A lack of adherence and completion of adjuvant hormonal therapy: Why?
June 29, 2010
The Advocate Says:
Though medication side effects and cost/insurance issues are possible reasons for non-compliance, I also think there is another factor. I believe that many patients are under the impression that once they have completed what they consider their primary treatment, (surgery, chemo, radiation), they "survived and beat cancer." Most patients would not even consider skipping a chemo or radiation appointment, because of its perceived importance and impact. With the final stage of therapy in oral form, sadly, it's importance could be misunderstood. Why take an asprin if I don't have a headache? Why take this pill, if I don't have cancer? (They removed the lump and chemo killed any remaining cancerous cells). This is an opportunity for advocates to continue educating newly diagnosed patients. Finaly, I think this is further proof that the seriousness of a breast cancer diagnosis has been completely minimized. Recurrent disease, mets, are still lacking in many breast cancer conversations.
-Rose Gerber, East Lyme, CT, Project LEAD® 2008, Clinical Trials Project LEAD® 2008, Quality Care Project LEAD® 2009
Study Design: Population-based cohort study of women in the Kaiser Permanente Northern California health system
Study Eligibility: Women in the Kaiser Permanente Northern California database who were diagnosed by pathology with Stage I-III hormone receptor-positive breast cancer between January 1, 1996 and June 30, 2008
Enrollment: 8,769 hormone receptor-positive breast cancer patients
Research Question: What are the factors associated with discontinuation and nonadherence to hormonal therapy?
Prescribed for 5 years or longer, hormonal therapy drugs (i.e. tamoxifen and aromatase inhibitors) are used to reduce recurrence and mortality from hormone receptor-positive breast cancer. However, the discontinuation rate for tamoxifen and aromatase inhibitors (i.e. Arimidex®, Femara®) has been estimated to be between 7 to 10% per year. Previous studies have indicated that only between 40 to 60% of patients with breast cancer finish their recommended courses of hormonal therapy.
To have a more comprehensive understanding of factors associated with discontinuation and nonadherence, investigators conducted a cohort study in women enrolled in Kaiser Permanente of Northern California health system. Using pharmacy records for hormonal therapy prescriptions and refill dates, the investigators reviewed data on the use of tamoxifen and aromatase inhibitors over a 10-year period to determine factors associated with discontinuation and nonadherence.
Discontinuation was associated with being in the younger (< 40) or older (>70) age group, having a lumpectomy, and having more comorbid conditions (additional diseases). Being of Asian/Pacific Islander ethnicity, being married, earlier year at diagnosis, receipt of adjuvant chemotherapy in the past, receipt of adjuvant radiation therapy, and longer prescription refill were associated with the completion of hormonal therapy at 4.5 years. Nonadherence was associated with African American race, lumpectomy, unknown tumor size, lymph node involvement, and having more comorbid conditions. Adherence with hormonal therapy was associated with being married and longer prescription refill interval.
Similar to other studies in the literature, longer prescription refill interval was associated with completion and full adherence to hormonal therapy. But the link between nonadherence and length of prescription refill may be a chance finding and requires further research to determine the exact impact. Limitations of the study included inability to determine the reasons for nonadherence and discontinuation and lack of complete recurrence data with electronic records which may have lead to misclassification bias.
Citations
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; DOI:10.1200/JCO.2009.25.9655
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