Changing Paradigms in Breast Cancer Therapeutics: An Extended Abstract
These trials showed that invasive breast cancer has the ability to spread systemically very early, even before a cancer can be detected on mammographic imaging. Subsequently, clinical trial findings have shown that the use of postmastectomy radiation therapy improves survival in a subset of patients. Therefore, at least in some patients, better local (anatomic) control in addition to systemic therapy may result in an improvement in survival. In 2000, the US National Institutes of Health conducted a consensus conference. Key recommendations from this conference included that women with estrogen and/ or progesterone receptor-positive breast cancer should receive hormonal therapy (tamoxifen). In addition, most women diagnosed with early-stage breast cancer should receive combination chemotherapy. Although it was clear that not all women required chemotherapy, there was no reliable way to determine which women were able to be treated successfully with local therapy (surgery or surgery and radiation) and hormonal therapy alone, and which women required the addition of chemotherapy. One of the greatest developments in the 21st century has been the development of a better understanding of the impact of genetic profiles on health and disease. In the clinical laboratory, breast tumors are tested for the hormone receptors (estrogen and progesterone) using immunohistochemistry, and for HER2 (human epidermal growth factor receptor 2) overexpression using either immunohistochemistry or fluorescent in situ hybridization. Advances in genetic or molecular profiling have provided increasing evidence that breast cancer is not a single disease process Breast cancer is the leading cause of cancer in women worldwide, with an incidence of 1,671,000 and a mortality of 522,000 according to GLOBOCAN 2012 [1] . Over the past several decades, breast cancer has increased in incidence, but in regions of the world with access to cancer care, mortality has decreased. During the same time, our understanding of the pathophysiology of breast cancer has changed dramatically. In the late 1800s, the standard treatment of breast cancer was radical mastectomy. This approach was based on an understanding of cancer as an anatomical disease. In short, the thinking at the time was that cancer spread in an orderly fashion from the breast to the regional lymph nodes and from there to distant sites. This understanding led to the development of Halsted’s radical mastectomy – more extensive surgeries were thought to remove the cancerous cells before the cells had time to spread. However, not all surgeons at the time of Halsted were able to replicate Halsted’s results, and it was noted that even patients with small tumors and radical surgery would sometimes experience a recurrence. It took over a century to perform randomized clinical trials demonstrating that breast cancer is a systemic disease and therefore extensive surgical therapy did not improve survival. In the 1970s, randomized clinical trials were initiated to resolve controversy over the surgical management of breast cancer. After 20 years of follow-up, no significant difference in overall survival was found between women who underwent mastectomy and those who underwent lumpectomy with or without postoperative breast irradiation [2, 3] . Received: October 13, 2015 Accepted: December 20, 2015 Published online: December 21, 2015