Overview

This single-arm phase II trial investigates whether a multimodal prehabilitation program can attenuate the postoperative inflammatory response in patients undergoing curative gastric cancer surgery. Major abdominal surgery induces a pronounced systemic inflammatory reaction that contributes to postoperative complications, delayed recovery, impaired functional status, and reduced tolerance to adjuvant therapy. Elevated postoperative C-reactive protein (CRP) trajectories have been associated with infectious complications, whereas a timely decline in CRP may reflect a more adequate immune response. Interventions that improve nutritional status, physical fitness, and psychological resilience before surgery may modulate these inflammatory processes.

The PING-P intervention combines three components starting two weeks before surgery and continuing for three weeks postoperatively: (1) structured exercise including resistance, aerobic and respiratory training supported by pulsed electromagnetic field (PEMF) therapy to both thighs twice weekly; (2) individualized nutritional therapy with counseling and provision of omega-3-enriched high-protein oral nutritional supplements twice daily to achieve ≥1.2 g/kg/day protein intake; and (3) psychological support using coaching and digital relaxation tools. The program is delivered in hospital and at home using a mobile application with regular monitoring and feedback.

The primary objective is to evaluate whether this multimodal approach reduces the proportion of patients with a poor postoperative immune response, defined as either a CRP peak ≥166 mg/L or a decrease from peak CRP to two days later of \<35%. CRP will be measured from postoperative day (POD) 1 to POD7 or until discharge.

Secondary objectives include assessment of feasibility (recruitment, retention, and adherence to ONS intake, PEMF sessions, and exercises), postoperative infectious and overall complications, intervention-related adverse events, functional recovery, nutritional status, body composition, and quality of life.

Adults with histologically proven gastric or esophagogastric junction cancer (Siewert II-III) scheduled for minimally-invasive curative gastrectomy at National University Hospital and Ng Teng Fong General Hospital, Singapore, will be enrolled. Exclusion criteria include distant metastases, emergency surgery, need for preoperative tube or parenteral feeding, inability to follow the program, or contraindications to oral nutrition.

A total of 25 participants will be recruited. The study will provide first data on whether targeted multimodal prehabilitation can favorably modify perioperative inflammation and inform the design of a future randomized trial.

Eligibility

Inclusion Criteria:

1. Adult patients (22 to 99 years).
2. Histologically confirmed gastric or esophagogastric junction cancer (Siewert type II/III).
3. Scheduled for curative surgery (laparoscopic or robotic subtotal, total, or proximal gastrectomy).
4. No distant metastasis (M0).
5. Tolerating oral intake.
6. Limited esophageal involvement (≤2 cm), no duodenal invasion. 6.7. Patients with musculoskeletal limitations (exercises will be adopted accordingly) 7.8. Informed consent provided and capable of complying with home-based program.

8.9. No indication for total parenteral or tube feeding. 9.10. ECOG status compatible with intervention. 10.11. ASA class I-III.

Exclusion Criteria:

1. Cognitive impairment, dementia, or psychiatric illness preventing consent or compliance.
2. Emergency surgery or intraoperative conversion to open surgery.
3. Need for preoperative enteral or parenteral feeding.
4. Severe comorbidities requiring multiple organ resection (except cholecystectomy).
5. Allergy or intolerance to components of the ONS product.
6. Severe mMotor impairments affecting ability to perform exercises or complete outcome assessments.
7. Patients under palliative care or rejecting curative treatment.
8. Pregnant and lactating females
9. Existing active electronic implants (e.g., pacemaker, defibrillator) or electromechanical medical device (e.g. insulin pump)
10. Inflamed areas or skin eruptions on the legs