Predictive factors in head and neck cancer.

As new knowledge of the molecular mechanisms of tumor development and progression is gained, studies are required to determine whether specific molecular genetic changes might be useful indicators in selecting patients for specific therapies. Alternatively, molecular or genetic changes may identify the patients at greatest risk for progression and relapse so that they can be treated with adjuvant therapy. p53 has an important function in the regulation of the cell cycle, DNA repair, and programmed cell death pathways. The Bcl-2 protein family has gained recent attention for its role in permitting or blocking apoptosis. Interaction between p53, Bcl-2, and other products of tumor suppressor genes or oncogenes are probably critical in tumor progression and response to treatment.