Family histories of cancer and joint contributions with exposures in the incidence of acute leukemia in adults.

摘要

Family history of cancer may be a marker for susceptibility to the effects of exposures on leukemia incidence. In a large case-control study of adult acute leukemia in adults and population-based controls, we estimated the effects of family histories of cancer alone and in combination with environmental risk factors. Analyses were carried out separately for proxy- and self-interviewed patients.;Relative risks for family histories were generally elevated in proxy-interviewed patients, with a reported family history of any (RR = 1.74, 95% CI: 1.26--2.39) and hematopoietic (RR = 1.81, 95% CI: 1.08--3.04) cancer associated with increased risk. In self-interviewed patients, family histories were generally not associated with increased incidence. Regardless of interview type history of breast cancer in sisters was associated with a two to three-fold increased incidence of adult acute leukemia, whereas history of breast cancer in mothers was not associated with increased incidence.;For all sites combined, occupational pure aromatic hydrocarbon exposure was associated with a three fold increased incidence in the presence of a family history, compared to no exposure in the absence of a family history (RR = 3.4, 95% CI: 1.6--7.0). Family history of breast cancer appeared to interact with ever smoking (RR = 2.4, 95% CI: 1.2--4.8), solvent exposure (RR = 1.9, 95% CI: 1.1--3.4), and diagnostic ionizing radiation exposure (RR = 2.1, 95% CI: 1.2--3.8). The joint effects for sibling breast cancer histories were stronger but less stable than those for family history of breast cancer in general. Results were not materially different for self-interviewed and proxy interviewed patients.;The role of family history of cancer in leukemia etiology may be obscured by differential reporting in patients and proxies, with proxies possibly providing more accurate family histories. Results were consistent with a synergy between family history of breast cancer and exposures in adult acute leukemia incidence. Family history of cancer, particularly breast cancer, may be a marker for susceptibility to the effects of these exposures on leukemia risk. Breast cancer and leukemia might share susceptibilities specific to these cancer sites, susceptibilities that might interact with exposures and contribute to adult acute leukemia incidence.