Oesophageal cancer surgery : nutritional determinants of survivorship

Sammanfattning: Oesophagectomy, the surgery offered as a curative treatment for cancer of the oesophagus is highly invasive with a radical change in anatomy and carries a risk for significant morbidity and mortality. The recovery is lengthy, burdened by deterioration in health-related quality of life (HRQOL). Eating difficulties and symptoms affecting patients’ nutritional status, termed nutrition impact symptoms (NIS) are commonly reported in the survivorship even up to 10 years after surgery. Clinically noticeable weight loss is a problem right from diagnosis but also persists after surgery as a troublesome trait of the survivorship. Hence, this thesis aimed to clarify how nutritional problems after surgery for oesophageal cancer influence HRQOL and survival, and to assess the role of dietitian support in improving nutritional status and thereby contribute to the clinical decision-making process. Studies I-IV included in this thesis are prospective cohort studies in design based on two large cohorts comprising of patients who underwent surgery for oesophageal cancer in Sweden. Studies I and II were based on a prospective cohort including patients operated between 2001 and 2005 and followed up for HRQOL and nutritional outcomes until 2015. Studies III and IV were based on a cohort of patients who underwent surgery from 2013 and 2016 and followed up for one and half years after surgery. Clinical variables obtained from medical charts of patients included in both the cohorts provided the possibility to adjust for potential confounders. In Study I, the interactive influence of eating difficulties and weight loss on HRQOL up to 10 years after oesophagectomy were assessed. Severe eating difficulties irrespective of the degree of weight loss were associated with clinically and significantly worse HRQOL in almost all aspects up to 10 years after surgery. Study II examined the combined effect of NIS and weight loss on specific HRQOL aspects at six months after surgery and five-year overall survival, stratified by preoperative body mass index (BMI). Patients with severe NIS, regardless of preoperative BMI status and extent of postoperative weight loss, exhibited worse HRQOL. Patients with a higher preoperative BMI and postoperative weight loss, showed worse survival when they experienced severe NIS after surgery. Study III investigated the impact of symptoms of early and late dumping syndrome at one year after surgery for oesophageal cancer on specific HRQOL aspects. Clinically and statistically relevant differences in several HRQOL aspects were seen in both early and late dumping when compared with no dumping, with late dumping showing worse effects. Study IV evaluated if preoperative dietitian support in addition to postoperative support and a high level of patient reported satisfaction of the support are associated with an improved nutritional status. No differences in nutritional status existed with respect to whether dietitian support was initiated preoperatively or postoperatively and with regards to the level of satisfaction of the support as reported by patients. In conclusion, symptoms that affect eating and in turn nutrition, experienced after surgery for oesophageal cancer are important determinants of HRQOL. In those who are overweight or obese before surgery the presence of severe nutritional problems after surgery adversely impacted survival. Patients with symptoms of dumping syndrome, especially late dumping have poorer HRQOL and need attention. Preoperative dietitian support and high level of patient satisfaction of the support did not determine the nutritional status but are integral components of nutritional status.