Chemoradiation in Gastrointestinal Cancer

Sammanfattning: Locally advanced inextirpable gastrointestinal cancer has poor prognosis and is associated with high morbidity. One treatment option is to use radiotherapy, often combined with chemotherapy (chemoradiation), either as preoperative treatment to facilitate surgery or in the palliative setting to relieve symptoms. The aim of this thesis was to investigate efficacy and toxicity of intensive chemoradiation including conformal radiotherapy and newer chemotherapeutic agents. Oxaliplatin and capecitabine together with 50 Gy radiotherapy was used in a national phase I-II study (CORGI), divided in two parts by tumor location. Among 61 patients with locally advanced colorectal cancer, primary tumor or local recurrence, with or without distant metastases, the objective local response rate was 58% and 79% went to surgical resection (paper I) The main side-effect was diarrhea. 39 patients with pancreatic or biliary tract cancer were included (paper II). The maximum tolerated chemotherapy doses were determined. Dose-limiting toxicity was nausea/vomiting. The local response rate was 21 %. In both CORGI studies there was a high frequency of sustained local control at two years. The most important risk factor for diarrhea during chemoradiation was the volume of small bowel that received >15 Gy (paper III). Enteritis is thought to be mediated by eradication of intestinal crypts. In a mouse model we found that adding oxaliplatin and 5-FU to radiation increased the mucosal damage (paper IV). Thus, chemoradiation is effective and feasible in several types of gastrointestinal cancers. Sparing small bowel from radiation is important.