It is important to assess patients' fitness for major cancer surgery which carries a high risk of mortality. Patients with poor heart and lung function have a higher risk of death after major cancer surgery. Cardiopulmonary exercise testing, CPET, is an objective measure of patients' fitness. Most patients, before surgery to resect their cancer, undergo a period of chemotherapy. Chemotherapy often regresses the cancer but also has adverse effects on cell function. Our hypothesis is that chemotherapy alters patient fitness, as assessed by CPET, prior to major cancer surgery. Participating patients will undergo fitness testing by CPET before and after their chemotherapy, prior to their surgery.