Phd Ceremony D.J. Bosch: Identification of risk-factors for perioperative morbidity and mortality during different phases in the treatment of esophageal cancer patients

Surgical resection of the esophagus remains the main curative treatment modality in patients with esophageal cancer, but is accompanied by a significant risk of complications. The aim of this thesis was to identify risk-factors for perioperative morbidity and mortality in patients with esophageal cancer.

In order to assess perioperative risk, several risk-prediction models have been developed. In this thesis we concluded that postoperative mortality after esophagectomy was best predicted by O-POSSUM, which was still unsuitable in daily practice. In general it is assumed that elderly patients (> 70 years) are at an increased risk for perioperative complications. However, we could not demonstrate significant differences in short -or long-term survival between older and younger patients. Nevertheless, complications were frequently observed in elderly patients.

Neoadjuvant chemoradiotherapy (CRT) is nowadays standard treatment of care in patients with esophageal cancer. Despite low reported toxicity, this thesis shows that neoadjuvant CRT is associated with an increased risk of preoperative thromboembolic processes. In addition, we observed more postoperative pneumonia and cardiac arrhythmias in patients treated with neoadjuvant CRT.Laboratory values are an important tool in early identification of patients with a complicated postoperative course. This thesis shows that well known values (C- reactive protein and lactate dehydrogenase), but also less known values (intestinal fatty acid binding protein and angiopoietin) are both important in early identification of postoperative complications. Furthermore, there are indications that cytokine concentrations are related to the degree of pathologic response after neoadjuvant CRT, which could be used to individualize treatment strategy.