Survival difference between non-Hispanic black and non-Hispanic white women with localized breast cancer: the impact of guideline-concordant therapy.

OBJECTIVES: This study examined the impact of guideline-concordant therapy on the survival difference between non-Hispanic black (NHB) and non-Hispanic white (NHW) women with localized breast cancer.
METHODS: Data analyzed were from the CDC's NPCR Patterns of Care study in which seven population-based state cancer registries participated. We randomly selected 2,362 women who were diagnosed with a first primary localized breast cancer in 1997. Data were abstracted from hospital records, supplemented by information from physician offices and by linkages with state vital records and the National Death Index database.
RESULTS: NHB women were more likely than NHW women to receive breast conserving surgery without radiation therapy. In addition, the percentage of NHB women with hormone receptor-positive tumors who received hormonal therapy was lower than that of NHW women. Among those with a tumor size > 3 cm, NHB women were more likely than NHW women to receive multiagent chemotherapy. After controlling for age, the risk of dying from all causes of death was 2.35 times as high for NHB women compared to NHW women. Controlling for treatment further reduced black-white difference in survival with adjustment for sociodemographic and clinical variables.
CONCLUSION: NHB women were less likely than NHW women to receive guideline-concordant radiation therapy after breast conserving therapy and hormonal therapy but were more likely to receive chemotherapy. Racial differences in treatment contribute significantly to the worse survival of NHB women compared with NHW women.