Histologically diagnosed cancers in South Africa, 1988

The National Cancer Registry (NCR) collects information on cancer diagnoses via a nation-wide network of public and private pathology laboratories. In 1988, 45 570 new laboratory-diagnosed cancer cases were reported to the NCR. Minimal age-standardised registration rates for black, white, coloured and Asian males were 112,2, 229,9, 192,2 and 91,6/100 000, respectively, and those for females 107,2,201,3 148,1 and 118,0. About 40% of cancers in females and 31,3% in males occurred in potentially economically active adults aged 15 - 54 years. The top five cancers in males were: (i) basal cell skin cancer; (ii) cancer of the prostate gland; (iii) cancer of the oesophagus; (iv) lung cancer; and (v) squamous cell skin cancer. In females they were: (i) cancer of the cervix; (ii) breast cancer; (iii) basal cell skin cancer; (iv) squamous cell skin cancer; and (v) cancer of the oesophagus. Despite under-reporting, a nwnber of cancers, especially those of the oesophagus and cervix in blacks and skin cancers in whites, rank among the highest in the world. Moreover, 40,4% of the cancers in adult males (15 - 64 years) and 15,2% of those in adult females were associated with tobacco use. It is recommended that: (i) regional cancer registries be set up in a number of regions to provide information on the true burden of cancer and to monitor interventions; (ii) a national screening programme for cancer of the cervix be established; (iii) detailed studies on lifestyle and dietary causes, especially of cancers related to tobacco consumption and cancers of the oesophagus, cervix and skin, be undertaken; and (iv) the impact of HIV on virus-related cancers be monitored

A role for the ecological study in the developing world

Retrospective case-control or prospective (followup) studies are important epidemiological tools and have provided useful infonnation on exposure disease associations. Prospective studies would be the ideal option, but m.any countries (Particularly in the developing world) do not have the necessary infrastructure to follow people up. Both retrospective and prospective studies are, however, som.etim. es conducted without due regard for their own lim.itations. These lim.itations are exacerbated when m.easures of exposure or disease are based on a single measurement and where the population under study is homogeneous with regard to exposure. The former is responsible for regression dilution bias and the latter for a lack of contrasts between exposure groups. Both factors would attenuate any relationship between exposure and disease. Ecological studies in epidemiology are weaker in design than case-control or prospective studies, but in some circumstances an ecological approach, which looks at the prevalence of an exposure or disorder in a number ofareas of varying disease rates, may offer some advantages

Radiation therapy services in South Africa

A survey of both private and public sector radiation therapy facilities in South Africa shows that they are available in only 7 major urban centres.About 20 000 cases are treated yearly by 58 therapists and 190 therapy radiographers, with 37 megavoltage and 24 X-ray machines. Brachytherapy, imaging and planning equipment is also inadequate. With limited epidemiological data it appears that less than 50% of all patients appropriately treated with radiation therapy present for such treatment. Increased referrals from sub-Saharan Africa place further strains on the system

Thyroid cancer in South Africa - an indicator of regional iodine deficiency

Objective. Because follicular thyroid cancers predominate in iodine-deficient and papillary cancers predominate in iodine replete populations. we have analysed national and regional (former Transvaal) incidences of these cancer types as a surrogate measure of the population iodine nutritional status in South Africa.Design. Statistical analysis, by race and sex, of differentiated thyroid cancers reported to the South African National Cancer Registry (1988), and of the computerised histology records of the Department of Anatomical Pathology, SAIMR (January 1990 to June 1994; Transvaal data).Main outcome measures. Relative frequencies of the two cancer types nationally and geographically in the Transvaal region.Main results. Thyroid cancer was underdiagnosed in populations other than white. Nationally, follicular histology accounted for 55% of all differentiated primary thyroid cancers, and predominated especially in black women. Follicular morphology predominated in blacks resident in the rural regions of the former Transvaal (58%), while papillary histology predominated in urban areas (of present-day Gauteng), irrespective of race (78%; P = 0.003).Conclusion. The national predominance of follicular thyroid cancer indicates that significant iodine deficiency exists in the country as a whole. The observed urban-rural differences in prevalences of follicular and papillary cancer types suggest regional differences in the severity of iodine deficiency. There is a need for a formal survey of the population iodine nutritional status in South Africa

Residual risk of transmission of HIV through blood transfusion in South Africa

Despite the ongoing review of donor recruitment criteria by local blood transfusion services and the developmnt of highly sensitive and specific testing for the presence of antibodies to HIV in blood and blood products, there remains a residue of HIV in donated blood. This is because of donors who are in the 'window period' between acquisition of HIV and seroconversion, human errors and limits to the sensitivity and specificity of current tests. Data available from a national survey of HIV seroprevalence in South African blood donors allowed for the estimation of the number of units screened negative but likely to be infected with HIV. Assuming window periods of 4,8 and 14 weeks, a test sensitivity of 99,9%, a specificity of 98,5% and a human error rate of 0,1%, the likely rate of HIV-infected blood in the South African blood transfusion supply ranges from 1,1 to 3,9/ 100 000 units, with a likely estimate of 2,2/100 000 units. In the current South African blood transfusion setting, between 8,1 and 28,2 units of blood per annum. will be HIV-positive with a likely estimate of 15,9 units. This corresponds to an odds ratio of between 1:90 909 and 1:25 641 units infected with HIV. These data are comparable with the risk in developed countries. The expected increase in the incidence and prevalence of HIV infection in all adult South African populations necessitates additional measures to ensure a blood supply which is as safe as possible. Some of these measures have already been taken by local blood transfusion services

