Endocrine therapy is one of the most common treatments for breast cancers that are hormone positive. Individuals are typically recommended to take endocrine therapy for five years or longer to reduce the risk of breast cancer recurrence and other poor outcomes. Despite evidence that treatment adherence improves morbidity and mortality, over half of patients are estimated to stop endocrine therapy before the prescribed duration (“early discontinuation”). Common reasons for this include side effects from treatment and cost.
An original study published June 17, 2021 in the Journal of the American Medical Association (JAMA) Oncology aimed to understand patient-level characteristics that predict early discontinuation of endocrine therapy. The researchers focused on modifiable risk factors, which can be targets for future screening tools and interventions.
The study used longitudinal data from the Trial Assigning Individualized Options for Treatment (TAILORx) from 954 patients to see if there was an association between discontinuing endocrine therapy (defined as stopping therapy < 4 years from the initial treatment for a reason other than death or cancer recurrence) and patient-level baseline characteristics including:
- Patient-level clinical and demographic factors
- Health-related quality of life (well-being, fatigue, and symptoms)
The results indicated that 106 participants (11.4%) had a 4-year early discontinuation rate. Patient characteristics that significantly increased the risk for early discontinuation included: age (under 40 years old), receiving endocrine therapy alone (versus chemoendocrine therapy), worse physical well-being, worse social well-being, depression, and use of antidepressants at baseline.
The authors note that these findings are in line with previous research studies that demonstrated the impact of age, poor quality of life, and depressive symptoms on early discontinuation of endocrine therapy. Nurse scientists have advanced this work, including Dr. Catherine Bender1 whose work reported similar findings. The study results differ from previous studies that showed chemotherapy and polypharmacy were not predictive of early discontinuation.
A limitation of this study was that daily adherence to endocrine therapy was not captured. A major strength of this study was the availability of four years of treatment data.
Considering these findings, the authors recommend oncology clinicians to consider referring at-risk patients for psychosocial care and/or physical rehabilitation to head off early discontinuation of endocrine therapy. Knowing the risk factors identified in this study can assist oncology nurses in creating clinical protocols to identify patients at risk for stopping their endocrine therapy and proactively support their treatment adherence. Interventions to prevent discontinuation and enhance adherence can also be employed, including protocols that promote bidirectional patient and provider communication about adherence.2 Many of these interventions are led by nurses, underscoring the key central role oncology nurses play in treatment adherence.3,4
1 Bender, C. M., Gentry, A. L., Brufsky, A. M., Casillo, F. E., Cohen, S. M., Dailey, M. M., … & Sereika, S. M. (2014). Influence of patient and treatment factors on adherence to adjuvant endocrine therapy in breast cancer. Oncology Nursing Forum, 41(3): 274-285.
2 Finitsis, D. J., Vose, B. A., Mahalak, J. G., & Salner, A. L. (2019). Interventions to promote adherence to endocrine therapy among breast cancer survivors: A meta‐analysis. Psycho‐oncology, 28(2), 255-263.
3 Ell, K., Vourlekis, B., Xie, B., Nedjat‐Haiem, F. R., Lee, P. J., Muderspach, L., … & Palinkas, L. A. (2009). Cancer treatment adherence among low‐income women with breast or gynecologic cancer: A randomized controlled trial of patient navigation. Cancer, 115(19), 4606-4615.
4 Ziller, V., Kyvernitakis, I., Knöll, D., Storch, A., Hars, O., & Hadji, P. (2013). Influence of a patient information program on adherence and persistence with an aromatase inhibitor in breast cancer treatment – The COMPAS study. BMC cancer, 13(1), 1-9.