Different mechanisms in the tumorigenesis of proximal and... : Current Opinion in Oncology (original) (raw)
Cancer biology
Different mechanisms in the tumorigenesis of proximal and distal colon cancers
Department of Clinical Genetics, Karolinska Hospital, Stockholm, Sweden
Correspondence to Annika Lindblom, MD, PhD, Department of Clinical Genetics, Karolinska Hospital, S 171 76 Stockholm, Sweden; e-mail: [email protected]
Abstract
Environment or genetic constitutions can lead to an increase of genetic or epigenetic events and increase the risk for malignancy. Genomic instability is seen in most types of malignancies. Two forms of genetic instability have been described in colorectal cancer: chromosomal instability (CIN), and microsatellite instability (MIN). Almost all sporadic MIN tumors occur in the proximal colon, whereas most sporadic CIN tumors are distributed in the distal colon. The two familial syndromes, familial adenomatous polyposis and Lynch syndrome, constitute models for the different carcinogenic mechanisms in CIN and MIN tumors, respectively. This article reviews the principal differences between CIN and MIN tumors, evidence for a proximal and distal route in carcinogenesis, gender differences, and aspects of methylation in CIN and MIN colorectal tumorigenesis.
© 2001 Lippincott Williams & Wilkins, Inc.