Comprehensive pre-surgery conditioning, with or without planned preoperative cancer therapy, before major abdominal or pelvic cancer operations.

Inclusion Criteria:

Patients are eligible for entry into the study (First Registration) only if ALL of the following criteria apply. No exceptions or waivers will be granted for patients who do not meet the eligibility criteria.

* Signed informed consent form.
* Age ≥18 years at time of signing informed consent form.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 per the treating cancer surgeon (Arm 1, Neoadjuvant therapy) or per both the treating cancer surgeon and the medical and/or radiation oncologists (Arm 2, no neoadjuvant therapy).
* Pre-frail or frail (based on the Fried Frailty Phenotype
* Probable or proven (histologically confirmed) pancreaticobiliary/periampullary (i.e., pancreatic cancer, cholangiocarcinoma, duodenal cancer, or ampullary cancer), ovarian cancer, kidney cancer, or bladder cancer based on central pathological review at Houston Methodist Hospital.
* Clinically non-metastatic (stage I-III) or metastatic (IV) disease.
* Technically resectable disease (no significant vascular, neural, or bony involvement and potential to safely achieve R0 resection) and potentially medically fit for EMCS per the treating cancer surgeon (surgical oncologist/HBP surgeon, gynecologic oncologist, or urologic oncologist).
* Tentatively scheduled to undergo elective pancreatectomy (open or minimally invasive pancreaticoduodenectomy or open distal pancreatectomy) for pancreaticobiliary/periampullary cancer, elective surgical cytoreduction for ovarian cancer, elective open radical nephrectomy for kidney cancer, or elective (open or minimally invasive) total cystectomy for bladder cancer by one of the study MPI or Co-Is \> 28 days after trial registration.
* Neoadjuvant therapy group only: Completed planned NAT (if any) at least 2 weeks prior to Study Registration.
* No neoadjuvant therapy group only: Medically fit and planned to receive NAT per the treating medical and/or radiation oncologist.
* Ability to comply with the CMMP intervention and study assessments as per protocol, in the MPI's judgment.
* Willing and able to consume a lactose-free, whey protein supplement (if not allergic to milk protein/soy and no history of galactosemia), marine protein supplement (if not allergic to marine protein/shellfish), or pea protein supplement (if not allergic to pea protein).
* Willing to provide tissue and blood specimens as per protocol.
* For patients receiving therapeutic anticoagulation: stable anticoagulant regimen.
* Access to a smart phone (personally or via caretaker who resides with the patient).
* Understands, speaks, and reads English.

Exclusion Criteria:

Patients are NOT eligible for entry into the study (First Registration) only ANY of the following criteria apply. No exceptions or waivers will be granted for patients who do not meet the eligibility criteria.

* Difficulty or inability to hear and/or understand loud speech and sounds.
* Unable to eat by mouth (e.g., tube feed dependent, on total parenteral nutrition, etc.)
* Oxygen dependent (or rest and/or with exertion).
* Significant cardiovascular disease (such as New York Heart Association (NYHA) Functional Classification III or IV, unstable angina, unstable arrhythmia, myocardial infarction, or cerebrovascular accident) within 3 months prior to initiation of trial treatment.
* Dependence on mobility device for ambulation other than a cane (e.g., crutches, walker, wheelchair).
* Active brain metastasis or leptomeningeal disease.
* Active bone metastasis and/or recent bone fracture.
* Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures (once monthly or more frequently). NOTE: Patients with indwelling catheters (e.g., PleurX) are allowed
* Planned receipt of investigational therapy/treatment (other than the protocol-mandated CMMP intervention) during the trial treatment.
* Major procedure/surgery within 12 weeks prior to initiation of trial treatment that would prevent the patient from complying with the CMMP intervention and study assessments as per protocol, in the MPI's judgment.
* Active physical/mental condition or personal/social circumstance that would prevent the patient from complying with the CMMP intervention and study assessments as per protocol, in the MPI's judgment.