According to results recently presented at the Madrid Breast Cancer Conference and published in the journal Breast Cancer Research, women with breast cancer whose cancer cells overexpress cyclo-oxygenase-2 (COX-2) have a poorer prognosis following treatment with Adriamycin® (doxorubicin)-based chemotherapy when compared to women whose cancer cells do not overexpress COX-2.
Breast cancer is diagnosed in over 200,000 women annually in the United States. Although cure rates remain high following standard therapy in women who do not have advanced breast cancer, a significant number ultimately succumb to their disease. Researchers are evaluating possible associations between patient and disease characteristics and outcomes of patients with breast cancer in order to individualize therapy and ultimately provide optimal outcomes for all patients.
COX-2 is an enzyme (protein) that plays a large role in inflammatory responses in the body. Recently, more results from studies have indicated that COX-2 may also have a role in the development or sustaining of some types of cancer. Further studies are necessary to confirm these findings; however, this information has led researchers to further evaluate its potential role in cancer treatment.
Researchers from Korea recently conducted a clinical study to evaluate the levels of COX-2 expressed by cancer cells and outcomes in women with breast cancer. This study included 178 patients who had early breast cancer that had spread to axillary (under the arm) lymph nodes. Patients were treated with the commonly utilized chemotherapy agent Adriamycin either alone or in combination with other chemotherapy agents. Overall, COX-2 was overexpressed in approximately 40% of cancers. Over-expression of COX-2 was associated with faster-growing cancers. In addition, women whose cancers overexpressed COX-2 had significantly shorter cancer-free survival times and overall survival compared to women whose cancers did not overexpress COX-2.
The researchers concluded that overexpression of COX-2 by breast cancer cells indicates a worse prognosis following Adriamycin-based chemotherapy. Future trials are necessary to determine if women whose breast cancer overexpresses COX-2 respond more favorably to other chemotherapy combinations, or more aggressive therapy. Women diagnosed with breast cancer may wish to speak with their physician regarding their individual risks and benefits of participating in a clinical trial further evaluating the role of COX-2 expression and associated outcomes with their disease. Two sources of information regarding ongoing clinical trials include the National Cancer Institute (www.cancer.gov) and www.cancerconsultants.com.
Reference: Han S, Kim J, Jung S, Song B. Cyclo-oxygenase-2 expression is associated with poor clinical outcome after doxorubicin-based chemotherapy in node-positive breast cancer: integration of tissue microarray. Proceedings from the VI Madrid Breast Cancer Conference: Changes in the treatment of breast cancer. Madrid, Spain, 1–3 June 2005.
Also published in Breast Cancer Research. 2005; 7(Suppl 1):P1 doi:10.1186/bcr1235