Biomedical subjects

D Trichopoulos

Publications and source records attributed to D Trichopoulos.

At least 181 records · Page 10Linked to original sources

PubMed1997

Intrauterine environment and breast cancer risk in women: a population-based study.

BACKGROUND: The established risk factors for female breast cancer, including nulliparity, age at first birth, age at menarche, and age at menopause, do not adequately explain the occurrence pattern of this cancer. Therefore, additional factors need to be considered to advance our understanding of the causes of breast cancer. Evidence obtained from animals and humans indicates that the perinatal period may be particularly important. Our earlier studies, based on a subsample of the present investigation, suggested that factors thought to be positively associated with estrogen levels during pregnancy are positively associated with breast cancer risk. However, the associated confidence intervals (CIs) were generally wide, indicating considerable variability in the data. PURPOSE: We studied a large number of incident breast cancer case patients and evaluated several perinatal variables in relation to breast cancer risk. These variables included some not previously studied, such as gestational age and neonatal jaundice. We also investigated twin membership as a predictor variable and death from breast cancer, in addition to occurrence of breast cancer, as an alternative outcome variable. METHODS: Birth records for all deliveries at five different hospitals in Sweden during the period from 1874 through 1961 were used to define a large cohort of women. Incident case patients with breast cancer in this cohort were ascertained through the National Cancer Registry or the Uppsala Regional Cancer Registry from 1958 through 1994. In a case-control study nested in the cohort, we abstracted data from birth records on 1068 women with incident breast cancer and on 2727 control subjects individually matched to the case patients on date of birth. We modeled the data through conditional logistic regression. All P values were derived from two-sided statistical tests. RESULTS: We found a markedly reduced risk for breast cancer in women whose mothers had pregnancy toxemia (odds ratio [OR] = 0.41; 95% CI = 0.22-0.79) and an excess risk on women who had neonatal jaundice (OR = 2.16; 95% CI = 1.27-3.67) or who were born before 33 weeks of gestation (OR = 3.96; 95% CI = 1.45-10.81). Compared with the risk for breast cancer in the singleton, the risk for breast cancer in dizygotic twins was increased, although this increase was not statistically significant (OR = 1.72; 95% CI = 0.92-3.20). There was no evidence in these data for a statistically significant or substantial association of breast cancer risk with birth size indicators (i.e., weight and length at birth and placental weight). CONCLUSION AND IMPLICATIONS: Because pregnancy toxemia is associated with low levels of estrogens and neonatal jaundice, severe prematurity, and dizygotic twins with high levels of estrogens, our findings suggest that estrogens and other hormonal factors, known to influence breast cancer risk in the adult, may also play a critical role during the intrauterine period.

Breast Neoplasms↗

PubMed1997

Epidemiology of road traffic accidents during pleasure travelling: the evidence from the Island of Crete.

During the six-month period April to September 1995, all 730 road traffic injury victims who contacted any of the three hospitals of the Heraklion District in the island of Crete, directly or through the Medical Emergency Transportation Network, were recorded. A special form was completed containing information about selected characteristics of the victims, nature of the injuries and conditions of the accident. All 39 fatalities owing to road traffic accidents were also registered. In the absence of data concerning the person-time at risk only proportional analyses could be performed. On the basis of Greek hospital discharge statistics in Heraklion District during 1992, one foreigner visitor was discharged owing to injuries of any type for every 18 Greeks. The corresponding ratio for road traffic accidents is close to 1:3, underlying the importance of road traffic accidents as the major health hazard during pleasure travelling. Left-side driving country nationals were at an increased risk for traffic accident when they drove a rented rather than an owned vehicle (p = 0.02), possibly on account of maladaptation during the adjustment period in the country of visit. Moreover, road traffic victims from left-side driving countries compared with foreigners from right-side driving countries were involved 2.5 times more frequently in accidents in which overpassing or other driving maneuvers require reflexes conditioned on reverse directionality (p = 0.02). Alcohol abuse was reported as a primary cause of accident in a significantly higher proportion of foreign nationals (p < 10(-6)) reflecting the fact that the latter group was on vacation. Alcohol intoxication was more common among Eastern European victims than among victims from European Union countries (p < 10(-5)). The likelihood of death following hospitalization ranged from 0% among those with a Glascow Coma Scale (GCS) score of 8 or higher, to 90% among those with GCS less than 8. After adjustment for exact GCS score there was no difference in the probability of death or the likelihood for admission to intensive care unit between Greek and foreign nationals. Road traffic accidents are a major hazard during pleasure travelling and victims of such accidents among travellers have a distinct epidemiologic profile compared with accidents of a similar nature among locals.

