[Neoadjuvant, adjuvant and palliative systemic therapy of colorectal cancer].

Neoadjuvant therapy is indicated for stage T3 /4 and all N1 rectal cancers. Usually, chemoradiotherapy with capecitabine or 5FU is applied within a timeframe of 5 1/2 weeks. 6 to 9 weeks later surgery is performed. The aim of neoadjuvant chemoradiotherapy is resectability and a low local recurrence rate. After surgery with curative intent, adjuvant chemotherapy increases the cure rate by 20% in node-positive (stage III) colon cancer. For most patients, 3 months of capecitabine/oxaliplatin are adequate. For high risk patients. 6 months of therapy are necessary if a Folfox regimen is used. In the palliative setting, understanding the biology of the tumor is the key to systemic therapy. Next generation sequencing of tumor DNA is mandatory. Mismatch repair proficient tumors benefit from dual chemotherapy in combination with an antibody. Median survival increases from 6 to 30 months through palliative chemotherapy. Mismatch repair deficient tumors are in need of immunotherapy. Long lasting remission have been observed in this population.