Adherence and patients? experiences with the use of erlotinib in NSCLC and capecitabine in colon cancer treatment; the influence on plasma concentration and the exploration of factors affecting the use in daily practice
01 / 2011 - unknown
The aim of the study is to gain insight into the relationship between adherence and the plasma concentration of erlotinib and to study the relationship between side effects and adherence to erlotinib and capecitabine in patients with NSCLC and coloncancer, respectively. The second part of this study is of an explorative nature. The relationships between patient characteristics, disease characteristics, side effects, quality of life, patients beliefs and attitude towards disease and medicines, adherence, dose adjustments and plasma concentration of erlotinib in patients with NSCLC will be studied. A prospective observational cohort study in which 40 patients starting with treatment with erlotinib and 66 patients starting with capecitabine will be followed up until 16 weeks. Adherence rate; a patient is adherent with the intake of 85% or more of the prescribed medication, the plasma concentration of erlotinib and the number and grade of side-effects will be assessed. Before the start of therapy with erlotinib or capecitabine and during week 2, 4, 8, 12 and 16 patients will be asked to fill in a questionnaire. Furthermore in week 4, 8 and 16 blood samples are collected, which will be analysed for plasma concentration of erlotinib or capecitabine.