A Perfect Storm: Patterns of care
Dignam20 examined survival by race in several National Surgical Adjuvant Breast and Bowel Project trials. He found that the benefit from systemic adjuvant therapy for reductions in disease recurrence and mortality was comparable between African American and white patients. His survey of trials consistently indicated equivalent disease-free survival, but a mortality deficit for African Americans also was found consistently. Among African Americans, the excess risk of mortality was 21% for those who were lymph node–negative and 17% for those who were lymph node–positive. The excess mortality risk was thought to be attributable to greater mortality from noncancer causes among African American patients rather than a failure of African Americans to respond to breast cancer treatment.
In contrast to Dignam’s findings20, Hershman et al.21 assessed the association between race and treatment discontinuation/delay, white blood cell counts, and survival in women enrolled in the Southwest Oncology Group adjuvant breast cancer trials. The study found that African American women were significantly more likely to experience treatment discontinuation/delay than were white women (87% vs. 81%, respectively; P = .04). These delays were not accounted for by toxicities, which were experienced in similar proportions by race. African American women also were more likely to miss appointments (19% vs. 9%; P = .0002); perhaps, as Hassett and Griggs22 speculated, this finding speaks to economic barriers, including the inability to arrange alternate child care, miss work, or afford transportation to the clinic. Despite these barriers to care for African American patients, they still received the same mean relative dose intensity (87% vs. 86%).
In their survival analysis, Hershman et al.21 controlled for treatment-related factors such as dose reductions and delays, body surface area, baseline white blood cell counts, and other predictors of survival and still found that African Americans had worse disease-free and overall survival than did white women. The authors concluded that the study was “unable to demonstrate that any factor related to treatment quality or delivery contributed to racial differences in survival between the groups.”21 The study thus established two important findings related to the disparity gap. First, even in the controlled setting of a clinical trial, African American patients faced barriers to optimal treatment,22 and second, despite attempts to control for treatment quality and delivery, African American women still had worse outcomes. These findings suggest that tumor biology and genomics remain important.
In next month’s installment, we will discuss interventions aimed at closing the racial survival disparity in breast cancer. Eliminating racial disparities in cancer mortality through effective interventions has become an increasingly important imperative in federal, state, and community health care programs.
Other installments of this column can be found in the Related Content box.
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9. Gwyn K, Bondy ML, Cohen DS, et al. Racial differences in diagnosis, treatment, and clinical delays in a population-based study of patients with newly diagnosed breast carcinoma. Cancer. 2004 Apr;100(8):1595-604.
10. Richards MA, Westcombe AM, Love SB, Littlejohns P, Ramirez AJ. Influence of delay on survival in patients with breast cancer: a systematic review. Lancet. 1999 Apr 3;353(9159):1119-26.
11. Griggs JJ, Culakova E, Sorbero ME, et al. Social and racial differences in selection of breast cancer adjuvant chemotherapy regimens. J Clin Oncol. 2007 Jun 20;25(18):2522-7.
12. Griggs JJ, Sorbero ME, Stark AT, Heininger SE, Dick AW. Racial disparity in the dose and dose intensity of breast cancer adjuvant chemotherapy. Breast Cancer Res Treat. 2003 Sep;81(1):21-31.
