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Biomedical subjects

E Buiatti

Publications and source records attributed to E Buiatti.

At least 55 records · Page 3Linked to original sources

Prevalence of precancerous lesions of the stomach in Venezuela.

Gastric biopsies from 1477 participants in a chemoprevention trial for precancerous lesions of the stomach in Venezuela were evaluated for the prevalence of precancerous lesions and Helicobacter pylori infection. These study subjects were selected from participants in an early detection program for gastric cancer using double-contrast X-ray. Overall, 94% had some type of chronic gastritis (CG) and were positive for H. pylori using Giemsa stain, 49% had atrophic gastritis, 34% had intestinal metaplasia (IM), and 6.5% had dysplasia. There were only three subjects (0.2%) with normal gastric mucosa, and 4% had only superficial gastritis. The prevalence of all of these precancerous lesions increased with age, but there was no clear difference by gender. The prevalence of the various lesions was higher in the antral mucosa than in the fundic mucosa. H. pylori infection was strikingly frequent in our study population, with prevalence rates ranging from 73% in subjects with superficial gastritis to 95% in those with atrophic gastritis and IM and 98% in those with CG. The prevalence of H. pylori was equally high in males and females, and it was significantly positively associated with the degree of infiltration of poly- and mononuclear cells and with that of active regeneration; it was inversely correlated with the degree of atrophy, IM, and dysplasia. Our findings support the precancerous nature of the various gastric lesions and the etiological role of H. pylori infection in CG.

Adult↗

Chemoprevention of stomach cancer.

A varied and balanced diet that is rich in fresh fruit and vegetables and poor in preserved foods is thought to represent the main protection against gastric cancer. Helicobacter pylori infection also appears to have a role in the disease; its eradication therefore represents another promising potential preventive measure. The effect of diet is supposed to be mediated by micronutrients with an antioxidant role, such as ascorbic acid, beta-carotene and alpha-tocopherol, which could act on different phases of the carcinogenic process, interrupting the progression of precancerous lesions towards cancer. The two trials ongoing in Latin America and the one planned in Europe all deal with the effect of antioxidants, with or without H. pylori eradication, on the progression/ regression rate of precancerous lesions of the stomach. The trial in Venezuela has an 80% power to detect a 50% reduction in the net progression of precancerous lesions in the group (from a high-risk population) undergoing a complex antioxidant treatment for 3 years. In this population a case-control study confirmed the protective effect of fresh fruits and vegetables in relation to gastric cancer. Other trials, which aimed to evaluate the chemopreventive potential of micronutrients on other cancer sites, have reported contradictory results concerning gastric cancer risk. When interpreting these results the following should be considered; a possible interaction between H. pylori infection and the antioxidants; the baseline levels of antioxidants in these populations; and the doses and duration of treatment.

Adult↗

Chemoprevention trial on precancerous lesions of the stomach in Venezuela: summary of study design and baseline data.

A double-blind, placebo-controlled trial is being conducted in a population at high risk for gastric cancer in Venezuela. The main aim of the trial is to assess the effect of antioxidant vitamins (beta-carotene, vitamin C and vitamin E) in blocking the progression of precancerous lesions of the stomach. Within the framework of a screening programme for stomach cancer, 2200 subjects of 35-69 years of age have been recruited. At study entry, a dietary questionnaire was completed, and gastroscopy with the collection of seven gastric biopsies was performed. After baseline examinations, the study participants were randomized to receive antioxidant treatment or placebo for three years. The treatment phase will be completed in mid-1998. At the end of the treatment phase, the investigations performed at study entry will be repeated. Before the initiation of the trial, various pilot studies were carried out that showed an extremely high prevalence of Helicobacter pylori infection (over 90%). Two eradication trials using anti-H. pylori treatments that give good results in Europe and North America gave very poor results in our study population. The low eradication rates achieved (5-20%) suggest a high prevalence of antibiotic-resistant H. pylori strains or high reinfection rates. These disappointing results led to deletion of an anti-H. pylori treatment phase of the main trial.

Adult↗

Evaluation of human trial design.

