Early discontinuation of tamoxifen

Abstract

BACKGROUND.Five years of treatment provides the optimum duration of tamoxifen therapy for the prevention of breast cancer recurrence and mortality. Durations of adjuvant tamoxifen therapy less than 5 years are associated with poorer outcomes for breast cancer patients. The purpose of the study was to assess rates of tamoxifen nonpersistence (early discontinuation) in women aged 35 years or older using prescription refill data from a national prescribing database.METHODS.A cohort of 2816 women commencing tamoxifen as initial hormonal therapy was identified between January 2001 and January 2004. The cumulative tamoxifen persistence rate was calculated for these women and the relation between nonpersistence and clinical and demographic variables assessed.RESULTS.Within 1 year of commencing treatment the cumulative tamoxifen nonpersistence rate was 22.1%. This is twice the rate of treatment discontinuation observed in other studies by this time. By the end of follow‐up at 3.5 years, the cumulative nonpersistence rate had increased to 35.2%. Determinants of nonpersistence identified included age and a history of antidepressant use.CONCLUSIONS.The rate of nonpersistence with tamoxifen therapy is higher than previously reported. This study demonstrates that persistence with tamoxifen cannot be assumed and raises concerns about persistence with other oral hormonal therapies for breast cancer and oral antineoplastics in general. Oncologists need to identify those at risk of nonpersistence and develop strategies to combat this barrier to treatment success. Cancer 2007. © 2007 American Cancer Society.

Compliance with adjuvant capecitabine in patients with stage II and III colon cancer: comparison of administrative versus medical record data

“…This approach was also frequently used in analyses involving oral hormonal therapies in breast cancer 35, 36, 37. PDC provides reliable information when a drug is administered on a daily basis since PDC is derived by determining the percentage of days over a defined time period in which the drug was dispensed.…”

The Challenges of Oral Agents as Antineoplastic Treatments

“…[27][28][29] In breast cancer patients taking long-term tamoxifen, younger women are more adherent. 7,30,31 In some instances, males, non Caucasians, those who have less than a high school education, and are low-income have been found to be less adherent. [32][33][34] Depression.…”

“…37, In cancer patients, increased depressive symptoms are associated with nonadherence. 31,33,38 The mechanism by which symptoms impact adherence remains unclear and likely complex, yet when identified could ultimately be a modifiable risk factor. 39 Scientists theorize that increased levels of depression may decrease the capability to be adherent.…”

“…7,11,30,31,42, Therefore, in a regimen that takes place over prolonged time, adherence declines drastically.…”

“…26,88 Lack of adherence to oral chemotherapy can contribute to variability in a drug's antineoplastic agent effect if a clinician incorrectly attributes the patient's worsening condition to an absence of drug activity and may lead to unnecessary testing and hospitalization. 31 …”