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D G Zaridze

Publications and source records attributed to D G Zaridze.

At least 37 records · Page 2Linked to original sources
PubMed1998

The effects of interaction between familial and reproductive factors on breast cancer risk: a combined analysis of seven case-control studies.

In this paper, a combined analysis was performed to study the interaction between familial risk and reproductive life factors. In particular, the interaction between familial risk and breast cell mitotic activity (BCMA), as assessed by duration of ovarian activity, was investigated because of the potential importance of mitotic activity on genetically susceptible cells. The present analysis included 3152 cases and 4404 controls in seven case-control studies from four countries. The interaction effect was estimated in each study separately, then combined using two different methods: a multivariate weighted average and a Bayesian random-effects model. The main effects of reproductive life factors on the risk of breast cancer were in agreement with the previous findings. In particular, an increased duration of BCMA before the first childbirth and over life was found to increase the risk of breast cancer (P < 0.001). Slightly increasing but non-significant, familial risks were observed with increasing number of children (P = 0.17), increasing age at first childbirth (P > 0.2) and increasing duration of BCMA (P > 0.2). There was no modification in familial risk with age at menarche and no clear pattern with menopause characteristics. A weak influence of reproductive and menstrual factors on the familial risk emerged from the present study.

Adult↗
PubMed1998

[Increased risk of occurrence of pulmonary adenocarcinoma in man is associated with the presence of rare alleles of the Hras1 minisatellite].

Data on allelotyping of minisatellite sequence within the Hras1 protooncogene locus in 60 patients with lung adenocarcinoma (LAC) are presented. Allele distribution was analyzed with respect to the effect of tobacco smoke carcinogens (smoking factor). Results were compared with the analogous data obtained for patients with squamous-cell-carcinoma and for individuals without cancer. In contrast to the patients with squamous cell-carcinoma, the frequency of the Hras1 locus rare alleles in patients with lung-adenocarcinoma was higher than in individuals without cancer. More striking difference between the latter groups was demonstrated for nonsmoking patients (17.6% versus 2.7% of healthy individuals, P = 0.0005). In smoking LAC patients, higher frequencies of the common a4 allele (2.5 kb in size under the MspI/HpaII digestion) were found. Our findings point to the combined effect of endogenous and exogenous factors on the development of lung adenocarcinomas in humans. In this work, we discuss the possible mechanism of association between the rare minisatellite alleles and the predisposition to lung cancer.

Adenocarcinoma↗
PubMed1996

Mortality in a cohort of Russian fertilizer workers.

OBJECTIVES: The study evaluated the mortality of workers exposed to precursors of N-nitroso compounds in a Russian fertilizer plant. METHODS: Workers employed at least two years between 1945 and 1985 in production departments or other services were included in the cohort, which comprised 2039 men and 2957 women followed from 1965 to 1990. The standardized mortality ratios (SMR) were calculated using cause-specific death rates for the Moscow region as reference. An internal comparison was carried out using Poisson regression modeling. Exposure to arsenic, nitrogen oxides, and sulfur dioxide was estimated from an industrial hygiene survey. RESULTS: The production and other workers had no excess of mortality from all causes or all neoplasms. However the male production workers had excess mortality from all cancers combined (SMR 143) and lung cancer (SMR 186) after a latency period of > or = 20 years. Men with the highest exposure to nitrogen oxides had a twofold increase in mortality from stomach cancer, with a marginally significant increasing trend between stomach cancer and cumulative exposure to nitrogen oxides for both genders. Excess mortality from all cancers and stomach cancer was found for the worker with the highest average exposure to arsenic, and excess lung cancer mortality could be attributed to exposure to arsenic. CONCLUSIONS: The investigation showed a weak association between employment in a fertilizer production plant and increased mortality from cancer. The results somewhat support the hypothesis that occupational exposure to precursors of N-nitroso compounds increases the risk of stomach cancer mortality, as does exposure to arsenic.

Arsenic↗
PubMed1995

Familial risk, abortion and their interactive effect on the risk of breast cancer--a combined analysis of six case-control studies.

