Older Women More Likely to Discontinue Tamoxifen
Factors such as comorbidities, having breast-conserving surgery also affect likelihood
WEDNESDAY, Dec. 19 (HealthDay News) -- Among elderly women with breast cancer, factors such as age, comorbidities, and having breast-conserving surgery without radiotherapy affect the likelihood that they will discontinue tamoxifen treatment before the recommended five years, according to a report published online Dec. 10 in the Journal of Clinical Oncology.
Cynthia Owusu, M.D., from Case Western Reserve University in Cleveland, Ohio, and colleagues identified predictors of tamoxifen discontinuation in 961 women aged 65 or older with stage I to IIB breast cancer who were prescribed tamoxifen from 1990-1994.
The researchers found that 49 percent of women discontinued tamoxifen before five years, even though five years of adjuvant therapy is considered most effective, they note. Women who discontinued treatment were more likely to be aged 75 years or older (hazard ratio 1.41-2.02), have more comorbidities at three years from diagnosis (HR, 1.52; for cardiopulmonary cormorbidities, 1.75), have an undetermined estrogen-receptor status (HR, 1.36), and have had breast-conserving surgery without radiation (versus mastectomy, HR, 1.62).
"Attention to non-adherence among older women at risk of discontinuation, particularly those receiving breast-conserving surgery without radiotherapy, might improve breast cancer outcomes for these women," Owusu and colleagues conclude.