ABSTRACT
Although screening programs and recent advances in rectal cancer treatment such as total mesorectal excision (TME) and neoadjuvant chemoradiation therapy, have improved survival both in Europe and in the United States,1 the American Cancer Society estimates that there will be about 40 340 new cases of rectal cancer in 2005 in the United States,2
and only 50% of these patients will be alive in 2010.3 Innovative treatments are required to improve these outcomes. Some researchers have selected angiogenesis as a promising target for novel therapies4-6 for rectal cancer, since high values of tumor microvessel density (MVD) have been correlated with poor outcome,7,8 and high vascular endothelial growth factor (VEGF) expression in this malignancy has been associated with disease progression and poor survival.9,10
An in-vivo marker of rectal cancer angiogenesis is, then, required for therapeutic monitoring of new antiangiogenic trials, since morphologic imaging, based on size criteria, may not be suitable for monitoring the effects of antiangiogenesis drugs.11
