Search

Background: Our prior studies of lung cancer suggested that a novel biomarker (pro-surfactant protein B or pro-SFTPB) might serve as a predictive marker for this disease. We aimed to determine the potential use of pro-SFTPB for distinguishing lung cancer cases from matched controls as a risk marker., Methods: Study subjects were drawn from the longitudinal Physicians' Health Study (PHS). Cases (n = 188) included individuals who were cancer-free at study enrollment but developed lung cancer during follow-up. Controls (n = 337) were subjects who did not develop lung cancer. Cases and controls were matched on date of study enrollment, age at enrollment, and smoking status and amount. Baseline plasma samples drawn at enrollment were analyzed for pro-SFTPB using ELISA to detect differences in protein expression levels for cases and controls., Results: Pro-SFTPB nondetectable status was significantly associated with lung cancer risk [OR = 5.88; 95% confidence interval (CI) 1.24-27.48]. Among subjects with detectable levels of the protein, increasing plasma concentration of pro-SFTPB was associated with higher lung cancer risk (OR = 1.41 per unit increase in log pro-SFTPB; 95% CI 1.08-1.84)., Conclusion: These results suggest a nonlinear, J-shaped association between plasma pro-SFTPB levels and lung cancer risk, with both nondetectable and higher levels of the marker being associated with lung cancer., Impact: These results show promise of a risk marker that could contribute to predicting risk for lung cancer development and to narrowing the high-risk population for low-dose computed tomography screening.

Background: Bulky DNA adducts are markers of exposure to genotoxic aromatic compounds, which reflect the ability of an individual to metabolically activate carcinogens and to repair DNA damage. Polycyclic aromatic hydrocarbons (PAHs) represent a major class of carcinogens that are capable of forming such adducts. Factors that have been reported to be related to DNA adduct levels include smoking, diet, body mass index (BMI), genetic polymorphisms, the season of collection of biologic material, and air pollutants., Methods: We pooled 11 studies (3,600 subjects) in which bulky DNA adducts were measured in human white blood cells with similar (32)P-postlabeling techniques and for which a similar set of variables was available, including individual data on age, gender, ethnicity, batch, smoking habits, BMI, and season of blood collection, and a limited set of gene variants., Results: Lowest DNA adduct levels (P = 0.006) were observed in the spring (median = 0.50 adducts per 10(8) nucleotides), followed by summer (0.64), autumn (0.70), and winter (0.85). The same pattern emerged in multivariate analysis but only among never smokers (P = 0.02). Adduct levels were significantly lower (P = 0.001) in northern Europe (the Netherlands and Denmark; mean = 0.60, median = 0.40) than in southern Europe (Italy, Spain, France, and Greece; mean = 0.79, median = 0.60)., Conclusions: In this large pooled analysis, we have found only weak associations between bulky DNA adducts and exposure variables. Seasonality (with higher adducts levels in winter) and air pollution may partly explain some of the interarea differences (north vs. south Europe), but most inter-area and interindividual variations in adduct levels still remain unexplained., Impact: Our study describes the largest pooled analysis of bulky DNA adducts so far, showing that interindividual variation is still largely unexplained, though seasonality seems to play a role., (©2010 AACR.)

The purpose of this review is to evaluate progress in molecular epidemiology over the past 24 years in cancer etiology and prevention to draw lessons for future research incorporating the new generation of biomarkers. Molecular epidemiology was introduced in the study of cancer in the early 1980s, with the expectation that it would help overcome some major limitations of epidemiology and facilitate cancer prevention. The expectation was that biomarkers would improve exposure assessment, document early changes preceding disease, and identify subgroups in the population with greater susceptibility to cancer, thereby increasing the ability of epidemiologic studies to identify causes and elucidate mechanisms in carcinogenesis. The first generation of biomarkers has indeed contributed to our understanding of risk and susceptibility related largely to genotoxic carcinogens. Consequently, interventions and policy changes have been mounted to reduce risk from several important environmental carcinogens. Several new and promising biomarkers are now becoming available for epidemiologic studies, thanks to the development of high-throughput technologies and theoretical advances in biology. These include toxicogenomics, alterations in gene methylation and gene expression, proteomics, and metabonomics, which allow large-scale studies, including discovery-oriented as well as hypothesis-testing investigations. However, most of these newer biomarkers have not been adequately validated, and their role in the causal paradigm is not clear. There is a need for their systematic validation using principles and criteria established over the past several decades in molecular cancer epidemiology.

