Indoor air pollution from solid fuels and risk of upper aerodigestive tract cancers in central and eastern Europe

BACKGROUND

Indoor air pollution from solid fuels is a potentially important risk factor for cancer, yet data on cancers from organs other than the lung are scarce. We investigated if indoor air pollution from coal and wood are risk factors for additional cancers, particularly that of the upper aerodigestive tract (oral cavity, larynx, pharynx and esophagus) in the high-risk areas of central and eastern Europe.

METHODS

We used data from multi-center hospital-based case-control study of 1065 histologically confirmed upper aerodigestive tract cancer cases and 1346 controls. Standardized questionnaires were used to collect information on residential fuel use for cooking and heating. Using unconditional logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) for upper aerodigestive tract cancer risk after adjusting for potential confounders.

RESULTS

Lifelong wood use was associated with pharyngeal and esophageal (OR 4.05, 95% CI: 1.30-12.68 and OR 2.71, 95% CI: 1.21-6.10, respectively). We observed an exposure-response relationship between duration of wood use and risk of pharyngeal cancer among those who had never used coal (P(trend)=0.04), ruling out the possibility of residual confounding by coal. Similarly, we observed an increased risk of laryngeal cancers and head & neck cancers among those who always used coal, with a noted exposure-response relationship (P(trend)<0.01).

CONCLUSIONS

Our results suggest a possible role of indoor air pollution from solid fuel use in head and neck carcinogenesis in the high risk area of central and eastern Europe.

Genomic copy number alterations in clear cell renal carcinoma: associations with case characteristics and mechanisms of VHL gene inactivation

Array comparative genomic hybridization was used to identify copy number alterations in clear cell renal cell carcinoma (ccRCC) patient tumors to identify associations with patient/clinical characteristics. Of 763 ccRCC patients, 412 (54%) provided frozen biopsies. Clones were analyzed for significant copy number differences, adjusting for multiple comparisons and covariates in multivariate analyses. Frequent alterations included losses on: 3p (92.2%), 14q (46.8%), 8p (38.1%), 4q (35.4%), 9p (32.3%), 9q (31.8%), 6q (30.8%), 3q (29.4%), 10q (25.7%), 13q (24.5%), 1p (23.5%) and gains on 5q (60.2%), 7q (39.6%), 7p (30.6%), 5p (26.5%), 20q (25.5%), 12q (24.8%), 12p (22.8%). Stage and grade were associated with 1p, 9p, 9q, 13q and 14q loss and 12q gain. Males had more alterations compared with females, independent of stage and grade. Significant differences in the number/types of alterations were observed by family cancer history, age at diagnosis and smoking status. Von Hippel–Lindau (VHL) gene inactivation was associated with 3p loss (P<E-05), and these cases had fewer alterations than wild-type cases. The fragile site flanking the FHIT locus (3p14.2) represented a unique breakpoint among VHL hypermethylated cases, compared with wild-type cases and those with sequence changes. This is the first study of its size to investigate copy number alterations among cases with extensive patient, clinical/risk factor information. Patients characterized by VHL wild-type gene status (vs sequence alterations) and male (vs female) cases had more copy number alterations regardless of diagnostic stage and grade, which could relate to poor prognosis.

Occupational exposure to dusts and risk of renal cell carcinoma

BACKGROUND

Occupational exposures to dusts have generally been examined in relation to cancers of the respiratory system and have rarely been examined in relation to other cancers, such as renal cell carcinoma (RCC). Although previous epidemiological studies, though few, have shown certain dusts, such as asbestos, to increase renal cancer risk, the potential for other occupational dust exposures to cause kidney damage and/or cancer may exist. We investigated whether asbestos, as well as 20 other occupational dust exposures, were associated with RCC risk in a large European, multi-center, hospital-based renal case-control study.

METHODS

General occupational histories and job-specific questionnaires were reviewed by occupational hygienists for subject-specific information. Odds ratios (ORs) and 95% confidence intervals (95% CIs) between RCC risk and exposures were calculated using unconditional logistic regression.

RESULTS

Among participants ever exposed to dusts, significant associations were observed for glass fibres (OR: 2.1; 95% CI: 1.1-3.9), mineral wool fibres (OR: 2.5; 95% CI: 1.2-5.1), and brick dust (OR: 1.5; 95% CI: 1.0-2.4). Significant trends were also observed with exposure duration and cumulative exposure. No association between RCC risk and asbestos exposure was observed.

CONCLUSION

Results suggest that increased RCC risk may be associated with occupational exposure to specific types of dusts. Additional studies are needed to replicate and extend findings.

