Re: asthma and the risk of lung cancer. findings from the Adverse Childhood Experiences (ACE).

Using data from 8,896 men and women aged 50-89 years from the Adverse Childhood Experiences Study who were free of a self-reported history of lung cancer or any cancer at baseline, we examined the association between self-reported asthma and incident lung cancer. The prevalence of smoking was 33% among those who developed lung cancer (n = 52) and 7% among those who did not. Asthma was reported by 17% of adults who developed lung cancer and by 9% of those who did not. After adjustment for age, gender, race/ethnicity, educational attainment, smoking status, number of cigarettes smoked per day, and growing up with a parent who smoked the risk of lung cancer was 2.1 (95% CI: 1.0, 4.4) times greater among adults with a history of asthma compared to those without. Among nonsmokers, a similar result was observed, although it did not attain statistical significance (RR: 2.1; 95% CI: 0.9, 5.1). Smoking-attributable lung cancer incidence and mortality are in part a function of the prevalence of smoking in the population. Thus, decreases in the prevalence of smoking in the United States that have occurred since its peak in the 1960s will inevitably result in a decline in the proportion of lung cancer in the population caused by smoking. We hope that our findings and those of others will stimulate research of the biologic mechanism(s) underlying the occurrence of lung cancer among nonsmokers so that possible treatments and prevention strategies may be developed.

Asthma and risk of death from lung cancer: NHANES II Mortality Study.

OBJECTIVE: Although smoking is the most important risk factor for lung cancer, nearly 10% of lung cancer is not attributable to smoking. Insights into risk factors for lung cancer other than smoking will become increasingly important, given decreasing trends in the prevalence of smoking. Prior research suggests asthma may increase the risk of lung cancer, particularly among nonsmokers. METHODS: We used Cox regression analyses of data from a nationally representative sample of 9087 adults aged 30-75 years included in the NHANES II Mortality Study (1976-1992) to estimate the relative risk (RR) of death from lung cancer associated with self-reported asthma, independent of smoking. RESULTS: Age-adjusted prevalence of smoking was 36.0%, and the age-adjusted prevalence of asthma was 6.1% (6.2% among nonsmokers) at baseline. During approximately 17 years of follow-up, 196 adults died of lung cancer (ICD-9 160-165). Among 6144 nonsmokers, the RR of lung cancer death comparing adults with asthma to those without was 1.69 (95% CI: 0.94-3.04) although the association was not statistically significant. For nonsmokers without a history of cancer, the RR was 2.53 (95% CI: 1.42-4.52). After exclusion of adults with emphysema and chronic bronchitis, the RR of lung cancer death associated with asthma was 3.54 (95% CI: 1.93-6.42). CONCLUSIONS: Consistent with prior reports, we observed an increased risk of lung cancer mortality associated with asthma among nonsmokers without a history of cancer.

Evaluation of chromosome breakage and DNA integrity in sperm: an investigation of remote semen collection conditions.

Collection of ejaculated semen at a remote site (outside of the laboratory) would facilitate participation rates and geographic diversity in reproductive epidemiology studies. Our study addressed concerns that remote collection and overnight mail return might induce chromosome/DNA damage. We collected semen from 10 healthy men. Part of each sample was snap frozen in liquid nitrogen and the rest held at 22 +/- 1 degrees C for 24 hours in a transport container (simulating ambient temperature during overnight return) then snap frozen. DNA breakage and fragmentation were measured using tandem-label sperm-fluorescence in situ hybridization (FISH), terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), and neutral comet assay. Tandem-label sperm-FISH and TUNEL detected no statistically significant difference between sperm fresh frozen (FF) and those frozen after 24 hours (F24). The mean frequency of chromosome breakage per 10 000 cells scored in sperm-FISH for FF and F24 was 10.5 +/- 1.3 breaks and 11.2 +/- 1.1 breaks, respectively (P =.69, Student's t test). The mean frequency of TUNEL-positive cells per 2000 cells scored in FF and F24 was 136 +/- 29 and 213 +/- 28 cells, respectively, which approached but did not reach statistical significance (P = 0.07, Student's t test). The neutral comet assay detected a statistically significant difference in DNA strand breakage between the 2 groups (percentage of DNA in the tail P = 0.037; tail moment P = 0.006; and tail length P = 0.033, all Student's t test). The mean frequency of damage denoted by tail length in micro m per 100 cells scored in FF and F24 was 175.0 +/- 15.5 and 152.2 +/- 17.6 micro m, respectively. Tandem-label sperm-FISH, TUNEL, and neutral comet assay are useful analytical techniques for laboratory-based studies of human sperm genomic integrity; however, for field studies incorporating the nonrefrigerated return of semen after 24 hours, only chromosome breakage at a level that can be detected using tandem-label sperm-FISH was unaffected. TUNEL and neutral comet assay need further study before they are used in specimens collected at remote sites and transported to a central laboratory.