Abstract
BACKGROUND: Nutritional and exercise interventions have shown beneficial effects after gastrectomy for gastric cancer. While digital health tools show promise in cancer care, their long-term effectiveness in patients with gastric cancer remains unclear. In addition, large-scale studies of personalized interventions initiated in the immediate postoperative period are lacking. OBJECTIVE: This study aimed to determine whether a personalized mobile health intervention incorporating exercise and nutrition confers additional benefits in weight change, body composition, nutritional status, physical fitness, and quality of life compared with standard care when applied continuously for 12 months after gastrectomy. METHODS: This multicenter, randomized controlled trial enrolled 257 patients who had undergone curative resection for stage I-III gastric cancer. Participants were randomly assigned (2:1) to either a 12-month personalized mobile health intervention group or a standard rehabilitation control group. The digital intervention incorporated a smartphone app and wearable device, offering exercise and dietary plans tailored to clinical parameters such as BMI, surgery type, and recovery stage. Standard care, including nutritional education, was provided to all patients. The primary outcome was a change in body weight over 12 months. Secondary outcomes included quality of life (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 [EORTC QLQ-C30] and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Stomach 22), nutritional status (Mini Nutritional Assessment Score), physical fitness (grip strength, 30-second chair stand test, and 2-minute walk test), physical activity (International Physical Activity Questionnaire-Short Form), pain intensity (average Numeric Rating Scale), body composition (skeletal muscle mass, lean body mass, and fat mass), BMI, hemoglobin, vitamin B(12), and albumin. Assessments were conducted at baseline and at 1, 3, 6, and 12 months postoperatively. RESULTS: No significant group-by-time effects were observed for weight change. Secondary outcomes showed no between-group differences, except for 1 subscale of the EORTC QLQ-C30, which lacked clinical significance. The intervention group reported high satisfaction and adherence to the mobile app, and no adverse events or incidents were observed during the 12-month study period. CONCLUSIONS: The digital health program integrating exercise and nutrition was safe and feasible, with high satisfaction and adherence among patients with gastric cancer. However, it was not superior to standard education in modifying the postoperative trajectory in patients with gastric cancer after surgery, including body weight change and related functional or nutritional outcomes. These findings suggest that future digital health programs should be precisely targeted and tailored to specific patient populations and recovery phases. TRIAL REGISTRATION: ClinicalTrials.gov NCT04907591; https://clinicaltrials.gov/ct2/show/NCT04907591.