Pathology of breast cancer in the last half century.

The past 50 years has been an era of technological innovation converging with the now dominant culture of testing hypotheses using clinical trials and case cohort methodology with rigorous statistical analysis. Great advances have been made in early diagnosis and, especially, less toxic and disfiguring primary therapy. Many of the advances in pathology have been in conjunction with efforts to support clinical initiatives, improve diagnostic reliability and translate basic science discoveries into tests that stratify patient management. Pathologists, with the support of epidemiologists, have lead significant advancements in the description and clinical significance of benign breast disease. Despite considerable efforts, the cure for breast cancer awaits better understanding of the pathophysiology of metastasis. We stand now at the brink a new era of technology, in which powerful genomic assays may be put to use in uncovering targets of therapy and defining mechanisms of disease progression. Pathologists must be active in ensuring that discoveries in this realm are optimized by assuring association with appropriate histological correlation and valid clinical endpoints.