Breast cancer: introduction

Abstract

The most frequent cancer type in females in the Western world is breast cancer, with a lifetime risk of the order of 1/10. Our understanding of the molecular events relating to breast cancer biology and pathogenesis has greatly increased over the last decade. The development of breast cancer involves several types of genes that need to be activated or inactivated in order to promote malignancy. The sequential steps in gene alterations with respect to tumour progression are not clear, and are far less well understood than what is currently the best example of tumour progression, that is, colo-rectal carcinoma. Still, the large number of alterations that have been identified in breast tumours at the genetic level fit the model of multistep carcinogenesis. Breast cancer is sometimes associated with predisposing mutations in the germline but is essentially a somatic cell genetic disease. In the present issue of Seminars in Cancer Biology selected topics on breast cancer biology and genetics are reviewed.