Polycyclic aromatic hydrocarbons (PAH), of which benzo[a]pyrene is a representative member, are combustion-related environmental pollutants and include known carcinogens. Laboratory animal studies indicate that the dose of PAHs to the fetus is on the order of a 10th that to the mother and that there is heightened susceptibility to PAH-induced carcinogenesis during the fetal and infancy periods. Carcinogen-DNA adducts, a measure of procarcinogenic genetic damage, are considered a biomarker of increased cancer risk. Here we compare the levels of benzo[a]pyrene-DNA adducts as a proxy for PAH-DNA damage measured in maternal blood and newborn cord blood obtained at delivery in four different populations of mothers (total of 867) and newborns (total of 822), representing a 30-fold range of exposure to ambient PAHs. The populations include residents in Northern Manhattan, participants in a study of the effects of the World Trade Center disaster, residents in Krakow, Poland, and residents in Tongliang, China. Mean adduct concentrations in both maternal and cord blood and the proportion of samples with detectable adducts, increased across the populations [Northern Manhattan < World Trade Center (WTC) < Krakow < Tongliang], consistent with the trend in estimated ambient exposure to PAHs (P < 0.001). For mothers, the means in the respective populations were Northern Manhattan (0.21 adducts per 10(8) nucleotides), WTC (0.23 adducts per 10(8) nucleotides), Krakow (0.28 adducts per 10(8) nucleotides), Tongliang (0.31 adducts per 10(8) nucleotides); the corresponding means in the newborns were Northern Manhattan (0.23), WTC (0.24), Krakow (0.29), Tongliang (0.31). The percentage of mothers with detectable levels of adducts in the respective populations were Northern Manhattan (36.8%), WTC (57.5%), Krakow (72.9%), Tongliang (73.4%); the corresponding percentages among the newborns were Northern Manhattan (42.4%), WTC (60.6%), Krakow (71.1%), Tongliang (79.5%). Despite the estimated 10-fold lower PAH dose to the fetus based on laboratory animal experiments, the adduct levels in the newborns were similar to or higher than in the mothers. This study suggests that the fetus may be 10-fold more susceptible to DNA damage than the mother and that in utero exposure to polycyclic aromatic hydrocarbons may disproportionately increase carcinogenic risk. The data support preventive policies to limit PAH exposure to pregnant women and children.

We investigated the association between alcohol consumption, GSTM1 genotype, and polycyclic aromatic hydrocarbon (PAH)-DNA adduct levels in breast tissue. Women referred for breast surgery were enrolled prior to surgery, responded to an interview, and gave a blood sample. Women diagnosed with ductal carcinoma in situ and invasive ductal or lobular cancer were defined as cases, and women with benign conditions without atypia were defined as controls. Paraffin-embedded tumor and nontumor tissue from cases and benign tissue from controls were retrieved from the pathology samples. GSTM1 genotype status was determined by PCR using WBC DNA, and PAH-DNA adduct levels were measured in breast tissue using immunohistochemistry. In tumor and nontumor tissue from cases, the GSTM1-null genotype was associated with increased adduct levels among current alcohol consumers but not among nondrinkers. In nontumor tissue, the interaction between genotype and alcohol consumption was significant (P=0.02), but in tumor tissue, the interaction did not achieve statistical significance (P=0.10). In benign tissue from controls, there was no association between genotype and adducts, regardless of drinking status. Among subjects with the null genotype who drank alcohol, adduct levels were significantly higher in tumor and nontumor tissue from cases than in benign tissue from controls. These results indicate the presence of a novel gene-lifestyle interaction that influences PAH-DNA adduct levels in breast tissue from cases but not controls. This apparent difference in PAH metabolism in response to alcohol may be an important clue as to how alcohol influences breast cancer risk.

