Schistosomiasis and the risk of bladder cancer in Alexandria, Egypt.

The relationship between history of schistosomiasis and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 190 subjects with incident, histologically confirmed invasive cancer of the bladder, and controls were 187 subjects admitted to hospital for acute, non-neoplastic, non-urinary tract conditions. Eighty-six cases (45%) vs 69 controls (37%) reported a history of urinary schistosomiasis. The corresponding multivariate odds ratio (OR) of bladder cancer -- after allowance for age, sex, education, smoking, other urinary infections and high-risk occupations -- was 1.72 (95% confidence interval (CI) 1.0-2.9). The ORs were 0.22 (95% CI 0.1-0.4) for intestinal schistosomiasis and 0.32 (95% CI 0.1-1.9) for schistosomiasis of other types. The OR for urinary schistosomiasis was higher in subjects who were younger at first diagnosis (OR of 3.3 for <15 years) and in those with a long time since first diagnosis (OR of 3.0 for > or = 35 years). The ORs were 15.8 for male ever-smokers with a history of urinary schistosomiasis, compared with never-smokers without such a history, and 3.2 for men ever-infected with urinary Schistosoma haematobium and ever-employed in high-risk occupations, compared with those never-infected and with no high-risk occupational history. This study confirms that clinical history of urinary schistosomiasis is significantly, but modestly, associated with increased bladder cancer risk, explaining some 16% of bladder cancer cases in this Egyptian population.     

Tobacco smoking, occupational exposure and bladder cancer in Argentina

The highest rate for bladder cancer in Latin America has been reported from La Plata, Argentina. A case-control study was carried out to investigate the reasons for this high rate. A total of 117 cases, 117 hospital controls and 117 neighbourhood sex- and age-matched controls were interviewed regarding their smoking and drinking habits and occupational exposures. Cigarette smoking and coffee drinking were identified as the major risk factors, and a significant association was also found for truck and railway drivers and for oil refinery workers. The relative risks for male smokers who ever smoked cigarettes vs. non-smokers was 4.3 (95% Cl: 1.9-10.3). The risk associated with black tobacco cigarettes was 2-3 times higher than that of blond cigarettes. For male ex-smokers the risk after 5 years of no smoking is less than one third of that of current smokers. The RR for drinking coffee was 2.4 (95% Cl: 1.4-4.4) after adjusting for the effects of tobacco smoking, and the risk increased with the number of cups per day. No association was found with the use of saccharin.     

Risk factors for non-melanomatous skin cancer in Alexandria,Egypt

The role of constitutional and environmental factors on the risk of non-melanomatous skin cancer was evaluated in a case-control study conducted in 1992 in Alexandria, Egypt, on 136 incident historically confirmed (99 basal-cell and 37 squamous-cell) cases of non-melanomatous skin cancer (NMSC) and 145 controls in hospital for a broad spectrum of acute non-sun-related dermatological conditions. In relation to skin colour, compared with brown-skinned subjects, the multivariate relative risks (RR) were 2.3 for olive-skinned subjects and 3.8 for fair/medium-skinned subjects. Three cases and 29 controls were black (RR = 0.2). The trend in risk with skin colour was significant. Likewise, compared with subjects with brown or hazel eyes, those with green or blue eyes had a RR of 3.1. In relation to acute sun reaction, compared with subjects reporting easy tanning, the RRs were 2.5 for subjects reporting moderate tanning and 4.7 for those reporting easy burning. The risk of NMSC was higher for subjects reporting an outdoor occupation than for those reporting an indoor occupation (RR = 7.7). A significant trend in risk was observed with degree of sun exposure: compared with subjects reporting light sun exposure, the RR was 3.0 for those reporting moderate exposure, and 6.1 for those reporting heavy sun exposure. There was an indication of a relationship between clothing pattern and skin-cancer risk: compared with subjects reporting frequent use of traditional Egyptian clothes, the RR for dressing in short clothes was 1.8. The presence of signs of photo damage was also associated with NMSC (RR = 3.7). Exposure to arsenic was reported by 10 cases and 1 control (RR = 9.5). A positive interaction between sun exposure and skin colour was observed, and the RR rose to 14.2 for medium-or fair-skinned subjects with heavy exposure compared with brown-or black-skinned subjects with light or moderate sun exposure. In this Egyptian population, over 60% of NMSC could be attributed to sun exposure and approximately 45% to skin colour.     

