David O. Nelson

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With increasing availability of drugs for impotence and advanced reproductive technologies for the treatment of subfertility, more men are fathering children at advanced ages. We conducted a study of the chromosomal content of sperm of healthy men aged 24-57 years to (a) determine whether father's age was associated with increasing frequencies of aneuploid(More)
BACKGROUND Although recent reviews have suggested active smoking to be a risk factor for breast cancer, the association with passive smoke exposure remains controversial. This risk association was explored in a large prospective study of women, the California Teachers Study. METHODS Detailed lifetime information on passive smoke exposure by setting (home,(More)
BACKGROUND Research is limited on the independent and joint effects of individual- and neighborhood-level socioeconomic status (SES) on breast cancer survival across different racial/ethnic groups. METHODS We studied individual-level SES, measured by self-reported education, and a composite neighborhood SES (nSES) measure in females (1,068 non-Hispanic(More)
BACKGROUND Thyroid cancer incidence is increasing worldwide. Incorporating 22 years of incidence data through 2009, we extend examination of these trends among a wide array of subgroups defined by patient (age, sex, race/ethnicity, and nativity), tumor (tumor size and stage), and neighborhood (socioeconomic status and residence in ethnic enclaves)(More)
PURPOSE To provide patients and physicians with population-based estimates of mortality from prostate cancer or other causes depending upon the primary treatment modality, stratified by patient age, tumor stage and grade. METHODS We conducted a 10-year competing-risk analysis of 45,440 men diagnosed with clinically localized (T1 or T2) prostate cancer in(More)
BACKGROUND Studies suggest that higher breast cancer rates in urban areas persist after accounting for the prevalence of known risk factors, leading to speculation that urban environmental exposures, such as air pollution, may play a role in the etiology of breast cancer. Combining modeled ambient air concentrations with data from a large prospective cohort(More)
BACKGROUND There is accumulating evidence that circadian disruption, mediated by alterations in melatonin levels, may play an etiologic role in a wide variety of diseases. The degree to which light-at-night (LAN) and other factors can alter melatonin levels is not well-documented. Our primary objective was to evaluate the degree to which estimates of(More)
BACKGROUND The Asian American and Pacific Islander (AAPI) population is heterogeneous and rapidly growing in the United States, with a high proportion concentrated in California. Although traditionally assumed to have lower rates of breast cancer than non-Hispanic white women, recent studies have suggested considerable variation in incidence by AAPI ethnic(More)
The objective of this study was to examine the risk of colorectal cancer associated with active smoking among members of the California Teachers Study (CTS), a large cohort of female public school employees for whom highly detailed smoking information is available. The analysis was conducted among the 122,264 CTS participants who lived in California at(More)