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  • The spectrum of HIV-1 related cancers in South Africa.

    16 October 2018

    Despite the high prevalence of infection by the Human Immunodeficiency Virus (HIV) in South Africa, information on its association with cancer is sparse. Our study was carried out to examine the relationship between HIV and a number of cancer types or sites that are common in South Africa. A total of 4,883 subjects, presenting with a cancer or cardiovascular disease at the 3 tertiary referral hospitals in Johannesburg, were interviewed and had blood tested for HIV. Odds ratios associated with HIV infection were calculated by using unconditional logistic regression models for 16 major cancer types where data was available for 50 or more patients. In the comparison group, the prevalence of HIV infection was 8.3% in males and 9.1% in females. Significant excess risks associated with HIV infection were found for Kaposi's sarcoma (OR=21.9, 95% CI=12.5-38.6), non-Hodgkin lymphoma (OR=5.0, 95%CI=2.7-9.5), vulval cancer (OR=4.8, 95%CI= 1.9-12.2) and cervical cancer (OR= 1.6, 95%CI= 1.1-2.3) but not for any of the other major cancer types examined, including Hodgkin disease, multiple myeloma and lung cancer. In Johannesburg, South Africa, HIV infection was associated with significantly increased risks of Kaposi's sarcoma, non-Hodgkin lymphoma and cancers of the cervix and the vulva. The relative risks for Kaposi's sarcoma and non-Hodgkin lymphoma associated with HIV infection were substantially lower than those found in the West.

  • Hormone replacement therapy and incidence of central nervous system tumours in the Million Women Study.

    16 October 2018

    We examined the relation between the use of hormone replacement therapy (HRT) and the incidence of central nervous system (CNS) tumours in a large prospective study of 1,147,894 postmenopausal women. Women were aged 56.6 years on average at entry, and HRT use was recorded at recruitment and updated, where possible, about 3 years later. During a mean follow-up of 5.3 years per woman, 1,266 CNS tumours were diagnosed, including 557 gliomas, 311 meningiomas and 117 acoustic neuromas. Compared with never users of HRT, the relative risks (RRs) for all incident CNS tumours, gliomas, meningiomas and acoustic neuromas in current users of HRT were 1.20 (95% CI: 1.05-1.36), 1.09 (95% CI: 0.89-1.32), 1.34 (95% CI: 1.03-1.75) and 1.58 (95% CI: 1.02-2.45), respectively, and there was no significant difference in the relative risks by tumour type (heterogeneity p = 0.2). In past users of HRT the relative risk was 1.07 (95% CI: 0.93-1.24) for all CNS tumours. Among current users of HRT, there was significant heterogeneity by the type of HRT with the users of oestrogen-only HRT at higher risk of all CNS tumours than users of oestrogen-progestagen HRT (RR = 1.42, 95% CI: 1.21-1.67 versus RR = 0.97, 95% CI: 0.82-1.16) (heterogeneity p < 0.001). Among current users of oestrogen-only and oestrogen-progestagen HRT, there was no significant heterogeneity by duration of use, hormonal constituent or mode of administration of HRT.

  • Is the time from HIV seroconversion a determinant of the risk of AIDS after adjustment for updated CD4 cell counts?

    16 October 2018

    OBJECTIVE: To evaluate the effect of time from seroconversion to a given CD4 cell count on progression to AIDS after that count after adjusting for updated CD4 cell counts. METHODS: Using pooled data from 19 seroconverter cohorts, we examined the association between the time from a CD4 <500 cells/mm 3, (<350, <200) to the first AIDS-defining event and time from seroconversion to that CD4 threshold. We adjusted for age, gender, exposure category, and HIV test interval in Cox models stratified by cohort. We estimated the residual effect of time from seroconversion, adjusting for updated CD4 cell counts. A cause-specific competing-risks model was then used to evaluate this residual effect on progression to each AIDS-defining disease. Analyses were censored on December 31, 1995. RESULTS: Of 3825, 3006, and 1804 individuals reaching CD4 thresholds of 500, 350, and 200, respectively, 1274, 1192, and 985, respectively, developed AIDS. We found a significant effect of time from seroconversion on the risk of AIDS even after adjusting for updated CD4 counts. For individuals reaching a CD4 threshold of 350 cells/mm 3, a 1-year increase from seroconversion was associated with an increase in risk of AIDS of 6% (3%-9%) ( p =.01). This effect appeared to be nonlinear. In the first 4 years, a 1-year increase from seroconversion was associated with an 11% increase in the risk of AIDS, but there was no apparent increase in risk after 4 years. The residual effect of time from seroconversion was significantly heterogeneous ( p =.002), with respect to the risk of individual AIDS-defining diseases. Findings were similar for CD4 thresholds of 500 and 200 cells/mm 3, respectively. CONCLUSIONS: We found a small, statistically significant, residual effect of time from seroconversion on the risk of AIDS. In practical terms, when considering an infected individual's risk of AIDS from a given CD4 cell count, there is little to be gained from knowing the time of seroconversion. However, this effect differs significantly among specific AIDS-defining diseases.

