Published online Jun 9, 2015. doi: 10.5497/wjp.v4.i2.168
Peer-review started: January 24, 2015
First decision: February 7, 2015
Revised: March 6, 2015
Accepted: April 1, 2015
Article in press: April 7, 2015
Published online: June 9, 2015
Processing time: 146 Days and 21.6 Hours
Tumor-targeting is becoming more and more important for cancer chemotherapy. Though many molecular-target drugs have been developed in the past two decades which shed some light on targeted tumor therapy, clinical results of those molecular-target drugs are not so encouraging especially for solid tumors, problems mostly relating to the heterogeneity and mutations of target molecules in human solid tumors. More general tumor-targeting strategy is thus anticipated. In this regard, the enhanced permeability and retention (EPR) effect which is a unique phenomenon of solid tumors based on the anatomical and pathophysiological nature of tumor blood vessels, is receiving more and more attentions. This EPR effect now served as a standard for tumor-targeted macromolecular anticancer therapy, namely nanomedicine. Many nanoplatforms have been developed as targeted drug delivery systems, including liposome, polymeric micelles, polymer conjugate, nanoparticles. Ample macromolecular drugs are now approved for clinical use or in clinical stage development, all of which by taking advantage of EPR effect, show superior in vivo pharmacokinetics and remarkable tumor selectivity, resulting in improved antitumor effects with less adverse effects. We thus believe EPR-based nanomedicine will be a solution for cancer in the future, whereas further consideration of factors involved in EPR effect and strategies to augment/improve EPR effect are warranted.
Core tip: Current cancer chemotherapy is less effective with adverse side effects, mostly due to lack of tumor-selectivity. Thus tumor-targeting is known the key for successful chemotherapy. Molecular-target therapy is such a strategy but the clinical results are disappointing probably due to the diversity of cancer-related molecules and enormous mutations. A more general tumor-targeting strategy is based on the unique physiophathological and anatomical features of solid tumors - enhanced permeability and retention (EPR) effect. Accordingly nanomedicine has been developed, with promising therapeutic potential and very less side effects. We thus believe EPR-based nanomedicine will be a solution for cancer in the future.