Randomized trials are considered the gold standard for evaluating chemopreventive agents. Compared with clinical trials, some specific design issues arise, requiring appropriate solutions: choice of chemopreventive agent(s); dose and chemical formulation of agent; choice of population; trial design; use of 'run-in phases' and pilot trials; sample size; monitoring of compliance; and duration and completeness of follow-up. Choice of the population, dose and length of intervention depend on the mechanism of action of the chemical(s) under study and its relationship with the natural history of the disease. The relationship between given and effective dose at a cellular level may also represent an efficacy determinant. A factorial trial design may be chosen on the basis of costs and of possible interaction between agents. Run-in phases and pilot studies are an efficient method for enhancing compliance and feasibility, although selection of good compliers may influence the expected frequency of outcome(s). Possible changes of exposure to the chemopreventive agent in the control group, due to spontaneous trends in the population, can reduce the power of the study and should be carefully monitored, together with compliance and side-effects. Length of follow-up and choice of validated end points represent crucial decisions in terms of validity of results and of their relevance for cancer prevention.

Anticarcinogenic Agents↗

Epidemiology of lung cancer.

Primary lung cancer is now the most frequent cancer in the world. Tobacco smoking still represents its predominant cause: a recent estimate attributes 80-85% of lung cancers to smoking and the epidemic of lung cancer mortality is still ongoing, with a major contribution from East European and developing countries. The study of smoking in association with lung cancer has contributed to the understanding of the carcinogenic process in humans, especially since molecular epidemiology techniques have been developed. However, the most probable carcinogenic model, still needs to be more clearly established. Presently, it can be summarised that smoking cessation is beneficial at any age, and more so when early. The contribution of passive smoking to lung cancer risk has been widely documented; its effect in terms of attributable number of cases, however, is not easily estimated at a population level. Some authors suggest that non-smoking-related lung cancer frequency is increasing over time. Exposure to environmental carcinogens with a major emphasis on those deriving from industrial processes, among which asbestos, and on air pollution due to traffic in urban areas has been advocated. Finally, a special interest has grown in the last years on possible protective factors for lung cancer, mainly diet-related (high intake of fresh fruits and vegetables), but results from the first large randomised chemoprevention trial based on alpha-tocopherol and beta-carotene treatment, dealt with "paradoxical" results.

Carcinogens, Environmental↗

[Gastrointestinal system tumors in Italian emigrants].

In this paper we present the risk of death for stomach, colon, rectum and pancreas cancers in Italian migrants to Canada, Argentina, Australia, France and England and Wales. Estimations of relative risks (RR) in Italian migrants, in residents in Italy and in Southern Italy relative to the local born in the host country are shown. Relative risks in Italian migrants to Australia were analysed also by duration of stay in the host country. The Italian migrants' cancer profile in intermediate between the origin and the host population: a reduction of risk of death for stomach cancer and an increase of risk for colorectal cancers are the main results. The results are discussed taking into account the analysis by duration of residence and the pattern of food prevalent in the different countries considered.

Adolescent↗

[Etiological epidemiology of gastric tumors].

Italy still ranks high among European countries for gastric cancer (GC) incidence and mortality. The main determinants of GC are nutritional: a dietary pattern "at high risk" is typically characterized by a large component of salted, preserved, monotonous and traditional foods, opposed to a "low risk" pattern, with a high-consumption of fresh fruit and vegetables and a varied diet. "Low risk" diet effect is supposed to be linked to its component in antioxidant micronutrients, which could positively interfere in the natural history of the disease. Other relevant identified factors are represented by cigarette smoking, some occupational exposures to dust and the infection with Helicobacter pylori. This last factor has been identified in several international studies, but its role in Italy needs further research.

Alcohol Drinking↗

Estimation and projections of stomach cancer trends in Italy.

Mortality data from official sources, and survival data from population-based cancer registries, are used for the estimation of incidence and prevalence of stomach cancer. Time trends of morbidity, survival, and mortality during the period 1970-90 are presented and analyzed. Incidence rates were decreasing during the considered period, but the rate of decrease was slowing down during the last decade. Almost stable rates, and even slightly increasing for women, were estimated for the youngest cohorts. Relative survival for stomach cancer was higher for women and for young ages; it was associated positively with period of diagnosis, and presented a significant South-North geographic gradient. Prevalence was estimated as decreasing during the period 1970-80, but increasing during the successive decade, due to both better survival and population aging. Projection of stomach cancer morbidity and mortality to the year 2000 showed that the disease should still be considered in Italy as a major public health problem.

Adult↗

Completeness of AIDS reporting and quality of AIDS death certification in Tuscany (Italy): a linkage study between surveillance system of cases and death certificates.

