Summary
Purpose
To estimate the proportion of older women who fail to complete 5 years of tamoxifen therapy and to identify predictors of non-adherence.
Patients and methods
We followed 462 women 65-years-old or older with stage I–IIIA breast cancer diagnosed in four US regions between 1996 and 1999 and who initiated tamoxifen therapy. We interviewed patients annually to assess tamoxifen adherence and collected information about predictors of adherence by medical record review, patient interview, and physician questionnaire.
Results
Thirty-one percent of patients who started tamoxifen failed to complete the recommended 5-year course. Patients who had initial severe side effects [hazard ratio (HR) per side effect=1.2, 95% confidence interval (CI) 0.97, 1.5] or developed them (HR per new side effect=1.3, 95% CI 1.0, 1.6) were more likely to discontinue. Patients with more prescription medications at baseline were less likely to discontinue (HR per baseline prescription equaled 0.90, 95% CI 0.81, 0.99), whereas patients who added a prescription were more likely to discontinue (HR per new prescription equaled 1.2, 95% CI 1.0, 1.4). Patients with positive views of tamoxifen at baseline (HR for a 10-point higher score=0.93, 95% CI 0.83, 1.0) and an improving view over follow-up (HR for a 10-point positive change=0.93, 95% CI 0.87, 1.0) were less likely to discontinue.
Conclusion
Five years of tamoxifen confers a significant benefit beyond 1–2 years of tamoxifen, so physicians should ask patients about side effects, other prescriptions, and beliefs about tamoxifen and should educate them about the benefits of completing adjuvant therapy.
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References
Early Breast Cancer Trialists’ Collaborative Group Effects of chemotherapy and hormonal therapy for early breast cancer on recurrence and 15-year survival: an overview of the randomized trials Lancet 365: 1687–1717, 2005
Lash TL, Silliman RA. Re: Prevalence of cancer Letter to the editor. J Natl Cancer Inst 90: 399–400, 1998
Powles T, Eeles R, Ashley S, Easton D, Chang J, Dowsett M, Tidy A, Viggers J, Davey J. Interim analysis of the incidence of breast cancer in the Royal Marsden Hospital tamoxifen randomised chemoprevention trial Lancet 352: 98–101, 1998
Fink AK, Gurwitz J, Rakowski W, Guadagnoli E, Silliman RA. Patient beliefs and tamoxifen continuance in older women with estrogen receptor-positive breast cancer J Clin Oncol 22: 3309–3315, 2004
Haynes RB, McDonald HP, Garg AX. Helping patients follow prescribed treatment: clinical applications JAMA 288: 2880–2883, 2002
Jackevicius CA, Mamdani M, Tu JV. Adherence with statin therapy in elderly patients with and without acute coronary syndromes JAMA 288: 462–467, 2002
Demissie S, Silliman RA, Lash TL. Adjuvant tamoxifen: predictors of use, side effects, and discontinuation in older women J Clin Oncol 19: 322–328, 2001
Partridge AH, Wang PS, Winer EP, Avorn J. Non-adherence to adjuvant tamoxifen therapy in women with primary breast cancer J Clin Oncol 21: 602–606, 2003
van Servellen G, Chang B, Garcia L, Lombardi E. Individual and system level factors associated with treatment non-adherence in human immunodeficiency virus-infected men and women AIDS Patient Care STDS 16: 269–281, 2002
Balkrishnan R. Predictors of medication adherence in the elderly Clin Ther 20: 764–771, 1998
Grunfeld EA, Hunter MS, Sikka P, Mittal S. Adherence beliefs among breast cancer patients taking tamoxifen Patient Educ Couns 59: 97–102, 2005