In a previous study in France, we reported that the relative risk of breast cancer associated with a family history of breast cancer was higher in those subjects with a history of abortions. The present study was undertaken to check the existence of this interaction in other studies and to investigate whether the interaction is modified by the time at which abortions occur. Data were obtained from six case-control studies in France, Australia and Russia, with information on family history of breast cancer and abortion for 2693 breast cancer cases and 3493 controls. The interaction effect was estimated in each study separately, then combined using a multivariate weighted average. The relative risk conferred by a family history of breast cancer increased with the number of abortions (1.8 for no abortion, 1.9 for one abortion, 2.8 for two or more). There was a significant interaction between total number of abortions and family history (P = 0.04), but this was no longer significant when adjusted for other risk factors. The familial risk was highest for those who had had an abortion before first childbirth (1.9 for abortion after first childbirth, 2.7 for abortion before first childbirth). The adjusted risk associated with family history was significantly higher in those with an abortion before first childbirth (P = 0.04). Our findings suggest a synergism between familial factors and abortion. The interaction was not substantially modified by the type of abortion (spontaneous or induced) but was modified by the time at which it occurred in relation to first childbirth. This suggests an effect of abortion itself rather than predisposition to abortion. Further studies of breast cancer cases, particularly among BRCA1 gene carriers and their families, could improve our understanding of this effect.

Abortion, Induced↗
PubMed1995

[Role of outdoor and indoor air pollution in the etiology of lung cancer].

The results of a case-control study of lung cancer risk in female non-smokers in Moscow are presented in the paper. The increase in a risk of lung cancer was found to be associated with outdoor pollution, the closure of the residence to chemical industry and ferrous and non-ferrous smelters, environmental tobacco smoke from husbands and exposure to radon (Rn) at home. The relative risk of lung cancer (RR) for those living in high air polluted versus relatively pure areas was 2.6 (95% CI = 1.2-5.6). RR of lung cancer related to the closure of the residence to chemical industry and ferrous and non-ferrous smelters were 2.0 (95% CI = 1.0-3.9) and 1.75 (95% CI = 1.0-3.1). The analysis has shown that there is an increase in lung cancer risk in women whose husbands smoke, which is as high as 1.9 (95% CI = 1.3-2.9). Lung cancer risk is associated with levels of exposure to Rn in the dwellings: RR was 2.48 (95% CI = 1.4-4.3) for the Rn concentration of > 24.3 Bq/m3 versus < 13 Bq/m3.

Adenocarcinoma↗
PubMed1994

Childhood cancer incidence in relation to distance from the former nuclear testing site in Semipalatinsk, Kazakhstan.

Rates of childhood cancer between 1981 and 1990 in the 4 administrative zones of Kazakhstan were studied to assess the relationship, if any, with distance from nuclear testing sites. Risk of various cancers among children aged 14 years or younger were estimated in relation to distance from (1) a site where testing in air was performed before 1963, (2) a site where underground testing took place thereafter, and (3) a reservoir, known as "Atom Lake," created by 4 nuclear explosions in 1965. Risk of acute leukaemia rose significantly with increasing proximity of residence to the testing areas, although the absolute value of the risk gradient was relatively small. The relative risk for those living less than 200 km from the air-testing site was 1.76 compared with those living 400 km or more away from the site. Similar relative risks were observed for the underground site and "Atom Lake." There was also some evidence of increased risk of brain tumours in association with proximity to the test sites. In 2 of the 4 zones studied, there was substantial regional variation in acute leukaemia rates which was not attributable to distance from the test site. The findings may be affected by potential confounders, notably urban/rural status and ethnic factors.

Adolescent↗
PubMed1994

[Morbidity and mortality of malignant tumors in the population of a Moscow district].

An epidemiologic study of malignant tumors was carried out in a cohort of population of a district in Moscow. The district is situated on the leeward side of a cluster of factories which discharge 270 cu tons of pollutants per year. Nine of the eleven apartment houses under study were put up in the 60-70 ies when the factories were in operation. The cohort included 1,095 males and females who had lived in that district at least 5 years until the start of the investigation. The tumor morbidity and mortality in this cohort were evaluated for the period of 1988-1992. Morbidity of virtually all known tumors and mortality proved to be in excess of all expectations. However, significant differences between the actual and expected levels were obtained in the total number of tumors, in females, only (actual number-24; expected number-13.76), and for breast tumors (7 and 2.82, respectively).