  • Oral bisphosphonates and risk of cancer of oesophagus, stomach, and colorectum: case-control analysis within a UK primary care cohort.

    16 October 2018

    OBJECTIVE: To examine the hypothesis that risk of oesophageal, but not of gastric or colorectal, cancer is increased in users of oral bisphosphonates. DESIGN: Nested case-control analysis within a primary care cohort of about 6 million people in the UK, with prospectively recorded information on prescribing of bisphosphonates. SETTING: UK General Practice Research Database cohort. PARTICIPANTS: Men and women aged 40 years or over-2954 with oesophageal cancer, 2018 with gastric cancer, and 10 641 with colorectal cancer, diagnosed in 1995-2005; five controls per case matched for age, sex, general practice, and observation time. MAIN OUTCOME MEASURES: Relative risks for incident invasive cancers of the oesophagus, stomach, and colorectum, adjusted for smoking, alcohol, and body mass index. RESULTS: The incidence of oesophageal cancer was increased in people with one or more previous prescriptions for oral bisphosphonates compared with those with no such prescriptions (relative risk 1.30, 95% confidence interval 1.02 to1.66; P=0.02). Risk of oesophageal cancer was significantly higher for 10 or more prescriptions (1.93, 1.37 to 2.70) than for one to nine prescriptions (0.93, 0.66 to 1.31) (P for heterogeneity=0.002), and for use for over 3 years (on average, about 5 years: relative risk v no prescription, 2.24, 1.47 to 3.43). Risk of oesophageal cancer did not differ significantly by bisphosphonate type, and risk in those with 10 or more bisphosphonate prescriptions did not vary by age, sex, smoking, alcohol intake, or body mass index; by diagnosis of osteoporosis, fracture, or upper gastrointestinal disease; or by prescription of acid suppressants, non-steroidal anti-inflammatory drugs, or corticosteroids. Cancers of the stomach and colorectum were not associated with prescription of bisphosphonate: relative risks for one or more versus no prescriptions were 0.87 (0.64 to 1.19) and 0.87 (0.77 to 1.00). The specificity of the association for oesophageal cancer argues against methodological problems in the selection of cases and controls or in the analysis. CONCLUSIONS: The risk of oesophageal cancer increased with 10 or more prescriptions for oral bisphosphonates and with prescriptions over about a five year period. In Europe and North America, the incidence of oesophageal cancer at age 60-79 is typically 1 per 1000 population over five years, and this is estimated to increase to about 2 per 1000 with five years' use of oral bisphosphonates.

  • Cervical carcinoma and reproductive factors: collaborative reanalysis of individual data on 16,563 women with cervical carcinoma and 33,542 women without cervical carcinoma from 25 epidemiological studies.

    16 October 2018

    The International Collaboration of Epidemiological Studies of Cervical Cancer has combined individual data on 11,161 women with invasive carcinoma, 5,402 women with cervical intraepithelial neoplasia (CIN)3/carcinoma in situ and 33,542 women without cervical carcinoma from 25 epidemiological studies. Relative risks (RRs) and 95% confidence intervals (CIs) of cervical carcinoma in relation to number of full-term pregnancies, and age at first full-term pregnancy, were calculated conditioning by study, age, lifetime number of sexual partners and age at first sexual intercourse. Number of full-term pregnancies was associated with a risk of invasive cervical carcinoma. After controlling for age at first full-term pregnancy, the RR for invasive cervical carcinoma among parous women was 1.76 (95% CI: 1.53-2.02) for > or => or =7 full-term pregnancies compared with 1-2. For CIN3/carcinoma in situ, no significant trend was found with increasing number of births after controlling for age at first full-term pregnancy among parous women. Early age at first full-term pregnancy was also associated with risk of both invasive cervical carcinoma and CIN3/carcinoma in situ. After controlling for number of full-term pregnancies, the RR for first full-term pregnancy at age <17 years compared with > or => or =25 years was 1.77 (95% CI: 1.42-2.23) for invasive cervical carcinoma, and 1.78 (95% CI: 1.26-2.51) for CIN3/carcinoma in situ. Results were similar in analyses restricted to high-risk human papilloma virus (HPV)-positive cases and controls. No relationship was found between cervical HPV positivity and number of full-term pregnancies, or age at first full-term pregnancy among controls. Differences in reproductive habits may have contributed to differences in cervical cancer incidence between developed and developing countries.