There are several suspected environmental risk factors for non-Hodgkin lymphoma (NHL). The associations between NHL and environmental chemical exposures have typically been evaluated for individual ...chemicals (i.e., one-by-one).
We determined the association between a mixture of 27 correlated chemicals measured in house dust and NHL risk.
We conducted a population-based case-control study of NHL in four National Cancer Institute-Surveillance, Epidemiology, and End Results centers--Detroit, Michigan; Iowa; Los Angeles County, California; and Seattle, Washington--from 1998 to 2000. We used weighted quantile sum (WQS) regression to model the association of a mixture of chemicals and risk of NHL. The WQS index was a sum of weighted quartiles for 5 polychlorinated biphenyls (PCBs), 7 polycyclic aromatic hydrocarbons (PAHs), and 15 pesticides. We estimated chemical mixture weights and effects for study sites combined and for each site individually, and also for histologic subtypes of NHL.
The WQS index was statistically significantly associated with NHL overall odds ratio (OR) = 1.30; 95% CI: 1.08, 1.56; p = 0.006; for one quartile increase and in the study sites of Detroit (OR = 1.71; 95% CI: 1.02, 2.92; p = 0.045), Los Angeles (OR = 1.44; 95% CI: 1.00, 2.08; p = 0.049), and Iowa (OR = 1.76; 95% CI: 1.23, 2.53; p = 0.002). The index was marginally statistically significant in Seattle (OR = 1.39; 95% CI: 0.97, 1.99; p = 0.071). The most highly weighted chemicals for predicting risk overall were PCB congener 180 and propoxur. Highly weighted chemicals varied by study site; PCBs were more highly weighted in Detroit, and pesticides were more highly weighted in Iowa.
An index of chemical mixtures was significantly associated with NHL. Our results show the importance of evaluating chemical mixtures when studying cancer risk.
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Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Quantitative measurements of environmental factors greatly improve the quality of epidemiologic studies but can pose challenges because of the presence of upper or lower detection limits or ...interfering compounds, which do not allow for precise measured values. We consider the regression of an environmental measurement (dependent variable) on several covariates (independent variables). Various strategies are commonly employed to impute values for interval-measured data, including assignment of one-half the detection limit to nondetected values or of "fill-in" values randomly selected from an appropriate distribution. On the basis of a limited simulation study, we found that the former approach can be biased unless the percentage of measurements below detection limits is small (5-10%). The fill-in approach generally produces unbiased parameter estimates but may produce biased variance estimates and thereby distort inference when 30% or more of the data are below detection limits. Truncated data methods (e.g., Tobit regression) and multiple imputation offer two unbiased approaches for analyzing measurement data with detection limits. If interest resides solely on regression parameters, then Tobit regression can be used. If individualized values for measurements below detection limits are needed for additional analysis, such as relative risk regression or graphical display, then multiple imputation produces unbiased estimates and nominal confidence intervals unless the proportion of missing data is extreme. We illustrate various approaches using measurements of pesticide residues in carpet dust in control subjects from a case-control study of non-Hodgkin lymphoma.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Bladder cancer mortality rates have been elevated in northern New England for at least five decades. Incidence rates in Maine, New Hampshire, and Vermont are about 20% higher than the United States ...overall. We explored reasons for this excess, focusing on arsenic in drinking water from private wells, which are particularly prevalent in the region.
In a population-based case-control study in these three states, 1213 bladder cancer case patients and 1418 control subjects provided information on suspected risk factors. Log transformed arsenic concentrations were estimated by linear regression based on measurements in water samples from current and past homes. All statistical tests were two-sided.
Bladder cancer risk increased with increasing water intake (Ptrend = .003). This trend was statistically significant among participants with a history of private well use (Ptrend = .01). Among private well users, this trend was apparent if well water was derived exclusively from shallow dug wells (which are vulnerable to contamination from manmade sources, Ptrend = .002) but not if well water was supplied only by deeper drilled wells (Ptrend = .48). If dug wells were used pre-1960, when arsenical pesticides were widely used in the region, heavier water consumers (>2.2 L/day) had double the risk of light users (<1.1 L/day, Ptrend = .01). Among all participants, cumulative arsenic exposure from all water sources, lagged 40 years, yielded a positive risk gradient (Ptrend = .004); among the highest-exposed participants (97.5th percentile), risk was twice that of the lowest-exposure quartile (odds ratio = 2.24, 95% confidence interval = 1.29 to 3.89).
Our findings support an association between low-to-moderate levels of arsenic in drinking water and bladder cancer risk in New England. In addition, historical consumption of water from private wells, particularly dug wells in an era when arsenical pesticides were widely used, was associated with increased bladder cancer risk and may have contributed to the New England excess.
