Sarcopenia is a syndrome characterized by progressive loss of skeletal muscle mass and strength and is associated with worse outcomes in cancer patients. It can negatively affect prognosis, increase postoperative complications, reduce tolerance to systemic therapy, and impair quality of life. Sarcopenia may be present even in patients with preserved nutritional status or overweight.

This study evaluated the proportion of patients with gastrointestinal cancer who were at risk of sarcopenia, as assessed by the SARC-F screening questionnaire, before initiation of systemic treatment and during treatment. Patients with a positive screening result could be referred for further nutritional evaluation and assessment of sarcopenia severity using anthropometric measurements and DXA, according to standard clinical practice.

Sarcopenia is a complex condition characterized by progressive and generalized loss of skeletal muscle mass and strength. In oncology patients, sarcopenia is associated with increased mortality, higher rates of postoperative complications, reduced response to systemic therapy, increased treatment-related toxicity, and decreased quality of life. Sarcopenia may occur independently of malnutrition and may also be present in patients with normal or increased body weight.

Sarcopenia is not only related to the presence of malignant disease but may also develop or worsen as a consequence of oncological treatment. Several antineoplastic therapies have been shown to negatively affect muscle mass and function.

Due to its significant negative clinical impact, early detection of sarcopenia risk is essential. The SARC-F questionnaire is a validated screening tool recommended by the European Working Group on Sarcopenia in Older People (EWGSOP2) for identifying individuals at risk of sarcopenia.

This prospective observational cohort study evaluated the proportion of patients with gastrointestinal cancers treated at the Institute of Oncology Ljubljana who screened positive for sarcopenia risk using the SARC-F questionnaire before initiation of systemic treatment and during treatment. The study also assessed changes in the proportion of patients at risk over time.

Patients with a positive SARC-F screening result could be referred to the Clinical Nutrition Outpatient Clinic for further evaluation, including anthropometric measurements and DXA assessment, in order to determine the severity of sarcopenia. Based on clinical evaluation and in agreement with the treating oncologist, multimodal and multidisciplinary preventive and therapeutic interventions could be introduced as part of routine clinical care.

The study was conducted over a two-year period.

Inclusion Criteria:

• Adult patients (≥18 years) with gastrointestinal cancer
• Patients planned for or receiving systemic anticancer treatment (adjuvant treatment or treatment of metastatic disease)
• Ability to complete the SARC-F screening questionnaire
• Written informed consent provided

Exclusion Criteria:

• Patients younger than 18 years
• Patients unable to complete the questionnaire (e.g., severe cognitive impairment or inability to cooperate)
• Patients not eligible for systemic anticancer treatment
• Refusal to participate in the study

Adult patients with gastrointestinal cancers treated at the Institute of Oncology Ljubljana, receiving systemic therapy either in the adjuvant setting or for metastatic disease. Patients will be screened for sarcopenia risk using the SARC-F questionnaire before treatment initiation and during systemic therapy.