Anastasia Tzonou

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.

Cigarette smoking and bladder cancer in men : A pooled analysis of 11 case-control studies

The primary risk factor for bladder cancer is cigarette smoking. Using a combined analysis of 11 case‐control studies, we have accurately measured the relationship between cigarette smoking and bladder cancer in men. Available smoking information on 2,600 male bladder cancer cases and 5,524 male controls included duration of smoking habit, number of cigarettes smoked per day and time since cessation of smoking habit for ex‐smokers. There was a linear increasing risk of bladder cancer with increasing duration of smoking, ranging from an odds ratio (OR) of 1.96 after 20 years of smoking (95% confidence interval [CI] 1.48–2.61) to 5.57 after 60 years (CI 4.18–7.44). A dose relationship was observed between number of cigarettes smoked per day and bladder cancer up to a threshold limit of 15–20 cigarettes per day, OR = 4.50 (CI 3.81–5.33), after which no increased risk was observed. An immediate decrease in risk of bladder cancer was observed for those who gave up smoking. This decrease was over 30% after 1–4 years, OR = 0.65 (0.53–0.79), and was over 60% after 25 years of cessation, OR = 0.37 (0.30–0.45). However, even after 25 years, the decrease in risk did not reach the level of the never‐smokers, OR = 0.20. (0.17–0.24). The proportion of bladder cancer cases attributable to ever‐smoking was 0.66 (0.61–0.70) for all men and 0.73 (0.66–0.79) for men younger than 60. These estimates are higher than previously calculated. Int. J. Cancer 86:289–294, 2000.

Tobacco smoking, alcohol consumption and their interaction in the causation of hepatocellular carcinoma

During a 4‐year period from January 1995 to December 1998, blood samples and questionnaire data were obtained from 333 incident cases of hepatocellular carcinoma (HCC), as well as from 360 controls who were hospitalized for eye, ear, nose, throat or orthopedic conditions in Athens, Greece. Coded sera were tested for hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti‐HCV) by third‐generation enzyme immunoassays, and information on smoking habits and beverage consumption was obtained. We found a significant dose‐response, positive association between smoking and HCC risk [≥ 2 packs per day, odds ratio (OR)=2.5].This association was stronger in individuals without chronic infection with either HBV or HCV (≥ 2 packs per day, OR=2.8). Consumption of alcoholic beverages above a threshold of 40 glasses per week increased the risk of HCC (OR=1.9). We also found evidence of a strong, statistically significant and apparently super‐multiplicative effect of heavy smoking and heavy drinking in the development of HCC (OR for both exposures=9.6). This interaction was particularly evident among individuals without either HBsAg or anti‐HCV (OR for both exposures=10.9). Coffee intake was not positively associated with HCC risk, but the reverse could not be excluded for the subgroup of chronically infected individuals. In conclusion, tobacco smoking and heavy alcohol consumption are associated with increased risk of HCC, especially when these 2 exposures occur together. Int. J. Cancer 85:498–502, 2000.

PSYCHOLOGICAL STRESS AND FATAL HEART-ATTACK - THE ATHENS (1981) EARTHQUAKE NATURAL EXPERIMENT

The effects of acute and subacute psychological stress caused by a sudden general disaster on mortality from atherosclerotic heart disease (underlying cause) and cardiac events (proximate cause) were investigated by comparing total and cause-specific mortality during the days after a major earthquake in Athens in 1981 with the mortality during the surrounding month and the corresponding periods of 1980 and 1982. There was an excess of deaths from cardiac and external causes on the days after the major earthquake, but no excess of deaths from cancer and little, if any, excess of deaths from other causes. The excess mortality was more evident when atherosclerotic heart disease was considered as the underlying cause (5, 7, and 8 deaths on the first three days, respectively; background mean deaths per day 2.6; upper 95th centile 5) than when cardiac events in general were considered as the proximate cause (9, 11, and 14 deaths on the first three days, respectively; background mean 7.1, upper 95th centile 12).

Occupation and bladder cancer among men in Western Europe

Objectives: We examined which occupations and industries are currently at high risk for bladder cancer in men. Methods: We combined data from 11 case–control studies conducted between 1976–1996 in six European countries. The study comprised 3346 incident cases and 6840 controls, aged 30–79 years. Lifetime occupational and smoking histories were examined using common coding. Results: Odds ratios for eight a priori defined high-risk occupations were low, and with the exception of metal workers and machinists (OR = 1.16, 95% CI = 1.02–1.32), were not statistically significant. Higher risks were observed for specific categories of painters, metal, textile and electrical workers, for miners, transport operators, excavating-machine operators, and also for non-industrial workers such as concierges and janitors. Industries entailing a high risk included salt mining, manufacture of carpets, paints, plastics and industrial chemicals. An increased risk was found for exposure to PAHs (OR for highest exposure tertile = 1.23, 95% CI = 1.07–1.4). The risk attributable to occupation ranged from 4.2 to 7.4%, with an estimated 4.3% for exposure to PAHs. Conclusions: Metal workers, machinists, transport equipment operators and miners are among the major occupations contributing to occupational bladder cancer in men in Western Europe. In this population one in 10 to one in 20 cancers of the bladder can be attributed to occupation.

