Background/Objectives: Colorectal cancer (CRC) has high prevalence and mortality, with a high frequency of malnutrition during chemotherapy (60–70%). Malnutrition reduces treatment tolerance, quality of life, and survival. The Patient-Generated Subjective Global Assessment (PG-SGA) is effective in detecting it, but its use is not systematic. This study aims to analyze the prevalence and degrees of malnutrition in CRC patients undergoing active chemotherapy, using the PG-SGA, and to propose its systematic implementation in oncology care protocols. Methods: Observational, cross-sectional, and descriptive study in patients with stage III–IV CRC receiving FOLFOX, XELOX, or irinotecan regimens. Nutritional status was assessed with PG-SGA and body composition by bioimpedance. Results: The study includes 91 patients. A total of 45.05% of patients required intensive nutritional intervention, 39.56% needed dietary and pharmacological measures, 10.99% required health education, and only 4.4% did not require intervention. FOLFOX was significantly associated with taste alterations (p < 0.001), nausea (p = 0.020), unpleasant odors, and eating problems; XELOX with diarrhea (p = 0.009) and xerostomia (p = 0.038). Irinotecan was related to poorer functional capacity (p = 0.042). Oxaliplatin was linked to loss of appetite (p = 0.034) and unpleasant odors (p = 0.035). Older age correlated with a greater need for intensive interventions. Conclusions: The study shows a high nutritional risk in oncology patients, particularly in those with colorectal cancer undergoing FOLFOX treatment, associated with symptoms that impair intake and functional capacity. The systematic implementation of nutritional screening from the onset of treatment, using tools such as the PG-SGA and GLIM criteria, is essential for early detection and individualized management, improving therapy tolerance, clinical outcomes, and quality of life.

Background/Objectives: Malnutrition is highly prevalent in patients with advanced colorectal cancer (CRC) and is associated with poorer treatment tolerance, reduced quality of life, and worse clinical outcomes. Chemotherapy regimens incorporating irinotecan are commonly used in later treatment lines but present a distinct toxicity profile characterized mainly by gastrointestinal symptoms and functional decline, which may negatively affect nutritional status. This study aimed to evaluate the impact of irinotecan-containing chemotherapy regimens on nutritional status and functional capacity in patients with advanced CRC using the Patient-Generated Subjective Global Assessment (PG-SGA). Methods: A cross-sectional observational study was conducted in 91 adult patients with histologically confirmed stage III–IV colorectal adenocarcinoma undergoing active systemic chemotherapy between November 2023 and June 2024. Demographic and clinical variables, treatment regimens, and exposure to irinotecan were recorded. Nutritional status was assessed using the PG-SGA, and body composition was evaluated by multifrequency bioelectrical impedance analysis. Associations between irinotecan exposure and nutritional, functional, and symptom-related variables were analyzed using χ² or Fisher’s exact tests. Results: Thirteen patients (14.3%) received irinotecan-containing regimens, most frequently combined with FOLFOX. Patients exposed to irinotecan presented higher PG-SGA scores, indicating a greater nutritional burden. Although most gastrointestinal symptoms did not reach statistical significance, early satiety (p = 0.041) and functional deterioration (p = 0.039) were significantly associated with irinotecan administration, while nausea (p = 0.089) and vomiting (p = 0.087) showed trends toward significance. The subgroup treated with FOLFOX–irinotecan also demonstrated a higher frequency of functional impairment compared with those receiving FOLFOX alone. Conclusions: Irinotecan-containing chemotherapy regimens in advanced CRC may be associated with a distinct pattern of nutritional deterioration primarily driven by functional decline and gastrointestinal symptoms affecting food intake. Systematic nutritional assessment using validated tools such as the PG-SGA may allow early identification of vulnerable patients and support the implementation of timely multimodal interventions aimed at improving treatment tolerance and clinical outcomes.

