OT3-02-01: A 1-Year Prospective Longitudinal Study of the Role of Psychosocial Factors in Adherence to Adjuvant Endocrine Therapy in Early Breast Cancer.
Authors: Song X , Verma S , Dent S , Clemons M , Graham N , Bedard M , Paquet L 
Published: June 2012

Background: Extensive evidence suggests that endocrine therapy (ET) and adherence to adjuvant ET directly impacts on disease-free and overall survival in women with hormone receptor positive (HR+) early stage breast cancer (EBC). Despite this, adherence to ET is suboptimal, with 35%-50% of patients discontinuing therapy earlier than recommended. Interventions to improve adherence are lacking, due in part to a poor understanding of the modifiable risk factors influencing adherence. Virtually all authors have focused on educational needs of patients and side effect management of ET but there remains a paucity of data on how potentially modifiable psychosocial factors present at outset of treatment initiation influence adherence. We believe that a better understanding of these factors may lead to interventions which enable women to adhere to long term life-saving therapies. This study aims to identify such factors guided by the Common-Sense Model of Self-Regulation which proposes that cognitive, emotional, coping and interpersonal factors are modifiable determinants of adherence.

Study Design: The study is a single centre prospective longitudinal quantitative study. Women diagnosed with HR+ EBC for which endocrine therapy is intended will be enrolled. Participants will complete questionnaires prior to initiating ET, then at 3, 6 and 12 months. The predictor variables are: 1) modifiable factors including illness and treatment cognitions, self-efficacy in coping with side effects anticipated or experienced, fear of breast cancer recurrence, trait anxiety, patient-physician interaction, 2) treatment-induced toxicities and 3) clinical factors including ET, chemotherapy, radiation, cancer stage and menopausal status. The outcome variable is adherence measured at each assessment post-treatment initiation with pill counts and participants'self-report.

Inclusion criteria: 1.Histologically proven Stage I, II, IIIa EBC; 2. Treatment with ET (tamoxifen or an aromatase inhibitor).

Specific Aims: To evaluate the impact on adherence to ET by 1) potentially modifiable psychosocial factors 2) side effects and 3) clinical factors.

Statistical Method: Adherence responses will be transformed into dummy coded variables (0=take ET as prescribed; 1=does not take ET as prescribed). For each assessment, several separate univariate logistic regressions will be conducted with demographic (age, education, work and marital status, ethnicity), cognitive (illness and treatment perception), emotional (fear of recurrence and anxiety), coping (self-efficacy), and patient-physician relationship (role preference, trust and satisfaction), severity of side effects and clinical factors, as independent predictors of adherence. Only predictors which are significant at the 0.25 level will be entered in subsequent hierarchical multiple regression models to identify the main determinants of adherence.

Accrual: Expected study accrual is 200 over 12–18 months. Accrual started in May of 2011 and 36 patients have been accrued to the study.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-02-01.