Breast Neoplasms↗
PubMed1993

Cancer incidence in the native peoples of far eastern Siberia.

Cancer incidence rates were examined in the native peoples of the far north-east of Siberia for the years 1977-1988. Particularly high rates of cancers of the stomach, lung, oesophagus and cervix were observed. For stomach cancer, the male and female age-standardized (to the world population) rates were 103.9 per 100,000 and 50.0 per 100,000 respectively. The corresponding lung cancer rates were 109.4 and 45.7, and for oesophageal cancer 83.9 and 35.0. The age-standardized cervical cancer rate was 38.5 per 100,000. Rates of these cancers were considerably higher than in native Alaskan peoples, although the latter had higher rates of breast and colorectal cancers. The rates were also much higher than those of the migrant peoples from Russia and elsewhere who have settled in the far north-east over the past 3 centuries, particularly at younger ages. Male rates of stomach and lung cancer were highest in the paleo-Asiatic peoples of the north, whereas male oesophageal rates were highest in the Taiga people. In females, rates of stomach and oesophageal cancers were highest in the paleo-Asiatic peoples, and rates of lung cancer were highest in the Taiga nationalities. Cervical cancer rates were highest in the Amuro-Sakhalin nationalities of the south. Further research is needed at individual levels to explain the very high risks and the differences among the ethnic groups.

Adolescent↗
PubMed1993

Risk of leukaemia after chemotherapy in a case-control study in Moscow.

In a case-control study of second primary cancers in Moscow, there were 165 cases and 294 controls, matched for site of first primary, duration of follow-up since first primary and relapse history. Of the cases, 18 were of acute, non-lymphocytic leukaemia (ANLL), with 39 matched controls. Risk of ANLL was assessed with respect to chemotherapy for the first primary tumour. The chemotherapeutic agents investigated were nitrogen mustard, cyclophosphamide, procarbazine, doxorubicin, bleomycin, vinblastine, vincristine, prednisone and combinations. Increased risks were associated with use of nitrogen mustard (odds ratio = 9.94, not significant), doxorubicin (odds ratio = 11.25, 0.1 > P > 0.05) and vincristine (odds ratio = 26.57, P < 0.05). Despite the small number of cases and potential confounding by other agents, these findings, together with those of previous studies, suggest that some non-alkylating agents may predispose to second malignancies.

Adolescent↗
PubMed1993

Effect of beta-carotene supplementation on the activity of ornithine decarboxylase (ODC) in stomach mucosa of patients with chronic atrophic gastritis.

Increase of ornithine decarboxylase (ODC) activity is known to be associated with cell proliferation and, very likely, with tumour promotion. This prompted us to study the activity of ODC in gastric mucosa of patients with chronic atrophic gastritis that has been considered as a precursor of stomach cancer. Examination of 124 patients with this disease revealed the considerable increase in ODC activity in atrophic mucosa (29.8 +/- 2.9 vs 7.9 +/- 1.8 units in normal mucosa, p = 0.001). Supplementation of the patient's diet with beta-carotene (20 mg daily during 3 weeks) results in a statistically significant decrease in ODC activity in gastric mucosa. The data obtained confirm the possibility of application of ODC determination to the detection of early premalignant lesions and suggest the antipromoter activity of beta-carotene in gastric carcinogenesis.

Adult↗
PubMed1992

Occupational cancer mortality among urban women in the former USSR.