TP53, EGFR, and KRAS mutations in relation to VHL inactivation and lifestyle risk factors in renal-cell carcinoma from central and eastern Europe

Renal-cell carcinomas (RCC) are frequent in central and eastern Europe and the reasons remain unclear. Molecular mechanisms, except for VHL, have not been much investigated. We analysed 361 RCCs (334 clear-cell carcinomas) from a multi-centre case-control study for mutations in TP53 (exons 5-9 in the whole series and exons 4 and 10 in a pilot subset of 60 tumours) and a pilot 50 tumours for mutations in EGFR (exons 18-21) or KRAS (codon 12) in relation to VHL status. TP53 mutations were detected in 4% of clear-cell cases, independently of VHL mutations. In non-clear-cell carcinomas, they were detected in 11% of VHL-wild-type tumours and in 0% of tumours with VHL functional mutations. No mutations were found in EGFR or KRAS. We conclude that mutations in TP53, KRAS, or EGFR are not major contributors to the RCC development even in the absence of VHL inactivation. The prevalence of TP53 mutations in relation to VHL status may differ between clear-cell and other renal carcinomas.

Vitamin d pathway genes, diet, and risk of renal cell carcinoma

Mediated by binding to the high-affinity vitamin D receptor (VDR), vitamin D forms a heterodimer complex with the retinoid-X-receptor (RXR). Variation in both genes has been shown to modify renal cell carcinoma (RCC) risk. Therefore, we investigated whether VDR and RXRA polymorphisms modify associations between RCC risk and frequency of dietary intake of vitamin D and calcium rich foods, and occupational ultraviolet exposure among 777 RCC case and 1035 controls from Central and Eastern Europe. A positive association was observed in this population between increasing dietary intake frequency of yogurt, while an inverse association was observed with egg intake frequency. RXRA polymorphisms, located 3' of the coding sequence, modified associations between specific vitamin D rich foods and RCC risk, while RXRA polymorphisms, located in introns 1 and 4, modified associations with specific calcium rich foods. Results suggest that variants in the RXRA gene modified the associations observed between RCC risk and calcium and vitamin D intake.

Tobacco smoking, body mass index, hypertension, and kidney cancer risk in central and eastern Europe

In a case–control study of kidney cancer in four central European countries, with 1097 incident cases and 1476 controls, we found an increased risk for self-reported hypertension and for obesity. Additional unknown risk factors are likely to be responsible for the high rates of kidney cancer in this region.

Renal cell carcinoma, occupational pesticide exposure and modification by glutathione S-transferase polymorphisms

This study investigated associations between occupational pesticide exposure and renal cell carcinoma (RCC) risk. To follow-up on a previous report by Buzio et al., we also considered whether this association could be modified by glutathione S-transferase M1 and T1 (GSTM1 and GSTT1) genotypes. About 1097 RCC cases and 1476 controls from Central and Eastern Europe were interviewed to collect data on lifetime occupational histories. Occupational information for jobs held for at least 12 months duration was coded for pesticide exposures and assessed for frequency and intensity of exposure. GSTM1 and GSTT1 gene deletions were analyzed using TaqMan assays. A significant increase in RCC risk was observed among subjects ever exposed to pesticides [odds ratio (OR): 1.60; 95% confidence interval (CI): 1.00-2.55]. After stratification by genotypes, increased risk was observed among exposed subjects with at least one GSTM1 active allele (OR: 4.00; 95% CI: 1.55-10.33) but not among exposed subjects with two GSTM1 inactive alleles compared with unexposed subjects with two inactive alleles (P-interaction: 0.04). Risk was highest among exposed subjects with both GSTM1 and GSTT1 active genotypes (OR: 6.47; 95% CI: 1.82-23.00; P-interaction: 0.02) compared with unexposed subjects with at least one GSTM1 or T1 inactive genotype. In the largest RCC case-control study with genotype information conducted to date, we observed that risk associated with pesticide exposure was exclusive to individuals with active GSTM1/T1 genotypes. These findings further support the hypothesis that glutathione S-transferase polymorphisms can modify RCC risk associated with occupational pesticide exposure.

Vitamin D receptor polymorphisms and renal cancer risk in Central and Eastern Europe

Previous studies investigated the role of vitamin D intake and cancer risk. The kidney is a major organ for vitamin D metabolism, activity, and calcium homeostasis; therefore, it was hypothesized that dietary vitamin D intake and polymorphisms in the vitamin D receptor (VDR) gene may modify renal cell carcinoma (RCC) risk. Three common VDR gene polymorphisms (BsmI, FokI, TaqI) were evaluated among 925 RCC cases and 1192 controls enrolled in a hospital-based case-control study conducted in Central and Eastern Europe. Overall associations with RCC risk were not observed; however, subgroup analyses revealed associations after stratification by median age of diagnosis and family history of cancer. Among subjects over 60 yr, reduced risks were observed among carriers of the f alleles in the FokI single-nucleotide polymorphism (SNP) (odds ratio [OR] = 0.61 for Ff and OR = 0.74 for ff genotypes) compared to subjects with the FF genotype (P trend = 0.04; P interaction = 0.004). Subjects with the BB BsmI genotype and a positive family history of cancer had lower risk compared to subjects with the bb allele (OR = 0.60; 95% CI: 0.33-1.1; P trend = 0.05). Genotype associations with these subgroups were not modified when dietary sources of vitamin D or calcium were considered. Additional studies of genetic variation in the VDR gene are warranted.

