Publication Date

2015-05-21

Availability

Embargoed

Embargo Period

2017-05-20

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Psychology (Arts and Sciences)

Date of Defense

2014-05-02

First Committee Member

Michael H. Antoni

Second Committee Member

Suzanne C. Lechner

Third Committee Member

Charles S. Carver

Fourth Committee Member

Gail H. Ironson

Fifth Committee Member

Stefan Glück

Abstract

Women diagnosed with early stage breast cancer experience elevated psychological distress associated with diagnosis and treatment that may have long term implications for disease progression and overall survival. Group-based Cognitive-Behavioral Stress Management (CBSM) has been shown to improve quality of life (QOL) and depressive symptoms in women with early stage breast cancer up to 12 months post-surgery. The current study aimed to examine whether women who received CBSM have better survival, breast cancer specific survival, and disease free interval at 8-15 year follow-up. The study also aimed to determine whether women in the CBSM group report less depressive symptoms and better QOL at the 8-15 year follow-up as compared to women in the control group. Finally, potential mediators of clinical endpoints and psychological outcomes were explored. From 1998-2005, women (N = 240) with non-metastatic stage 0-IIIb breast cancer were enrolled in a randomized controlled trial comparing a 10-week group-based CBSM intervention to a 1-day group psychoeducational control seminar. Information related to demographic characteristics, treatment, medical history, and psychosocial functioning was collected at baseline (T1), 6 months (T2), 12 months (T3), and 5-years (T5). In 2013, at the 8-15 year (T6) follow-up, information was collected via tumor registry and medical chart review regarding survival, cause and date of death, and status of breast cancer (i.e., recurrence or disease free). Women who were reachable and agreeable at T6 (N = 100) completed the Functional Assessment of Cancer Therapy-Breast (FACT-B) and the Center for Epidemiologic Studies-Depression (CES-D) scales. Kaplan-Meier Survival Curves and Cox Proportional Hazards Models were conducted to determine whether women in the CBSM group differed from women in the control group on clinical outcomes of all-cause mortality, breast cancer-related mortality, and disease free interval. Biomedical confounders, specifically age, stage of disease, time elapsed from surgery to baseline assessment, tumor size, HER-2/neu receptor status, chemotherapy receipt, radiation receipt, and hormonal therapy receipt, were included in the Cox Proportional Hazards Models. Linear regressions were conducted to evaluate intervention group differences in QOL and depressive symptoms. Bootstrapped linear regressions were employed to test mediation hypotheses of whether change in affect over the 12-month study period mediated the intervention effects on either clinical or psychological outcomes. At a median follow-up of 11 years, 47 women had a breast cancer recurrence and 30 women were deceased, with 22 having had breast-cancer related mortalities. Results of Cox Proportional Hazards analyses controlling previously stated covariates showed that women with early stage breast cancer who were randomly assigned to the CBSM group had a 79% reduced risk of all-cause mortality (95% CI [0.05, 0.91]; p = .037) compared to the control group. Risk for breast cancer recurrence was 56% lower than the control group (95% CI [0.18, 1.04]; p = .062) although not significantly lower. Similarly, risk for breast-cancer specific mortality was lower in the CBSM group, HR = 0.23 (95% CI [0.05, 1.08]), but not significantly so (p = .063). Women in the CBSM group reported greater physical (p =.003) and emotional well-being (p =.053) on the FACT-B and less depressive symptoms (p =.036) and negative affect (p =.032) on the CES-D at T6. Mediation hypotheses were not supported in bootstrapped linear regressions. A CBSM intervention may provide long-term protective effects for women with early stage breast cancer by reducing risk of all-cause mortality, lowering depressive symptoms, and improving quality of life. The mediators of these effects remain unknown. This research bolsters the evidence for the effects of psychosocial interventions on physical and psychological health outcomes in breast cancer patients and has implications for clinical practice.

Keywords

Breast Cancer; Cognitive-Behavioral Stress Management; Survival; Recurrence: Quality of Life; Depression

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