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Abstract
Colorectal cancer (CRC) is one of the leading causes of morbidity and mortality.
Colorectal cancer is the fourth most common cancer in the United States and the second leading cause of cancer mortality. Nearly 150.000 new cases were diagnosed with estimated 50.000 deaths expected annually in the United States (Jernal Aet al.
2004).
Due to the importance of this disease, screening and early detection using Fecal occult blood test , biological markers tests, digital rectal examination, sigmidoscopy, colonoscopy and others especially for patients at average risk have proven to reduce colorectal cancer mortality in large-scale randomized controlled trials (Pignone et al 2002).
The important biological pathways as; Epidermal growth factor receptors (EGFR), Vascular endothelial growth factor receptor(VEGER), and Cyclo-oxygenase-2 (COX-2) with their inhibitors and their role in disease control rate and survival will be discussed in this essay.
Targeted therapies represent a new era of cancer therapy.
Some of the most encouraging advances seen in cancer treatment are the result of decades of basic research studying the complex processes that direct a healthy cell to become cancerous and a cancerous cell to develop into a tumor that is capable of spreading throughout the body.
Targeted therapy consists of different types of drugs,Monoclonal antibodies that attach to tumor cells and either mark the cell for attack by the immune system, block specific transmembrane receptors, or deliver chemotherapeutic or radioactive drugs. Drugs that inhibit signaling pathways for growth and proliferation within tumor cells and Therapy to block expression of oncogenes (Gene therapy)The fact that tumors are dependent on angiogenesis for growth and metastasis has led to the development of antiangiogenic strategies for cancer treatment, vascular endothelial growth factor (VEGF-A) is a key mediator of normal and tumor angiogenesis.
The epidermal growth factor receptor (EGFR) is an important mediator of normal cellular processes such as growth, survival, differentiation and morphogenesis it was identified in 1962, and was purified and characterized by Stanley Cohen in 1980, work for which he drugs are very expensive. Their economic cost is giving pause to payers and patients, insurance providers, and pharmaceutical manufacturers.