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Biomedical subjects

V Beral

Publications and source records attributed to V Beral.

At least 73 records · Page 4Linked to original sources
PubMed1997

Association between human immunodeficiency virus type 1 infection and cancer in the black population of Johannesburg and Soweto, South Africa.

A case-control study of 913 black cancer patients (aged 15-50 years) was undertaken to measure the association between human immunodeficiency (HIV) infection and cancers believed to have an infective aetiology. Controls were patients with cancers believed not to be infective in origin. The prevalence of HIV in the controls of 7.3% (24 of 325) was similar to the background HIV seropositivity in this population. Odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, year of diagnosis, marital status and sex were calculated. There was a strong association between HIV infection and Kaposi's sarcoma (KS), with 27 of 33 cases being HIV seropositive, OR = 61.8 (95% CI 19.7-194.2) and an elevated association with non-Hodgkin's lymphoma (NHL), with 27 of 40 cases being HIV seropositive [OR = 4.8 (95% CI 1.5-14.8)]. The elevated odds ratio for KS associated with HIV infection accords with the observed increases in the incidence of KS in several sub-Saharan African countries where the prevalence of HIV is high. The odds ratio for NHL associated with HIV infection was lower than that reported in developed countries, and the reason for this is not clear. No other cancers, including cervical and liver cancers, showed significantly elevated odds ratios associated with HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Risk factors for Kaposi's sarcoma in HIV-positive subjects in Uganda.

BACKGROUND: Kaposi's sarcoma (KS) is associated epidemiologically with HIV infection and with human herpesvirus 8 (HHV-8 or KSHV). Both KS and HIV infection are common in Uganda. We conducted a case-control study of 458 HIV-seropositive. Ugandan adults with KS and 568 HIV-seropositive subjects without KS to examine risk factors for HIV-associated KS. METHODS: We recruited newly diagnosed adult KS cases from five hospitals in Kampala, Uganda and controls from a large referral clinic for HIV infection at Mulago Hospital. All cases and controls were counselled and tested for HIV and answered an interviewer-administered questionnaire about their home, socio-economic conditions, lifestyle and sexual behaviour before they became ill. Only HIV-seropositive subjects were included in the analysis. RESULTS: There were 295 males and 163 females with KS and 227 male and 341 female controls. Age distribution was similar but there was a higher proportion of cases (45%) than controls (29%) residing in rural regions of Uganda. KS cases were more likely than controls to have a higher level of education (X2 for trend, 4.8; P = 0.03), to have occupations associated with affluence [chi 2 for heterogeneity, 17.3 on 5 degrees of freedom (df); P = 0.004] and to come from larger settlements [adjusted odds ratio (OR) for settlements of > 1000 versus 10-99 houses, 1.8; 95% confidence interval (CI), 1.1-3.0]. Cases were more likely than controls to have high household income (chi 2 for trend, 32.6; P < 0.001) and other markers of urban or rural wealth such as owning several cows (chi 2 for trend, 9.5; P = 0.002). Cases were more likely to travel away from home (adjusted OR, 1.6; 95% CI, 1.1-2.3) and more likely to have spent increasing time in contact with water (chi 2 for trend, 12.3; P < 0.001). Few indices of sexual behaviour were related to risk of KS, including reported number of sexual partners. Cases were more likely than controls to be married to one rather than several spouses (adjusted OR, 1.6; 95% CI, 1.2-2.2) and to have reported a history of sexually transmitted diseases (STD) (adjusted OR, 1.6; 95% CI, 1.2-2.3). CONCLUSIONS: Among HIV-infected subjects, KS cases are characterized by better education and greater affluence, compared with controls. Urban address, travel away from home, exposure to water, monogamous marriage and self-reported STD were also more frequent among KS cases than controls. The higher socio-economic status of persons with HIV and KS may be a marker for enhanced exposure to a possibly sexually transmitted agent, or for a delayed exposure to a childhood infection. The risk posed by exposure to water among KS cases requires further study.

AIDS-Related Opportunistic Infections↗
PubMed1997

Spontaneous abortion in dry cleaning workers potentially exposed to perchloroethylene.