Background: Renal cell carcinoma and hypertension (a well-established renal cancer risk factor) are both more frequent among blacks than whites in the United States. The association between ...hypertension and renal cell carcinoma has not been examined in black Americans. We investigated the hypertension—renal cancer association by race, and we assessed the role of hypertension in the racial disparity of renal cancer incidence. Methods: Participants were enrolled in a population-based case-control study in Detroit and Chicago during 2002—2007 (number of cases: 843 whites, 358 blacks; number of controls: 707 whites, 519 blacks). Participants reported their history of hypertension and antihypertensive drug use. We used unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for demographic characteristics, smoking, body mass index, and family history of cancer. Results: Hypertension doubled renal cancer risk (OR = 2.0 CI = 1.7—2.5) overall. For whites, the OR was 1.9 (CI = 1.5—2.4), whereas for blacks it was 2.8 (2.1—3.8) (P for interaction = 0.11). ORs increased with time after hypertension diagnosis (P for trend <0.001), reaching 4.1 (CI = 2.3—7.4) for blacks and 2.6 (CI = 1.7—4.1) for whites after 25 years. ORs for poorly controlled hypertension were 4.5 (CI = 2.3—8.8) for blacks and 2.1 (CI = 1.2—3.8) for whites. If these estimates correctly represent causal effects and if, hypothetically, hypertension could be prevented entirely among persons aged 50—79 years, the black/white disparity in renal cancer could be reversed among women and reduced by two-thirds among men. Conclusions: Hypertension is a risk factor for renal cancer among both blacks and whites, and might explain a substantial portion of the racial disparity in renal cancer incidence. Preventing and controlling hypertension might reduce renal cancer incidence, adding to the known benefits of blood pressure control for heart disease and stroke reduction, particularly among blacks.
Background Cigarette smoking is a well-established risk factor for bladder cancer. The effects of smoking duration, intensity (cigarettes per day), and total exposure (pack-years); smoking cessation; ...exposure to environmental tobacco smoke; and changes in the composition of tobacco and cigarette design over time on risk of bladder cancer are unclear. Methods We examined bladder cancer risk in relation to smoking practices based on interview data from a large, population-based case–control study conducted in Maine, New Hampshire, and Vermont from 2001 to 2004 (N = 1170 urothelial carcinoma case patients and 1413 control subjects). We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression. To examine changes in smoking-induced bladder cancer risk over time, we compared odds ratios from New Hampshire residents in this study (305 case patients and 335 control subjects) with those from two case–control studies conducted in New Hampshire in 1994–1998 and in 1998–2001 (843 case patients and 1183 control subjects). Results Regular and current cigarette smokers had higher risks of bladder cancer than never-smokers (for regular smokers, OR = 3.0, 95% CI = 2.4 to 3.6; for current smokers, OR = 5.2, 95% CI = 4.0 to 6.6). In New Hampshire, there was a statistically significant increasing trend in smoking-related bladder cancer risk over three consecutive periods (1994–1998, 1998–2001, and 2002–2004) among former smokers (OR = 1.4, 95% CI = 1.0 to 2.0; OR = 2.0, 95% CI = 1.4 to 2.9; and OR = 2.6, 95% CI = 1.7 to 4.0, respectively) and current smokers (OR = 2.9, 95% CI = 2.0 to 4.2; OR = 4.2, 95% CI = 2.8 to 6.3; OR = 5.5, 95% CI = 3.5 to 8.9, respectively) (P for homogeneity of trends over time periods = .04). We also observed that within categories of intensity, odds ratios increased approximately linearly with increasing pack-years smoked, but the slope of the increasing trend declined with increasing intensity. Conclusions Smoking-related risks of bladder cancer appear to have increased in New Hampshire since the mid-1990s. Based on our modeling of pack-years and intensity, smoking fewer cigarettes over a long time appears more harmful than smoking more cigarettes over a shorter time, for equal total pack-years of cigarettes smoked.
Purpose To clarify the contemporary clinical epidemiology of renal cell carcinoma we present trends in clinical presentation and treatment in patients enrolled in a population based case-control ...study. Materials and Methods The National Cancer Institute performed a population based case-control study in metropolitan Detroit and Chicago from 2002 through 2007. In 1,136 patients with renal cell carcinoma who consented to an epidemiological interview and medical record review we ascertained detailed information on social and medical history, methods of renal cell carcinoma detection and diagnosis, cancer severity and treatment(s) received. From these data we assessed the demographic and cancer specific characteristics of study cases, and trends in clinical presentation, diagnosis and treatment. Results Most patients with renal cell carcinoma had localized or regional tumors, including 52% with tumors 4 cm or less. The proportion of asymptomatic cases increased from 35% in 2002 to 50% in 2007 (p <0.001). Hypertension and diabetes were common in patients (58% and 17%, respectively) and 24% had at least 2 significant comorbid conditions at cancer diagnosis. While the use of laparoscopic surgery increased with time (p <0.001), fewer than 1/5 patients underwent nephron sparing surgery. Conclusions The proportion of patients presenting with small, asymptomatic renal cell carcinoma continues to increase. Most of these cases are still treated with radical nephrectomy, although increasingly via a laparoscopic approach. Since most patients with small renal cell carcinomas have 1 or more renal function relevant comorbidities, there is an imperative to increase the use of nephron sparing surgery.
