Prehabilitation aims to utilise the time before surgery to improve a patient’s physiological status through exercise, nutritional support and psychological interventions. This thesis aims to determine the effects of prehabilitation on post-operative outcomes in patients with oesophago-gastric cancer and establish the mechanism by which this occurs.

Through comparison of patients who have completed prehabilitation with propensity score matched controls, prehabilitation was found to be associated with a significantly lower incidence of post-operative pneumonia and shorter length of stay following oesophageal cancer surgery. During prehabilitation, cardiorespiratory fitness was preserved during neoadjuvant chemotherapy (NAC) and then increased immediately prior to surgery. Completing increasing amounts of physical activity was associated with a lower risk of post-operative pneumonia.

Using this local cohort data, changes in body composition during prehabilitation were studied through analysis of CT images. This identified less decline in skeletal muscle during NAC in prehabilitation patients compared to controls. Completing higher volumes of exercise was associated with greater loss of visceral adipose tissue (VAT), and loss of VAT is associated with a lower risk of post-operative complications.

Through a systematic review I found evidence that exercise can reduce inflammation in cancer patients undergoing oncological treatment. Therefore, I also explored the effect of prehabilitation on systemic inflammation and inflammation within VAT. Using sandwich enzyme linked immunosorbent assays, a significant reduction in plasma TNF during NAC was seen with prehabilitation, with correlation between the exercise volume and change in TNF. Finally, using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry on VAT samples, differences in the VAT inflammation were identified between pre-NAC patients, post-NAC prehabilitation patients and post-NAC controls.

In conclusion, this thesis has identified significantly improved post-operative outcomes with prehabilitation in oesophageal cancer patients, with positive impacts upon cardiorespiratory fitness, body composition and inflammation.