Purpose: Although quality of life (QoL) improves over time for most breast cancer survivors (BCS), BCS may show different patterns of QoL. This study sought to identify distinct QoL trajectories among BCS and to examine characteristics associated with trajectory group membership.
Methods: BCS (N = 653) completed baseline assessments within 8 months of diagnosis. QoL was assessed by the Functional Assessment of Cancer Therapy-Breast (FACT-B) at baseline and 6, 12, and 18 months later. Finite mixture modeling was used to determine QoL trajectories of the trial outcome index (TOI; a composite of physical well-being, functional well-being, and breast cancer-specific subscales) and emotional and social/family well-being subscales. Chi-square tests and F tests were used to examine group differences in demographic, cancer-related, and psychosocial variables.
Results: Unique trajectories were identified for all three subscales. Within each subscale, the majority of BCS had consistently medium or high QoL. The TOI analysis revealed only stable or improving groups, but the emotional and social/family subscales had groups that were stable, improved, or declined. Across all subscales, women in "consistently high" groups had the most favorable psychosocial characteristics. For the TOI and emotional subscales, psychosocial variables also differed significantly between women who started similarly but had differing trajectories.
Conclusions: The majority of BCS report good QoL as they transition from treatment to survivorship. However, some women have persistently low QoL in each domain and some experience declines in emotional and/or social/family well-being. Psychosocial variables are consistently associated with improving and/or declining trajectories of physical/functional and emotional well-being.
Keywords: Breast cancer; Psychosocial; Quality of life; Survivorship; Trajectories.