Published online Mar 28, 2014. doi: 10.3748/wjg.v20.i12.3059
Revised: November 26, 2013
Accepted: January 6, 2014
Published online: March 28, 2014
With the increasing clinical use of cytostatic and novel biologic targeted agents, conventional morphologic tumor burden assessments, including World Health Organization criteria and Response Evaluation Criteria in Solid Tumors, are confronting limitations because of their difficulties in distinguishing viable tumor from necrotic or fibrotic tissue. Therefore, the investigation for reliable quantitative biomarkers of therapeutic response such as metabolic imaging or functional imaging has been desired. In this review, we will discuss the conventional and new approaches to assess tumor burden. Since targeted therapy or locoregional therapies can induce biological changes much earlier than morphological changes, these functional tumor burden analyses are very promising. However, some of them have not gone thorough all steps for standardization and validation. Nevertheless, these new techniques and criteria will play an important role in the cancer management, and provide each patient more tailored therapy.
Core tip: Accurate tumor burden assessment is a critical component of patient management and the investigation of new therapies. With the increasing clinical use of novel biologic targeted agents or locoregional therapies, morphological analysis confronted limitations, and new methods to assess tumor burden were desired. Advances in imaging technique enable us to assess tumor functions such as viability, vascular physiology, or metabolism, which can be new approaches to assess tumor burden.