A Perfect Storm: Patterns of care
Misuse of treatment
Once treatment is initiated, African Americans often receive inappropriate therapy, studies have demonstrated. In a prospective analysis of 957 patients in 101 oncology practices, Griggs et al.11 found more frequent use of non–guideline concordant adjuvant chemotherapy regimens in African American women. In a univariate analysis, African American patients were more likely than were whites to receive a nonstandard regimen (19% vs. 11%; P = .047). Although we will discuss further in this column whether guidelines based on clinical trials are appropriate for African American patients, the study demonstrates that these women are not uniformly receiving standard-of-care treatment.
Underuse of treatment
In addition to misuse of treatment, studies also have examined undertreatment of African American patients with breast cancer. One study investigated chemotherapy administration among African American patients with stage I-III breast cancer at 10 different treatment sites. Compared with white patients, African Americans received a lower dose proportion (actual vs. expected dose) and lower relative dose intensity.
The authors found that between-group differences in biological and medical characteristics, such as tolerance of therapy, comorbidities, and leukocyte counts, did not explain these variations in treatment. In fact, despite the association between lower leukocyte counts and African American ethnicity, there was no evidence that white blood cell levels accounted for the difference in dose proportion or relative dose intensity. Significantly, the authors discovered that more African Americans had chemotherapy dose reductions in the first cycle of treatment, perhaps indicating physician assumptions regarding African American patients’ ability to tolerate chemotherapy.12
Silber et al.8 also examined differences in the administration of chemotherapy between white and African American breast cancer patients. The authors found that 3.7% of African Americans received both an anthracycline and a taxane; that figure rose to 5.0% among whites who were matched to African Americans at presentation.
Bickell et al.13 explored further racial disparity in the underuse of adjuvant breast cancer treatment. The researchers examined the medical records of 677 women treated surgically for stage I or II breast cancer. The study defined underuse as omissions of radiotherapy after breast-conserving surgery, adjuvant chemotherapy after resection of hormone receptor–negative tumors ≥ 1 cm, or hormonal therapy for receptor-positive tumors ≥ 1 cm. Underuse of appropriate adjuvant treatment was found in 34% of African American patients versus 16% of white patients (P less than .001). There were racial disparities present in all three adjuvant therapies assessed.
Hormonal therapy has been shown effective in clinical trials for preventing breast cancer recurrence and death in women with early-stage breast cancer.14 The study by Bickell et al.13 documented underuse of this treatment in African American patients. Partridge et al.15 conducted the largest study of oral antineoplastic use outside of a clinical trial setting. Their study consisted of 2,378 primary breast cancer patients enrolled in New Jersey’s Medicaid or pharmaceutical assistance program; the main outcome was the number of days covered by filled tamoxifen prescriptions in the first year of therapy. The study found that nonwhite patients had significantly lower adherence rates than did whites. Although further investigation is needed to determine the drivers of this nonadherence in African American patients, medication cost has been proposed as a significant factor leading to underuse of these agents. Streeter et al.16 analyzed a nationally representative pharmacy claims database for oral antineoplastics and calculated abandonment rates for the initial claim. Not surprisingly, high cost sharing and low incomes were associated with a higher abandonment rate (P < .05). Despite being an important component of health equity research, treatment adherence has been identified by the Association of American Medical Colleges as a critically underrepresented area of disparities-focused health services research.17 More attention to this area is needed to understand the underuse of hormonal therapies in African American breast cancer patients.
The treatment strategies that have been shown to be delayed, underused, or misused in African American patients in the aforementioned studies have improved disease-free and overall survival in large randomized trials. Furthermore, diminished total dose and dose intensity of adjuvant chemotherapy both have been associated with lower breast cancer survival rates.18,19 These quality-of-care failures in breast cancer treatment for minority patients are thought to partially explain the survival disparity between African Americans and whites. It has been proposed that patients in both groups derive a similar benefit from systemic therapy when it is administered in accordance with their clinical and pathologic presentation,20 but that assumption becomes more nuanced when the clinical trial experience is reviewed.
Clinical trial experience