Glutathione S -transferase polymorphisms, cruciferous vegetable intake and cancer risk in the Central and Eastern European Kidney Cancer Study

High consumption of cruciferous vegetables has been associated with reduced kidney cancer risk in many studies. Isothiocyanates, thought to be responsible for the chemopreventive properties of this food group, are conjugated to glutathione by glutathione S-transferases (GSTs) before urinary excretion. Modification of this relationship by host genetic factors is unknown. We investigated cruciferous vegetable intake in 1097 cases and 1555 controls enrolled in a multicentric case-control study from the Czech Republic, Poland, Romania and Russia. To assess possible gene-diet interactions, genotyped cases (N = 925) and controls (N = 1247) for selected functional or non-synonymous polymorphisms including the GSTM1 deletion, GSTM3 3 bp deletion (IVS6 + 22-AGG) and V224I G>A substitution, GSTT1 deletion and the GSTP1 I105V A>G substitution. The odds ratio (OR) for low (less than once per month) versus high (at least once per week) intake of cruciferous vegetables was 1.29 [95% confidence interval (CI): 1.02-1.62; P-trend = 0.03]. When low intake of cruciferous vegetables (less than once per month) was stratified by GST genotype, higher kidney cancer risks were observed among individuals with the GSTT1 null (OR = 1.86; 95% CI: 1.07-3.23; P-interaction = 0.05) or with both GSTM1/T1 null genotypes (OR = 2.49; 95% CI: 1.08-5.77; P-interaction = 0.05). These data provide additional evidence for the role of cruciferous vegetables in cancer prevention among individuals with common, functional genetic polymorphisms.

Mortality from cardiovascular diseases and exposure to inorganic mercury

OBJECTIVE

To study the mortality from cardiovascular and other chronic non-neoplastic diseases after long term exposure to inorganic mercury. Limited information is available on the effect of chronic exposure to mercury on the cardiovascular system.

METHODS

The mortality was studied among 6784 male and 265 female workers from four mercury mines and mills in Spain, Slovenia, Italy, and the Ukraine. Workers were employed between 1900 and 1990; the follow up period lasted from the 1950s to the 1990s. The mortality of the workers was compared with national reference rates.

RESULTS

Among men, there was a slight increase in overall mortality (standardised mortality ratio (SMR) 1.08, 95% confidence interval (95% CI) 1.04 to 1.12). An increased mortality was found from hypertension (SMR 1.46, 95% CI 1.08 to 1.93), heart diseases other than ischaemic (SMR 1.36, 95% CI 1.20 to 1.53), pneumoconiosis (SMR 27.1, 95% CI 23.1 to 31.6), and nephritis and nephrosis (SMR 1.55, 95% CI 1.13 to 2.06). The increase in mortality from cardiovascular diseases was not consistent among countries. Mortality from hypertension and other heart diseases increased with estimated cumulative exposure to mercury; mortality from ischaemic heart disease and cerebrovascular diseases increased with duration of employment, but not with estimated exposure to mercury. Results among women were hampered by few deaths.

CONCLUSION

Despite limited quantitative data on exposure, possible confounding, and likely misclassification of disease, the study suggests a possible association between employment in mercury mining and refining and risk in some groups of cardiovascular diseases.

Cohort studies of chloroprene-exposed workers in Russia

Two retrospective cohort studies were conducted to assess the risk of cancer among workers exposed to chloroprene (2-chloro-1,3-butadiene) (CP). One is a study of incidence and mortality among 2314 production workers employed in the CP production plant in Yerevan, Armenia, between 1940 and 1988. The cohort was followed up for cancer incidence for the years 1979-1990 and for cancer mortality for 1979-1988. The second study is a mortality study among 5185 shoe manufacturing workers in Moscow who used polychloroprene latex and glue. Shoe workers were employed between 1940 and 1976, and followed from 1979 through 1993. The standardized incidence ratios (SIR) and standardized mortality ratios (SMR) were calculated using the Armenian and Moscow population as reference. An internal comparison analysis based on Poisson regression modeling was conducted. In the Yerenan cohort, incidence and mortality from all cancers were below expectation, but increased incidence (SIR, 3.27; 95% confidence interval (CI), 1.47-7.27), and mortality (SMR, 3.39; CI, 1.09-10.5) from liver cancer were noted. A dose-response relationship was suggested between the risk of liver cancer and indices of CP exposure. For the entire Moscow cohort, all-cause mortality was close to expectation and all-cancer mortality was increased. There was an increase in the mortality from liver cancer (SMR, 2.4; CI, 1.1-4.3), kidney cancer (SMR, 1.8; CI, 0.9-3.4), and leukemia (SMR, 1.9; CI, 1.0-3.3). Mortality from liver cancer and leukemia was associated with various indicators of CP exposure. A similar, although less consistent, pattern was found for kidney cancer. The association between CP exposure and risk of leukemia may be due to concomitant exposure to benzene. The results for liver cancer point towards a carcinogenic effect of CP.