Accidents, Traffic↗

PubMed1997

Serum immunoglobulin G subclasses in healthy infants and children in Greece.

Serum concentrations of immunoglobulin IgG1, IgG2, IgG3 and IgG4 were determined by radial immunodiffusion in a sample of 414 healthy Greek children, who were admitted to the major Teaching Hospital for Children in Athens for minor surgical operations. Statistical analysis was performed by multiple regression after logarithmic transformation of the immunoglobulin values. There was a statistically significant increase of IgG3 with age, whereas IgG1, IgG2 and IgG4 levels reached a turning point at the age of five years. Older than 5 years male children were found to have marginally higher IgG4 levels than females. Low socioeconomic class was positively and significantly associated (9% increase) with IgG1 levels only among the older age group. History of frequent infections was associated with a 16% increase of IgG1 levels in the younger (less than 5 years) (p = 0.01) and with a 47% increase of IgG4 among the older age group (p = 0.03). Atopic history was associated with a 16% increase of IgG1 in the younger (p = 0.02). The findings of the present study provide an insight on the determinants and the clinical significance of IgG subclass levels among children.

Adolescent↗

PubMed1997

Risk of lung cancer from environmental exposures to tobacco smoke.

Epidemiologic evidence on the relation between environmental tobacco smoke and cancer is reviewed. The labeling of tobacco smoke as an environmental cause of lung cancer has been challenged based on allegations of bias in the epidemiologic data. However, tobacco smoke has been shown to increase the risk of lung cancer down to the lowest exposure levels. Environmental tobacco smoke contains the same carcinogenic compounds as those found in the tobacco smoke inhaled directly by the smoker. Nonsmokers environmentally exposed have elevated levels of tobacco smoke byproducts in biological samples. These observations alone are sufficient to identify tobacco smoke as an environmental carcinogen. The epidemiologic studies showing that environmental exposure to tobacco smoke is associated weakly but consistently with increased risk of lung cancer. While these epidemiologic studies have been challenged, it does not appear that the observed epidemiologic associations are due to misclassification or confounding. Indeed, the epidemiologic results, particularly among the studies with superior data collection methods and better control of bias and confounding, find consistent associations between environmental tobacco smoke and lung cancer. This paper summarizes the evidence that environmental exposure to tobacco smoke increases the risk of lung cancer, and considers the criticisms of the epidemiologic evidence which have been raised.

Bias↗

PubMed1997

Serum steroids in relation to prostate cancer risk in a case-control study (Greece).

Blood samples were collected from 52 incident cases of histologically confirmed prostate cancer and 52 age- and town of residence-matched healthy controls in Athens, Greece. Samples were analyzed blindly in Boston, Massachusetts (USA) for testosterone (T), estradiol (E2), sex hormone-binding globulin (SHBG), and dihydrotestosterone (DHT). The data were modeled using multiple logistic regression with adjustment for age, height, body mass index (wt/ht2), years of schooling, and mutually among hormones. DHT was associated inversely, significantly, and strongly with the risk of prostate cancer, whereas T was associated marginally positively, and E2 was associated nonsignificantly inversely with the disease. No association was observed in this study with respect to SHBG.

Aged↗

PubMed1997

The relationship between dietary fat intake and risk of colorectal cancer: evidence from the combined analysis of 13 case-control studies.