OBJECTIVES: To investigate the association between spontaneous abortion and work within dry cleaning units in the United Kingdom where the solvent perchloroethylene is used. METHODS: A retrospective occupational study of reproductive outcome in 7305 women aged 16 and 45 years, who were currently or previously employed in dry cleaning or laundry units in the United Kingdom. Data on workplace exposures and reproductive outcome were obtained by postal survey. A sample of reported spontaneous abortions was validated from medical records. Machine operator versus non-operator was used as a surrogate for exposure to perchloroethylene in dry cleaning units as no data on individual doses were available for women in this study. RESULTS: The response rate was higher for current workers of dry cleaning units (78%), than for past workers of dry cleaning units (46%). Similarly, the response for current laundry workers (65%) was higher than that for past laundry workers (40%). Overall, the reproductive characteristics of the respondents were similar to expectation. Examination of exposure at the time of pregnancy, however, showed that the rate of spontaneous abortion varied according to the type of work the women did during the pregnancy or in the three months before conception: being lowest for pregnancies not exposed to either dry cleaning or laundry work (10.9%), higher for those exposed to laundry work (13.4%), and higher still for those exposed to dry cleaning work (14.8%). Within the group of pregnancies exposed to dry cleaning, the proportion was higher if the woman reported that she worked as an operator at the time of the pregnancy (17.1%) rather than as a non-operator (11.6%). Adjusted odds ratios for the period 1980-95 showed that the risk was over 50% higher in operators than non-operators (p = 0.04). The physical demands of the two jobs are likely to be similar. A higher risk was found when work as a dry cleaning operator was compared with no work in either dry cleaning or laundry units during pregnancy. Exposure to dry cleaning as a non-operator was not associated with any excess risk. CONCLUSIONS: Women who worked in dry cleaning shops at the time of their pregnancy or in the three months before who described themselves as operators were about half as likely again to report that their pregnancy ended in a spontaneous abortion than women who described themselves as non-operators.

Abortion, Spontaneous↗
PubMed1997

Socioeconomic differences in reproductive behaviour.

There are marked socioeconomic variations in the risk of female reproductive cancers. We examine here data from the World Fertility Surveys, the Demographic and Health Surveys, and other national surveys, to assess whether these variations in cancer risk might be explained, at least in part, by socioeconomic variations in reproductive behaviour. There were marked socioeconomic differentials in achieved parity, age at first birth, final childlessness, duration of breastfeeding, and possibly also age at menopause. These differentials were present in almost all settings: countries with low and high levels of modernization, and countries with low and high levels of fertility. In general, women of higher socioeconomic status and with more education had lower fertility and later age at first birth, but a greater prevalence of childlessness, shorter duration of breastfeeding and later age at menopause. However, the size and even the direction of these differentials varied markedly from country to country according to its level of economic development and, within each country, from generation to generation of women. It is possible that some of these socioeconomic differences may be narrowing in recent generations in Western countries. There was little evidence of socioeconomic variations in age at menarche. The observed socioeconomic differentials in most aspects of reproductive behaviour could potentially account for some of the socioeconomic variation in the risk of female reproductive cancers. However, this relationship could not be assessed directly because such analysis would require birth-cohort-specific data on socioeconomic variations in reproductive behaviour and in cancer risks. Unfortunately, these data are not available.

Adult↗
PubMed1996

Effect of ambient solar ultraviolet radiation on incidence of squamous-cell carcinoma of the eye.

BACKGROUND: We have investigated the geographic distribution of squamous-cell carcinoma of the eye to assess whether solar ultraviolet light is a risk factor for this disease. METHODS: We used routinely collected population-based cancer incidence data and published measurements of ambient solar ultraviolet light in our analysis. FINDINGS: The incidence of squamous-cell carcinoma of the eye declined by 49% of each 10 degrees increase in latitude (p < 0.0001), falling from more than 12 cases per million per year in Uganda (latitude 0.3(0)) to less than O.2 per million per year in the UK (latitude > 50(0)). Solar ultraviolet radiation decreases with increasing latitude, and the incidence of squamous-cell carcinoma of the eye decreased by 29% per unit reduction in ultraviolet exposure (p < 0.0001). INTERPRETATION: Our results are compatible with the hypothesis that exposure to solar ultraviolet light is an important cause of squamous-cell carcinoma of the eye.

Age Factors↗
PubMed1996

Cancer in Rwanda.