Ingestion of disinfection byproducts has been associated with bladder cancer in multiple studies. Although associations with other routes of exposure have been suggested, epidemiologic evidence is ...limited.
We evaluated the relationship between bladder cancer and total, chlorinated, and brominated trihalomethanes (THMs) through various exposure routes.
In a population-based case–control study in New England (
=(1,213) cases;
=(1,418) controls), we estimated lifetime exposure to THMs from ingestion, showering/bathing, and hours of swimming pool use. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression adjusted for confounders.
Adjusted ORs for bladder cancer comparing participants with exposure above the 95th percentile with those in the lowest quartile of exposure (based on the distribution in controls) were statistically significant for average daily intake mg/d of total THMs OR=1.53 (95% CI: 1.01, 2.32),
-trend=0.16 and brominated THMs OR=1.98 (95% CI: 1.19, 3.29), p-trend=0.03. For cumulative intake mg, the OR at the 95th percentile of total THMs was 1.45 (95% CI: 0.95, 2.2),
-trend=0.13; the ORs at the 95th percentile for chlorinated and brominated THMs were 1.77 (95% CI: 1.05, 2,.99),
-trend=0.07 and 1.78 (95% CI: 1.05, 3.00),
-trend=0.02, respectively. The OR in the highest category of showering/bathing for brominated THMs was 1.43 (95% CI: 0.80, 2.42),
-trend=0.10. We found no evidence of an association for bladder cancer and hours of swimming pool use.
We observed a modest association between ingestion of water with higher THMs (>95th percentile vs.<25th percentile) and bladder cancer. Brominated THMs have been a particular concern based on toxicologic evidence, and our suggestive findings for multiple metrics require further study in a population with higher levels of these exposures. Data from this population do not support an association between swimming pool use and bladder cancer. https://doi.org/10.1289/EHP89.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
ObjectivesTrichloroethylene, a chlorinated solvent widely used for metal degreasing, is classified by the International Agency for Research on Cancer as a kidney carcinogen. Other chlorinated ...solvents are suspected carcinogens, most notably the cleaning solvent perchloroethylene, although it is unclear whether they are associated with kidney cancer. We investigated kidney cancer associations with occupational exposure to 6 chlorinated solvents (trichloroethylene, perchloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, chloroform, and methylene chloride) within a case–control study using detailed exposure assessment methods.MethodsCases (n=1217) and controls (n=1235) provided information on their occupational histories and, for selected occupations, on tasks involving potential exposure to chlorinated solvents through job-specific interview modules. Using this information, an industrial hygienist assessed potential exposure to each solvent. We computed ORs and 95% CIs for different exposure metrics, with unexposed participants as the referent group.Results1,1,1-trichloroethane, carbon tetrachloride, chloroform, and methylene chloride were not associated with kidney cancer. Among jobs with high exposure intensity, high cumulative hours exposed to perchloroethylene was associated with increased risk, both overall (third tertile vs unexposed: OR 3.1, 95% CI 1.3 to 7.4) and after excluding participants with ≥50% exposure probability for trichloroethylene (OR 3.0, 95% CI 0.99 to 9.0). A non-significant association with high cumulative hours exposed to trichloroethylene was observed (OR 1.7, 95% CI 0.8 to 3.8).ConclusionsIn this study, high exposure to perchloroethylene was associated with kidney cancer, independent of trichloroethylene. Additional studies are needed to further investigate this finding.
Purpose
Use of antihypertensive medications has been associated with renal cell carcinoma (RCC), but it is unclear whether specific types of medications increase RCC risk independent of the effect of ...hypertension, or whether the association varies by histologic subtype. To address this question, we analyzed data from a U.S. population-based case–control study of RCC.
Methods
We collected information on participants’ use of drugs to treat hypertension, heart problems, weight control, and swelling. We computed odds ratios (ORs) and 95% confidence intervals (CIs) for each of four major drug classes, separately for participants with (643 cases, 443 controls) and without (500 cases, 718 controls) a history of hypertension, using unconditional logistic and polytomous regression models.
Results
None of the antihypertensive drug types was associated with RCC overall. Among participants with a history of hypertension, papillary RCC was associated with long-term use of diuretics (OR = 3.1, 95% CI = 1.4–6.7 for 16+ years, 16 cases, 31 controls; P-trend = 0.014) and calcium channel blockers (OR = 2.8, 95% CI = 1.1–7.4 for 16+ years, 8 cases, 14 controls; P-trend = 0.18), while corresponding ORs for clear cell RCC were weaker (ORs 0.9 and 1.5, respectively) and nonsignificant. The only significant finding among those with no hypertension history was an association between calcium channel blockers and papillary RCC (OR = 17.9, 95% CI = 5.9–54.5) that was based on small numbers (8 cases, 9 controls). There was little evidence of an association between RCC and use of ACE inhibitors or beta blockers.
Conclusions
Our study, while inconclusive for overall RCC, provides, to our knowledge, the first evidence supporting an association between antihypertensive medications and papillary RCC. These subtype-specific findings, although based on small numbers, warrant further investigation.
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