Chlorpyrifos (CPF) is a commonly used organophosphate insecticide (OP). In adults, exposure to OPs has been inconsistently associated with reduced lung function. OP exposure and lung function has not been assessed in adolescents. The objective of this study was to assess CPF exposure and lung function among Egyptian adolescents. We conducted a 10-month study of male adolescent pesticide applicators (n = 38) and non-applicators of similar age (n = 24). Urinary 3,5,6-trichloro-2-pyridinol (TPCy), a CPF-specific metabolite, was analyzed in specimens collected throughout the study. Spirometry was performed twice after pesticide application: day 146, when TCPy levels were elevated and day 269, when TCPy levels were near baseline. Applicators had higher levels of TCPy (mean cumulative TCPy day 146 = 33,217.6; standard deviation (SD) = 49,179.3) than non-applicators (mean cumulative TCPy day 146 = 3290.8; SD = 3994.9). Compared with non-applicators, applicators had higher odds of reporting wheeze, odds ratio = 3.41 (95% CI: 0.70; 17.41). Cumulative urinary TCPy was inversely associated with spirometric measurements at day 146, but not at day 269. Although generally non-significant, results were consistent with an inverse association between exposure to CPF and lung function.

We evaluated the association between methylation of 9 genes, SCGB3A1, GSTP1, RARB, SYK, FHIT, CDKN2A, CCND2, BRCA1, and SFN in tumor samples from 720 breast cancer cases with clinicopathological features of the tumors and survival. Logistic regression was used to estimate odds ratios (OR) of methylation and Cox proportional hazards models to estimate hazard ratios (HR) between methylation and breast cancer related mortality. Estrogen receptor (ER) and progesterone receptor (PR) positivity were associated with increased SCGB3A1 methylation among pre- and post-menopausal cases. Among premenopausal women, compared with Stage 0 cases, cases of invasive cancer were more likely to have increased methylation of RARB (Stage I OR = 4.7, 95% CI: 1.1–19.0; Stage IIA/IIB OR = 9.7, 95% CI: 2.4–39.9; Stage III/IV OR = 5.6, 95% CI: 1.1–29.4) and lower methylation of FHIT (Stage I OR = 0.2, 95% CI: 0.1–0.9; Stage IIA/IIB OR = 0.2, 95% CI: 0.1–0.8; Stage III/IV OR = 0.6, 95% CI: 0.1–3.4). Among postmenopausal women, methylation of SYK was associated with increased tumor size (OR = 1.7, 95% CI: 1.0–2.7) and higher nuclear grade (OR = 2.0, 95% CI 1.2–3.6). Associations between methylation and breast cancer related mortality were observed among pre- but not post-menopausal women. Methylation of SCGB3A1 was associated with reduced risk of death from breast cancer (HR = 0.41, 95% CI: 0.17–0.99) as was BRCA1 (HR = 0.41, 95% CI: 0.16–0.97). CCND2 methylation was associated with increased risk of breast cancer mortality (HR = 3.4, 95% CI: 1.1–10.5). We observed differences in methylation associated with tumor characteristics; methylation of these genes was also associated with breast cancer survival among premenopausal cases. Understanding of the associations of DNA methylation with other clinicopathological features may have implications for prevention and treatment.