Data are presented on the frequency of malignant tumours registered at the population-based cancer registry in the southern prefecture of Butare, Rwanda, from May 1991 until 2 months before the outbreak of civil war in April 1994. Beginning in 1992, subjects were also interviewed about socio-demographic and life-style factors that have been associated with cancer risk in the West. The distribution of cancer in Rwanda is similar to that in other countries in sub-Saharan Africa. The most frequent cancers are those with possible infectious aetiologies: liver cancer (12%), cervical cancer (12%) and stomach cancer (9%). In addition, cancers known to be associated with HIV infection are relatively frequent (Kaposi's sarcoma [6%] and non-Hodgkin's lymphoma [3%]). Chronic infection, including infection with HIV, high parity and multiple sexual partners are important determinants of cancer incidence in this population. Tobacco consumption is low in Rwanda and there are few tobacco-related tumours, such as lung and laryngeal cancer. Other tumours believed to be associated with aspects of Western life-style, such as colorectal and breast cancer, are also relatively infrequent.

Adolescent↗
PubMed1996

Breast cancer mortality rates are levelling off or beginning to decline in many western countries: analysis of time trends, age-cohort and age-period models of breast cancer mortality in 20 countries.

Age-standardised mortality rates for breast cancer were examined for 20 countries in Europe, North America, Australia and New Zealand from 1950 to 1992 and age-birth cohort and age-period of death models were fitted to the data. Breast cancer mortality rates generally increased in the earlier decades, but more recently rates have levelled off or begun to decline in most countries. Only in 4 of the 20 countries studied, Belgium, Hungary, Poland and Spain, was there no evidence of a decline or leveling off or mortality in recent birth cohorts or in recent years. In the other countries the decline in mortality appeared to be in part due to birth cohort effects and in part due to period effects. The birth cohort effects were suggestive of a decline in breast cancer rates among women born after about 1920 and were evident in many countries especially Canada, The Netherlands, The United Kingdom and the United States. The decline in mortality in women born after 1920 appeared to be in part related to a reduction in childlessness and a reduction in age at first birth in those generations. As well as the birth cohort effects, there was some evidence of a recent overall decline in mortality rates in several countries, e.g. Austria, FRG, Greece and the UK, and this may be due to an increase in survival resulting from improved management and treatment of women with breast cancer.

Adult↗
PubMed1996

Health of children born to medical radiographers.

OBJECTIVES: To develop a reliable method for collecting information on reproductive outcome in an occupational setting; and to investigate the health of children born to medical radiographers. METHODS: The study population comprised 6730 members of the College of Radiographers who were, at the time of survey; aged between 30 and 64 years, on the current membership file of the College, and were resident in Britain. RESULTS: The postal method developed proved to be reliable, with around 87% of questionnaires being returned. The observed frequencies of reproductive events were broadly in line with findings from other studies: of the 9208 pregnancies reported, 83% were livebirths, 12% were miscarriages (gestational age < 20 weeks), 1% were stillbirths (gestational age > or = 20 weeks), and 1% were other rarer spontaneous adverse events (ectopic pregnancy, blighted ovum, and hydatidiform mole). There was little difference between men and women in the frequency of adverse reproductive events reported, with the exception that male radiographers reported fewer medical terminations, the proportions being 3.1% and 1.4% for women and men respectively. Among children, the overall risks of major congenital malformation (RR 1.0, 95%CI 0.9-1.2), chromosomal anomaly (RR 1.4, 95%CI 0.8-2.3), and cancer (RR 1.2 95%CI 0.7-2.0) were as expected based on general population rates. Borderline excesses of chromosomal anomalies other than Down's syndrome in the children of female radiographers (RR 3.9, 95%CI 1.3-9.0, based on five observations), and cancer in the children of male radiographers (RR 2.7, 95%CI 0.9-6.5, based on five observations) were noted. The numbers on which these risks are based are small and the findings should be interpreted cautiously. CONCLUSIONS: The postal methods developed for obtaining information about reproductive events and child health proved to be reliable in men, as well as in women. Overall, the findings for medical radiographers are reassuring. Dose-response relations could not, however, be examined as long term dose records of radiographers are not routinely kept in an accessible form.

