Occupational risk factors of lung cancer in São Paulo, Brazil

OBJECTIVES

This study estimated the risk of occupational exposure for lung cancer in the metropolitan region of São Paulo, the largest urbanized and industrialized area in Brazil.

METHODS

In this hospital-based case-referent study of 398 cases and 860 referents, the cases were matched to referents according to age, gender, and hospital and personally interviewed for information on lifetime job history, smoking habits, passive smoking exposure, cancer in relatives, socioeconomic status, and migratory history. The analysis concerned industrial titles and occupational categories. With the use of a job-exposure matrix, exposure to asbestos, polynuclear aromatic hydrocarbons, arsenic, dust, nickel and chromium was assessed.

RESULTS

For the men in the 56 industrial and 122 occupational categories examined, an excess risk of lung cancer was found in the machinery industry [odds ratio (OR) 1.62, 95% confidence interval (95% CI) 1.02-2.55). In pottery manufacturing the risk (OR 2.21, 95% CI 1.00-4.87) was increased for workers exposed > or = 10 years (OR 6.43, 95% CI 1.12-37.01). Textile workers employed for > or = 10 years with a latency of > or = 40 years had an elevated risk (OR 21.93, 95% CI 1.96-245.0). In the analysis using the job-exposure matrix no risk was detected for the specific lung cancer carcinogens examined. For the women, no significantly elevated risk was observed.

CONCLUSIONS

The results of this study revealed risks of lung cancer for men in the machinery industry and for pottery and textile workers with long-term exposure.

[Comparison of 5 methods to estimate the prevalence of diabetes mellitus in population-based studies]

To aid in the search for more practical and reliable methods for use in population-based studies of diabetes mellitus, this article compares five ways of estimating prevalence rates. The analysis was performed on secondary data from a cross-sectional study of a cluster sample of the adult population in nine state capitals in Brazil. The original study was carried out from 1986 to 1988. The 21,846 participants were classified as diabetic or not diabetic by five different methods: household questionnaires administered to the entire sample population (M1); individual questionnaires administered to the selected population (M2); measurement of fasting glucose levels in capillary blood, with levels > or = 120 mg/dL as the cutoff (M3); individual questionnaire and fasting capillary blood glucose > or = 120 mg/dL (M4); and individual questionnaire plus fasting capillary blood glucose > or = 120 mg/dL and capillary glucose 2 hours after oral glucose loading > or = 200 mg/dL (M5). Agreement between the methods was determined by comparison of the rates obtained and use of the kappa coefficient. The age-adjusted prevalence rates of diabetes varied according to the method used. Values obtained with M1 were lower than those indicated by M2; M3 values were higher than M2 values, except in the age group 60-69 years; and with M5 the rates were higher than with M4, except among persons 30-39 years old. With regard to the age-adjusted rates found by the various methods, M1 detected 84% of the M2 estimate, M2 detected 91% of the M3, M3 detected 70% of the M4, and M4 detected 86% of the M5. Previously diagnosed diabetes cases accounted for 64% and 55% of the totals estimated by M4 and M5, respectively. Kappa values were at least 0.70 for M1 compared against M2, M1 against M4, M2 against M4, and M3 against M4. Based on the results of this study, it was concluded that the questionnaires used in M1 and M2 constituted appropriate methods for detecting previously diagnosed cases of diabetes mellitus, and their use is recommended for the purposes of health services planning or evaluation. Fasting glucose measurement (M3) as the sole method did not show a significant advantage over the individual questionnaire (M2). Of the combined or multiple methods, fasting glucose together with the individual questionnaire (M4) was efficient in comparison to M5, which incorporated measurement of blood glucose 2 hours after oral glucose ingestion.

Myelodysplastic syndromes (MDS): prognostic factors and scoring systems

OBJECTIVE

To evaluate the score systems of Cassano and Sanz and suggest a new one.

DESIGN

Case series.

LOCATION

Teaching hospitals: EPM UNIFESP and Faculdade de Medicina de Botucatu.

PARTICIPANTS

59 patients diagnosed from 1979 to 1992.

INTERVENTION

Evaluation of clinical-laboratorial data.

MEASUREMENT

Statistical comparison, uni and multivariate analysis and actuarial survival curves.

RESULTS

Cassano's system divided the patients into high and low risk (p = 0.0966) while Sanz's gave high, intermediate and low risk (p = 0.0108). The univariate analysis showed hemoglobin, WBC count, E/M ratio, liver size and blast percentage in BM as statistically significant. The multivariate analysis showed blast percentage in BM (p = 0.004) and Hb (p = 0.050) as significant. Our system, considering the multivariate analysis data, divided the patients into high, intermediate and low risk (p = 0.0038).

CONCLUSIONS

Sanz's system was more functional than Cassano's, while ours showed predictive survival value and ease of use in clinical practice.

[Cytogenetic abnormalities as prognostic factors in acute myeloid leukemia]

The study of chromosomal abnormalities in AML has become very important in the diagnosis and in the characterization of subtypes since they are related to defined clinical, morphological and immunological features as well as treatment outcome and survival.