Tobacco smoking and all-cause mortality in a large Australian cohort study: findings from a mature epidemic with current low smoking prevalence

This study finds that up to two-thirds of deaths in current smokers  in Australia can be attributed to smoking. Abstract Background The smoking epidemic in Australia is characterised by historic levels of prolonged smoking, heavy smoking, very high levels of long-term cessation, and low current smoking prevalence, with 13% of adults reporting that they smoked daily in 2013. Large-scale quantitative evidence on the relationship of tobacco smoking to mortality in Australia is not available despite the potential to provide independent international evidence about the contemporary risks of smoking. Methods This is a prospective study of 204,953 individuals aged ≥45 years sampled from the general population of New South Wales, Australia, who joined the 45 and Up Study from 2006–2009, with linked questionnaire, hospitalisation, and mortality data to mid-2012 and with no history of cancer (other than melanoma and non-melanoma skin cancer), heart disease, stroke, or thrombosis. Hazard ratios (described here as relative risks, RRs) for all-cause mortality among current and past smokers compared to never-smokers were estimated, adjusting for age, education, income, region of residence, alcohol, and body mass index. Results Overall, 5,593 deaths accrued during follow-up (874,120 person-years; mean: 4.26 years); 7.7% of participants were current smokers and 34.1% past smokers at baseline. Compared to never-smokers, the adjusted RR (95% CI) of mortality was 2.96 (2.69–3.25) in current smokers and was similar in men (2.82 (2.49–3.19)) and women (3.08 (2.63–3.60)) and according to birth cohort. Mortality RRs increased with increasing smoking intensity, with around two- and four-fold increases in mortality in current smokers of ≤14 (mean 10/day) and ≥25 cigarettes/day, respectively, compared to never-smokers. Among past smokers, mortality diminished gradually with increasing time since cessation and did not differ significantly from never-smokers in those quitting prior to age 45. Current smokers are estimated to die an average of 10 years earlier than non-smokers. Conclusions In Australia, up to two-thirds of deaths in current smokers can be attributed to smoking. Cessation reduces mortality compared with continuing to smoke, with cessation earlier in life resulting in greater reductions

Desegregating health statistics and health research in South Africa

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Preanalytical stability of antibodies to pathogenic antigens

Background: Serologic testing for antibodies against epitopes from pathogens is a valuable tool for investigating the relationship between infection and disease. This study comprehensively evaluates the impact of preanalytic variation on antibody seropositivities to a selected set of antigens arising from delays in processing of blood samples, preprocessing storage temperature, and vacutainer type. Methods: We assessed peripheral blood collected from 29 volunteers in four different Vacutainer types [ethylenediaminoetetraacetic acid (EDTA), acid-citrate-dextrose (ACD), lithium heparin (LH), serum separator tubes (SST)], and stored at 4°C or room temperature for 0, 1, 2, 3, 4, 5, and 6 days before processing. Multiplex serology was used to determine antibody reactivity against 35 antigens derived from human papillomaviruses, human polyomaviruses, Epstein- Barr virus, and Helicobacter pylori. Cohen's k statistic was used to measure agreement on seropositivity status between samples exposed to standard and nonstandard clinical practice conditions. Results: For samples processed without delay, k was not associated with storage-temperature (P value range 0.23 to 0.95) or vacutainer type (P value range, 0.35-0.89). Kappa did not significantly decline with increasing delays in processing for any vacutainer-type storage temperature combination (P slope range, 0.06-1.00). Conclusions: Antibodies to epitopes from various pathogenic infectious agents can be measured reliably from samples stored in SST, EDTA, ACD, or LH vacutainers at either room temperature or 4°C for up to 6 days before processing. Impact: Serologic testing is robust to several preanalytic options. These findings are particularly important for epidemiologic studies recruiting participants from remote settings where sample exposure to preanalytic conditions can vary considerably. Cancer Epidemiol Biomarkers Prev; 26(8); 1337-44

Early Life UV and Risk of Basal and Squamous Cell Carcinoma in New South Wales, Australia

Sun exposure is the main cause of squamous (SCC) and basal cell carcinoma (BCC) although pattern and amount differ by cancer type, and sun sensitivity is the major host risk factor. Our study investigated risk factors and residential ambient UV in a population‐based sample of Australian 45 and Up Study participants: 916 BCC cases, 433 SCC cases, 1224 controls. Unconditional logistic regression models adjusting for key covariates demonstrated 60% increased BCC risk and two‐fold increased SCC risk with sun sensitivity, and three‐ and four‐fold increased risk, respectively, with solar keratoses. BCC but not SCC risk increased with higher early‐life residential UV in all participants (odds ratio (OR) = 1.54; 95% CI 1.22–1.96 for intermediate; OR = 1.31; 95% CI 1.03–1.68 for high UV at birthplace) and similarly in Australian‐born participants (P‐values < 0.05). Risk of SCC but not BCC increased with long‐term cumulative sun exposure assessed by self‐reported outdoor work (OR 1.74, 95% CI 1.21–2.49). In conclusion, sun sensitivity is important for both cancers, early‐life UV but not cumulative UV appears to increase BCC risk, the former an apparently novel finding, and SCC risk appears only to be related to long‐term cumulative sun exposure

Risk factors for erectile dysfunction in a cohort of 108 477 Australian men

Objectives: To quantify relationships between erectile dysfunction (ED), ageing and health and lifestyle factors for men aged 45 years and older. Design: Cross-sectional, population-based study seeking data on health, sociodemographic and lifestyle facto