Aging is a stage of human development marked by losses, grief, and the need to adapt to age-related changes and limitations. In this context, the diagnosis and treatment of an onco-hematological disease such as Multiple Myeloma (MM) add further challenges.

This study aimed to understand the factors influencing the quality of life (QoL) of elderly patients with multiple myeloma, considering functional, emotional, symptomatic, existential, and sociodemographic aspects.

The sample comprised 50 patients (equal sex distribution), mostly self-identified as White (n = 31) and Catholic (n = 31), with a mean age of 67.7 years (SD = 8.8). Most had up to elementary education, 29 were married, and 45 were retired or unemployed, with a mean income of two minimum wages (SD = 1.17). The mean time since diagnosis was 4.5 years (SD = 4.71), and all patients were in outpatient follow-up at a public hematology center in São Paulo state, Brazil. Instruments included the PHQ-9, EORTC QLQ-C30, Karnofsky Performance Index, and MLQ-QSV. Data were analyzed using Spearman’s correlation and Pearson (p < 0.05).

Functional domains showed relatively high mean scores: physical (62.6), role (73.3), emotional (69.0), cognitive (74.6), and social functioning (76.6). Most prevalent symptoms were pain (38.6), fatigue (32.7), and financial difficulties (32.0). The average PHQ-9 score was 7.72 (SD = 5.87), suggesting mild depressive symptoms. The Karnofsky Index averaged 81.79 (SD = 7.58). Presence of meaning in life was high (M = 27.0; SD = 6.66), and search for meaning was moderate (M = 22.48; SD = 9.80). Higher PHQ-9 scores were significantly associated with insomnia (ρ = 0.558), fatigue (ρ = 0.433), dyspnea (ρ = 0.433), pain (ρ = 0.393), nausea (ρ = 0.362), and diarrhea (ρ = 0.355), as well as lower scores in cognitive (ρ = -0.586), emotional (ρ = -0.481), role (ρ = -0.421), physical (ρ = -0.428), and social functioning (ρ = -0.391), global QoL (ρ = -0.422), and presence of meaning (ρ = -0.448). Significant interrelations were found among domains: physical functioning correlated with role (r = 0.506), emotional (r = 0.412), cognitive (r = 0.385) functioning and QoL (r = 0.432); emotional functioning with social (r = 0.556), cognitive (r = 0.296), and presence of meaning (r = 0.493); presence of meaning with cognitive (r = 0.388), social functioning (r = 0.416), and QoL (r = 0.293). Fatigue and pain showed negative correlations with multiple domains: fatigue with physical (r = -0.506), role (r = -0.501), and cognitive (r = -0.519); pain with physical (r = -0.466), role (r = -0.554), and cognitive functioning (r = -0.562). The presence of meaning in life was positively associated with better psychosocial functioning, reinforcing its protective and integrative role in overall health.

These findings highlight the negative impact of fatigue and pain on functioning, the relevance of depressive symptoms as cross-cutting markers of worse outcomes, and the protective role of existential meaning. They support the need for multidimensional care approaches for MM patients, addressing not only clinical symptoms but also psychological and existential dimensions of illness.