Alcohol consumption, smoking and risk of gastric cancer: case-control study from Moscow, Russia

OBJECTIVES

To examine the risk of gastric cancer associated with alcohol consumption and smoking in men and women in Moscow, Russia.

MATERIALS AND METHODS

A case-control study which includes 448 cases and 610 controls was conducted. Cases consisted of patients with newly diagnosed histologically confirmed gastric cancer. Controls were patients admitted during the study period to the hospital with diagnoses other than cancer and/or gastrointestinal diseases. Information on demographic variables, smoking, alcohol consumption and diet was collected from all subjects. Venous blood was drawn from 361 cases and 441 controls. A serological test for Helicobacter pylori immunoglobulin G was performed.

RESULTS

Alcohol consumption, particularly vodka consumption, was found to increase the risk of gastric cancer. In men the effect of hard liquor drinking was stronger for cancer of the cardia (OR = 3.4, CI = 1.2-10.2), while in women the effect was stronger for cancer of sites other than gastric cardia (OR = 1.5, CI = 1.0-2.3). Smoking increased the risk of developing gastric cancer in men, but not in women. In men a dose-response relationship between mean number of cigarettes smoked per day (p = 0.03), pack-years of cigarettes smoked (p = 0.01) and duration of smoking (p = 0.08) and the risk of cancer of gastric cardia was observed. Further statistical analysis revealed interactions between effect of smoking and alcohol consumption and between smoking and H. pylori infection status.

CONCLUSIONS

The findings further support the role of alcohol consumption and smoking in the etiology of gastric cancer.

Alcohol consumption, smoking and risk of gastric cancer: case-control study from Moscow, Russia

OBJECTIVES

To examine the risk of gastric cancer associated with alcohol consumption and smoking in men and women in Moscow, Russia.

MATERIALS AND METHODS

A case-control study which includes 448 cases and 610 controls was conducted. Cases consisted of patients with newly diagnosed histologically confirmed gastric cancer. Controls were patients admitted during the study period to the hospital with diagnoses other than cancer and/or gastrointestinal diseases. Information on demographic variables, smoking, alcohol consumption and diet was collected from all subjects. Venous blood was drawn from 361 cases and 441 controls. A serological test for Helicobacter pylori immunoglobulin G was performed.

RESULTS

Alcohol consumption, particularly vodka consumption, was found to increase the risk of gastric cancer. In men the effect of hard liquor drinking was stronger for cancer of the cardia (OR = 3.4, CI = 1.2-10.2), while in women the effect was stronger for cancer of sites other than gastric cardia (OR = 1.5, CI = 1.0-2.3). Smoking increased the risk of developing gastric cancer in men, but not in women. In men a dose-response relationship between mean number of cigarettes smoked per day (p = 0.03), pack-years of cigarettes smoked (p = 0.01) and duration of smoking (p = 0.08) and the risk of cancer of gastric cardia was observed. Further statistical analysis revealed interactions between effect of smoking and alcohol consumption and between smoking and H. pylori infection status.

CONCLUSIONS

The findings further support the role of alcohol consumption and smoking in the etiology of gastric cancer.

Aspirin protects against gastric cancer: results of a case-control study from Moscow, Russia

A case-control study of stomach cancer which includes 448 cases and 610 hospital controls has been conducted in Moscow, Russia. Information on life-style habits, such as smoking, alcohol consumption, diet, medical history and use of different medications including aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) was collected using a self-administered structured questionnaire. Venous blood was drawn from 361 cases and 441 controls. A serological test for Helicobacter pylori immunoglobulin G was performed to detect infected individuals. Use of aspirin and other NSAIDs was associated with protection against cancer of the stomach (OR = 0.60, 95% CI 0.41-0.90). Analysis by subsite revealed that aspirin did not affect the risk of cancer of the gastric cardia but had a protective effect for non-cardia gastric cancer. The OR associated with use of aspirin adjusted for age and education for both sexes combined was 0.49 (95% CI 0.31-0.77). A decrease in relative risk was statistically significant for men (OR = 0.48, 95% CI 0.25-0.92) and women (OR = 0.52, 95% CI 0.28-0.97). Controlling for major risk factors did not attenuate the reduction in risk. The observed associations were also present in individuals who were H. pylori immunoglobulin G-positive. There was no reduction in risk associated with aspirin and/or non-aspirin NSAIDs among non-infected subjects.

