Abstract
Two great challenges in cancer diagnosis and prevention are 1) the detection of specific preinvasive neoplastic lesions that give origin to malignant tumors and 2) the identification of those markers that predict the outcome of individual cancer patients. Neoplastic lesions may derive from epithelial or nonepithelial cellular populations. Often, preinvasive neoplastic lesions are small, multiple and may display wide ranges of diversity. Morphological alterations characterizing preinvasive neoplastic lesions include nuclear pleomorphism consisting of increased variation in nuclear size, shape, and hyperchromatism, abnormal mitoses, abnormal nucleolar patterns and altered or absent differentiation. The evolution of these types of lesions may take three directions: spontaneous regression, progression toward a fully malignant phenotype, or stasis, remaining as a preinvasive neoplastic lesion. Although there are discrepancies in terminology used by pathologists to describe these types of early neoplastic lesions, they are most frequently referred to as preinvasive neoplasia, dysplasia, carcinoma in situ, intraepithelial neoplasia, or as incipient cancer.
Carcinogenesis is an indivisible continuum of molecular and morphological changes that may culminate in the development of invasive tumors. Studies in which the molecular features of preinvasive neoplastic lesions are correlated with molecular features of matching invasive lesions, for example, a colorectal cancer with an adenomatous polyp forming its edge, should be useful in identifying molecular features associated with greater risks of progression. Similarly, studies of prognostic factors in specific cancers may identify molecular features associated with aggressive behavior.
In this session we will discuss the molecular aspects of early preinvasive neoplastic lesions; specifically, alterations in genes regulating proliferation, differentiation, apoptosis and invasiveness as well as chromosomal aberrations and microsatellite instability will be addressed. We will argue that the identification of molecular changes associated with neoplastic transformation will lead to the development of new molecular markers for the early detection of preinvasive neoplastic and malignant lesions, assessment of cancer risk, assessment of responses to preventive or therapeutic interventions, and separation of less aggressive neoplastic lesions from more aggressive lesions.
Citation Information: Cancer Prev Res 2011;4(10 Suppl):CN05-01.
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