The Hungarian cross-cultural adaptation of the MMQL-AF for measuring quality of life in adolescents with cancer.

With improvements in childhood cancer survival, attention has shifted toward health-related quality of life (HRQoL) and long-term treatment effects. This study aimed to validate the Hungarian version of the Minneapolis-Manchester Quality of Life Instrument - Adolescent Form (MMQL-AF) and explore factors associated with HRQoL among adolescents and young people with cancer. Ninety-two patients with cancer (46 receiving active treatment and 46 ≥ 1 year post-treatment) and 46 healthy controls completed the MMQL-AF. The MMQL-AF was translated into Hungarian in accordance with Beaton et al. and TARES (2024) guidelines. Reliability was assessed using Cronbach's alpha and intra-class correlation coefficients (ICCs). Validity was evaluated by correlations with the Hungarian Pediatric Quality of Life Inventory (PedsQL 4.0) and by comparing scores across groups. Five items were removed during confirmatory factor analysis (CFA) to improve model fit. The MMQL-AF demonstrated acceptable reliability (Cronbach's alpha 0.73-0.90; ICC 0.78-0.96; RMSEA = 0.062; 90% CI: 0.055-0.069; CFI = 0.828; TLI = 0.814; SRMR = 0.079; GFI = 0.962) and strong concurrent validity with PedsQL scores. Cancer patients reported significantly lower HRQoL than healthy peers (mean 3.58 vs. 3.81; mean difference 0.23; 95% CI: 0.05-0.41; p = 0.012). No significant difference emerged between patients on active treatment and patients off treatment. Patients with bone, soft-tissue, or central nervous system tumors reported worse outcomes (p = 0.015). Positive parental relationships were strongly associated with a better outlook (p < 0.001). The Hungarian MMQL-AF demonstrated acceptable reliability and validity for assessing HRQoL among adolescents and young people with cancer. Tumor type and family environment were associated with differences in the well-being of the patients. This instrument enables comprehensive HRQoL assessment in Hungarian pediatric oncology, supporting identification of at-risk groups and informing survivorship care strategies tailored to medical and psychosocial needs.