Abstract
Background and Objectives: Medication adherence is a key determinant of treatment effectiveness in early-stage breast cancer, particularly during long-term systemic therapies. As breast cancer is increasingly diagnosed at younger ages, a growing number of women continue to carry active parenting responsibilities during treatment. However, the associations between parenting-related psychosocial factors and medication adherence remain insufficiently explored. This study aimed to examine the associations between parenting stress, spiritual well-being, and medication adherence in women with early-stage breast cancer who maintain active parenting roles. Materials and Methods: This multicenter, cross-sectional study included 432 women with early-stage (I-III) breast cancer receiving active systemic therapy across nine oncology centers. Parenting stress was assessed using the Parenting Stress Scale (PSS), spiritual well-being using the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (FACIT-Sp-12), and medication adherence using the 6-item Modified Morisky Adherence Scale (MMAS-6). Spearman correlation analyses and multivariable linear regression models were used to evaluate associations between variables. Mediation analysis was performed using Hayes' PROCESS macro (Model 4) with 5000 bootstrap samples to assess statistical mediation. Results: Parenting stress was positively associated with poorer medication adherence (ρ = 0.248, p < 0.01), whereas spiritual well-being was negatively associated with non-adherence (ρ = -0.225, p < 0.01). Parenting stress showed a strong inverse association with spiritual well-being (ρ = -0.597, p < 0.01). In multivariable regression analyses, both parenting stress and spiritual well-being were independently associated with medication adherence (β = 0.180, p = 0.002 and β = -0.199, p = 0.001, respectively). Mediation analysis demonstrated a significant indirect statistical association between parenting stress and medication adherence through spiritual well-being (indirect effect = 0.0155), consistent with partial statistical mediation. Conclusions: Medication adherence among women with early-stage breast cancer and active parenting responsibilities is associated with psychosocial context in addition to clinical factors. Parenting stress is associated with poorer adherence, whereas greater spiritual well-being is associated with better adherence within a statistical mediation framework. These findings generate hypotheses for future longitudinal and interventional studies.