Transplacental exposure to carcinogenic air pollutants from the combustion of fossil fuels is a growing health concern, given evidence of the heightened susceptibility of the fetus. These mutagenic/carcinogenic pollutants include aromatic compounds such as polycyclic aromatic hydrocarbons that bind to DNA, forming chemical-DNA adducts. We have investigated the genotoxic effects of transplacental exposure in humans by analyzing aromatic-DNA adducts and the frequency of gene mutations at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus in umbilical cord and maternal blood samples. Here we show, in a cross-sectional study of 67 mothers and 64 newborns from the Krakow Region of Poland, that aromatic-DNA adducts measured by (32)P-postlabeling are positively associated with HPRT mutant frequency in the newborns (beta = 0.56, P = 0.03) after controlling for exposure to tobacco smoke, diet, and socioeconomic status. In contrast to the fetus, HPRT mutations and DNA adducts do not reflect similar exposure periods in the mother, and the maternal biomarkers were not correlated. Adducts were higher in the newborn than the mother, indicating differential susceptibility of the fetus to DNA damage; but HPRT mutation frequency was 4-fold lower, consistent with the long lifetime of the biomarker. These results provide the first demonstration of a molecular link between somatic mutation in the newborn and transplacental exposure to common air pollutants, a finding that is relevant to cancer risk assessment.

In this matched case-control study nested within the prospective Physicians' Health Study, we evaluated whether DNA damage in blood samples collected at enrollment significantly predicted risk, consistent with our hypothesis that cases have greater biological susceptibility to polycyclic aromatic hydrocarbons and other aromatic tobacco carcinogens. The subjects were 89 cases of primary lung cancer and 173 controls, all males, matched on smoking, age, and duration of follow-up. Aromatic-DNA adducts were measured in WBCs by the nuclease P1-enhanced (32)P-postlabeling method that primarily detects smoking-related adducts. Among current smokers, but not former or nonsmokers, there was a significant increase in mean adduct levels of cases compared with controls (11.04 versus 5.63; P = 0.03). "Healthy" current smokers who had elevated levels of aromatic DNA adducts in WBCs were approximately three times more likely to be diagnosed with lung cancer 1-13 years later than current smokers with lower adduct concentrations (odds ratio, 2.98; 95% confidence interval, 1.05-8.42; P = 0.04). We were not able to discern case-control differences in former smokers and nonsmokers. The findings are of interest because they suggest that individuals who become cases have greater biological susceptibility to tobacco carcinogens, a biological difference, which manifests most clearly while exposure is ongoing.

Oxidative DNA damage and antibodies to that damage have been implicated in lung, breast, and colorectal cancer. In this observational validation study, the relationship between anti-5-hydroxymethyl-2'-deoxyuridine (HMdU) autoantibody (aAb) and plasma micronutrients was assessed in 140 heavy smokers by ELISA. Anti-HMdU aAbs were 50% higher in women after adjustment for cigarettes/day (CPD; P = 0.002), although men smoked more and had higher plasma cotinine levels. The women reported taking more vitamin C (P < 0.005) and had higher plasma levels of alpha-carotene and beta-carotene (P < 0.001) and cryptoxanthin (P < 0.01) than men. Neither CPD nor cotinine was associated with aAb titers. Anti-HMdU aAbs were associated inversely with alpha-tocopherol (P = 0.10), retinol (P = 0.06), and age (P = 0.04) in women but not in men. In contrast to the men, women 50 years of age (P = 0.05). Given the same duration of exposure, women had higher anti-HMdU aAbs and also reached peak levels at a lower cumulative smoking exposure (30 years) compared with male smokers (40 years). Subjects smoked an average of 28.9 +/- 0.81 CPD and initiated smoking at 17.2 +/- 0.33 (SE) years of age. Therefore, smokers who reported smoking for 30 years were typically <50 years old. Women

