Care and survival of Mexican American women with node negative breast cancer: historical cohort evidence of health insurance and barrio advantages.

We hypothesized 3-way ethnicity by barrio by health insurance interactions such that the advantages of having adequate health insurance were greatest among Mexican American (MA) women who lived in barrios. Barrios were neighborhoods with relatively high concentrations of MAs (60% or more). Data were analyzed for 194 MA and 2,846 non-Hispanic white women diagnosed with, very treatable, node negative breast cancer in California between 1996 and 2000 and followed until 2011. Significant interactions were observed such that the protective effects of Medicare or private health insurance on radiation therapy access and long term survival were largest for MA women who resided in MA barrios, neighborhoods that also tended to be extremely poor. These paradoxical findings are consistent with the theory that more facilitative social and economic capital available to MA women in barrios enables them to better absorb the indirect and direct, but uncovered, costs of breast cancer care.