The objective of this study was to examine the effects of the intake of dietary fat upon colorectal cancer risk in a combined analysis of data from 13 case-control studies previously conducted in populations with differing colorectal cancer rates and dietary practices. Original data records for 5,287 cases of colorectal cancer and 10,470 controls were combined. Logistic regression analysis was used to estimate odds ratios (OR) for intakes of total energy, total fat and its components, and cholesterol. Positive associations with energy intake were observed for 11 of the 13 studies. However, there was little, if any, evidence of any energy-independent effect of either total fat with ORs of 1.00, 0.95, 1.01, 1.02, and 0.92 for quintiles of residuals of total fat intake (P trend = 0.67) or for saturated fat with ORs of 1.00, 1.08, 1.06, 1.21, and 1.06 (P trend = 0.39). The analysis suggests that, among these case-control studies, there is no energy-independent association between dietary fat intake and risk of colorectal cancer. It also suggests that simple substitution of fat by other sources of calories is unlikely to reduce meaningfully the risk of colorectal cancer.

Adult↗

PubMed1997

Aggregation of childhood leukemia in geographic areas of Greece.

A total of 872 children aged up to 14 years, who were diagnosed with leukemia in Greece during the decade 1980-89, were allocated by place of residence to the 601 administrative districts of the country. Evaluation of spatial clustering was done using the Potthoff-Whittinghill method, which validly assesses heterogeneity of leukemia risk among districts with variable expected numbers of cases. There was highly significant evidence for spatial clustering occurring particularly among children living in urban and, to a lesser extent, semi-urban areas. The evidence was stronger for children younger than 10 years old, applied also to children in different five-year age groups, and persisted when cases of acute lymphoblastic leukemia were analyzed separately. These findings provide support to the hypothesis that localized environmental exposures could contribute to the etiology of childhood leukemia, but they cannot distinguish between exposures of physical or chemical nature, nor can they exclude socially conditioned patterns of exposure to infectious agents.

Adolescent↗

PubMed1997

Insulin-like growth factor 1 in relation to prostate cancer and benign prostatic hyperplasia.

Blood samples were collected from 52 incident cases of histologically confirmed prostate cancer, an equal number of cases of benign prostatic hyperplasia (BPH) and an equal number of apparently healthy control subjects. The three groups were matched for age and town of residence in the greater Athens area. Steroid hormones, sex hormone-binding globulin, and insulin-like growth factor 1 (IGF-1) were measured in duplicate by radioimmunoassay in a specialized US centre. Statistical analyses were performed using multiple logistical regression. The results for IGF-1 in relation to prostate cancer and BPH were adjusted for demographic and anthropometric factors, as well as for the other measured hormones. There was no relation between IGF-1 and BPH, but increased values of this hormone were associated with increased risk of prostate cancer; an increment of 60 ng ml(-1) corresponded to an odds ratio of 1.91 with a 95% confidence interval of 1.00-3.73. There was also some evidence for an interaction between high levels of testosterone and IGF-1 in relation to prostate cancer. This finding suggests that, in addition to testosterone, IGF-1 may increase the risk of prostate cancer in humans.

Aged↗

PubMed1997

The risk profile of childhood leukaemia in Greece: a nationwide case-control study.

The risk profile of childhood leukaemia in Greece was studied through a case-control investigation that included all 153 incident cases of the disease, ascertained throughout the country during 1993 and 1994, and two hospital controls for every case matched for gender, age and place of residence. The data were analysed using conditional logistic regression and the associations are expressed in terms of adjusted odds ratios (OR) and their 95% confidence intervals. Cases were born to mothers of a higher standard education, the OR for an increment of four schooling years being 1.48 (1.17-1.87) and had higher birth weight, the OR for an increment of 500g being 1.36 (1.04-1.77). Pet ownership and birth after a pregnancy with anaemia were associated with increased risk, the ORs being 2.18 (1.14-4.16) and 2.60 (1.39-4.86) respectively. From the frequency analyses, indicative inverse associations were found with birth order, household crowding and previous hospitalization with allergic diseases, whereas indicative positive associations were found with diabetes mellitus during pregnancy and with neonatal jaundice. Substantial or significant elevations were not found with respect to maternal smoking and coffee drinking during pregnancy, diagnostic radiography and ultrasonographic examinations or blood transfusions. A significant inverse association with maternal consumption of alcohol could be due to multiple comparisons, but a detrimental effect can probably be excluded. A non-significant positive association with total shots of viral vaccinations and a weak non-significant inverse association with breast feeding were also found. We interpret the findings of this study as being compatible with acute childhood leukaemia being linked with delayed development of herd immunity to fairly common infectious agents, in conjunction with accelerated perinatal and early post-natal growth.