Human and experimental evidence indicates that the developing fetus may be more susceptible than the adult to the effects of certain carcinogens, including some polycyclic aromatic hydrocarbons (PAHs). Factors that can modulate susceptibility include proliferation rates, detoxification capabilities, and DNA repair capacity. Biomarkers can facilitate quantification of age-related susceptibility among human populations. In this study, we report on three biomarkers measured in paired blood samples collected at birth from 160 Polish mothers and newborns: 70 pairs from Krakow (a city with high air pollution including PAHs) and 90 pairs from Limanowa (an area with lower ambient pollution but greater indoor coal use). Biomarkers were: WBC aromatic-DNA adducts by (32)P-postlabeling and PAH-DNA adducts by ELISA (as indicators of DNA damage from PAHs and other aromatics) and plasma cotinine (as an internal dosimeter of cigarette smoke). Correlations were assessed by Spearman's rank test, and differences in biomarker levels were assessed by the Wilcoxon signed-ranks test. A significant correlation between paired newborn/maternal samples was seen for aromatic-DNA adduct levels (r = 0.3; P < 0.001) and plasma cotinine (r = 0.8; P < 0.001) but not PAH-DNA adduct levels (r = 0.14; P = 0.13). Among the total cohort, levels of the three biomarkers were higher in newborn samples compared with paired maternal samples. The difference was significant for aromatic-DNA adduct levels (16.6 +/- 12.5 versus 14.21 +/- 15.4/10(8) nucleotides; P = 0.002) and plasma cotinine (14.2 +/- 35.5 versus 8.3 +/- 24.5 ng/ml; P < 0.001) but not for PAH-DNA adduct levels (7.9 +/- 9.9 versus 5.9 +/- 8.2/10(8) nucleotides; P = 0.13). When analyses were restricted to the 80 mother/newborn pairs from whom the blood sample was drawn concurrently (within 1 h of each other), levels of all of the three biomarkers were significantly higher in the newborn compared with paired maternal blood samples (P < 0.05). Results suggest reduced detoxification capabilities and increased susceptibility of the fetus to DNA damage, especially in light of experimental evidence that transplacental exposures to PAHs are 10-fold lower than paired maternal exposures. The results have implications for risk assessment, which currently does not adequately account for sensitive subsets of the population.

A major goal in molecular epidemiology is to identify preventable environmental risk factors and susceptible subpopulations. In a hospital-based molecular epidemiological case-control study of breast cancer, we investigated the relationship between DNA damage from exposure to polycyclic aromatic hydrocarbons (PAHs) and susceptibility attributable to inherited deletion of the xenobiotic detoxifying gene, glutathione S-transferase M1 (GSTM1). Prior to breast surgery, women (n = 227) were enrolled and interviewed and donated a blood sample. PAH-DNA adduct levels were measured by immunohistochemistry in breast tissue samples retrieved from pathology blocks, and GSTM1 genotype was determined by PCR using WBC DNA. The GSTM1 analysis included 95 cases and 87 benign breast disease controls. GSTM1 genotype was not associated with breast cancer case-control status (odds ratio = 0.73; 95% confidence interval, 0.37-1.44). However, the GSTM1 null genotype predicted PAH-DNA adduct levels in malignant (beta = 0.407; P = 0.003) and nonmalignant (beta = 0.243; P = 0.05) breast tissue from cases. This relationship was not seen in tissue from controls (beta = 0.095; P = 0.341). When tissue from controls was compared with tumor tissue from cases, there was a significant case-control difference in PAH-DNA adduct levels among women who were GSTM1 null. There was no such case-control difference among women who were homozygous or heterozygous for GSTM1. There was an interaction between GSTM1 and case-control status on adduct levels in breast tissue (P = 0.002). The results suggest that genetic susceptibility to the formation of PAH-DNA adducts in breast tissue may play a role in breast cancer development.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants; a number are carcinogenic. Metabolic polymorphisms may modulate susceptibility to PAH-induced DNA damage and carcinogenesis. This study investigates the relationship between PAH-DNA adduct levels (in maternal and newborn WBCs) and two polymorphisms: (a) an MspI RFLP in the 3' noncoding region of cytochrome P4501A1 (CYP1A1); and (b) an A-->G transition in nucleotide 313 of glutathione S-transferase P1 (GSTP1), resulting in an ile105val substitution. CYP1A1 catalyzes the bioactivation of PAH; the CYP1A1 MspI RFLP has been associated with cancer of the lung. GSTP1 catalyzes the detoxification of PAH; the val allele has greater catalytic efficiency toward PAH diol epoxides. The study involves 160 mothers and their newborns from Poland. Regression models controlled for maternal smoking and other confounders. No association was seen between maternal adduct levels and either polymorphism, separately or combined. However, adduct levels were higher among newborns with the CYP1A1 MspI restriction site (heterozygotes and homozygotes combined) compared with newborns lacking the restriction site (P = 0.06). Adducts were higher among GSTP1 ile/val and ile/ile newborns compared with GSTP1 val/val newborns (P = 0.08). Adduct levels were 4-fold higher among GSTP1 ile/ile newborns having the CYP1A1 restriction site compared with GSTP1 val/val newborns who lacked the CYP1A1 restriction site (P = 0.04). This study demonstrates a significant combined effect of phase I and phase II polymorphisms on DNA damage from PAHs in fetal tissues. It illustrates the importance of considering interindividual variation in assessing risks of transplacental exposure to PAHs.

