Bryan Langholz

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A variant of the case-cohort design is proposed for the situation in which a correlate of the exposure (or prognostic factor) of interest is available for all cohort members, and exposure information is to be collected for a case-cohort sample. The cohort is stratified according to the correlate, and the subcohort is selected by stratified random sampling.(More)
The Oncotype DX assay was recently reported to predict risk for distant recurrence among a clinical trial population of tamoxifen-treated patients with lymph node-negative, estrogen receptor (ER)-positive breast cancer. To confirm and extend these findings, we evaluated the performance of this 21-gene assay among node-negative patients from a community(More)
OBJECTIVE To investigate the associations of maternal and grandmaternal smoking before, during, and after pregnancy with childhood asthma. DESIGN, SETTING, AND PARTICIPANTS We conducted a case-control study nested within the Children's Health Study in southern California. The case patients consisted of 338 children with asthma that had been diagnosed in(More)
Early-life experiences and environmental exposures have been associated with childhood asthma. To investigate further whether the timing of such experiences and exposures is associated with the occurrence of asthma by 5 years of age, we conducted a prevalence case-control study nested within the Children's Health Study, a population-based study of > 4,000(More)
We describe the use of multivariate regression for testing allelic association in the presence of linkage, using marker genotype data from sibships. The test is valid, provided that the correct mean structure is modeled but does not require the correlation structure within families to be specified. The test can be implemented using standard statistical(More)
CONTEXT The risk of breast cancer in BRCA1 and BRCA2 mutation carriers has been examined in many studies, but relatively little attention has been paid to the degree to which the risk may vary among carriers. OBJECTIVES To determine the extent to which risks for BRCA1 and BRCA2 carriers vary with respect to observable and unobservable characteristics. (More)
The recently developed case-cohort method of sampling from a cohort is compared with the nested case-control method. Corrected asymptotic relative efficiency results show that the case-cohort design for single "disease" outcomes offers less improvement for intervention trials for which there is no random censoring than originally suggested. Furthermore,(More)
PURPOSE To investigate the relationship between traffic density and the risk of childhood leukemia. METHODS The study group consisted of 212 cases and 202 controls from the London et al. (1991) study of childhood leukemia conducted in the Los Angeles area during 1978 to 1984. Using GIS methods, traffic counts on all streets within 1500 feet of each(More)
BACKGROUND A cohort mortality study among 5886 chemical manufacturing workers was completed in 1987 and showed increased mortality due to pancreatic cancer. PURPOSE We conducted a nested case-control study of pancreatic cancer among these chemical manufacturing workers to identify risk factors for this disease. METHODS Twenty-eight verified cases of(More)
During a 21-year period, 66 patients with uterine sarcomas were treated at California Medical Center. Histological diagnoses were mixed mesodermal sarcoma in 32 patients (48%), leiomyosarcoma in 24 (36%), and endometrial stromal sarcoma in 10 (15%) patients. The majority of patients (73%) had Stage I tumors. The treatment consisted of surgery alone in 27(More)