'Disturbing' Disparity in Use of Key Breast Cancer Drug

Lidia Schapira, MD


April 25, 2016

Disparities in Use of Human Epidermal Growth Hormone Receptor 2–Targeted Therapy for Early-Stage Breast Cancer

Reeder-Hayes K, Peacock Hinton S, Meng K, Carey LA, Dusetzina SB
J Clin Oncol. 2016 Apr 11. [Epub ahead of print]

Study Summary

The purpose of the study was to investigate the rates and patterns of receipt of trastuzumab in patients with early HER2-positive breast cancer (stages I-III) diagnosed in 2010 and 2011. Using the SEER-Medicare database, investigators examined a national cohort of Medicare beneficiaries and used insurance claims to track the use of trastuzumab in the 12 months after diagnosis, as well as to identify the chemotherapy drugs used in combination with trastuzumab.

They found that 50% of white women and 40% of black women received trastuzumab—either a trastuzumab-containing regimen such as TCH (docetaxel, carboplatin, and trastuzumab) or ACTH (doxorubicin hydrochloride, cyclophosphamide, paclitaxel, and trastuzumab), a combination of trastuzumab and a taxane, or trastuzumab alone. Among women with stage III disease, 74% of white and 56% of black patients received trastuzumab. After adjustments for biology, poverty, and comorbidity, black women were 25% less likely to receive trastuzumab within 1 year of diagnosis than their white counterparts. The investigators concluded that "significant racial disparities exist in the receipt of this highly effective therapy." They suggested that further research to identify barriers to use of trastuzumab could potentially improve recurrence and survival outcomes in this population.


This is the first report that queries the SEER database specifically in looking for receipt of HER2-directed therapy for curable breast cancer in the Medicare population. SEER data represent about 28% of the US cancer population and almost the entire population of breast cancer patients older than 65 years of age. Of 1362 women with HER2-positive disease, 85% were white, 7.6% were black, and 7% were classified as "other." Two thirds of this group were node negative and three quarters had endocrine-sensitive disease; these characteristics probably influenced treatment recommendations.

The finding that black women were 25% less likely to receive trastuzumab within 1 year of diagnosis is disturbing and confirms the persistence of inequities in treatment, on the basis of factors other than biology, comorbidities, and access to care. It is not unreasonable to assume that racial disparities in the receipt of trastuzumab-based therapy probably affect outcomes in this minority population.

The authors appropriately comment on the fact that there is still little evidence to guide treatment for women with small tumors that are node negative. The lack of clarity about the benefits of adjuvant anti-HER2 therapy for women with stage I disease, especially those who are older and estrogen receptor–positive, accounts for the variability in treatment recommendations.

However, the variations in treatment should be equally distributed among all groups, and such was not the case. The researchers rightly point out that anti-HER2 treatment is effective, innovative, and nontoxic and should be made available to all women who can benefit.


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