To assess the risks of early life exposure to environmental tobacco smoke (ETS), we tested whether four biomarkers in peripheral blood were associated with home ETS exposure in Hispanic and African-American children. The biomarkers included cotinine (a metabolite of nicotine) and three indicators of molecular and genetic damage from mutagens/carcinogens, protein adducts formed by the carcinogens 4-aminobiphenyl (4-ABP) and polycyclic aromatic hydrocarbons (PAHs), and sister chromatid exchanges (SCEs). We also explored possible ethnic differences in biomarkers. The study cohort comprised 109 Hispanic and African-American preschool children (1-6 years of age). Plasma cotinine was analyzed by gas chromatography, 4-ABP-hemoglobin adducts by gas chromatography-mass spectroscopy, PAH-albumin adducts by ELISA, and SCEs by cytogenetic techniques. Data on the amount of smoking by mothers (average 10.5 cigarettes per day) and other household members and regular visitors (average 6.5 cigarettes per day) were obtained by interview-administered questionnaires. Cotinine, 4-ABP-hemoglobin adducts, and PAH-albumin were significantly higher (P < 0.05) in the ETS-exposed children compared with the unexposed. SCEs were marginally higher (P = 0.076). African-American children had higher levels of cotinine (P = 0.059) and PAH-albumin (P = 0.02) than Hispanic children, after controlling for exposure to ETS. These results indicate molecular and genetic damage in minority children with

The organochlorines, dichloro-diphenyl-trichloroethane and polychlorinated biphenyl (PCB) are pervasive environmental contaminants. Results from previous studies have been conflicting regarding the relationship between the internal dose of these organochlorine residues and breast cancer risk. To determine whether these compounds are present in breast cyst fluids and whether cyst fluid and plasma concentrations are correlated, we analyzed organochlorines in paired cyst fluid and plasma samples from 24 subjects using gas chromatography and electron capture detection. All but one of the women had a history of multiple cysts, suggesting that they were at elevated risk for future breast cancer. DDE (a metabolite of dichloro-diphenyl-trichloroethane) was present in 22 of the cyst samples and PCB was detected in 19 of the cyst samples. Organochlorine levels were more concentrated in the plasma than in breast cyst fluids. Levels of DDE in plasma were significantly correlated with those in cyst fluid (r = 0.73; P < 0.001); in contrast to PCB levels in cyst and plasma (r = 0.37; P = 0.12). Congener specific analysis of the PCBs showed that some individual congeners were preferentially excluded from or concentrated in the cyst fluid. To our knowledge, this study is the first to demonstrate that PCB and DDE are present in cyst fluids and thus in contact with the ductal epithelium of the breast. These results support the use of plasma DDE as a proxy for DDE in the target tissue in research on the role of environmental factors in breast cancer.