Aspirin protects against gastric cancer: results of a case-control study from Moscow, Russia

A case-control study of stomach cancer which includes 448 cases and 610 hospital controls has been conducted in Moscow, Russia. Information on life-style habits, such as smoking, alcohol consumption, diet, medical history and use of different medications including aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) was collected using a self-administered structured questionnaire. Venous blood was drawn from 361 cases and 441 controls. A serological test for Helicobacter pylori immunoglobulin G was performed to detect infected individuals. Use of aspirin and other NSAIDs was associated with protection against cancer of the stomach (OR = 0.60, 95% CI 0.41-0.90). Analysis by subsite revealed that aspirin did not affect the risk of cancer of the gastric cardia but had a protective effect for non-cardia gastric cancer. The OR associated with use of aspirin adjusted for age and education for both sexes combined was 0.49 (95% CI 0.31-0.77). A decrease in relative risk was statistically significant for men (OR = 0.48, 95% CI 0.25-0.92) and women (OR = 0.52, 95% CI 0.28-0.97). Controlling for major risk factors did not attenuate the reduction in risk. The observed associations were also present in individuals who were H. pylori immunoglobulin G-positive. There was no reduction in risk associated with aspirin and/or non-aspirin NSAIDs among non-infected subjects.

Cancer occurrence among European mercury miners

OBJECTIVES

To study the carcinogenicity of inorganic mercury in humans.

METHODS

We studied the mortality from cancer among 6784 male and 265 female workers of four mercury mines and mills in Spain, Slovenia, Italy and the Ukraine. Workers were employed between the beginning of the century and 1990; the follow-up period lasted from the 1950s to the 1990s. We compared the mortality of the workers with national reference rates.

RESULTS

Among men, there was no overall excess cancer mortality; an increase was observed in mortality from lung cancer (standardized mortality ratio [SMR] 1.19, 95 percent confidence interval [CI] 1.03-1.38) and liver cancer (SMR 1.64, CI 1.18-2.22). The increase in lung cancer risk was restricted to workers from Slovenia and the Ukraine: no relationship was found with duration of employment or estimated mercu ry exposure. The increase in liver cancer risk was present both among miners and millers and was stronger in workers from Italy and Slovenia: there was a trend with estimated cumulative exposure but not with duration of employment, and the excess was not present in a parallel analysis of cancer incidence among workers from Slovenia. No increase was observed for other types of cancer, including brain and kidney tumours. Among female workers (Ukraine only), three deaths occurred from ovarian cancer, likely representing an excess.

CONCLUSIONS

Exposure to inorganic mercury in mines and mills does not seem strongly associated with cancer risk, with the possible exception of liver cancer; the increase in lung cancer may be explained by co-exposure to crystalline silica and radon.

Cancer occurrence among European mercury miners

OBJECTIVES

To study the carcinogenicity of inorganic mercury in humans.

METHODS

We studied the mortality from cancer among 6784 male and 265 female workers of four mercury mines and mills in Spain, Slovenia, Italy and the Ukraine. Workers were employed between the beginning of the century and 1990; the follow-up period lasted from the 1950s to the 1990s. We compared the mortality of the workers with national reference rates.

RESULTS

Among men, there was no overall excess cancer mortality; an increase was observed in mortality from lung cancer (standardized mortality ratio [SMR] 1.19, 95 percent confidence interval [CI] 1.03-1.38) and liver cancer (SMR 1.64, CI 1.18-2.22). The increase in lung cancer risk was restricted to workers from Slovenia and the Ukraine: no relationship was found with duration of employment or estimated mercu ry exposure. The increase in liver cancer risk was present both among miners and millers and was stronger in workers from Italy and Slovenia: there was a trend with estimated cumulative exposure but not with duration of employment, and the excess was not present in a parallel analysis of cancer incidence among workers from Slovenia. No increase was observed for other types of cancer, including brain and kidney tumours. Among female workers (Ukraine only), three deaths occurred from ovarian cancer, likely representing an excess.

CONCLUSIONS

Exposure to inorganic mercury in mines and mills does not seem strongly associated with cancer risk, with the possible exception of liver cancer; the increase in lung cancer may be explained by co-exposure to crystalline silica and radon.

