Nutritional status and dietary needs of patients before the initiation of treatment for gastrointestinal cancers.

<b>Introduction:</b> Gastrointestinal cancers are among the most commonly diagnosed malignancies and are associated with poor prognosis. An accurate assessment of nutritional status prior to the initiation of cancer treatment significantly influences both treatment effectiveness and patient tolerance.<b>Aim:</b> To evaluate the nutritional status and dietary needs of patients with gastrointestinal cancers before the start of oncological therapy.<b>Material and methods:</b> A retrospective analysis was conducted on data from 361 patients diagnosed with gastric, pancreatic, or colorectal cancer, who received dietary consultations prior to the initiation of cancer therapy in outpatient clinics in the Lesser Poland (2022-2024). The evaluation included body mass index (BMI), the Nutritional Risk Screening scale (NRS 2002), selectively available biochemical parameters, and the dietary interventions recommended.<b>Results:</b> A high risk of malnutrition (NRS ≥ 3) was identified in 62% of patients, most commonly among those with pancreatic cancer (77%) and gastric cancer (72%). There was no evident dependence between BMI and the risk of malnutrition. High-calorie diets were recommended for the majority of high-risk patients (85%), often in combination with immunonutrition in cases of planned surgical treatment.<b>Conclusions:</b> The findings confirm the need for routine nutritional screening at the diagnostic stage and the implementation of personalized dietary interventions as part of oncological prehabilitation. Moreover, the results highlight the necessity for physicians to more frequently order biochemical tests, such as albumin, prealbumin, and transferrin, which are essential for a reliable assessment of nutritional status prior to cancer treatment. The absence of these data in many cases impedes early detection of malnutrition and the initiation of appropriate therapeutic measures.