Predictive Cancer Biomarkers

Personalized cancer treatment became a standard approach in the treatment of human cancers in twenty-first century. Among predictive cancer biomarkers, the estrogen and progesterone receptors (ER, PR) have the longest history: they have been used in the clinic to predict responses to endocrine therapy in breast cancer for over 40 years. ¹ Similarly, the HER2 receptor status measurements have been used clinically to predict responsiveness to trastuzumab (Herceptin) in breast cancers for over 15 years. The success of the personalized approach in oncology has multiple determinants. Among others, most prominent is the nature of the disease, which is multifactorial in principle and requires patient stratification in order to select the most appropriate treatment to achieve meaningful therapeutic benefit and to substantiate the relative high cost of therapy. Thus, biomarker driven drug discovery is a widely accepted paradigm in biopharmaceutical industry and molecular tumor examination and became standard prerequisite for indication of targeted biological therapy in routine clinical practice. During the last decade, many new validated predictive biomarkers for several cancer types have been introduced into clinical practice, and several promising biomarkers are undergoing clinical evaluation. This review is to recapitulate the current predictive biomarkers used in clinical practice (Figure 7.5.1, Table 7.5.1).384 385 386