Exposure to environmental tobacco smoke and risk of lung cancer in non-smoking women from Moscow, Russia

The association between exposure to ETS and the risk of lung cancer in life-time non-smoking women was investigated by means of a hospital based case-control study in Moscow, Russia. The main importance of our study is that it was conducted on a population with a specific smoking pattern from which no information is available on health effects of ETS. A total of 189 incident cases of histologically confirmed lung cancer were identified in 2 principal cancer treatment hospitals in Moscow. A total of 358 female oncology patients from the same hospitals were selected as controls. The controls matched by the hospitals to the cases were similarly restricted to never-smokers. Women diagnosed with cancer of the upper respiratory organs were ineligible for selection as controls. Personal interviews of cases and controls were conducted in the hospital wards, using a closed-form structured questionnaire. An elevated risk of lung cancer was observed in women whose husbands smoked. The odds ratio (OR) adjusted by age and education for husband's smoking was 1.53 (95% CI, 1.06-2.21). Smoking by other members of the family, by colleague's, or by fathers in the women's childhood do not affect the risk of lung cancer. The risk is higher for women whose husbands smoke "papirosy" (OR 2.12; 95% CI, 1.32-3.40), a special Russian type of cigarettes with a long mouthpiece, and usually very high levels of tar (> 30 mg/cig) and nicotine (> 1.8 mg/cig). Our study suggests that the association between exposure to ETS of the spouse and risk of lung cancer in non-smoking women is somewhat stronger for squamous-cell carcinoma (OR, 1.94; 95% CI, 0.99-3.81) than for adenocarcinoma (OR, 1.52; 95% CI, 0.96-2.39).

Exposure to environmental tobacco smoke and risk of lung cancer in non-smoking women from Moscow, Russia

The association between exposure to ETS and the risk of lung cancer in life-time non-smoking women was investigated by means of a hospital based case-control study in Moscow, Russia. The main importance of our study is that it was conducted on a population with a specific smoking pattern from which no information is available on health effects of ETS. A total of 189 incident cases of histologically confirmed lung cancer were identified in 2 principal cancer treatment hospitals in Moscow. A total of 358 female oncology patients from the same hospitals were selected as controls. The controls matched by the hospitals to the cases were similarly restricted to never-smokers. Women diagnosed with cancer of the upper respiratory organs were ineligible for selection as controls. Personal interviews of cases and controls were conducted in the hospital wards, using a closed-form structured questionnaire. An elevated risk of lung cancer was observed in women whose husbands smoked. The odds ratio (OR) adjusted by age and education for husband's smoking was 1.53 (95% CI, 1.06-2.21). Smoking by other members of the family, by colleague's, or by fathers in the women's childhood do not affect the risk of lung cancer. The risk is higher for women whose husbands smoke "papirosy" (OR 2.12; 95% CI, 1.32-3.40), a special Russian type of cigarettes with a long mouthpiece, and usually very high levels of tar (> 30 mg/cig) and nicotine (> 1.8 mg/cig). Our study suggests that the association between exposure to ETS of the spouse and risk of lung cancer in non-smoking women is somewhat stronger for squamous-cell carcinoma (OR, 1.94; 95% CI, 0.99-3.81) than for adenocarcinoma (OR, 1.52; 95% CI, 0.96-2.39).

Cancer incidence and mortality among beta-naphthylamine and benzidine dye workers in Moscow

BACKGROUND

Cancer incidence and mortality were evaluated among 4581 aniline dye production workers in Moscow.

METHODS

A historical cohort was assembled and followed-up from 1 January 1975 to 31 December 1989. Moscow district oncologic dispensary registries furnished case ascertainment and employer records provided job exposure data. Expected cancers and deaths were calculated based on gender-, age-, and calendar time-specific incidence and mortality rates for the Moscow general population applied to the cohort's person-years of follow-up. Disease-specific standardized mortality and incidence values were derived from ratios of observed to expected cancers.

RESULTS

Men experienced elevated total cancer mortality (standardized mortality ratio [SMR] = 125; 95% CI: 110-142) and urinary bladder cancer mortality (SMR = 279; 95% CI: 192-391), and increased all malignancy (standardized incidence ratio [SIR] = 142; 95% CI: 125-160), oesophageal (SIR = 203; 95% CI: 108-347), respiratory tract (SIR = 154; 95% CI: 120-194) and bladder (SIR = 394; 95% CI: 268-559) cancer incidence. Women had elevated oesophageal (SMR = 313; 95% CI: 124-664) and bladder (SMR = 311; 95% CI: 149-571) cancer mortality and elevated all malignancy (SIR = 124; 95% CI: 106-144), oesophageal (SIR = 348; 95% CI: 140-719), and bladder (SIR = 861; 95% CI: 458-8002) cancer incidence. Bladder cancer rate increased with employment duration and younger age first hired. Rate estimates were highest among beta-naphthylamine exposed workers but was also increased among workers with other chemical exposures. A cancer prevention and control effort that limited benzidine exposure to < or = 3 years was apparently unsuccessful as indicated by a significant excess of bladder cancer (SIR = 1773; 95% CI: 356-5180) among these workers.

CONCLUSION

Relative rates of oesophageal, lung, and stomach cancer were also elevated among all workers, but did not increase with total years worked, age first hired, or year first hired, suggesting a non-occupational aetiology.