Adolescent↗

PubMed1997

A controlled evaluation of a community injury prevention project in two Greek islands.

BACKGROUND: During the 20-month period September 1993 to April 1995, a health education injury prevention programme focusing on home injuries among the young (< or = 18 years old) and elderly (> or = 65 years old) on the Greek island of Naxos was undertaken, its effectiveness was evaluated by comparing the subsequent injury experience in sentinel population groups in Naxos as well as in Spetses, another island of similar sociodemographic profile, where no such intervention programme had been formally implemented. METHODS: On the island-of Naxos an injury prevention campaign was initially undertaken involving virtually all opinion leaders and implemented through lectures, workshops and publicity in the local media. The main intervention focused on 172 households on the island of Naxos and was done by trained local collaborators who visited each household weekly to provide injury prevention advice and assess home safety. Similar visits were done by untrained collaborators in 177 households on the island of Spetses in order to assure collaboration of household members in the comparative evaluation stage of the programme. The process evaluation was based on ascertained changes of safety features and attitudes in the participating households, whereas the outcome evaluation was based on the incidence of injuries among members of the participating households in the two islands over a period of 8.5 months (255 days). RESULTS: On the intervention island of Naxos there were statistically significant improvements with respect to 11 of the 28 examined variables, whereas on the island of Spetses, such improvement was only noted for one variable. The age-adjusted incidence rate ratio of injuries overall among the target groups, contrasting the intervention and the control households was 0.85 with 90% confidence interval (CI): 0.69-1.05. With respect to home accidents the corresponding ratio was 0.79 with 90% CI: 0.60-1.04. CONCLUSIONS: An intensive and focused injury prevention intervention had only modest success when injuries themselves were the outcome variable.

Accidents, Home↗

PubMed1997

Reproducibility and relative validity of an extensive semi-quantitative food frequency questionnaire using dietary records and biochemical markers among Greek schoolteachers.

BACKGROUND: We evaluated the reproducibility and relative validity of a 190-item semi-quantitative food frequency questionnaire (FFQ) to be used in a large prospective study in the Athens area of Greece. METHODS: In all, 42 men and 38 women, aged 25-67 years, completed two self-administered semi-quantitative FFQ spaced approximately 1 year apart. Within this 1-year interval, participants visited the study centre monthly and completed an interviewer-administered 24-hour diet recall questionnaire. We also collected two venous blood and three 24-hour urine samples from participants at randomly selected periods during the year between the two administrations of the dietary questionnaire. RESULTS: Mean values for intake of most nutrients assessed by the two FFQ were in good agreement while those assessed by the two different dietary methods were reasonably similar for most nutrients. Intraclass correlation coefficients for energy-adjusted nutrient intakes assessed by questionnaires one year apart averaged 0.57 (range 0.24-0.75) and were not substantially different between genders. Correlation coefficients between the energy-adjusted nutrients measured by repeated 24-hour recalls and the semi-quantitative FFQ ranged from 0.25 for beta-carotene and polyunsaturated fats to > 0.50 for saturated fats, cis-linoleic acid, calcium and phosphorus (average: 0.46 for men and 0.39 for women). Reliability and relative validity were very high for alcohol intake. Dietary intakes from the FFQ were significantly correlated to plasma levels of vitamin C, but not beta-carotene or cholesterol. Dietary protein intake assessed by both FFQ was correlated (0.36, 0.30) with average urinary nitrogen excretion levels from three 24-hour urine samples. CONCLUSIONS: These data indicate that the semi-quantitative FFQ is reproducible and provides a reasonably reliable measure of intake. Significant correlations between diet and an independent biochemical marker further corroborate the relative validity of our questionnaire in this Greek population.

Adult↗

PubMed1997

Routinely reported sexually transmitted diseases presage the evolution of the AIDS epidemic.