Tobacco smoking, coffee drinking, and occupation as risk factors for bladder cancer in Greece

Patients with bladder cancer (250 males and 50 females), consecutively admitted during a 2-year period in the major cancer hospital of Athens, and an equal number of age- and gender-matched comparison patients with orthopedic conditions were interviewed regarding demographic, socioeconomic, and biomedical characteristics, including their occupations and their use of coffee and tobacco prior to the onset of their present disease or condition. Analyses of the data showed that cigarette smoking is an important, statistically significant and dose-dependent risk factor for bladder cancer, particularly in males (tobacco smoking is rare among older Greek women); drinking 2 or more cups of Greek coffee per day appears to be a risk factor for bladder cancer, independent of tobacco smoking, although the association is neither strong nor dose dependent; and a priori specified "high-risk" occupations were associated with an increased rate ratio for bladder cancer among men less than 65 years and among women in general but not among older men. The overall results of this study indicate that the established risk factors for bladder cancer in the United States and in other developed countries are, apparently, equally important for bladder cancer in Greece, despite the differences in composition and conditions of use of Oriental tobacco and Greek coffee and in the activities and exposures to carcinogens in the Greek work place.     

Tobacco smoking, GSTP1 polymorphism, and bladder carcinoma

BACKGROUND: Although cigarette smoking is considered a major risk factor for bladder carcinoma, little is known about the interaction between metabolic genes such as glutathione-S-transferase P1 and tobacco smoking in this process. GSTP1 may play a role in detoxification of tobacco-related carcinogens. METHODS: In this case-control study of 145 cases with bladder carcinoma (male:female = 7.5:1) and 170 noncancer controls (male:female = 3.7:1), the relation between genetic polymorphisms of GSTP1 and susceptibility to bladder carcinoma was investigated and the gene-environment interaction between tobacco smoking and GSTP1 polymorphism was evaluated. Epidemiological data were collected for all cases and controls by a standard questionnaire. Polymorphisms of GSTP1 were measured by polymerase chain reaction-restriction fragment length polymorphism. The logistic regression model in SAS was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). RESULTS: Cigarette smoking was confirmed as a risk factor of bladder carcinoma with an OR of 3.1 (95% CI: 1.7-5.9) after controlling for potential confounding factors. The OR for pack-years of smoking as a continuous variable was 2.4 (95% CI: 2.0-2.8). The ORs were 7.6 (95% CI: 1.18-49.51) for isoleucine/valine (Ile/Val) and 6.5 (95% CI: 1.01-41.56) for Ile/Ile when the homozygous Val/Val was considered as comparison group after adjusting for age, gender, race, and education. The adjusted OR for interaction between smoking and the GSTP1 (any Ile genotype) was 11.42 (95% CI: 0.53-248.15). CONCLUSIONS: The results indicate that the Ile 105 allele is associated with an increased risk of bladder carcinoma and suggest that individuals who smoke and possess the Ile allele might be at increased risk for bladder carcinoma.     

Smoking and bladder cancer in Egypt

A case control study of smoking was carried out on 365 Egyptian males with bladder cancer divided into 278 patients (76%) with previous urinary bilharziasis and 87 (24%) without past infestation. The smoking index was significantly higher in both bilharzial and non-bilharzial patients with bladder cancer than their controls. A significant association was found between heavy and moderate cigarette smoking and bladder cancer developing in non-bilharzial subjects. The local habit of “meassel” smoking did not differ significantly between bladder cancer patients and controls.     

Systemic management of bladder cancer in Egypt: revisited

Bladder cancer is still the most frequent malignant tumor among Egyptian males. It has a peculiar biologic, clinico-pathologic features and responsiveness to chemotherapy profile than that observed in Western countries. The current review aims to demonstrate the present state-of- art in using systemic therapy as part of the management options available to treat such patients at different stages of their disease. Individualizing therapy for these patients based on more rationale basis is the challenge that oncologists must face in the near future.     

Epidemiology of lung cancer: smoking, secondhand smoke, and genetics

The link between smoking and development of lung cancer has been demonstrated, not only for smokers but also for those exposed to secondhand smoke. Despite the obvious carcinogenic effects of tobacco smoking, not all smokers develop lung cancer, and conversely some nonsmokers can develop lung cancer in the absence of other environmental risk factors. A multitude of genetic factors are beginning to be explored that interact with environmental exposure to alter the risk of developing this deadly disease. By more fully appreciating the complex interrelationship between genetics and other risks the development of lung cancer can be more completely understood.     

