Perinatal factors, growth and development, and osteosarcoma risk.

Osteosarcoma incidence patterns suggest an aetiologic role for perinatal factors, and growth and development. Osteosarcoma patients (n = 158) and controls with benign orthopaedic conditions (n = 141) under age 40 were recruited from US orthopaedic surgery departments. Exposures were ascertained by interview, birth, and growth records. Age- and sex-adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated. Current height and age- and sex-specific height percentiles were not associated with osteosarcoma risk. Male cases, however, appeared to have an earlier adolescent growth period, and earlier attainment of final height (OR = 7.1; 95% CI = 1.6-50 for <19 vs 19+ years), whereas earlier puberty appeared protective with ORs of 0.41 (95% CI 0.18-0.89) and 0.68 (95% CI 0.31-1.5) for developing facial and pubic hair, respectively. High birth weight was associated with an elevated osteosarcoma risk (OR = 3.9; CI = 1.7-10 for 4000 g vs 3000-3500 g), although there was no trend in risk with increasing weight. These data provide some evidence that osteosarcoma is related to size at birth and in early adolescence, while earlier puberty in male subjects may be protective.

Cancer mortality in the U.S. flour industry.

The mortality experience among 22,938 white males who were enrolled in the life insurance program of the American Federation of Grain Millers was assessed for the period 1955 through 1985 in a cohort mortality analysis and in a nested case-control analysis. Significantly fewer deaths were observed among this group than expected for all causes of death combined [standardized mortality ratio (SMR) = 89] compared with the number of deaths observed among the general population of U.S. white males of the same age. Excess risks for developing non-Hodgkin's lymphoma (NHL) (SMR = 149), leukemia (SMR = 136), and pancreatic cancer (SMR = 133) were restricted to workers employed in flour mills, where pesticides are used more frequently than in other segments of the industry. In the nested case-control analysis, excess risks for developing these cancers were also observed in these workers, but the relative risk for developing NHL [odds ratio (OR) = 4.2] was approximately twice that for developing pancreatic cancer (OR = 2.2) and that for developing leukemia (OR = 1.8). Within the flour mills, the workers who had ever worked in the maintenance department (OR = 8.1) or in the elevator department (OR = 2.8) were at particularly elevated risk of developing NHL, suggesting that exposures in these departments should receive further attention.

Measurement of coffee and caffeine intake: implications for epidemiologic research.

Reported associations between coffee or caffeine intake and benign breast disease, cancers, and cardiovascular diseases have generally been weak and inconsistent. The apparent discrepancies in these studies might be attributable to imprecision in the measurement of coffee and caffeine intake. A study of a random sample of 2,714 U.S. adults disclosed considerable misclassification of total caffeine intake and, to a lesser extent, coffee intake when the estimates were limited to only the number of cups of coffee consumed. Adjustment for the following factors is recommended: amount of caffeinated and decaffeinated coffee consumed both on weekdays and on weekends; the size of the container used; the method used to brew caffeinated coffee; and the amount of caffeine imbibed from tea and soft drinks. Intake of coffee varied markedly between seasons of the year and over time. Random misclassification of coffee and caffeine intake would have the effect of obscuring dose-response relationships to disease incidence.

Confounders contributing to the reported associations of coffee or caffeine with disease.

The role of caffeine or coffee in causing or promoting the incidence of serious disease is equivocal. Two design factors may account for the discrepancies in reported findings on the effects of coffee drinking: (a) imprecision of measurement and (b) confounding variables. A study of 2,714 white U.S. adults disclosed that, of 32 risk factors analyzed by linear and logistic regression, only sex and cigarette smoking were found to be important potential confounders of caffeine and coffee intake. Partial R2 values of the other 30 risk factors were relatively small and were inconsistent for each sex. It is unlikely that any of these factors could explain any of the reported associations between caffeine or coffee consumption and certain diseases. However, certain weak associations with caffeine or coffee intake should be included in the study design when they are known to be risk factors of a disease under investigation. These factors for men are dietary fat intake, vitamin C intake, and body mass index; and for women are vitamin use, alcohol intake, stress, and perceived health status.