Epidermal growth factor receptor (EGFR) inhibitors have emerged as important drugs in cancer therapy, providing a proven survival advantage for some patients with non–small-cell lung cancer, colorectal cancer, head and neck cancer, and pancreas cancer.
Breast cancer is the most common female malignancy in the Western world. Two-thirds of all breast cancers are estrogen receptor (ER)-positive, a phenotypic characteristic that is prognostic of disease-free survival and predictive of response to endocrine therapy.
Historically, breast tumor classification and therapeutic decisions have relied on immunohistochemical (IHC) techniques for characterizing biomarkers such as estrogen receptor (ER), progesterone receptor (PR), and the epidermal growth factor receptor 2 (HER2), as described in the review by Ma and colleagues. However, these markers have been found to be inadequate for fully predicting a patient’s response to a given breast cancer treatment such as endocrine therapy.
This article reviews ongoing progress in the effort to identify predictors of endocrine therapy responsiveness for breast cancer and discusses the value of “pre-treatment” vs “on-treatment” tumor profiling for predicting outcomes.
Luteinizing hormone-releasing hormone analogs (LHRHa) are often used alone or in combination with tamoxifen to suppress ovarian function in premenopausal women with endocrine-responsive breast cancer. However, aromatase inhitiors (AIs) are now the preferred first-line endocrine treatment for postmenopausal women with breast cancer.
SAN ANTONIO-Data presented at SABCS 2008 by the ATAC Trialists’ Group extends the value of the Oncotype DX Recurrence Score in assessing risk of distant recurrence in breast cancer patients receiving an aromatase inhibitor.
Based on the 1995 Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) Overview, tamoxifen is now the standard of care for premenopausal women with hormone receptor–positive early breast cancers.[1]
Developed over a century ago,[1] endocrine therapy remains the most effective and the most clearly targeted form of systemic therapy for breast cancer. Endocrine treatments work best in women whose tumors are positive for estrogen receptors (ER) and/or progesterone receptors (PR).
The optimal endocrine therapy for premenopausal women with hormone receptor–positive early breast cancer remains elusive. Dr. Pritchard presents a thoughtful review of this important topic, including the historic context for the current controversy regarding the utility of ovarian suppression (either by medication or permanent ablation) in the adjuvant treatment of young women with breast cancer.
Patients with operable triple-negative breast cancer are at increased risk for recurrence if their tumor has higher levels of a protein-encoding gene implicated in migration, proliferation, and other cellular processes, reported Joseph A. Sparano, MD, from the Eastern Cooperative Oncology Group.
Lapatinib (Tykerb) plus letrozole (Femara) may delay disease progression in metastatic breast cancer patients, according to an international phase III trial. Patients who benefited from the protocol were those who overexpressed the HER2/neu protein and the epidermal growth factor receptor and were also hormone receptor-positive.
Neoadjuvant therapy that includes trastuzumab (Herceptin) prolongs event-free survival and has an acceptable safety profile in women with HER2-positive locally advanced breast cancer, based on results from the largest trial testing such therapy in this setting.
Expression of the microtubule-binding protein Tau is not a reliable means of selecting breast cancer patients for adjuvant paclitaxel chemotherapy, investigators from Houston’s M.D. Anderson Cancer Center stated, adding that while Tau expression does predict survival, it does so in an unexpected way.
Data presented by the ATAC Trialists’ Group extends the value of the Oncotype DX Recurrence Score in assessing risk of distant recurrence in breast cancer patients receiving an aromatase inhibitor.
The cure for cancer lies in the biology of circulating and disseminating tumor cells that, unfortunately, evade detection and treatment very easily, according to one of the world’s leaders in the field. In a plenary lecture, Klaus Pantel, MD, described the properties and clinical relevance of the cells that eventually cause metastatic relapse but remain elusive at primary diagnosis.
The concept of bisphosphonates as anticancer agents took a leap forward this week thanks to results from the AZURE trial. Investigators from the UK reported that patients receiving zoledronic acid along with neoadjuvant chemotherapy experienced a doubling in complete pathological response.
Oncology NEWS International guest editor Dr. Andrew D. Seidman recommends SABCS 2008 lectures on modern molecular science, molecular profiling, and the American Association of Cancer Research distinguished lectureship in breast cancer research.
Insight into the molecular workings of HER2-positive breast cancer has paved the way for targeted agents that are showing great promise in clinical trials, according to a presentation at SABCS 2008. José Baselga, MD, from Barcelona, offers a primer on pertuzumab, trastuzumab-DM1, heat shock protein 90, and other agents that will provide “tremendous opportunity” in HER2-positive cancer treatment.
Emerging knowledge about breast cancer biology must be integrated into clinical trials in order to personalize treatment in patients with early breast cancer. Two speakers at an educational session on clinical trial design discussed our advancing understanding of basic science and the ways in which that can change and refine the design of clinical trials.
Estrogen-receptor–positive advanced breast cancer patients who have become resistant to endocrine therapies can derive clinical benefit from 6-mg daily doses of estradiol, according to a phase II study conducted at Washington University in St. Louis.
Combining endocrine therapy with signal transduction inhibition is an effective means of overcoming endocrine resistance in at least some populations of patients with breast cancer. Stephen R.D. Johnston, MA, PhD, director of clinical research and development at the Royal Marsden Hospital in London, discussed the data on this emerging strategy during an SABCS plenary lecture.
Aromatase inhibitors were associated with greater reductions in the risk of breast cancer recurrence in comparison with tamoxifen, according to a meta-analysis involving nearly 20,000 hormone receptor-positive early breast cancer patients.
Women with breast cancer who have isolated tumor cells or micrometastases in their sentinel lymph nodes are at increased risk for recurrence, even if their cancer otherwise has favorable features. Adjuvant systemic therapy, however, can attenuate that elevated risk, according to the findings of a major Dutch study.
The American Association for Cancer Research will provide scientific expertise to Love/Avon Army of Women, an organization that seeks to link more than one million women volunteers with cancer researchers across the country to discover breast cancer causes and to aid in prevention.
CHICAGO-Targeted radiation of breast cancer after lumpectomy reduces treatment time from six and a half weeks to five days, while reducing pain and improving cosmetic outcome, according to a study presented at RSNA 2008 (abstract SSC19-02).
