DUARTE, Calif., December 12, 2010 — City of Hope researchers and clinicians are presenting novel data, including overcoming acquired treatment resistance and cultural barriers to screening, at this year’s 33rd annual San Antonio Breast Cancer Symposium from Dec. 8 to 12 at the Henry B. Gonzalez Convention Center in San Antonio.
Highlights of the studies being presented include:
Heat Shock Protein 90 Inhibitors: New Targeted Therapy to Overcome Aromatase Inhibitor Resistance
Aromatase inhibitors (AI) are drugs used to treat estrogen-responsive breast cancers. However, over time some patients will relapse due to the cellular changes that allow the cancer to develop resistance to AI therapy. In examining the mechanisms of acquired AI therapy resistance and possible ways to bypass it, Shiuan Chen, Ph.D., director of City of Hope’s Division of Tumor Cell Biology, compared three types of breast cancer cells — AI sensitive, intrinsically AI resistant and acquired AI resistant — in their responses to AI therapy and a heat shock protein 90 (HSP90) inhibitor, a drug that interferes with a chaperone protein’s ability to help other proteins to fold properly and is essential for cell proliferation and survival.
In the laboratory study, Chen and his team found that HSP90 inhibitors arrested cell division and induced cell death for both intrinsic and acquired AI resistant breast cancer cells, while working synergistically with AI for cells still responsive to hormone therapy.
“Our study demonstrates that HSP90 inhibitors can be used in conjunction with AI therapy, which could both extend the treatment period for patients on AI therapy before the cells develop resistance as well as potentially treating drug resistant tumors,” Chen said.
Advances in Breast Cancer Risk Assessment, Screening and Prevention: Adapting the Lessons to an Underserved Latina Population
Breast cancer is the most common cancer and leading cause of cancer death in Latina women. Relatively frequent BRCA gene mutations place them at higher risk of developing breast and ovarian cancers at a younger age. While Latinas have a disproportionate burden of cancer, they have limited access to genetic counseling and testing. Jeffrey Weitzel, M.D., chief of City of Hope’s Division of Clinical Cancer Genetics, will discuss some of the obstacles for Latinas to get care, and the use of novel high-throughput genomic tools as cost-effective genetic testing strategies for women with likely inherited risk factors.
“Our clinical studies indicate that underserved patients who attend their scheduled consultations show a positive impact on cancer screening and prevention behaviors,” Weitzel said, “and that by adapting culturally sensitive interventions and using bilingual cancer risk counselors, we significantly increase participation in this underserved population, which can help them take positive steps to preventing the disease or treating it at earlier stages.”
Delayed Chemotherapy-induced Nausea and Vomiting in Asian Women with Breast Cancer
Despite advances in symptom management, chemotherapy-induced nausea and vomiting (CINV) continues to be a significant and distressing side effect of breast cancer treatment. Thehang Luu, M.D., clinical assistant professor in City of Hope’s Department of Medical Oncology & Therapeutics Research, had observed that patients of different ethnicities presented varying severity of side effects to chemotherapy, leading her to conduct a statistical analysis to see what factors may be associated to higher risk of CINV.
“Even when accounting for other variables, we have found that Asian patients experience more severe CINV than non-Asians,” Luu said. “Based on our analysis, CINV was also more prevalent in patients under 50 years of age, and those who were suffering from gastroesophageal reflux disease.”
Luu said further studies are needed to understand the underlying causes, but this data suggests that health care professionals should consider individual risk profiles and tailor their therapy to ensure optimal outcomes with minimal side effects.