Polycyclic aromatic hydrocarbon-DNA adducts were measured by ELISA in peripheral leukocytes from 119 non-small cell lung cancer patients and 98 controls at the Columbia-Presbyterian Medical Center. Thirty-one cases had adduct measurements in leukocytes, lung tumor, and nontumor specimens collected at surgery, and 34 had paired leukocyte and tumor specimens. Information on smoking, diet, and occupational exposure was collected. After adjustment for age, gender, ethnicity, season, and smoking, adducts in leukocytes were significantly higher in cases (P < 0.01) than controls; the odds ratio was 7.7 (95% confidence interval = 1.7-34; P < 0.01). Adducts in leukocytes were increased significantly in smokers and ex-smokers compared to nonsmokers among cases and controls (separately and combined) after adjusting for age, gender, ethnicity, and season (P < 0.05). The cases and controls differed in several respects: (a) adducts increased with the number of cigarettes smoked among the 51 cases who were current smokers (P = 0.05) but not among the current smokers in the controls; and (b) a seasonal variation in DNA binding, corresponding to that reported for aryl hydrocarbon hydroxylase inducibility, was observed in cases but not in controls. Among the cases, adducts in leukocytes were correlated more strongly with adducts in the lung tumor tissue than with those in nontumor lung tissue. The results in leukocytes are consistent with a constitutional susceptibility to lung cancer, which results in greater DNA damage from carcinogens in cigarette smoke. They suggested that it may ultimately be possible to use biomarkers such as adducts to identify individuals who would benefit most from early intervention.

The formation of polycyclic aromatic hydrocarbon-DNA adducts was studied in peripheral blood lymphocytes obtained from men with occupational and environmental exposure. Subjects included coke factory workers, residents from the vicinity of the cokery, and rural region inhabitants (16 individuals in each exposure group). Adducts were determined by immunohistochemical analysis using a polyclonal antiserum recognizing benzo(a)pyrene and related polycyclic aromatic hydrocarbon diol epoxide-DNA adducts, a biotinylated secondary antiserum, and streptavidin-conjugated FITC. Propidium iodide was used to quantitate nuclear DNA. Dual fluorescence intensities were simultaneously measured with a Zeiss Axiovert microscope and a Bio-Rad MRC-600 argon laser scanning confocal attachment. Adducts were significantly elevated (P < 0.001) in both occupational and environmental groups, as compared to the rural control group by Mann-Whitney U test. The distribution of the data indicated the existence of cells with relatively higher adduct levels. The percentages of these so called "higher adduct-level cells" were 13.6, 11.5, and 3.7 in cokery workers, environmentally exposed individuals, and rural controls, respectively. The immunohistochemical method allows visualization and relative quantitation of polycyclic aromatic hydrocarbon-DNA adducts in individual lymphocytes. It requires a much smaller amount of blood than the previously used 32P-postlabeling and ELISA methods, which used isolated bulk DNA. It can also be used for adduct quantitation in biopsy material. The results of this pilot study indicate that this technique is a promising addition to biomonitoring studies.