In Italy, the AIDS cases defined according to the CDC criteria are reported to the National AIDS Registry (RAIDS, compulsory surveillance system). The aim of the present study is to evaluate the completeness of AIDS cases reported and the quality of AIDS death certification in an Italian Region (Tuscany, about 3,500,000 inhabitants). The 737 AIDS cases reported to RAIDS as residents in Tuscany (1987-91) were cross-linked (key link: name and date of birth) with the data of the Mortality Registration system of the Region (RMR). For the residents in Tuscany decreased with a 279.1 death diagnosis (the code for AIDS deaths stated by the Italian Census Bureau) and not reported to RAIDS as AIDS cases, the clinical records were reviewed to check whether the diagnosis fitted the 1987-CDC diagnostic criteria. This study shows that there is a high completeness (97-98%) of the AIDS cases resident in Tuscany, reported to the RAIDS. The quality of RAIDS data is not as good with regard to life status assessment (23% of under-reporting of death). In Tuscany, the death certification for AIDS (code 279.1 of ICD IX) has a sensitivity of 88% and a specificity around 100% in comparison to RAIDS. About 50% of 'false negatives' in death certification are due to causes of death presumably unrelated to HIV infection. The evaluation of the quality of AIDS surveillance and mortality data is important in the assessment of the impact for AIDS epidemic in a target population.

Acquired Immunodeficiency Syndrome↗

Chronic lymphocytic leukaemias and non-Hodgkin's lymphomas by histological type in farming-animal breeding workers: a population case-control study based on job titles.

OBJECTIVES: A population based case-control study was conducted in a highly agricultural area in the north east of Italy to evaluate the association between farming and animal breeding and the risk of developing non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukaemia (CLL). METHODS: Occupational histories and other data were collected by personal interview on 164 NHLs, 23 CLLs, diagnosed in 1988-90, and on 977 controls. This paper only reports the results of the analysis relative to the coding of job titles through the modified International Labour Office (ILO) classification. Estimates of odds ratios (ORs) for occupational variables were calculated, after adjustment for sex, age, altitude of municipality, first degree familiarity, and previous Herpes zoster infection. RESULTS: From the analysis of the most frequent occupational categories, no occupation showed a significantly high risk. When the two job titles farmers only and farmer-breeders who are also involved in animal breeding are classified within the extremely varied occupation of agriculture or animal-breeding or fishing, a high risk for NHLs and CLLs is seen in the farmer-breeders (OR 1.79, 95% CI 1.22 - 2.63). Analyses according to histological type show that the risks are concentrated in CLLs and in low grade NHLs. No effect or trend by period at work or duration of employment in farming and animal breeding was found. CONCLUSION: Subjects working in agriculture associated with animal breeding are at high risk of NHL/CLLs, particularly CLLs and low grade NHLs. This finding could be related to the use of chemicals in agriculture or to exposure to animal transmitted diseases or specific chemicals used in animal breeding.

Adolescent↗

Population-based breast cancer survival. Mammographic screening activities in central Italy.

BACKGROUND: The aim of this study was to evaluate the effect on 5-year survival of patients with invasive breast cancer relative to demographic and clinical variables (age, residence, and disease diffusion) and to early diagnostic procedures performed in the area. METHODS: The observed (Kaplan-Meier method) and relative 5-year survival in 1263 patients with invasive breast cancer in the Province of Florence, Italy, between 1985-1986 (source: Tuscany Cancer Registry) are presented. The results were compared with those of other European areas and of the Surveillance, Epidemiology, and End Results Program. The Cox model is used to evaluate the effects of age at diagnosis (5-year age groups), disease diffusion (localized, regional, distant, unspecified), residence (Municipality of Florence, screening area, other municipalities), and source of diagnosis (Center for the Study and Prevention of Cancer, hospitals) on observed survival. RESULTS: Observed 5-year survival was 68.4% (Kaplan-Meier method) and relative 5-year survival was 75.4%. Relative survival for patients younger than age 35 at diagnosis was high (82.3%); it decreased slowly from 80.5% in the group of patients 35-44 years of age, to 74.0% in those 65-74 years of age, and steeply decreased to 68.1% in those 75 years of age and older. Relative 5-year survival in Florence was lower only than that observed in Switzerland (Geneva) and in the USA (whites). Five-year prognosis was worse in women 70 years of age or older, in advanced stages, in residents of municipalities not involved in the screening program, and in cases diagnosed in hospitals. The gain in survival may be explained partially by lead-time effect and by length bias due to early diagnosis both in self-referred women and in screening-detected cases. In these cases, though, the better prognosis, although attenuated, persisted after adjustment by disease diffusion. CONCLUSIONS: The results suggest that the early diagnosis of breast cancer in self-referred women affects prognosis, at least concerning 5-year survival. Moreover, although lead-time effect and length bias cannot be excluded in this study, screening by personal invitation may reduce the disadvantage in the survival of patients with breast cancer often observed in rural areas.

