MOLECULAR BIOLOGY

The goal is to provide the right treatment to the right patient. The role of the pathologist is to accurately assess the biomarkers—something that is often difficult and complex. The oncologist’s role is to treat the patient using one of several standardized therapies (e.g., hormone therapy for ER/PR-positive breast carcinomas, trastuzumab for Her-2-positive breast carcinomas).

The International Programme on Chemical Safety of the World Health Organization, in collaboration with the United Nations and the International Labour Organization, defines a biomarker as any substance, structure, or process that can be measured in the body and may influence or predict the incidence of disease.

A biomarker is any molecule found in blood, fluids, or tissues whose expression indicates a normal or pathological condition. Biomarkers may be prognostic, predictive, or both.

• Prognostic biomarkers are independent prognostic factors, meaning their presence or absence is associated with the overall clinical outcome of a patient (i.e., risk of recurrence and mortality).
• Predictive biomarkers, on the other hand, can predict whether a patient will respond to a specific treatment.