Decreased Appetite in Cancer Patients Treated with immune checkpoint inhibitors (ICIs): The MOUSEION-012 Systematic Review and Meta-Analysis

Introduction: Malnutrition is a frequent and harmful side effect of anticancer therapy, and even though it is known that cancer patients require sufficient nutritional support, nutrition is still not one of the first factors considered in routine clinical practice. The MOUSEION-012 meta-analysis explored the incidence of decreased appetite events among cancer patients receiving immunotherapy as monotherapies or in combination with other anticancer agents. Methods: The MOUSEION-012 meta-analysis was recorded with PROSPERO n. CRD420251004424 and performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). Proportions were assessed for any grade of decreased appetite and for grade ≥ 3 and two separate subgroups of meta-analysis were performed. Results: A total of 36 manuscripts were included, specifically, 23 were observational studies and 13 were RCTones. A total of 11233 observations and 2317 events were recorded and heterogeneity among the studies was high and significant (P<0.001; tau2 = 1.23; I2 = 95.3% with a 95%-CI: [94.5%; 96.0%]) in Any Grade group. Considering Grade ≥ 3, a total of 11233 observations and 146 events were registered. The high heterogeneity among studies was significant (P<0.001; tau2 = 5.63; I2 = 77% with a 95%-CI: [70.2%; 82.2%]). Considering RCTstudies, a total of 15 studies were included, with a total of 10216 observations (5331 in the experimental group and 4885 in the control group) and 1920 events. Heterogeneity among the studies was high and significant (P<0.001; tau2 = 0.25; I2 = 85.4% with a 95%-CI: [77.4%; 90.6%]) for Any Grade group. Considering Grade ≥ 3, a total of 10216 observations (5331 in the experimental group and 4885 in the control group) and 124 events were reported. The heterogeneity across studies was moderate and significant (P=0.009; tau2 =075; I2 = 53.9% with a 95%-CI: [15.5%; 74.8%]). Conclusion: Appetite loss in cancer patients continues to be a significant clinical and research concern, and even while we have more options than ever before for managing cancer-related appetite loss, several challenges remain regarding the best ways to manage this symptom and enhance the quality of life for patients who experience it. In fact, appetite loss may be strictly linked to cancer cachexia, a multifactorial syndrome characterized by a progressive loss of skeletal muscle mass, along with adipose tissue wasting, systemic inflammation and other metabolic abnormalities leading to functional impairment.