Silliman RA, Guadagnoli E, Rakowski W, Landrum MB, Lash TL, Wolf R, Fink A, Ganz PA, Gurwitz J, Borbas C, Mor V. Adjuvant tamoxifen prescription in women 65 years and older with early stage breast cancer J Clin Oncol 20: 2680–2688, 2002
Fleming ID. AJCC Cancer Staging Manual 5th Edn. Lippincott Williams & Wilkins Philadelphia 1997
Ware J. SF-36 Health Survey, Manual and Interpretation Guide The Health Institute Boston 1993
Coscarelli-Schag CA, Ganz PA, Heinrich RL. Cancer rehabilitation evaluation system – short form (CARES-SF): a cancer-specific rehabilitation and quality of life instrument Cancer 68: 1406–1413, 1991
Day R, Ganz PA, Costantino JP, Cronin WM, Wickerham DL, Fisher B. Health-related quality of life and tamoxifen in breast cancer prevention: a report from the National Surgical Adjuvant Breast and Bowel Project P-1 Study J Clin Oncol 17: 2659–2669, 1999
Fisher B, Costantino J, Redmond C, Poisson R, Bowman D, Couture J, Dimitrov NV, Wolmark N, Wickerham DL, Fisher ER. A randomized clinical trial evaluating tamoxifen in the treatment of patients with node-negative breast cancer who have estrogen-receptor-positive tumors N Engl J Med 320: 479–484, 1989
Fisher B, Costantino JP, Wickerham DL, Redmond CK, Kavanah M, Cronin WM, Vogel V, Robidoux A, Dimitrov N, Atkins J, Daly M, Wieand S, Tan-Chiu E, Ford L, Wolmark N. Tamoxifen for prevention of breast cancer: report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study J Natl Cancer Inst 90: 1371–1388, 1998
Winer EP, Hudis C, Burstein HJ, Wolff AC, Pritchard KI, Ingle JN, Chlebowski RT, Gelber R, Edge SB, Gralow J, Cobleigh MA, Mamounas EP, Goldstein LJ, Whelan TJ, Powles TJ, Bryant J, Perkins C, Perotti J, Braun S, Langer AS, Browman GP, Somerfield MR. American society of clinical oncology technology assessment on the use of aromatase inhibitors as adjuvant therapy for post-menopausal women with hormone-receptor-positive breast cancer: status report 2004 J Clin Oncol 23: 619–629, 2005
Prochaska JO, Velicer WF, Rossi JS, Goldstein MG, Marcus BH, Rakowski W, Fiore C, Harlow LL, Redding CA, Rosenbloom D. Stages of change and decisional balance for 12 problem behaviors Health Psychol 13: 39–46, 1994
Janis IL, Mann L. Psychological Analysis of Conflict, Choice, and Commitment Macmillan London 1977
Horne R, Weinman J. Patients’ beliefs about prescribed medicines and their role in adherence to treatment in chronic physical illness J Psychosom Res 47: 555–567, 1999
Ruggiero L. Transtheoretical model: applications in the prevention and treatment of cancer Med Pediatr Oncol 1: 69–74, 1998
Rakowski W, Andersen MR, Stoddard AM, Urban N, Rimer BK, Lane DS, Fox SA, Costanza ME. Confirmatory analysis of opinions regarding the pros and cons of mammography Health Psychol 16: 433–441, 1997
Osterberg L, Blaschke T. Adherence to medication N Engl J Med 353: 487–497, 2005
Garber MC, Nau DP, Erickson SR. The concordance of self-report with other measures of medication adherence: a summary of the literature Med Care 42: 649–652, 2004
Acknowledgments
Data collection and analyses were supported by grants R01 CA/AG70818 from the National Cancer Institute and National Institute on Aging and R01 CA84506 from the National Cancer Institute. Dr Lash was supported, in part, by K07 CA87724 from the National Cancer Institute. Dr Silliman was supported, in part, by K05 CA92395 from the National Cancer Institute.
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Lash, T.L., Fox, M.P., Westrup, J.L. et al. Adherence to tamoxifen over the five-year course. Breast Cancer Res Treat 99, 215–220 (2006). https://doi.org/10.1007/s10549-006-9193-0
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DOI: https://doi.org/10.1007/s10549-006-9193-0