1,721,322 research outputs found
Oral contraceptives and cervical neoplasia: pooled information from retrospective and prospective epidemiologic studies
No full textA positive association between the use of oral contraceptives and the risk of cervical neoplasia has been suggested by different sources. This paper examines epidemiologic evidence on this issue through pooled computation of relative risks emerging from 21 studies, subdivided into three main categories: studies based on routine cytologic screening programs, case-control investigations and prospective studies. The pooled estimates of the relative risks for ever vs never use of oral contraceptives were broadly similar and slightly above unity (1.4 from cytologic screening programs, 1.1 from case-control and 1.4 from prospective studies). The risk increased with duration of use and, generally, lower relative risk estimates derived from the older studies, necessarily based on short-term use of oral contraceptives. A particularly limited increase in risk was apparent from case-control investigations. Furthermore, when allowance was made for the major covariates (mostly indicators of sexual habits), a noticeable decrease in the excess risk was evident. In conclusion, although statistical significance of moderate differences in risk can be obtained by pooling data from several studies, a risk of the magnitude of that for the association between oral contraceptives and cervical neoplasia may well be due to bias and confounding. In addition, since sexual behavior only indicates the probability of having been exposed to some sexually transmitted agent (most likely human papilloma virus), the greatest additional contribution may come from a case-control study in which adjustment for such exposure is possible
Genital and urinary tract diseases and prostate cancer risk
No full textThe objectives of this study were to investigate whether venereal diseases, prostatic and urinary infections, and other selected conditions of the genital and urinary tracts may have a role in the development of prostate cancer. We analysed data from a hospital-based case-control study conducted between 1985 and 1992 in Italy, including 280 cases of prostatic cancer and 689 controls, hospitalized for acute, non-neoplastic, non-genital or urinary tract conditions. We calculated odds ratios and 95% confidence intervals using unconditional multiple logistic regression. The odds ratios of prostate cancer were 0.64 for history of selected venereal diseases, 0.53 for prostatitis, 0.67 for benign prostatic hyperplasia, 1.53 for urinary tract stones and 1.76 for cystitis. No relationship, however, was observed for cystitis &rt; 5 years before prostate cancer. The present study, based on satisfactorily reproducible information on medical history, did not found any association between genital and urinary tract diseases and prostate cancer risk. European Journal of Cancer Prevention 15:254-257 (c) 2006 Lippincott Williams & Wilkins
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dietary Factors and Non-Hodgkin’s Lymphoma: A Case-Control Study in the Nort heastern Part of Italy
No full textThe role of various life style factors, including dietary habits, in the etiology of non-Hodgkin‘s lymphoma was investigated using data from a case-control study conducted in the northeastern part of Italy. This study was done on 208 histologically confirmed non-Hodgkin‘s lymphomas and 401 control subjects who were in the hospital for acute, nonimmunologic, or neoplastic conditions. Dietary histories concerned the frequency of consumption per week of alcohol, beverages that contain methylxanthine, and 14 select food items or groups of foods (including major sources of proteins, fat, fibers, and vitamin A in the Italian diet). The consumption of milk, liver, butter, oil (chiefly polyunsaturated oils), coffee, tea, and cola was positively related with non-Hodgkin‘s lymphoma risk. The consumption of whole-grain bread and pasta showed a protective effect. When a logistic model was fitted that included the aforementioned food items in addition to major nondietary covariates, all of the foods, except liver and beverages that contain methylxanthine, remained significant. Interestingly, these associations are in agreement with the positive correlation that is emerging internationally between the consumption of fat and proteins and non-Hodgkin‘s lymphoma
Anthropometric measures and risk of cancers of the upper digestive and respiratory tract
No full textData from a case-control study on the upper digestive and respiratory tract cancers were analyzed to investigate the relationship with anthropometric measures. The data set included 538 oropharyngeal, 410 esophageal, and 388 laryngeal cancer cases and 2,102 controls in hospital for acute nonneoplastic diseases, unrelated to tobacco or alcohol use, recruited in the same catchment areas as the cases. Lower body weight appeared to be an indicator of oropharyngeal and esophageal cancer and, more moderately, of laryngeal cancer. The multivariate odds ratio (OR) for oropharyngeal cancer was 5.0 for subjects in the lowest compared with the highest quartile of weight. The corresponding ORs were 6.2 for esophageal and 2.2 for laryngeal cancer. When quartiles of body mass index (BMI) were considered, the ORs in the lowest quartile were 4.0 for oropharyngeal, 6.3 for esophageal, and 2.4 for laryngeal cancer. Subjects in the lowest quartile of height had ORs of 2.0 for oropharyngeal, 1.6 for esophageal, and 1.4 for laryngeal cancer. When all the upper digestive and respiratory tract neoplasms were considered together, the OR for subjects with lower BMI who were also current smokers compared with never-smokers with higher BMI was 11.4. The OR was 5.0 for those consuming six or more drinks/day and with low BMI. Although the nature of the association needs to be clarified, these data suggest that leanness may be involved in the process of upper digestive and respiratory tract carcinogenesis
Alcohol consumption and risk of prostate cancer
No full textBecause alcohol influences metabolism and serum levels of sex hormones and specifically increases metabolic clearance of testosterone, some role of alcohol consumption in the process of prostatic carcinogenesis is biologically plausible. The relationship between prostate cancer and total alcohol consumption was therefore investigated in a case-control study conducted in Northern Italy between 1985 and 1992 on 281 cases and 599 controls admitted to hospital for acute nonneoplastic diseases apparently unrelated to alcohol and tobacco consumption. No noteworthy relationship was found for major measures of alcohol intake: compared with teetotallers, the multivariate relative risks (RRs) of prostate cancer, after adjustment for age, study center, education, marital status, body mass index, and smoking status, were 1.3, 0.9, 1.2, and 1.1, respectively, for men drinking fewer than three, three to less than five, five to less than eight, or more than eight alcoholic beverages per day. None of the estimates was significant, nor was the trend in risk significant. Multivariate risks were also close to unity in the separate analysis of intake of wine (RR = 1.2 and 0.9 for or = 40 yrs, multivariate RRs = 1.1 and 1.3, respectively), and the alcohol-related risk estimates were similar for men or = 70 years of age.(ABSTRACT TRUNCATED AT 250 WORDS
An epidemiological study on the relationship between oral contraceptives and benign breast disease
No full textThe relationship of benign breast disease (BBD) and oral contraceptive (OC) use was analyzed in a case-control study conducted in Milan on 288 women with clinically relevant and histologically confirmed BBD (cases) and 285 age matched controls with a spectrum of acute conditions apparently unrelated to OC use. Compared to women who had never used OCs, the relative risk (RR) for users was 1.0 (95% confidence interval: 0.6-1.5). Likewise, there was no siginficant association with duration of use; however, a significantly lower relative risk emerged in women taking OCs during the year before breast biopsy (RR=0.4; 95% confidence interval: 0.2-0.8). The protection in current users increased with increasing duration of use. In spite of this finding, the overall results of the study do not support the hypothesis that OC use protects against development of histologically confirmed and clinically relevant benign breast diseas
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