Cohort study of adherence to adjuvant endocrine therapy, breast cancer recurrence and mortality

Abstract

Background:Adjuvant endocrine therapy is recommended for women with oestrogen receptor-positive breast cancer, but many women do not take the medication as directed and they stop treatment before completing the standard 5-year duration.Methods:This retrospective cohort study conducted between 1993 and 2008 of all women with incident breast cancer, who are residing in the Tayside region of Scotland, examined adherence to prescribed adjuvant tamoxifen or aromatase inhibitors (AIs). Survival analysis examined the effect of adherence on all-cause mortality, breast cancer death and recurrence, using linked prescribing, cancer registry, clinical cancer audit, hospital discharge and death records.Results:A total of 3361 women with breast cancer were followed for a median 4.47 years (interquartile range (IQR)=2.04–8.55). The median overall adherence was 90% (IQR=90–100%), but the annual adherence reduced after a longer period from diagnosis. Low adherence of <80% was associated with poorer survival (hazard ratios=1.20; 95% confidence interval=1.03–1.40, P=0.019). There was no significant difference for low adherence over the treatment period and recurrence, or breast cancer death, but patients with high annual adherence for 5 years had better outcomes than those with 3 or less.Conclusion:Low adherence to all adjuvant endocrine therapy for women with breast cancer, whether tamoxifen or AI, increases the risk of death.

Fatores associados à adesão e à persistência na hormonioterapia em mulheres com câncer de mama

“…This relation has also been observed in previous studies 6,23 , in which women with more involved lymph nodes presented a higher rate of discontinuity and, as a consequence, lower success in the employed therapy, which also reaffirms the known inverse relation between the survival rate and the cancer stage at the moment of diagnosis 7 .…”

“…Nevertheless, the desirable results many times are not achieved due to problems such as low adherence and low persistence in the recommended treatment, whose associated factors should be carefully evaluated. Evidence ensures that benefits in the change from the mortality and disease recurrence rates only happen effectively if the treatment is completely followed 6,7 . Attention has been given to adherence and persistence studies (A & P) due to the concept that clinical results of the treatment are not only affected by how patients take the drugs, but also by the period of uninterrupted use 8 .…”

Persistence and Compliance Among U.S. Patients Receiving Pazopanib or Sunitinib as First-Line Therapy for Advanced Renal Cell Carcinoma: A Retrospective Claims Analysis

“…26,27 Studies have consistently demonstrated lower compliance in real-world practice than in clinical trials. [28][29][30] Although a clinical trial demonstrated similar efficacy and differing safety profiles of pazopanib and sunitinib as …”

A Systematic Review of Adherence to Oral Antineoplastic Therapies

“…For the 1-year time point, average rates of adherence to endocrine therapy ranged from 77% [33] to 100% [34], with 23% [35,36] to 40% [29] of patients meeting criteria for poor adherence according to a particular threshold (i.e., medication possession ratio ,80%). Longitudinal investigations show that rates of adherence to oral endocrine therapy generally decline over time, with some studies showing rates dropping to approximately 50% adherence by 5-year follow-up [14,33,35,37]. Also shown in Table 3, a total of 19 studies addressed rates of adherence to oral nonendocrine antineoplastic therapies in samples of patients with various cancer types: 47.4% (n 5 9) chronic myeloid leukemia, 26.3% (n 5 5) mixed cancers, 15.8% (n 5 3) breast cancer, 5.3% (n 5 1) hepatocellular carcinoma, and 5.3% (n 5 1) gastrointestinal cancer.…”

“…Published reviews reveal quite variable, and sometimes alarmingly low, rates of adherence to these medications, even as low as 16% [9][10][11][12]. Moreover, studies show statistically significant associations between medication nonadherence and clinical and utilization outcomes, including cancer progression, more inpatient days, higher total health care spending, and worse survival [13][14][15][16][17][18].…”