Abnormalities, Radiation-Induced↗
PubMed1995

Is the apparent rise in cancer mortality in the elderly real? Analysis of changes in certification and coding of cause of death in England and Wales, 1970-1990.

The effect of changes in recording and coding of cause of death on trends in cancer mortality in England and Wales in persons aged 45 and over during 1970-1990 is reviewed. During this period, all-cancer mortality rates increased only at ages over 75 in males and over 55 in females. Rises in cancer mortality were largely due to increases in cancer of lung, prostate and unspecified site in men, and of lung, breast and unspecified site in women. Death coding and certification artefacts were much larger in older persons. In those aged 75-84, a change in the position of recording cancer on the death certificate could potentially account for 46% of the recorded increase in prostate-cancer mortality and 28% of the increase in breast-cancer mortality. The decrease in recorded mortality from ill-defined terminal events was far greater than the increase in cancer mortality in this age group. The rise in all-cancer mortality in the elderly was partly due to an increase in lung-cancer mortality, and data artefacts explained a large proportion of the increase in the other common specified cancers in those aged 75-84. The use of routine mortality statistics to chart progress against cancer lacks validity at older ages because of imprecision in certification of cause of death.

Aged↗
PubMed1995

Effects of low doses and low dose rates of external ionizing radiation: cancer mortality among nuclear industry workers in three countries.

Studies of the mortality among nuclear industry workforces have been carried out, and nationally combined analyses performed, in the U.S., the UK and Canada. This paper presents the results of internationally combined analyses of mortality data on 95,673 workers (85.4% men) monitored for external exposure to ionizing radiation and employed for 6 months or longer in the nuclear industry of one of the three countries. These analyses were undertaken to obtain a more precise direct assessment of the carcinogenic effects of protracted low-level exposure to external, predominantly gamma, radiation. The combination of the data from the various studies increases the power to study associations between radiation and specific cancers. The combined analyses covered a total of 2,124,526 person-years (PY) at risk and 15,825 deaths, 3,976 of which were due to cancer. There was no evidence of an association between radiation dose and mortality from all causes or from all cancers. Mortality from leukemia, excluding chronic lymphocytic leukemia (CLL)--the cause of death most strongly and consistently related to radiation dose in studies of atomic bomb survivors and other populations exposed at high dose rates--was significantly associated with cumulative external radiation dose (one-sided P value = 0.046; 119 deaths). Among the 31 other specific types of cancer studied, a significant association was observed only for multiple myeloma (one-sided P value = 0.037; 44 deaths), and this was attributable primarily to the associations reported previously between this disease and radiation dose in the Hanford (U.S.) and Sellafield (UK) cohorts. The excess relative risk (ERR) estimates for all cancers excluding leukemia, and leukemia excluding CLL, the two main groupings of causes of death for which risk estimates have been derived from studies of atomic bomb survivors, were -0.07 per Sv [90% confidence interval (CI): -0.4, 0.3] and 2.18 per Sv (90% CI: 0.1, 5.7), respectively. These values correspond to a relative risk of 0.99 for all cancers excluding leukemia and 1.22 for leukemia excluding CLL for a cumulative protracted dose of 100 mSv compared to 0 mSv. These estimates, which did not differ significantly across cohorts or between men and women, are the most comprehensive and precise direct estimates of cancer risk associated with low-dose protracted exposures obtained to date. Although they are lower than the linear estimates obtained from studies of atomic bomb survivors, they are compatible with a range of possibilities, from a reduction of risk at low doses, to risks twice those on which current radiation protection recommendations are based.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1994

Paraplegia and squamous cell carcinoma of the bladder in young women: findings from a case-control study.

A death certificate-based case-control study was conducted on 207 women aged 25-44 who died of bladder cancer in England and Wales in the period 1971-89 and 411 controls matched on sex, year of death and age at death. An odds ratio of 12.0 (95% CI 1.5-99.7) was found for women with a history of paraplegia. Four of the six paraplegic women were reported to have had squamous cell carcinoma of the bladder compared with only 19 of the 201 non-paraplegic women. These findings suggest that squamous cell carcinomas of the bladder, especially in paraplegics, may be the result of chronic urinary tract infection.

Adult↗
PubMed1994

Primary infertility: characteristics of women in North America according to pathological findings.