Breast cancer is the second leading cause of cancer death among American women. Known risk factors account for only approximately one-third of the 182,000 new cases diagnosed each year in the United States. There is both concern and debate over the contribution of environmental exposures related to lifestyle, occupation, and ambient pollution, particularly in high risk areas such as Long Island, NY and the rest of the northeastern United States. Biomarkers such as carcinogen-DNA adducts can help to explore the role of environmental risk factors for breast cancer by documenting DNA damage from specific carcinogens directly in human tissue. In this pilot study, a total of 31 breast tissue samples were analyzed by the 32P-postlabeling method for carcinogen-DNA adducts characteristic of complex mixtures of aromatic compounds (such as polycyclic aromatic hydrocarbons) and tobacco smoke. The samples included tumor and tumor-adjacent tissues from 15 women with breast cancer and normal tissue samples from 4 women undergoing breast reduction. Among the breast cancer cases, the mean aromatic/hydrophobic-DNA adduct level in all tissues assayed was 5.3 +/- 2.4 (SD) adducts/10(8) nucleotides compared to 2.3 +/- 1.5 among the samples from the noncancer patients. Breast tissue (tumor and/or nontumor) from 30% (5 of 15) of women with breast cancer displayed a pattern of adducts (referred to as a diagonal zone of radioactivity) associated previously, in studies of other tissues, with exposure to tobacco smoke. The 5 positive samples were from current smokers; tissue samples from the 8 nonsmoking cases did not show this characteristic pattern (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Coal tar-treated psoriasis patients were used as a model population to test a newly developed enzyme-linked immunosorbent assay (ELISA) for urinary excretion of benzo(a)pyrene and related polycyclic aromatic hydrocarbons (PAHs). The ability of the ELISA to detect exposure was also compared with that of two previously established biomonitoring methods, measurement of urinary 1-hydroxypyrene by high performance liquid chromatography with fluorescence detection and mutagenicity measured by the Salmonella typhimurium mutagenesis assay. Urine samples were collected from 57 patients and 53 untreated volunteers. Urinary excretion of PAH metabolites, measured by competitive ELISA with a monoclonal antibody (4D5), was elevated in patients (mean, 730 +/- 1370 mumol/mol creatinine) compared with untreated volunteers (110 +/- 90 mumol/mol creatinine; P < 0.0001). 1-Hydroxypyrene also was elevated in patients (mean, 547 +/- 928 mumol/mol creatinine) compared with volunteers (mean, 0.14 +/- 0.17 mumol/mol creatinine; P < 0.0001). Much larger differences between mean values in patients and volunteers were observed with the 1-hydroxypyrene assay compared with the PAH metabolite ELISA. No significant effect of smoking could be detected by either assay. Analysis by the Salmonella typhimurium mutagenesis assay indicated elevated mutagenicity in urine from patients (1410 +/- 2750 revertants/mmol creatinine) compared with volunteers (715 +/- 846 revertants/mmol creatinine; P = 0.072). In all subjects, there was a good correlation between the PAH metabolites and both 1-hydroxypyrene (r = 0.717; P < 0.0001) and urinary mutagenicity (r = 0.317; P = 0.004). These results suggest that the ELISA, which easily can be carried out on large numbers of samples, can be used for monitoring urinary excretion of PAHs in a high exposure population. Ongoing studies are designed to determine its applicability to lower exposure populations.

Blood samples from 36 germ cell tumor patients receiving chemotherapy with either cisplatin or carboplatin in combination with other drugs [etoposide or vinblastine, cyclophosphamide, dactinomycin, and bleomycin (VAB-6)] were analyzed for the presence of 7 different biological markers. The biomarkers included platinum-protein adducts, platinum-DNA adducts, sister chromatid exchange (SCE), micronuclei (MN), and somatic gene mutation at the hypoxanthine phosphoribosyl transferase (HPRT) locus and the glycophorin A (GPA) loci (NO and NN). Patients were asked to donate 9 serial blood samples: a pretreatment sample followed by another drawn 12-24 h after each of four cycles of treatment and a final sample provided 3-6 months after the last cycle. Most individuals gave 7-8 samples; 7 individuals donated all 9. Because of limited amounts of cells in some cases, it was not possible to carry out all 7 assays on every sample. Pt-protein adducts, Pt-DNA adducts, and SCE showed a direct and consistent effect of treatment and were very highly correlated. A significant correlation was also seen between both Pt-protein and Pt-DNA adducts and HPRT mutation. All of the posttreatment samples were significantly elevated compared to the baseline sample. These markers also remained elevated 3-6 months after the end of treatment. By contrast, MN, HPRT mutation, and GPA mutation (both NO and NN variants) showed varying patterns of dose response, probably reflective of the differing biology of these markers scored in lymphocytes (MN and HPRT) and erythrocytes (GPA). MN were significantly elevated in the posttreatment samples drawn at cycles 2 and 3. Although induction of HPRT mutation was only of marginal significance, results here are for the mutant frequency determination assay only. In progress is the potentially more informative analysis of the type of mutations by Southern blot and the sequencing of mutations to look for characteristic mutational spectra. The GPA assay showed a significant increase over baseline in samples drawn after cycles 3 and 4 (NO variants) and after cycles 2, 3, and 4 (NN variants). The level of GPA mutation (both NO and NN variants) was clearly elevated even 3-6 months after the last cycle of chemotherapy. Correlations were seen between HPRT and MN as well as between GPA NO and GPA NN variants. Analysis of biomarkers by treatment group does not reveal a consistent pattern or trend across all cycles.(ABSTRACT TRUNCATED AT 400 WORDS)

