by Emma Bright
More than 3.1 million women with a history of breast cancer live in the United States. In 2018 alone, 266,000 women were diagnosed, but since 1990, the death rate from breast cancer has declined. This progress has been attributed to increased disease awareness as well as improvements in screening and treatments.1 One such treatment is endocrine therapy, which blocks or eliminates the production of hormones that promote tumor growth. Endocrine therapy (i.e., tamoxifen and aromatase inhibitors) is delivered in pill form and is appropriate for the approximately 75% of women diagnosed with hormone receptor-positive breast tumors.2 Current guidelines suggest that women take endocrine therapy daily for five or more years.3 Women who adhere to endocrine therapy (i.e., who take the medication as prescribed) are less likely to have cancer recurrence than are women who do not.4 Despite endocrine therapy’s benefits non-adherence is common.5 The benefits of endocrine therapy coupled with the rates of non-adherence make it important to identify factors that help and hinder women in adhering to their medication. Most previous research addressed medical (e.g., chemotherapy use) and demographic (e.g., age) contributors to endocrine therapy adherence, however, we were interested in understanding potentially modifiable factors which may influence adherence. Specifically, we examined factors that have been previously linked to medication adherence in other diseases: social support, coping strategies, and depressive symptoms. In this study, we tested a model in which social support and coping processes predict adherence through their contribution to depressive symptoms.
The Endocrine Therapy Experience Study
We recruited women with breast cancer who were receiving their first prescription for endocrine therapy from a large community breast oncology clinic in Southern California for a study of their experience with taking endocrine therapy. We administered interviews and questionnaires at prescription initiation, one, four, and 12 months later. These interviews and questionnaires assessed depressive symptoms, strategies for coping with cancer, and social support from oncologists and loved ones. At the beginning of the study, women received a medication event monitoring system (MEMS) cap and instructions for its use. MEMS caps electronically record the date and time when a pill bottle is opened and provide an objective measure of medication adherence.
Findings from the study revealed women who had greater social support from oncologists and loved ones at the beginning of the study had lower depressive symptoms one month later, which in turn was related to better adherence at four months. Sociodemographic factors like age and education and cancer-related factors such as the time elapsed since diagnosis did not predict adherence. Women’s strategies for coping with the cancer experience did not predict depressive symptoms or adherence.
Conclusions and Future Directions
This study’s findings have at least two important public health implications. First, the results suggest that screening for and treating depressive symptoms in women diagnosed with breast cancer could be an effective strategy to enhance women’s mental health and potentially to improve adherence and reduce breast cancer recurrence and death.
Second, the findings suggest that adherence may be improved by leveraging women’s social relationships. Support from both loved ones and oncologists either through direct tangible support or emotional support may help in bolstering adherence. For example, a woman’s social network may provide support by picking up a prescription at the pharmacy or compassionately listening to her discuss her experience with side effects. Taken together with results from our and others’ labs, our findings suggest that clear communication and active listening on the part of oncologists can influence women’s medication adherence.6 A next step will be to develop and test effective approaches women can use to communicate their needs for support to their loved ones and oncologists.
Author’s note: This article was based on research conducted by Emma Bright and Annette Stanton which was published in the Journal of Clinical and Consulting Psychology. This research was supported by funding from the Breast Cancer Research Foundation.
Emma Bright is a doctoral candidate in the Department of Psychology. Broadly, her research focuses on how individuals and their caregivers cope with and adjust to chronic stressors, such as cancer. She was the recipient of CSW’s 2018 Elizabeth Blackwell, MD, Graduate Award.
- American Cancer Society. Cancer facts and figures 2018. 2018; https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2018.html.
- Adjuvant therapy for breast cancer. NIH Consensus Statement; 2000:1-35.
- Burstein HJ, Temin S, Anderson H, et al. Adjuvant endocrine therapy for women with hormone receptor-positive breast cancer: American society of clinical oncology clinical practice guideline focused update. J Clin Oncol. 2014;32(21):2255-2269.
- Hershman DL, Kushi LH, Shao T, et al. Early discontinuation and nonadherence to adjuvant hormonal therapy in a cohort of 8,769 early-stage breast cancer patients. J Clin Oncol. 2010;28(27):4120-4128; Makubate B, Donnan PT, Dewar JA, Thompson AM, McCowan C. Cohort study of adherence to adjuvant endocrine therapy, breast cancer recurrence and mortality. Br J Cancer. 2013;108(7):1515-1524.
- Murphy CC, Bartholomew LK, Carpentier MY, Bluethmann SM, Vernon SW. Adherence to adjuvant hormonal therapy among breast cancer survivors in clinical practice: a systematic review. Breast Cancer Res Treat. 2012;134(2):459-478.
- Stanton AL, Petrie KJ, Partridge AH. Contributors to nonadherence and nonpersistence with endocrine therapy in breast cancer survivors recruited from an online research registry. Breast Cancer Res Treat. 2014;145(2):525-5; Wuensch P, Hahne A, Haidinger R, et al. Discontinuation and non-adherence to endocrine therapy in breast cancer patients: is lack of communication the decisive factor? J Cancer Res Clin Oncol. 2015;141(1):55-60.