Over 1.5 million new cancer cases were identified in the United States in 2010, and despite continued advances in cancer treatment, approximately 500,000 cancer-related deaths occurred in the same year (1). For a long time, cancer therapies were a one-size-fits-all, depending on the cancer type. In recent years however, the need has emerged to develop a more enlightened paradigm in which treatments are better tailored towards the individual uniqueness of the cancer (2).

Personalized Medicine is a catch phrase that reflects the current understanding that no two patients are alike. The primary goal of personalized medicine is to develop patient-specific treatments that can hopefully reduce unnecessary side effects as well as the overall cost of cancer care by using therapies that are most likely to be effective in the population that is most likely to benefit (3).

The field of personalized medicine is rapidly expanding and Targeted Therapies are the cornerstone of the personalized medicine revolution. Targeted therapies are drugs that block the growth and spread of cancer by interfering with specific molecules involved in tumor growth and progression and as such, may be more effective than other types of treatment, including chemotherapy and radiotherapy, and less harmful to normal cells (4).

According to the National Cancer Institute (NCI), many targeted cancer therapies have been approved by the U.S. Food and Drug Administration (FDA) while others are being studied in clinical trials. Some key examples of classes of agents include (4):

* Signal transduction inhibitors, which block specific enzymes and growth factor receptors involved in cancer cell proliferation

* Modifiers of proteins that regulate gene expression and other cellular functions

* Inducers of apoptosis

* Inhibitors of tumor blood vessel growth

* Monoclonal antibodies that deliver toxic molecules to cancer cells

* Cancer vaccines and gene therapy


Nevertheless, targeted therapies have some limitations. Chief among these is the potential for cells to develop resistance. As a result, targeted therapies may work best in combination, either with other targeted therapies or with more traditional therapies (4).

Cancer is a complex genetic disease and as more is learned about the genetic mechanics of cancer growth, the hope is that this knowledge will be leveraged to identify new molecular diagnostics and provide new strategies for tailoring therapies to fit the needs of each cancer patient's unique biology.


1. CA Cancer J Clin. 2010 Sep–Oct;60(5):277-300

2. http://www.lef.org/magazine/mag2010/apr2010_Cancer-Treatment-Utilizing-Advanced-CTC-Molecular-Analysis_01.htm

3. Sonali Smith, MD, ASCO Annual Meeting 2009

4. http://www.cancer.gov/cancertopics/factsheet/Therapy/targeted

About the Author: Karen Ventii, PhD, is a medical writer based in Atlanta, Ga.

The views expressed are those of the author and are not necessarily those of Scientific American.