Background: Body composition may be a relevant determinant of metabolic and fun-ctional vulnerability in patients with colorectal cancer. This study aimed to investigate the association between different therapeutic strategies and body composition parameters. Methods: An observational, analytical, cross-sectional study was conducted in adult pa-tients with colorectal adenocarcinoma receiving active antineoplastic treatment at Hospital Universitario de Badajoz, Spain, consecutively recruited between November 2023 and June 2024. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment (PG-SGA), and body composition was evaluated by multifrequency bio-electrical impedance analysis (BIA). Fat mass, fat-free mass, skeletal muscle mass, bone mass, protein mass, total body water, visceral fat, and basal metabolic rate were assessed. Patients were stratified according to treatment modality: surgery alone, FOREST protocol, neoadjuvant chemotherapy, adjuvant chemotherapy, and combined neoadju-vant-adjuvant chemotherapy. Between-group differences were assessed using ANOVA and association tests, complemented by regression models. Statistical significance was set at p< 0.05. Results: A total of 91 patients were included, with a mean age of 64.97±9.92 years; 56 (61.5%) were men. Significant differences between treatment modalities were observed in bone mass (p=0.023), protein mass (p=0.002), skeletal muscle mass (p=0.022), fat-free mass (p=0.022), and basal metabolic rate (p=0.039). Patients receiving adjuvant chemotherapy alone exhibited the lowest values for protein mass, skeletal muscle mass, fat-free mass, and basal metabolic rate, whereas those receiving combined neoadju-vant-adjuvant chemotherapy showed the highest values. No significant differences were observed in the remaining body composition parameters. Conclusions: Body composition differs significantly according to therapeutic modality, particularly in parameters related to skeletal muscle mass and physiological reserve. These findings support incorporating body composition assessment into comprehensive clinical and nutritional evaluation to identify patients with reduced physiological reserve and potentially greater treatment vulnerability. However, the cross-sectional design precludes causal inference. Prospective longitudinal studies are warranted to determine changes in body composition and their impact on treatment-related toxicity and clinical outcomes.

Background/Objectives: Malnutrition is highly prevalent in patients with advanced colorectal cancer (CRC) and is associated with poorer treatment tolerance, reduced quality of life, and worse clinical outcomes. Chemotherapy regimens incorporating irinotecan are commonly used in later treatment lines but present a distinct toxicity profile characterized mainly by gastrointestinal symptoms and functional decline, which may negatively affect nutritional status. This study aimed to evaluate the impact of irinotecan-containing chemotherapy regimens on nutritional status and functional capacity in patients with advanced CRC using the Patient-Generated Subjective Global Assessment (PG-SGA). Methods: A cross-sectional observational study was conducted in 91 adult patients with histologically confirmed stage III–IV colorectal adenocarcinoma undergoing active systemic chemotherapy between November 2023 and June 2024. Demographic and clinical variables, treatment regimens, and exposure to irinotecan were recorded. Nutritional status was assessed using the PG-SGA, and body composition was evaluated by multifrequency bioelectrical impedance analysis. Associations between irinotecan exposure and nutritional, functional, and symptom-related variables were analyzed using χ² or Fisher’s exact tests. Results: Thirteen patients (14.3%) received irinotecan-containing regimens, most frequently combined with FOLFOX. Patients exposed to irinotecan presented higher PG-SGA scores, indicating a greater nutritional burden. Although most gastrointestinal symptoms did not reach statistical significance, early satiety (p = 0.041) and functional deterioration (p = 0.039) were significantly associated with irinotecan administration, while nausea (p = 0.089) and vomiting (p = 0.087) showed trends toward significance. The subgroup treated with FOLFOX–irinotecan also demonstrated a higher frequency of functional impairment compared with those receiving FOLFOX alone. Conclusions: Irinotecan-containing chemotherapy regimens in advanced CRC are associated with a distinct pattern of nutritional deterioration primarily driven by functional decline and gastrointestinal symptoms affecting food intake. Systematic nutritional assessment using validated tools such as the PG-SGA may allow early identification of vulnerable patients and support the implementation of timely multimodal interventions aimed at improving treatment tolerance and clinical outcomes.