STUDY OBJECTIVE: To determine, in women with primary infertility, whether specific characteristics or behavioural factors are associated with the various pathological conditions identified as contributing to the infertility. DESIGN: Case-control study. SETTING: Seven institutions in the USA or Canada. PARTICIPANTS: Study subjects were 1750 women who presented with primary infertility, among whom the main pathological cause of infertility was male factor (417), tubal obstruction (231), endometriosis (194), luteal phase defects (153), other ovulatory problems (193), cervical abnormalities (92), and polycystic ovarian disease (84) and 1765 control women who delivered their first child at the same institution. MAIN RESULTS: Except for tubal obstruction and polycystic ovarian disease, the characteristics and behaviours of the women with infertility did not differ appreciably according to the pathological conditions recorded. Women with tubal obstruction had had more sexual partners, an earlier age at first intercourse, were more likely to have used an intrauterine device but less likely to have used a condom, and were more likely to have smoked cigarettes and to have used various recreational drugs than the other women. Women with polycystic ovarian disease were more obese, had had fewer sexual partners, and were less likely to have used cigarettes, contraceptives, and recreational drugs than the other women. CONCLUSIONS: Sexually transmitted infections seem to increase the risk of tubal obstruction but not other causes of infertility. Obesity is associated with polycystic ovarian disease. These data offer few clues to the aetiology of infertility attributed to endometriosis, cervical abnormalities, luteal phase defects, other ovulatory defects, or to male factors.

Age Factors↗
PubMed1994

Cervical cancer.

The overall incidence of and mortality from cervical cancer has declined in western countries and in most developing countries. In women under 40 years of age, however, mortality rates are levelling off or increasing in most countries. The earliest and most marked increases in young women occurred in England and Wales, Scotland, Ireland, New Zealand and Australia. Mortality rates in young women from eastern European countries began to increase later than in the UK, but the increases are of concern because baseline mortality rates are high in these countries. The reasons for the overall decline in cervical cancer are largely unknown but appear to be linked to improvements in the general standard of living. The increases in young women may well be due to the increasing prevalence of HPV infection. Screening for cervical cancer has undoubtedly led to a decline in cervical cancer incidence and mortality in many countries, but its contribution to the trends is difficult to assess without further information.

Adult↗
PubMed1994

Combined analysis of mortality in three United Kingdom nuclear industry workforces, 1946-1988.

Mortality during 1946-1988 has been analyzed in 75,006 employees of the United Kingdom Atomic Energy Authority, the Atomic Weapons Establishment and the Sellafield plant of British Nuclear Fuels. All-cause mortality was 19% lower than national rates among workers monitored for external radiation exposure and 18% lower among nonmonitored workers. Cancer mortality was also lower than national rates and was similar in the two groups of workers [rate ratio (RR) = 0.96]. Of 29 specific cancer sites examined, only for cancers of the pleura and uterus were there statistically significant excesses of mortality in monitored workers relative to nonmonitored workers [RR = 7.08, two-sided P (2P) = 0.008 and RR = 3.02, 2P = 0.003, respectively]. There was little association between cumulative external radiation and risk of death from all cancers combined 10 or more years after exposure [z for trend = +0.11, one-sided P (1P) = 0.5]. A positive association was observed for leukemia (assuming a 2-year lag between external radiation and increasing risk of death) (1P = 0.009) but not for other cancers associated with external radiation in previous analyses (lung, uterus, prostate and multiple myeloma, all 1P > or = 0.1). Positive associations (1P < or = 0.05) were also observed for melanoma and other skin cancers (1P = 0.03) and ill-defined and secondary cancers (1P = 0.04), but these results are difficult to interpret and, given the number of associations examined, may be chance findings. Estimates of excess relative risk per sievert were -0.02 (95% CI = -0.5-+0.6) for all cancers except leukemia and +4.18 for leukemia (95% CI = +0.4-+13.4). The positive estimates for leukemia contrast with negative values found for workers in the United States, although the confidence intervals obtained in the two studies overlap. While our estimates of risk are compatible with those derived from studies of A-bomb survivors, the statistical uncertainty associated with them is such that the data are consistent with risks ranging from no additional risk to twice the risk for cancers other than leukemia and, for leukemia, from one-fifth to three times the risk in A-bomb survivors.

Cause of Death↗