Because AIDS is largely transmitted through sexual intercourse, the descriptive epidemiology of sexually transmitted diseases of short incubation period could presage the incidence trend of AIDS after a time interval that approximates the incubation period of the disease. We have evaluated this hypothesis using data from the 50 states in the United States routinely reported to the Centers of Disease Control and Prevention from 1979 to 1994. We have estimated the dependence of the slope of the annual incidence rate of AIDS over the period 1987-1994 on the intercept and the slope of one or more of three common sexually transmitted diseases: gonorrhea, chancroid, and syphilis. When the parameters of two sexually transmitted diseases were used as predictor variables, the adjusted multiple correlation coefficient (Radj) ranged from 0.70 to 0.77. When the parameters of all three sexually transmitted diseases studied were used in the regression model, the Radj reached a high value of 0.79. We conclude that incidence data of three common sexually transmitted diseases during an 8-year period presage the evolution of the AIDS epidemic during the subsequent 8-year period.

Acquired Immunodeficiency Syndrome↗

PubMed1997

Evidence that adult life risk factors influence the expression of familial propensity to breast cancer.

In the context of a study in Athens comprising 692 cases and 1,261 controls, we have evaluated the effect on breast cancer risk of the joint action of first-degree relative family history and established adult life risk factors. We created a risk score by assigning the value of 1 to women at high risk with respect to any of these risk factors and 0 otherwise, and summing these values, using weights equal to the excess odds ratio. The odds ratio for a tertile increment in the risk score was 1.5 [95% confidence interval (CI) = 1.3-1.8] among women without family history, and 2.3 (95% CI = 1.1-5.1) for women with family history. Our findings imply that women with a family history of breast cancer may benefit disproportionately by reduced exposure to adult life risk factors.

Adult↗

PubMed1997

An assessment, and reproducibility of food frequency data provided by hospital controls.

In order to assess the comparability and reproducibility of information from a questionnaire used in a case-control study on digestive tract cancers conducted in Italy, a total of 400 subjects were randomly selected from a large sample of hospital controls and contacted at home to repeat the interview. Of these, 294 (73%) subjects were re-interviewed. Mean values of intake were computed for the 400 subjects selected, and among the 294 responders for the first and second interview. These values were comparable, most of them being within a 10% range. Spectrum correlation coefficient (rs) values of consumption between the first and second interview were > 0.65 for consumption of pastries, pasta or rice, bread, fish, milk, green vegetables, eggs and apples; between 0.50 and 0.65 for meat, chicken, liver, ham, cold cuts, cheese, fruit, cabbage, carrots, tomatoes, peppers, salad, citrus fruit and melon; and lower than 0.50 for a few infrequently eaten foods. For all foods, the estimated average weekly intake in the second interview increased consistently and substantially with increasing tertile of the first interview. This study shows a satisfactory comparability of dietary information from subjects interviewed at home with that provided during their original interview in the hospital, and a good reproducibility of information collected in the two settings.

Case-Control Studies↗

PubMed1997

The role of dairy products and non alcoholic beverages in bone fractures among schoolage children.

In order to assess consumption of the calcium rich dairy products, intake of non alcoholic beverages and physical activity as risk factors for bone fractures among schoolage children, a case control study was undertaken in Athens, Greece. During 1995 one hundred children 7 to 14 years old (74 boys and 26 girls) with single uncomplicated fractures of the upper and lower extremities and no evidence of coexisting metabolic condition affecting bone fragility were compared with 100 age- and gender-matched controls. The analysis was undertaken by modeling the data through conditional logistic regression. Several indicators point to an increased risk of fractures among physically active children, although none of the individual variables was statistically significant. Somatometric factors were not related to fractures, although children with more advanced stage of development at Tanner's scale were apparently at increased risk. Intake of dairy products and of carbonated non cola beverages was not related to the occurrence of fractures. By contrast, intake of non carbonated beverages, mainly fruit juices, and of cola beverages were significantly associated with elevated risks of fractures [for an increase of one-half can per day, the odds ratios and associated 95% confidence intervals were 1.6 (1.2 to 2.3) and 1.7 (1.2 to 2.6) respectively]. In the absence of other common elements between cola and non carbonated beverages the positive associations of these beverages, with bone fractures probably reflect the increased rehydration needs of active children who are also at high risk for injuries.

