UCSF

Objectives

Latina breast cancer patients are 20 percent more likely to die within 5 years after diagnosis compared with white women, even though they have a lower incidence of breast cancer, lower general mortality rates, and some better health behaviors. Existing data only examine disparities in the utilization of breast cancer care; this research expands the study question to which utilization factors drive the shorter survival in Latina women compared with white women.

Methods

This longitudinal linked Surveillance Epidemiology and End Results (SEER)-Medicare cohort study examined early stage breast cancer patients diagnosed between 1992 and 2000 and followed for 5-11 years after diagnosis (N=44,999). Modifiable utilization factors included consistent visits to primary care providers and to specialists after diagnosis, consistent post-diagnosis mammograms, and receipt of initial care consistent with current standards of care.

Results

Of the four utilization factors potentially driving this disparity, a lack of consistent post-diagnosis mammograms was the strongest driver of the Latina breast cancer survival disparity. Consistent mammograms attenuated the hazard of death from 23% [hazard ratio, HR, (95% confidence interval, 95%CI)=1.23 (1.1,1.4)] to a nonsignificant 12% [HR (95%CI)=1.12 (0.7,1.3)] and reduced the excess hazard of death in Latina women by 55%. Effect modification identified that visits to primary care providers have a greater protective impact on the survival of Latina compared to white women [HR (95%CI)=0.9 (0.9,0.9)].

Conclusions

We provide evidence that undetected new or recurrent breast cancers due to less consistent post-diagnosis mammograms contribute substantially to the long-observed Latina survival disadvantage. Interventions involving primary care providers may be especially beneficial to this population.