PURPOSE

To evaluate the relative importance of cytogenetic abnormalities may have in AML patients.

METHODS

13 AML patients were studied during diagnosis. Cytogenetic study was performed on bone marrow aspirate material.

RESULTS

M1 and M2 FAB subtypes were the most frequent (61.6%). The patients' median age was 38 years. Cytogenetic analysis showed abnormal karyotype in 61.5% of the cases and 15.3% of whom had abnormalities considered as good prognosis [t(15;17) and t(8;21)]. At the evaluation day there were 3 patients alive, two in continuous complete remission and 1 in a second remission. The median total survival time was 7 months. Patients were divided into two groups: a "good prognosis" one, that joined 5 patients with normal karyotype and 2 with the translocations t(15;17) and t(8;21) and another, the "bad prognosis" one, with 8 patients with unfavorable chromosomal abnormalities. The good prognosis group had a median survival time of 9 months versus 6.2 months in the other, but this was not statistically significant (p = 0.18), probably owing to the small number of cases in the groups. But when one observes the cases separately see that patients with translocations (8;21) and (15;17), known as good prognosis, had longer survivals.

CONCLUSION

The different survival time between the two groups showed the importance of cytogenetic study to distinguish the patient who will have favorable evolution.

Chronic myeloid leukemia (CML): prognostic factors and survival analysis

The prognostic value of different factors upon diagnosis of CML was analysed in 45 Philadelphia (Ph1)-positive patients. The median survival was 48 months. Univariate analysis showed 5 poor prognostic factors (male sex, under 45 years-old, bone marrow blasts greater than or equal to 10 percent, blood basophils greater than or equal to 6 percent and blood eosinophils greater than or equal to 6 percent) which provided for the development of a clinical staging system: Stage I with none or one factor and a two-year survival rate of 100 percent; Stage II with two or three factors and two-year survival of 72.2 percent; and Stage III with four or five factors and two-year survival of 0 percent (p = 0.00016). Multivariate survival analysis showed that combination of blood basophilia and bone marrow blasts had the strongest predictive relationship to survival time. We conclude that a combination of pretreatment factors identifies different risk subcategories in CML patients and is helpful in assessing the overall prognosis and the treatment approach.

[Industrial work and lung cancer]

In a hospital-based case-control study, 316 lung cancer cases and 536 controls were interviewed for their occupational, smoking, passive smoking, cancer in the family and residential histories as well as social economic status, by trained interviewers, using a standardized questionnaire. Cases and controls were matched by hospital, sex and age. The study was carried out between 1st July 1990 and 31st January 1991 in 14 hospitals in the Metropolitan Region of S. Paulo, the most highly industrialized and urbanized region in Brazil. Score criteria were developed for the ordering of the individuals of the study by occupational exposure to know carcinogens to the lung, in order to evaluate this exposure during the occupational life of each person. The criteria accumulated information on exposure to carcinogens as regards type, sector of work and time in each employment. The unconditional logistic regression analysis showed an odds ratio of 1.97 (95% IC: 1.52 to 2.55) for the highest exposure group. This result showed that workers linked to the production sectors of several industries have about twice the risk of developing lung cancer as workers involved in non-industrial activities.

Methodological considerations in case-control studies to evaluate BCG vaccine effectiveness

Several case-control studies evaluating the effectiveness of BCG vaccine in the last decade have presented contradictory results like previous prospective studies. Methodological differences could explain some of the case-control study results. This study explores the possibility that contradictory results could be imputed to the choice of different series of controls. Three controls were compared for each case of tuberculous meningitis: neighbourhood, hospital and household. BCG effectiveness estimates were 86.8%, 92.0% and 29.5%, respectively. The data indicated an interaction between BCG vaccine status and tuberculous focus. This could have influenced the lower effectiveness estimates found when cases were compared with household controls. The paper discusses aspects related to case-control studies applied to evaluate BCG effectiveness such as: incubation period and sufficient time since vaccination to allow development of an immune response; the presence of a tuberculous focus among the groups of cases and controls and the interaction between focus and BCG vaccination; recall bias; and optimum selection of controls in case-control studies in the context of infectious diseases.

[Risk factors for chronic non-communicable diseases: a domiciliary survey in the municipality of São Paulo, SP (Brazil). Methodology and preliminary results]

The non-communicable chronic diseases are important causes of death in Brazil, mainly in the great urban centres. There are various risk factors related to these diseases, whose remotion or attenuation would contribute to a fall in mortality. The methodology of the first comprehensive multicenter study into risk factors of non-communicable chronic diseases carried out in Latin America is explained. In Brazil, this study was carried out in the cities of S. Paulo, SP and Porto Alegre, RS. Preliminary results from the city of S. Paulo as to the prevalence of arterial hypertension (22.3%), tabagism (37.9%), obesity (18.0%), alcoholism (7.7%) and sedentarism (69.3%) are presented. These results are compared with existing data from Brazil and other countries, and the relationship between various risk factors and the mortality from cardiovascular diseases in S. Paulo and some developed countries is discussed.