Adjuvant Therapy in Colon Cancer The goal of improving adjuvant treatment can be reached in two ways: firstly, by developing more effective drugs and protocols and, secondly, by selecting suitable patients on the basis of clinical and molecular factors. In UICC (Union internationale contre le cancer) stage II, microsatellite instability (MSI) is a strong prognostic factor. Whether it can also be used as a predictive marker is currently a matter of controversy because the available data are contradictory. The question whether or not the MSI status should be checked before treatment decisions are made in stage II patients can therefore not be clearly answered at present. For adjuvant treatment in stage III, with capecitabine/oxaliplatin (XELOX) there is now a new protocol available that is based on the orally administered prodrug capecitabine. With regard to the question of how much older patients in this stage may also benefit from a combination chemotherapy, new - and contradictory - data have emerged recently: firstly, preliminary results of two new studies have given rise to safety concerns and, secondly, an analysis by the `ACCENT Collaborative Group' indicated lower efficacy of the `newer' adjuvant protocols in older people. These findings, however, have now been called into question as a result of a new subgroup analysis from the XELOXA study. The expert group therefore recommended that the decision whether to treat patients older than 70 years with an ( oral) fluoropyrimidine alone or in combination with oxaliplatin should be based on clinical parameters such as biological age and comorbidities.