Occupational cancer mortality was evaluated among approximately three million female pensioners from urban areas of the former USSR. In 1970, these women experienced 14,918 cancer deaths. Occupational data were obtained from death certificates and the 1970 USSR National Population Census. Thirty-five occupational groups, including nine predominantly professional or office-work groups and 26 groups involving physical labor, were evaluated. The expected mortality rates were based on the urban female population of the USSR in 1970. Data for all cancer sites combined, and cancers of the esophagus, stomach, colon, rectum, lung, breast, cervix, and hematopoietic system are presented. Among all female pensioners, there were significant increases of all cancers combined (rate ratio [RR] = 1.05), and cancers of the breast (RR = 1.3), cervix (RR = 1.3), and the hematopoietic system (RR = 1.2), and a significant deficit of cancer of the esophagus (RR = 0.8). Many well-established associations between cancer and occupation among men were observed among the study group of female pensioners, such as stomach and lung cancer among miners, and hematopoietic malignancies among scientists and physicians. Other associations, to be investigated further, also were observed, such as excess lung cancer among waitresses. The peak employment period for this cohort of women was during World War II and the postwar period, when Soviet women outnumbered men almost two-to-one. Consequently, many of the women held jobs that are typically held by men. Thus, this study provides valuable information on occupational risks to women that may be relevant in other countries where women increasingly are being employed in jobs traditionally held by men.

Adult↗
PubMed1992

Nass use, cigarette smoking, alcohol consumption and risk of oral and oesophageal precancer.

In a cross sectional study, conducted in Uzbekistan, an area with a high incidence of oral and oesophageal cancer, 1569 men were interviewed regarding use of nass quid, cigarette smoking and alcohol drinking. All subjects in the study had an oral examination, and oesophagoscopy was performed in 1344 men. Nass use and cigarette smoking emerged as independent risk factors for oral leukoplakia. The prevalence odds ratio (OR) for life-time nass intake equivalent rose from 1.0 in never-users to 5.17 [95% confidence interval (CI), 3.10-8.61] in the highest category; for total pack-years of cigarettes smoked the risk rose from 1.0 in never-smokers to 10.03 (95% CI, 4.9-20.6) in the highest category. There was a significant trend in risk (P < 0.001), for both factors. In the group with oral leukoplakia, the effect of nass use and cigarette smoking appeared to be additive. Cigarette smoking was also found to be an independent risk factor for oesophageal lesions and was significantly associated with chronic oesophagitis. The risk of chronic oesophagitis in the group with the highest pack-years of cigarettes smoked was approximately double that among non-smokers [Odds ratio (OR) = 2.47; 95% CI 1.34-4.56]. There was a weak association between nass use and oesophageal pathology: the highest life-time intake equivalent was associated with an OR of 1.56 (95% CI 1.09-2.23). Alcohol intake was not found to be independently associated with the presence of oral and oesophageal precancerous lesions.

Age Factors↗
PubMed1992

Oesophageal cancer in the Republic of Karakalpakstan.

Regional and temporal patterns of variation in the incidence of cancer of the oesophagus in the Central Asian republic of Karakalpakstan were analysed. Karakalpakstan (population about 1200,000) is an area with high rates of this disease. Incidence data within regions (data from 1988-1989), ethnic groups (data from 1987-1989) and calendar periods (data from 1973-1987) were available for analysis, with corresponding official population estimates. No significant difference was observed between rates in urban and rural environments, although significant regional variation was observed (P less than 0.05). The highest rate observed was in the Muinak, the northern region, with world age-standardized rates (ASR) of 125.96 for males and 150.65 for females. There was a very significant difference among ethnic groups (P less than 0.001). The ethnic group with the highest incidence was the Kazakh people, with an ASR of 68.0 in males and 86.3 in females. Incidence in the republic as a whole declined in the period from 1973 to 1987. Incidence of cancer of the oesophagus is still high in Karakalpakstan, despite the decline. Incidence is likely to be strongly related to factors associated with region of residence and with ethnicity.

Adolescent↗
PubMed1992

[The role of endogenous and exogenous factors in the etiology of skin melanoma].

The results of case-control study of skin melanoma carried out in Moscow are presented. They point to considerable influence of endogenous factors on the relative risk of melanoma. The risk of melanoma is increased by such factors as light color of the skin, presence of freckles and moles. Exposure to UV-radiation raised the risk of melanoma, however, after relevant adjustment for the said factors relative risk was reduced. Consumption of greens and high blood levels of alpha-tocopherol significantly decreased the risk of melanoma. Female users of oral contraceptives had significantly lower risk of skin melanoma.

Body Constitution↗