called Targeted Therapies: What Is Right for You? featured Andrew Seidman, M.D. and moderator Jennifer Armstrong, M.D. answering your questions about different kinds of targeted therapies and how they work.
Editor's Note: This conference took place in July 2006.
The materials presented in these conferences do not necessarily reflect the views of Breastcancer.org. A qualified healthcare professional should be consulted before using any therapeutic product or regimen discussed. All readers should verify all information and data before employing any therapies described here.
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