Iron foundry workers, exposed to high levels of polycyclic aromatic hydrocarbons (PAHs), silica, and metal fumes and dusts, are at elevated risk of lung cancer. Benzo(a)pyrene and a number of structurally related PAHs are metabolically activated to diol epoxides (e.g., 7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenzo(a) pyrene) which are mutagenic, carcinogenic in experimental animals, and form covalent adducts with DNA. The levels of these adducts were measured in an enzyme-linked immunosorbent assay using a polyclonal anti-benzo(a)pyrene diol epoxide-I-DNA antibody which cross-reacts with DNA modified by diol epoxides of structurally related PAHs. DNA was analyzed from peripheral blood cells of 35 Finnish foundry workers and 10 controls. Workers were classified as having low (less than 0.05 micrograms/m3), medium (0.05-0.2 micrograms/m3), or high (greater than 0.2 micrograms/m3) exposure to benzo(a)pyrene (as an indicator of PAH). When adjustment was made for cigarette smoking and time since vacation, benzo(a)pyrene exposure was significantly related to adduct levels (P = 0.0001). Each of the three exposure groups had significantly elevated adduct levels compared to controls. Among the exposed workers, the low group differed significantly from the high and medium categories. This study supports the usefulness of monitoring adduct formation in a population occupationally exposed to carcinogens.

In a molecular epidemiological study of lung cancer cases (n = 81) and noncancer controls (n = 67), polycyclic aromatic hydrocarbon (PAH)-DNA adducts were evaluated in peripheral blood leukocytes from all subjects and in a smaller number of lung tissue specimens collected prior to or at surgery. Sister chromatid exchanges (SCE) in lymphocytes were also studied in a subset of cases and controls. Questionnaire, medical record, or tumor registry data provided a family history of cancer, as well as information on cigarette smoking, dietary and occupational exposure to PAHs, and other factors related to SCEs. In both cases and controls PAH-DNA adducts in leukocytes measured by an enzyme-linked immunosorbent assay were not significantly related to age, sex, ethnicity, amount of cigarette smoking, passive smoking, dietary charcoal, or caffeine consumption. Nor did family history of cancer or histological type of cancer significantly affect adduct levels. However, when subjects were stratified by smoking status (current, former, and nonsmoker), lung cancer cases who were current smokers had significantly higher levels of covalent adducts than current smoker controls. A seasonal variation was observed in PAH-DNA binding, with a peak in adduct levels during July-October. This peak corresponds to that seen in a prior study of aryl hydrocarbon hydroxylase inducibility by other investigators. The finding of significant levels of PAH-DNA adducts in former smokers and non-smokers supports an earlier observation that this marker is not smoking specific but reflects a pervasive and variable "background" exposure to PAH. These results are consistent with a genetically determined enhancement of PAH-DNA adduct formation in leukocytes of lung cancer cases which is evident in current smokers. The results in lung tissue are limited by the small number of samples. Adduct levels were not significantly increased in lung tissue of smokers compared with nonsmokers. An inverse linear correlation was seen between adduct values in lung tissue and age of the donors. SCEs were significantly related to pack years of smoking. However, there was no difference in the frequency of SCE between cases and controls; nor were SCE and DNA adducts significantly correlated in this small sample.