The goal of the clinical trial is to evaluate the feasibility and efficacy of physical training for elderly cancer patients at risk of cancer cachexia. The main questions it aims to answer are:

• Whether a physical training program is feasible in elderly cancer patients with cachexia?
• What is the efficacy of a physical training program in reducing the severity of cancer cachexia in elderly cancer patients?

Participants will receive a 12-week supervised patient-tailored intensity-modulated physical training and being assessed for the severity of cancer cachexia before and after the training.

The trial is to investigate the feasibility and efficacy of an artificial intelligence-based patient-tailored intensity-modulated physical training for cancer patients aged over 65 at risk of cancer cachexia. The primary endpoint is simplified cancer CAchexia SCOre (MiniCASCO) reduction. Secondary endpoints include geriatric assessment, physical activity and sarcopenia. This is an open-label, single-arm, single-center phase II investigator-initiated trial. The investigators assume a reduction of MiniCASCO by 10% after trial intervention. Under a statistical power of 80% and a probability of type I error at 0.1 (two-tailed), a minimal of 49 participants will be enrolled. All participants will receive a 12-week supervised physical training and nutritional intervention. Efficacy assessments will be conducted at baseline (week 0), post-intervention (week 12) and follow-up period (week 24). The investigators anticipate that the optimal patient-tailored training program is feasible and improves the symptoms and severity of elderly cancer cachexia. The results may shed light on the debilitating and burdensome condition and provide information on future clinical trials.

Inclusion Criteria:

1. Subjects aged equivalent to or over 65 years with an existing cancer requiring antineoplastic treatments at trial enrollment, as defined by presence of a catastrophic disease certificate for malignancy in National Health Insurance (NHI)-Taiwan.
2. Subjects receive at least one systemic antineoplastic treatment within 12 weeks since trial enrollment, which includes chemotherapy, immunotherapy, hormonal, targeted and cellular therapy of whichever initial therapeutic intent (curative, palliative or salvage).
3. Subjects fulfill either cancer cachexia or pre-cachexia. (3.1) Cancer cachexia: A maximal weight loss of at least 5% from the baseline within 6 months in those whose BMI equivalent to or over 20 kg/m2 or at least 2% in those whose BMI less than 20 kg/m2; (3.2) Pre-cachexia: A maximal weight loss of 1% to 5% from the baseline within 6 months in patients whose BMI equivalent to or over 20 kg/m2 or 1% to 2% in those whose BMI less than 20 kg/m2 plus any of the following: an elevated serum C-reactive protein above upper normal limits (ULN), impaired fasting glucose or known diabetes mellitus, use of high-dose corticosteroid (over 10 mg prednisone equivalent daily), hypogonadism (disease-related or iatrogenic) or insufficient calorie intake of less than 20 kcal/kg/day
4. Subjects are in a clinical status with an expected life span exceeding 6 months and Eastern Cooperative Oncology Group (ECOG) 0 to 1 or Karnofsky Performance Scale (KPS) 80 to 100 at trial enrollment.
5. Subjects are physically and mentally capable and willing for conducting the planned physical training and agreed to comply the educational instructions and a wearable device during trial intervention.
6. Subjects are functionally and cognitively capable to be informed of the trial contents and objectives (including obtaining peripheral blood sampling for trial investigation), and agree to sign the written consent for enrollment.

Exclusion Criteria:

1. Subjects have tumor in situ or curatively treated malignant disease which requires no further antineoplastic treatments.
2. Subjects are anticipated to receive any surgery, radiotherapy or intervention that prevents or hinders a planned physical training within 28 weeks since trial enrollment.
3. Subjects experience a progressive body weight loss which fulfills the criteria for cancer cachexia or pre-cachexia but complicates with other confounding causes.
4. Subjects have cachexia caused by etiologies not limited to cancer.
5. Subject's malignant disease is considered unstable and thereby unfit for a planned physical training.
6. Subjects have an underlying medical illness causing severely impaired organ functions.
7. Subjects have an active infection requiring hospitalized treatment or intravenous anti-pathogen therapies.
8. Subjects who receive other experimental treatments or interventions for cancer cachexia.
9. Subjects are planning to conceive or already in pregnancy.
10. Subjects are currently participating in any other observational studies concerning cancer cachexia.

The study protocol, statistical analysis plan and individual information are to be shared upon reasonable request to the study principal investigator.