Tobacco smoking and cancer: a meta-analysis

We conducted a systematic meta-analysis of observational studies on cigarette smoking and cancer from 1961 to 2003. The aim was to quantify the risk for 13 cancer sites, recognized to be related to tobacco smoking by the International Agency for Research on Cancer (IARC), and to analyze the risk variation for each site in a systematic manner. We extracted data from 254 reports published between 1961 and 2003 (177 case-control studies, 75 cohorts and 2 nested case-control studies) included in the 2004 IARC Monograph on Tobacco Smoke and Involuntary Smoking. The analyses were carried out on 216 studies with reported estimates for 'current' and/or 'former' smokers. We performed sensitivity analysis, and looked for publication and other types of bias. Lung (RR = 8.96; 95% CI: 6.73-12.11), laryngeal (RR = 6.98; 95% CI: 3.14-15.52) and pharyngeal (RR = 6.76; 95% CI: 2.86-15.98) cancers presented the highest relative risks (RRs) for current smokers, followed by upper digestive tract (RR = 3.57; 95% CI: 2.63-4.84) and oral (RR = 3.43; 95% CI: 2.37-4.94) cancers. As expected, pooled RRs for respiratory cancers were greater than the pooled estimates for other sites. The analysis of heterogeneity showed that study type, gender and adjustment for confounding factors significantly influence the RRs estimates and the reliability of the studies.     

Epidemiology of bladder cancer.

Approximately 49,000 persons in the United States develop bladder cancer each year, and about 9700 die of it. White men face a lifetime risk of almost 3%; white women and black men face a risk of about 1%, and black women, about 0.5%. Cigarette smoking is accepted widely as a cause of bladder cancer. Smoking accounts for about half of bladder cancer diagnosed among men and about one third of that among women. Moderate to heavy smokers typically show a two to five fold risk of bladder cancer, compared with persons who never smoked. When cigarette smokers quit smoking, their bladder cancer risk falls measurably within 2 to 4 years, but probably does not continue to decline with increasing years since quitting and does not appear to return to the baseline level of nonsmokers. Occupational exposure to certain aromatic amines causes human bladder cancer. Clear evidence of bladder cancer risk also is apparent for a small number of occupational groups: dye workers, rubber workers, leather workers, painters, truck drivers, and aluminum workers. Many other occupational groups have been reported to have increased bladder cancer risk, but evidence for these is not as strong. Coffee drinking has been studied extensively as a potential risk factor, but the inconsistency of the observed associations suggests that the relationship is either quite weak, noncausal, or dependent in a complex way on unmeasured factors. Artificial sweeteners confer little or no excess bladder cancer risk. Alcohol consumption apparently does not affect risk either. Consumption of fruits, vegetables, and foods high in vitamin A have been suggested as possible protective factors; consumption of high-fat foods, pork, and beef have been suggested as possible risk factors. Further epidemiologic research is needed to elucidate the role of diet in human bladder carcinogenesis. Less common risk factors for bladder cancer include ionizing radiation, cyclophosphamide use, and abuse of phenacetin-containing analgesics. Schistosomiasis infection may contribute substantially to the bladder cancer burden in Egypt and elsewhere, though not in the United States.(ABSTRACT TRUNCATED AT 400 WORDS)     

Cigarette smoking and bladder cancer

The relation between cigarette smoking and risk of bladder cancer was analysed in a case-control study in Northern Italy of 337 cases of histologically confirmed invasive bladder cancer and 392 controls admitted to the same network of hospitals with acute, non-neoplastic, non-urological conditions. Compared with never-smokers, the multivariate relative risk (RR) was 1.9 (95% confidence interval, CI 1.2–3.1) for ex-smokers and 3.3 (95% CI 2.2–5.0) for current smokers. The risk was directly and significantly related to duration of smoking (RR 3.5 for 30 years or more) and dose (RR 3.9 for 20 cigarettes per day or more), and consistent among strata of sex and age (though the RRs were systematically higher at older ages). Smokers of black tobacco only had a RR of 3.7, compared with 2.6 for smokers of blond cigarettes or mixed types. The interaction between tobacco and several occupations associated with bladder cancer risk fitted an additive rather than a multiplicative model: compared with non-exposed never-smokers, RR was 2.5 for exposed non-smokers, 2.8 for non-exposed smokers and 3.7 for occupationally exposed smokers.     

