Abstract
A recent study by Keikes et al. (Clin Colorectal Cancer. 2018;17:58-64) focused on adherence to the Dutch colorectal cancer guideline and concluded that adherence was suboptimal. This commentary puts their results in context. Guidelines are useful for those oncologists who lack time to study the original literature. Medical oncologists nowadays have become more and more specialised in a few tumour types, engage in continuous medical education, and discuss controversial issues at (inter)national meetings. Hence, skilled oncologists will not always follow guidelines where alternative choices are in the best interest of the patient. Especially in the metastatic setting, the patient's wishes, combined with balancing quality and quantity, consideration of co-morbidities, and a need to be cost-effective, may influence therapeutic choices and thereby results in best practice. Lack of adherence can have multiple reasons. For instance, the guideline might be outdated, it may not cover all therapeutic options, or oncologists may not be familiar with the guidelines.