The aim of this thesis was to define prognostic and predictive biomarkers in colorectal cancer for improved risk stratification and treatment benefit in the individual patient, with the... Show moreThe aim of this thesis was to define prognostic and predictive biomarkers in colorectal cancer for improved risk stratification and treatment benefit in the individual patient, with the introduction of precision medicine in the near future as the ultimate goal. By __definition, precision medicine is a multi-faceted approach to medicine that integrates molecular and clinical research with patient data and clinical outcome, and places the patient at the center of all elements. This thesis is divided in three parts. In Part one prognostic biomarkers in CRC are investigated, in Part two aspirin treatment and related predictive biomarkers for aspirin treatment benefit in colon cancer are investigated and finally, in Part three, the use of predictive and prognostic biomarkers in clinical practice, its utility and the road to precision medicine are discussed. Show less
OBJECTIVES To assess survival in relation to aspirin use after diagnosis in older adults with colon cancer. DESIGN Subgroup analysis of a previously published cohort and retrospective study.... Show moreOBJECTIVES To assess survival in relation to aspirin use after diagnosis in older adults with colon cancer. DESIGN Subgroup analysis of a previously published cohort and retrospective study. SETTING Individuals registered in the Eindhoven Cancer Registry (ECR) between 1998 and 2007, linked to prescriptions of low-dose aspirin (80 mg) registered in a community pharmacy database. PARTICIPANTS Five hundred thirty-six individuals aged 70 and older diagnosed with colon cancer with or without aspirin use after diagnosis. MEASUREMENTS Survival was analyzed with user status as a time-dependent covariate. Multivariate Poisson regression survival models were used to study the effect of aspirin on overall survival. RESULTS One hundred seven participants (20.0%) started aspirin after being diagnosed with colon cancer; 429 (80.0%) were not prescribed aspirin. Three hundred thirty-nine participants (63.2%) had died by the end of follow-up. Aspirin use after diagnosis was associated with longer overall survival (rate ratio (RR) = 0.51, 95% confidence interval (CI) = 0.38-0.70, P < .001). Multivariate proportional hazards regression analysis revealed that aspirin use was associated with longer overall survival (adjusted RR = 0.59, 95% CI = 0.44-0.81, P = .001). CONCLUSION Aspirin use after the diagnosis of colon cancer in older adults was associated with longer survival. Low-dose aspirin could be used as an effective adjuvant therapy in older adults with colon cancer. Show less