Precision treatment for cancer: role of prognostic and predictive markers

Precision or personalized treatment can be defined as using the biological characteristics of a patient's disease in order to administer the most effective therapy at the optimum dose. The aim of this article is to discuss the use of prognostic and predictive markers to aid precision treatment in patients with cancer. Prognostic markers help to differentiate between indolent and life-threatening disease and thereby identify who should or should not receive adjuvant systemic therapy following surgical removal of a primary tumor. Predictive markers, on the other hand, help to identify upfront those patients who are likely to be responsive or resistant to a specific therapy. The use of prognostic and predictive markers can thus help to match each patient to the most effective and least toxic therapy and as a result avoid preventable toxicity and unnecessary costs.