Cancer Control Research
5R03CA070608-03
Kumanyika, Shiriki K.
DEFINING DIET RELATED BREAST CANCER RISKS IN BLACK WOMEN
AbstractBreast cancer mortality is higher in black than in white women. The
incidence of pre-menopausal breast cancer is higher in black than in
white women and, in some age groups, is increasing at a faster rate than
in white women. These and other aspects of breast cancer epidemiology
suggest the need for within-race studies of the causes and prevention of
breast cancer in black women. Dietary factors, as universal and
potentially-modifiable risk factors are of substantial interest in this
respect. Yet, the contribution of diet to breast cancer etiology has been
difficult to specify, partly due to methodological problems with dietary
assessment. The proposed studies are motivated by evidence suggesting
that effective implementation of the needed studies of diet in breast
cancer etiology in black women is especially impeded by methodological
problems: food frequency or dietary history methods that have acceptable
validity in white populations appear to have less validity in black
populations. These problems can be overcome, in part, by the application
of certain statistical approaches to correct for measurement error--
approaches requiring repeated-measures data collected from the same
population with a more accurate method. Studies are proposed to 1) assess
the validity of food frequency questionnaire data collected from a sample
of black women, and 2) quantify the impact of the associated error on
epidemiologic analyses of diet and breast cancer risk. We will use
telephone and mail contacts to collect 3 unannounced 24-hour dietary
recalls and one 3-day food record from a geographically dispersed sample
of 400 black women. The women will be sampled from a large cohort of
black women who completed a food frequency questionnaire as part of their
enrollment in a large cohort study. The recall and record data will
constitute reference data approximating "true" intake and will support
comprehensive statistical modeling to quantify random variation (i.e.,
intraperson differences in nutrient intakes from day-to-day) and bias
(systematic departures of nutrient intakes estimated from the food
frequency questionnaire). Separate analyses will be done for each of
several key nutrients of interest in relation to breast cancer etiology,
including energy, total fat, saturated fat, dietary fiber, beta carotene,
vitamin C, vitamin E, and alcohol. Deattenuation and correction factors
derived from the dietary assessment studies will be used in exploratory
analyses of dietary risk factors for incident breast cancer using data
from the prospective study data base. Thus, this research will yield
statistical methods for enhancing the ability to assess diet-related
breast cancer risks in black women as well as relevant pilot data to
support future studies.
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