RESUMEN
Breast cancer development and progression are believed to be a sequential process, from normal to hyperplastic, to in situ, and to invasive and metastatic stages. Given that over 90% of cancer deaths are caused by invasive and metastatic lesions, countless factors and multiple theories have been proposed as the triggering factor for the cascade of actions of cancer invasion. However, those factors and theories are largely based on the studies of cell lines or animal models. In addition, corresponding interventions based on these factors and theories have failed to reduce the incidence rate of invasive and metastatic lesions, suggesting that previous efforts may have failed to arm at the right target. Considering these facts and observations, we are proposing "A focal aberrant degeneration in the myoepithelial cell layer (MECL) as the most likely triggering factor for breast cancer invasion". Our hypothesis is based on our recent studies of breast and multiple other cancers. Our commentary provides the rationale, morphologic, immunohistochemical, and molecular data to support our hypotheses. As all epithelium-derived cancers share a very similar architecture, our hypothesis is likely to be applicable to invasion of all cancer types. We believe that human tissue-derived data may provide a more realistic roadmap to guide the clinic practice.
RESUMEN
Over the past two decades, the global efforts for the early detection and intervention of prostate cancer seem to have made significant progresses in the basic researches, but the clinic outcomes have been disappointing: (1) prostate cancer is still the most common non-cutaneous cancer in Europe in men, (2) the age-standardized prostate cancer rate has increased in nearly all Asian and African countries, (3) the proportion of advanced cancers at the diagnosis has increased to 8.2% from 3.9% in the USA, (4) the worldwide use of PSA testing and digital rectal examination have failed to reduce the prostate cancer mortality, and (5) there is still no effective preventive method to significantly reduce the development, invasion, and metastasis of prostate cancer Together, these facts strongly suggest that the global efforts during the past appear to be not in a correlated target with markedly inconsistent basic research and clinic outcomes. The most likely cause for the inconsistence appears due to the fact that basic scientific studies are traditionally conducted on the cell lines and animal models, where it is impossible to completely reflect or replicate the in vivo status. Thus, we would like to propose the human prostate basal cell layer (PBCL) as "the most effective target for the early detection and intervention of prostate cancer". Our proposal is based on the morphologic, immunohistochemical and molecular evidence from our recent studies of normal and cancerous human prostate tissues with detailed clinic follow-up data. We believe that the human tissue-derived basic research data may provide a more realistic roadmap to guide the clinic practice and to avoid the potential misleading from in vitro and animal studies.