Predictors and Interdependence of Quality of Life in a Random Sample of Long-Term Young Breast Cancer Survivors and Their Biological Relatives.

Purpose: Quality of life (QOL) among young breast cancer survivors (YBCS) is often worse than QOL of older breast cancer survivors or age-matched peers without a history of cancer. Families commonly support YBCS, particularly during treatment, but little is known about long-term YBCS and family member QOL. The purpose of this study was to identify demographic, clinical, and psychosocial predictors of physical and mental QOL in YBCS and biological relatives and investigate associations between their QOL (i.e., QOL interdependence).

Methods: This secondary data analysis includes a random sample of long-term YBCS (≤ 45 years old at diagnosis) and up to two female relatives at baseline (post-treatment) and 18-month follow-up. The sample consists of 189 dyads (YBCS and one relative) and 121 triads (YBCS and two relatives). Actor-partner interdependence models (APIMs) were used to estimate the influence of YBCS's and relatives' demographic, clinical, and psychosocial factors on their own QOL (actor effects) and the other persons' QOL (partner effects).

Results: For YBCS and relatives, QOL at the baseline was associated with their QOL at 18-months. YBCS's perceived cancer risk was associated with their own and relatives' QOL. Older relatives' physical QOL at baseline was associated with younger relatives' physical QOL at follow-up. Age, race, marital status, years since diagnosis, education, out-of-pocket costs of care, routine sources of care, income, family support, fear of recurrence, anxiety, and depression were also significant predictors of QOL.

Conclusions: Findings revealed independent and interdependent effects on QOL. These predictors point to potential targets of support for families.

Trial Registration: ClinicalTrials.gov ID: NCT01612338.