Selection of appropriate cellular and molecular biologic diagnostic tests in the evaluation of cancer.

In this article, the use of cellular and molecular markers to diagnose and stage tumors is discussed. Their role in the evaluation of tumor prognosis and tumor susceptibility also is covered. The immunologic, cytogenetic, and molecular phenotype is discussed. Traditional markers are compared with newer methodologic approaches including evaluation of oncogenes, tumor suppressor genes, and genes that predict tumor susceptibility. These discussions are presented in relation to specific tumors. Finally, statements one might use to decide which tests to perform are presented.