Fats used in seasoning and breast cancer risk: a case-control study in Moscow, Russia

BACKGROUND

As part of a case-control study of breast cancer conducted in Moscow the relationship between consumption of fat in seasoning and risk of breast cancer was assessed.

DESIGN

The study comprised 92 cases and 110 controls. Cases were newly diagnosed consecutive cases seen at the breast clinic of the Cancer Research Centre of the Russian Academy of Medical Sciences during the year 1990. None of the patients had been previously treated for breast or other cancers and none had distant metastases. Patient were interviewed in the Clinic within two days of admission. Controls were recruited from women visiting their friends and relatives treated in the same Cancer Centre.

RESULTS

Four levels of frequency of use of butter and vegetable oils, and four levels for combined sources were created to evaluate the association between use of fat in seasoning and breast cancer risk. Compared to low use, a non-significant increase in risk was observed for the highest intake of butter (Odds Ratio (OR) = 1.5, 95% Confidence Interval (CI) (0.8, 3.0)). High frequency of use of vegetable oil in seasoning decreased the risk of breast cancer. For the highest category of use, the adjusted OR was 0.2 (95% CI (0.1, 0.5)). Frequent use of mayonnaise also appeared to be associated with a decrease in the risk of breast cancer (OR = 0.1; 95% CI (0.01, 0.4)). For total fat seasoning consumption (vegetable oil+mayonnaise), the adjusted OR for highest category of intake was 0.1 (95% CI (0.03, 0.3)).

CONCLUSIONS

The results of the study suggest a negative association between consumption of fat used for seasoning (except butter) and breast cancer risk. This may be a direct effect or due to increased consumption of salad-type vegetables by high consumers of these sources of fats. The topic should be addressed in other studies in different populations.

Chemoprevention of oral leukoplakia and chronic esophagitis in an area of high incidence of oral and esophageal cancer

This intervention trial carried out in Uzbekistan (former USSR) in an area with a high incidence of oral and esophageal cancer involved random allocation of 532 men, 50 to 69 years old, with oral leukoplakia and/or chronic esophagitis to one of four arms in a double-blind, two-by-two factorial design, with active arms defined by the administration of (a) riboflavin; (b) a combination of retinol, beta-carotene, and vitamin E; or (c) both. Weekly doses were 100,000 IU of retinol, 80 mg of vitamin E, and 80 mg of riboflavin. The dose of beta-carotene was 40 mg/d. Men in the trial were followed for 20 months after randomization. The aim of the trial was to determine whether treatment with these vitamins or their combination could affect the prevalence of oral leukoplakia and/or protect against progression of oral leukoplakia and esophagitis, conditions considered to be precursors of cancer of the mouth and esophagus. A significant decrease in the prevalence odds ratio (OR) of oral leukoplakia was observed after 6 months of treatment in men receiving retinol, beta-carotene, and vitamin E (OR = 0.62; 95% confidence interval (CI): 0.39 to 0.98). After 20 months of treatment, no effect of vitamin supplementation was seen when the changes in chronic esophagitis were compared in the four different treatment groups, although the risk of progression of chronic esophagitis was lower in the subjects allocated to receive retinol, beta-carotene and vitamin E (OR = 0.65; 95% CI: 0.29 to 1.48) A secondary analysis not based on the randomized design revealed a decrease in the prevalence of oral leukoplakia in men with medium (OR = 0.45; 95% CI: 0.21 to 0.96) and high (OR = 0.59; 95% CI: 0.29 to 1.20) blood concentrations of beta-carotene after 20 months of treatment. Risk of progression of chronic esophagitis was also lower in men with a high blood concentration of beta-carotene, odds ratios being 0.30 (95% CI: 0.10 to 0.89) and 0.49 (95% CI: 0.15 to 1.58) for medium and high levels, respectively. A decrease in risk, also statistically not significant, was observed for high vitamin E levels (OR = 0.39; 95% CI: 0.14 to 1.10). These results were based on levels of vitamins in blood drawn after 20 months of treatment.

Diet and colorectal cancer: results of two case-control studies in Russia

Two case-control studies of diet and colorectal cancer were conducted in Moscow and Khabarovsk. The Moscow study comprised 100 cases of colorectal cancer and 100 neighbourhood controls. The Khabarovsk study consisted of 117 cases of colorectal cancer and 117 population controls. A history of the usual dietary intake one year prior to interview was taken using a food frequency questionnaire. Effects were adjusted in analysis for energy intake and education. Significantly reduced risks were observed with high intakes of cellulose (P = 0.001), beta-carotene (P = 0.002), vitamin C (P = 0.007), polyunsaturated fatty acids (PUFA) (P = 0.004), cholesterol (P = 0.04), and with a high ratio of PUFA to saturated fatty acids (SFA) (P = 0.002). Significant increases in risk were observed in association with high ratios of intakes of protein to cellulose (P = 0.002) and of fat to cellulose (P = 0.008). High intake of total fat was associated with non-significant decrease in the risk (P = 0.12), while high intake of SFA resulted in statistically non-significant increase in risk (P = 0.40). Significant reductions in risk were associated with high frequencies of consumption of vegetables (P = 0.001) and fruit (P = 0.009). There were results suggestive of a decreased risk with a high frequency of milk consumption (P = 0.06) and an increased risk in association with a ratio of meat to vegetable frequencies (P = 0.09). After adjustment among factors effecting risk of colorectal cancer statistically significant increase in the risk was seen only for protein/cellulose ratio and significant protective effect for PUFA/SFA ratio, beta-carotene and vegetable consumption.

