Characterizing Postoperative T and B Cell Dysfunction in Cancer Surgery Patients, Using COVID-19 as a Model Antigen

Inclusion criteria

• Patients with a diagnosis of a primary abdominal malignancy consented to undergo major surgery with a planned length of stay of 3 or more days.
• Eligible patients must have signed a consent for surgical resection of the malignancy.
• Adequate hematological function defined as: platelet count ≥ 100 x 109/L, absolute neutrophil count ≥ 1 x 109/L, white blood count ≥ 2.5 x 109/L, hemoglobin count ≥ 90 g/L.
• Adequate organ functioning, including: total bilirubin ≤ 1.5 x upper limit of normal (ULN); AST, ALT < 2.5 x ULN; INR <1.5 ; CrCl>30mL/min.
• Ability to understand and provide a signed informed consent form (ICF) approved by the Institutional Review Board (IRB/IEC/REB).
• Ability to comply with protocol requirements.

Exclusion criteria

• Documented significant immunodeficiency due to underlying illness (e.g. HIV/AIDS) and/or medication (e.g. systemic corticosteroids, azathioprine, cyclosporin A). Subjects may be on physiologic doses of replacement prednisone or equivalent doses of corticosteroid (<7.5 mg daily).

• History of autoimmune disease (even if controlled with medication) such as but not restricted to, inflammatory bowel disease, systemic lupus erythematosus, ankylosing spondylitis, scleroderma, or multiple sclerosis.
• Allergies or any contraindication to the use of tadalafil or any components of Cialis® or the influenza vaccine (including eggs), Agriflu®.
• Serious intercurrent chronic or acute illness, or other illness considered by the investigator as an unwarranted high risk for an investigational product.
• Patients who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months.
• Patients with resting hypotension (BP <90/50 at rest) or hypertension (BP >170/110 at rest).
• Patients with cardiac failure or coronary artery disease causing unstable angina.