Breast cancer 2004: Progress and promise on the clinical front

Abstract

Carcinoma of the breast is the most common cancer in u.s. women (excluding skin cancer), and the second leading cause of cancer-related mortality. In 2004, it is estimated that 215,000 u.s. women will develop invasive breast cancer, and 40,000 women will die of the disease. Advancing age and female sex are the two greatest risk factors for the development of breast cancer, although family history, reproductive and hormonal history, lifestyle and environmental factors all contribute to risk. Models are available to help estimate risk of developing breast cancer in individual patients. Inherited mutations, specifically in the genes BRCA1 and BRCA2, account for approximately 5-10% of all breast cancer cases. Significant advances have recently been made in both the primary prevention of breast cancer (including chemoprevention), and secondary prevention (early detection through breast imaging). Breast mri as a tool for screening high risk women is a particularly exciting new tool. When breast cancer is diagnosed, optimal treatment involves a multidisciplinary approach, including surgery, radiation therapy, and systemic therapies. In the field of breast surgery, breast conservation and sentinel lymph node biopsy techniques have allowed substantially decreased surgery in appropriated selected patients with corresponding decreases in complication rates and long-term sequelae. Radiation oncologists are comparing partial breast irradiation versus conventional whole breast radiation in an attempt to minimize toxicity and treatment time, and maximize efficacy. The field of breast medical oncology has evolved at a rapid pace in the past decade, with numerous new hormonal agents, chemotherapeutic agents, and biologically targeted therapies in clinical use and under investigation. The addition of 'adjuvant' systemic therapy to the treatment of early stage breast cancer patients has dramatically reduced relapse and death rates. Unfortunately, metastatic recurrence still occurs. Once the cancer has spread beyond the breast and locoregional nodal areas it is felt to be incurable, although still treatable. A better understanding of breast cancer biology has led to the development of a host of new biologically targeted agents, many of which hold substantial promise for improving quality of life and survival rates in metastatic breast cancer patients.