Endogenous plasma sex hormones in pre- and postmenopausal women with breast cancer: results from a case-control study in Moscow

Plasma sex hormone-binding globulin (SHBG), testosterone, total oestradiol (E2) and proportion of E2 not bound to blood proteins (percentage free E2) have been measured in a case-control study to test whether any of these factors are related to the risk of breast cancer. The cases studied were 27 premenopausal and 34 postmenopausal women with newly diagnosed localized breast cancer who were admitted to the All-Union Cancer Research Centre, Moscow. The controls were an equivalent number of women from the same neighbourhood. These were matched for age (within 2 years) and menopausal status. The average levels of E2 in cases were significantly higher than controls (p = 0.004 and p < 0.001 for pre- and postmenopausal groups, respectively). Percentage free E2 was significantly raised only in premenopausal cases (p = 0.019). The plasma concentrations of testosterone and SHBG were similar for both pre- and postmenopausal groups. Raised E2 or percentage free E2 was associated with an increased relative risk of breast cancer. However, only E2 levels (crude or adjusted for body build) were significantly related to risk in the two menopausal sets (p = 0.022 and p = 0.002, respectively). High percentage free E2 was associated with almost a threefold increase in the risk of breast cancer in premenopausal women; however, this increase was not statistically significant (p = 0.083). The levels of SHBG or testosterone, crude or adjusted for body build and E2 concentration, were not related to risk of breast cancer.

Diet, alcohol consumption and reproductive factors in a case-control study of breast cancer in Moscow

A case-control study was conducted in Moscow to assess the effect of diet on risk of breast cancer, and also to study the established reproductive risk factors. A notable finding of the study, which covered 139 case-control pairs matched by age and neighbourhood, is that dietary factors are more important for post-menopausal than for pre-menopausal breast cancer. The decreased risk of post-menopausal breast cancer was associated with high intakes of cellulose (OR 0.04; 95% CI 0.01-0.31), mono- and disaccharides (OR 0.02; 95% CI 0.002-0.27), vitamin C (OR 0.20; 95% CI 0.06-0.70), beta-carotene (OR 0.09; 95% CI 0.02-0.49), and also polyunsaturated fatty acids (OR 0.14; 95% CI 0.03-0.69). High intakes of total fat resulted in a statistically non-significant decrease in the odds ratio (OR 0.52; 95% CI 0.04-6.99), while saturated fats slightly increased the risk of breast cancer (OR 1.67; 95% CI 0.24-11.78). Protein intake was also associated with increased risk of breast cancer (OR 4.62; 95% CI 0.69-30.70). Alcohol use significantly increased the risk of breast cancer in postmenopausal women (OR 3.39; 95% CI 1.37-8.38). In general, the results of our study indicate that high risk of breast cancer is associated with high intakes of nutrients derived from animal products, and low risk with high intake of those from vegetables and fruits.

Assessment of major carcinogens and alkaloids in the tobacco and mainstream smoke of USSR cigarettes

Tobacco and mainstream smoke of USSR cigarettes were analyzed for carcinogens. The pH values of suspensions of the tobacco (5.4-5.6) and the nitrate content of the tobaccos (0.4-1.7%) were as expected for flue-cured and sun-cured tobaccos and mixtures thereof. The nicotine levels of the cigarette tobaccos (0.76-0.94%) and total alkaloid content (0.85-1.08%) were relatively low compared with tobaccos used in Western European and US cigarettes. The concentrations of tobacco-specific N-nitrosamines in the cigarette tobaccos were also low (N'-nitrosonornicotine 0.36-0.85 microgram/g) compared with those in bright, oriental and blended cigarette tobaccos in Western countries (0.3-19 microgram/g). The 2 non-filter and 4 filter cigarettes from the USSR had slow burning rates and yielded 14.0-16.7 puffs/cigarette, while puff yields for commercial cigarettes in Western countries average less than or equal to 11 puffs/cigarette. Consequently, tar and benzo(a)pyrene yields in the smoke of all cigarettes as well as nitrosamine yields were high, especially in the smoke of the filter cigarettes. It appears that an increase in the burning rates of these cigarettes should lead to lower smoke yields.