Diet and cancer of the stomach: a case-control study in Greece.

A case‐control study focusing on the role of diet in the etiology of gastric cancer was undertaken in Piraeus, the sister city of Athens, in a population characterized by ethnic homogeneity but substantial heterogeneity with respect to dietary habits. The case series consisted of 110 consecutive patients with histologically confirmed adenocarcinoma of the stomach, admitted to two teaching hospitals during a 3‐year period; the control series consisted of orthopedic patients admitted to a nearby hospital for accidents, fractures and other orthopedic disorders, during the same time period. Dietary histories concerning the frequency of consumption (per month or per week) of about 80 food items were obtained by the same interviewer. Cases reported significantly less frequent consumption of lemons, oranges, brown bread, and raw, salad‐type vegetables (particularly lettuce, onions and cucumbers) and, independently, significantly more frequent consumption of pasta, beans and nuts. A relative risk of about 40 was found between extreme quintiles when the above 9 food Items were combined in a linear risk score. Use of an index constructed from the study material will clearly overestimate the level of risk between the extreme quintiles, but nevertheless the risk differences appear noteworthy, and consistent with the international variation in the incidence of gastric cancer. No significant associations were found with alcoholic beverages, coffee or tea.

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 intakeof dietary fat upon colorectal cancer risk in a combined analysis of datafrom 13 case-control studies previously conducted in populations withdiffering colorectal cancer rates and dietary practices. Original datarecords for 5,287 cases of colorectal cancer and 10,470 controls werecombined. 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 13studies. However, there was little, if any, evidence of anyenergy-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 (Ptrend = 0.39). The analysis suggests that, among these case-control studies,there is no energy-independent association between dietary fat intake andrisk of colorectal cancer. It also suggests that simple substitution of fatby other sources of calories is unlikely to reduce meaningfully the risk ofcolorectal cancer.

IGF‐I and IGF‐II in relation to colorectal cancer

Recent data suggest that the IGF system plays an important role in the pathogenesis of several forms of human cancer, and there is evidence that IGFs acting in an autocrine and paracrine manner may also affect colorectal cancer risk. We have conducted a case‐control study on the island of Crete, Greece, to examine the potential relation between circulating IGF‐I and ‐II and their major binding protein (IGF‐BP3), on the one hand, and colorectal cancer, on the other. IGF‐I, IGF‐II and IGF‐BP3 were determined in the serum from 41 patients with colorectal cancer and 50 healthy controls; data were analyzed using unconditional multiple logistic regression, adjusting for age, gender, education, height and BMI, as well as mutually. Both IGF‐I and IGF‐II were positively, while IGF‐BP3 was inversely, associated with risk for colorectal cancer, though none of these relations reached statistical significance. However, individuals with IGF‐I and –II values in the upper 2 tertiles of the respective distributions had a significantly elevated odds ratio for colorectal cancer (OR = 5.2, 95% confidence interval 1.0–26.8) compared with those in the lower tertile in both distributions. Our results provide evidence that high levels of circulating IGF‐I and ‐II might be associated with colorectal cancer. Int. J. Cancer 83:15–17, 1999.

Diet and cancer of the prostate: a case‐control study in Greece

The nutritional aetiology of prostate cancer was evaluated in Athens, Greece, through a case‐control study that included 320 patients with histologically confirmed incident prostate cancer and 246 controls without history or symptomatology of benign prostatic hyperplasia or prostate cancer, treated in the same hospital as the cases for minor diseases or conditions. Among major food groups, milk and dairy products as well as added lipids were marginally positively associated with risk for prostate cancer. Among added lipids, seed oils were significantly and butter and margarine non‐significantly positively associated with prostate cancer risk, whereas olive oil was unrelated to this risk. Cooked tomatoes and to a lesser extent raw tomatoes were inversely associated with the risk for prostate cancer. In analyses focusing on nutrients, rather than foods, polyunsaturated fats were positively and vitamin E inversely associated with prostate cancer. We conclude that several nutrition‐related processes jointly contribute to prostate carcinogenesis. Int. J. Cancer 80:704–708, 1999.

Tobacco, ethanol, coffee, pancreatitis, diabetes mellitus, and cholelithiasis as risk factors for pancreatic carcinoma

A hospital-based case-control study of pancreatic cancer was conducted in Athens in 1991–92. One hundred and eighty-one patients operated on for cancer of the exocrine pancreas in eight teaching hospitals formed the case series, whereas hospital patient controls and hospital visitor controls formed two independent comparison series. Cases and controls were matched by hospital, gender, and age in 1:1:1 ratio, and every matched triplet was interviewed in person by the same researcher. Results indicate that tobacco smoking increased the risk of pancreatic cancer, whereas neither coffee drinking nor consumption of alcoholic beverages were associated with the disease. Diabetes mellitus, cholelithiasis, and pancreatitis were associated positively with risk of pancreatic cancer, whereas allergic asthma was inversely (but not significantly) related to the disease. There was a suggestion that earlier age at menarche was associated with increased risk of pancreatic cancer and that parous women were at lower risk. No consistent associations were noted with respect to gastrectomy, other medical conditions or operations, birth order, height, weight, broad occupational groups, or other reproductive variables. The two comparison series were remarkably similar with respect to the whole spectrum of the study variables.