Adult↗

Reproductive history and gastric cancer among post-menopausal women.

A total of 339 post-menopausal women with gastric cancer (GC) and 515 population controls were interviewed in a multicenter study in Italy for information on reproductive history, dietary habits and other socio-demographic variables. After adjusting for these factors, GC risk was significantly higher among women reporting menopause below age 45, while no effect was shown for age at menarche, parity, age at first livebirth, and number of abortions. When age at menopause was considered together with age at menarche for an index of fertility years, GC risk showed a significant inverse relation to duration of fertility. These results suggest a protective role for endocrine or other factors related to late age at menopause or to length of fertility. These findings may be relevant to explain the fact that rates of GC reported among females are lower than among males around the world, and suggest the need for further research into hormonal and other related risk factors.

Age Distribution↗

Cancer mortality in Italian migrants to Canada.

The present study reports on the analysis of cancer mortality in Italian first-generation migrants resident in Canada, deceased in the period between 1964-1985 (5,801 males: 3,267 females). Mortality in migrants is compared to that of the host population as well as to that in the migrants' country of origin. This is carried out both on a national level (Italy), and on a regional level with those regions that have made the greatest contribution to the Italian migratory flow (Southern Italy). Compared with the Canada-born population, significantly higher risks were evident for nasopharynx, stomach, liver and gallbladder tumors in migrants. Lower risks were observed for the oral cavity, esophagus, colon, rectum, pancreas (females), larynx, lung, melanoma, breast, ovary, prostate, bladder (females), and non-Hodgkin's lymphoma in migrants. This is consistent with that evidenced in the comparison between Italy and Canada. The data are discussed in relation to the results of other studies on Italian migrants and the prevalence of main risk factors.

Age Distribution↗

Occupational exposures as risk factors for gastric cancer in Italy.

Occupational associations with gastric cancer were investigated in a multicenter case-control study in Italy involving interviews with 640 histologically confirmed male cases and 959 controls, randomly selected from the resident populations of the study areas. From information on the three jobs each person held the longest, risks were evaluated according to employment in 35 occupations (ever or 21+ years) and to estimated exposure (ever or 21+ years) to six chemicals using a job-exposure matrix. All risk estimates were adjusted by personal, demographic, and dietary variables identified as gastric-cancer risk factors in previous analyses. The only significantly increased risk was observed for sailors, seamen, and allied groups (ever employed: odds ratio [OR] = 2.9; 95 percent confidence interval [CI] = 1.1-8.0; 21+ years: OR = 3.1, CI = 0.8-13). Nonsignificant increases after 21+ years of employment were observed for forestry workers, miners, and janitors and cleaners. Crude ORs were elevated significantly among farmers, but adjusting for demographic and lifestyle factors largely eliminated the association: a nonsignificant 30 percent excess risk remained for farm laborers, but there was no rise in risk among long-term farm laborers and no excess among farm owners. Application of the job-exposure matrix revealed excess risks of borderline significance associated with potential exposure to mineral dusts and nitrogen oxides. For subjects with 21+ years of potential exposure, nonsignificantly increased risks were related to mineral dusts, asbestos, fertilizers, and nitrosamines.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Difficulty in eradicating Helicobacter pylori in a population at high risk for stomach cancer in Venezuela.

The bacterium Helicobacter pylori (HP) has been implicated in the etiology of precancerous lesions of the stomach and there is evidence suggesting that it may influence the efficacy of chemoprevention of gastric cancer with vitamin C. Eradication seldom has been attempted in populations from developing countries, with a high prevalence of HP frequently resistant to metronidazole. A randomized, double-blind, controlled trial to evaluate the efficacy of colloidal bismuth subcitrate (120 mg q.i.d.) and amoxycillin (500 mg q.i.d.) in eradicating HP was conducted in 220 subjects drawn from a population with a high prevalence of metronidazole-resistant HP in Tachira state, Venezuela. One month after completion of two weeks' treatment, eradication rates of 6.5 percent in the treatment group and two percent in the placebo group were estimated on the basis of HP diagnosis in biopsies, and of 13.9 percent compared with 3.9 percent on the basis of a 14C-urea breath test, although the negative predictive value of the breath test was very low compared with HP diagnosis in biopsies. In the treatment group, particularly among males, a significant decrease in bacterial load was detected. Reasons for failure of treatment in high HP-prevalence areas are discussed, and it is suggested that primary prevention of HP infection may be the optimal approach to reducing levels of stomach cancer in these high-risk groups.

Adult↗