Majority of Older Women with Early Stage Breast Cancer Fail to Adhere to Tamoxifen Regimen

 Behind the Cancer Headlines®

January 3, 2008 


Research out of the Ireland Cancer Center of University Hospitals Case Medical Center, in collaboration with six integrated health plans that are part of the Cancer Research Network, found that the majority of older women with early stage breast cancer fail to adhere to the standard of treatment – five years of daily oral use of the chemo-prevention drug Tamoxifen. Writing in the Journal of Clinical Oncology, Cynthia Owusu, MD, of the Ireland Cancer Center (ICC) and colleagues determined that premature tamoxifen discontinuation is quite common and deserves closer attention. 

“We in the medical community have long believed we were caring for these women appropriately and this study determines that these patients over age 65 are being woefully undertreated,” said Owusu, who runs the ICC’s geriatric oncology program and was lead author of the study. “Going forward we need to develop strategies to improve breast cancer outcomes for these women.”  

The study looked at 961 women over the age of 65 who had early stage hormone positive breast cancer. Previous research has shown that five years of tamoxifen is more effective than two years of use. However, information on tamoxifen discontinuation has been scant. Owusu and her group sought to identify factors that predict premature tamoxifen continuation.  

They found that nearly 50% of the women in the study discontinued tamoxifen before the completion of five years. The women most likely to stop taking the treatment were women over age 75, women who developed other medical illnesses during the first three years of follow-up and those who had their breast lumps removed but failed to receive radiation after their surgery. The discontinuation of tamoxifen may result in earlier recurrences, and ultimately, increased breast cancer mortality.  

“This study is the first to show that closer attention to non-adherence among older women at risk of premature discontinuation might improve breast cancer survival for these women,” explains Owusu. “These findings have major clinical implications for this large group of breast cancer survivors. It means we have to really examine what to do to counteract this discontinuation, such as working more closely with primary care providers and increasing patient education. We really have to pay close attention to older patients more likely to fall into this category.” 

“These results remind us to educate our patients about the value of prompt diagnosis and complete treatment. Only through closer follow-up care for older women with breast cancer, will we achieve optimal results and allow these women to lead healthy lives,” said Stanton Gerson, MD, Director of the Ireland Cancer Center. 



Journal of Clinical Oncology, February 2008, published online December 21, 2007

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