Adolescent↗

PubMed1997

Infection with hepatitis B and C viruses, social class and cancer.

The hepatitis B and C viruses (HBV and HCV) are major etiological factors in the occurrence of hepatocellular carcinoma (HCC) worldwide, but most especially in developing countries where the majority of liver cancer cases can be found. In parallel with the geographic distribution of HCC, high levels of HBV endemicity are concentrated in the developing world. The association between chronic infection with HBV and low social class is quite strong; socioeconomic factors such as low educational attainment, lower social stratum, and crowded urban residence have been reported to predict higher HBV chronic carrier prevalence in both developed and developing countries. More importantly, the effect of poverty on HBV endemicity is clearly evident among younger age groups, and earlier chronic HBV infection seems to increase the risk of development of HCC. As assays for detecting HCV antibodies have only recently become available, the data on the relationship between HCV infection and socioeconomic status are much fewer. However, the limited number of studies that have investigated the seroepidemiology of HCV report an association between higher prevalence of antibodies to HCV and indicators of low social class. It would appear that the striking correlation between HCC and low socioeconomic status is largely related to the impact of poverty on the spread of HBV and probably HCV.

Age Factors↗

PubMed1996

Birthweight as a risk factor for breast cancer.

BACKGROUND: The mammary gland is largely undifferentiated before birth and may be particularly susceptible to intrauterine influences that could increase the risk of cancer through acceleration of cell proliferation or other pregnancy-related processes. Studies of migrant populations, animal data, and limited epidemiological evidence suggest that breast cancer may originate in utero. In a nested case-control study we assessed whether birthweight and other perinatal factors are associated with risk of breast cancer. METHODS: This case-control study was nested within the cohorts of the two Nurses' Health Studies. We used self-administered questionnaires to obtain information from the mothers of 582 nurses with invasive breast cancer and the mothers of 1569 nurses who did not have breast cancer (controls). Information on risk factors for breast cancer during adulthood were obtained from the nurses; multiple logistic regression analysis adjusted for these risk factors. FINDINGS: Birthweight was a significant predictor of breast-cancer risk. With women who weighed 4000 g or more at birth as the reference category, the adjusted odds ratios for breast cancer were 0.86 (95% CI 0.59-1.25) for birthweights of 3500-3999 g, 0.68 (0.48-0.97) for birthweights of 3000-3499 g, 0.66 (0.45-0.98) for birthweights of 2500-2999 g, and 0.55 (0.33-0.93) for birthweights below 2500 g (p for trend 0.004). Prematurity was not significantly associated with risk of breast cancer. INTERPRETATION: Birthweight is significantly associated with breast-cancer risk, which suggests that intrauterine factors or processes affect the risk of breast cancer in the offspring. High concentrations of pregnancy oestrogens may have an important role in breast carcinogenesis, but other pregnancy hormones or intrauterine factors may also be involved.

Adult↗

PubMed1996

Life-style factors and medical conditions in relation to esophageal cancer by histologic type in a low-risk population.

A case-control study of esophageal cancer was conducted in Athens, Greece, during the 3-year period 1989-1991. Cases were 43 patients with incident esophageal squamous-cell carcinoma and 56 patients with incident esophageal adenocarcinoma hospitalized in any one of the 9 major hospitals in Athens, whereas controls were 200 injury patients admitted to the only Athens accident hospital. The data were analyzed by modeling through multiple logistic regression. Tobacco smoking and alcohol drinking were associated with both histologic types, but the odds ratios were generally lower than those observed in several other investigations. It may be that the high consumption of vegetables and fruits by the Greek population cushions the deleterious effect of tobacco, while the intake of ethanol in the form of wine during meals reduces the impact of this substance on the esophageal mucosa. A preference for very hot temperature for beverages and food was associated with significant elevation of the odds ratio to about 1.8 for esophageal cancer in general. There was non-significant evidence in our data to support earlier reports that aspirin intake may reduce the risk of cancer of the esophagus. Overall, we found no striking difference in the risk profile of the 2 histologic types of esophageal cancer.

Aged↗