Epidemiology of bladder cancer in the Samara region

Correlation and regression analyses were used to study effects of exogenic and endogenic epidemiological factors. The findings of the two methods were almost identical. Of epidemiological factors in males under 50 years of age most essential were smoking and drinking regime. With age, cancer of the bladder more frequently arises due to infravesical and urinary inflammation. In males over 70 years of age smoking and infravesical obstruction are leading causes. Smoking is a leading cause of bladder cancer in women of all age groups. A drinking regime is the second cause of bladder cancer in patients under 60 years of age, while inflammation is more essential for bladder cancer onset in patients over 60.     

Urinary pH, cigarette smoking and bladder cancer risk

Glucuronide conjugates of 4-aminobiphenyl and its N-hydroxy metabolite can be rapidly hydrolyzed in acidic urine to undergo further metabolic activation and form DNA adducts in the urothelium. We conducted a large multicenter case-control study in Spain to explore the etiology of bladder cancer and evaluated the association between urine pH and bladder cancer risk, alone and in combination with cigarette smoking. In total, 712 incident urothelial cell carcinoma cases and 611 hospital controls directly measured their urine pH with dipsticks twice a day (first void in the morning and early in the evening) during four consecutive days 2 weeks after hospital discharge. We found that a consistently acidic urine pH ≤6.0 was associated with an increased risk of bladder cancer [odds ratio (OR) = 1.5, 95% confidence interval (CI): 1.2-1.9] compared with all other subjects. Furthermore, risk estimates for smoking intensity and risk of bladder cancer among current smokers tended to be higher for those with a consistently acidic urine (OR = 8.8, 11.5 and 23.8) compared with those without (OR = 4.3, 7.7 and 5.8, respectively, for 1-19, 20-29 and 30+ cigarettes per day; P(interaction) for 30+ cigarettes per day = 0.024). These results suggest that urine pH, which is determined primarily by diet and body surface area, may be an important modifier of smoking and risk of bladder cancer.     

Tobacco smoking, alcohol consumption, and laryngeal cancer in Madrid.

The associations between cigarette smoking and alcohol consumption and laryngeal cancer were examined in a case-control study carried out between 1982 and 1985 in Madrid. The analysis was based on 50 histologically confirmed male cases and 103 age- and sex-matched controls (45 hospitalized and 58 from the general population). A dose-response effect was observed for cigarette smoking, with an odds ratio (OR) of 4.33 (95% confidence interval of 1.22 to 15.41) for smokers of 30 or more cigarettes per day, when compared with those smoking less than 10 cigarettes per day. The risk clearly rose in line with the length of the smoking habit. In addition, for smokers of black tobacco, the risk was more than double that for smokers of blond tobacco, irrespective of the depth of inhalation. ORs for alcohol consumption rose significantly in accordance with the average grams intake per week and the overall lifetime consumption, but not with years of drinking. The time trends of risks for duration of alcohol consumption suggest the existence of phenomena related to individual susceptibility. A dose response effect was observed in supraglottal and glottal tumors. The effect of the joint exposure to both tobacco and alcohol fit to a multiplicative model.     

Tobacco smoking and gastric cancer: Review and meta-analysis

Although declining, gastric cancer (GC) is estimated to be second in frequency worldwide. Major causes appear to be environmental rather than genetic. A relationship has been suggested between tobacco smoking and GC. A number of epidemiological studies have been performed dealing with this question. All the cohort studies showed a significantly increased risk of GC of the order of 1.5–2.5 for cigarette smokers. Evidence from case-control studies is less consistent. We have carried out a meta-analysis on the 40 studies providing a quantitative estimate of the association between GC risk and tobacco smoking. Results suggest a risk of stomach cancer among smokers of the order of 1.5–1.6 as compared to non-smokers. The summary relative risk was higher in men (1.59) than in women (1.11). Several studies examined the dose-response relationship which existed in 4 cohort studies and 6 case-control studies. We estimated the number of GC cases attributable to tobacco smoking occurring worldwide: in total, over 80,000 cases of GC (11% of all estimated cases) may be attributed to tobacco smoking each year. This figure is larger than that estimated for other cancers for which association with tobacco smoking is clearly established, such as pancreatic and renal cancers. Int. J. Cancer 72:565–573, 1997. © 1997 Wiley-Liss, Inc.