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

    3 July 2018

    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.

  • Cervical cancer.

    3 July 2018

    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.

  • Screening for cervical cancer: is there a place for incorporating tests for the human papillomavirus?

    3 July 2018

    Well organized screening programmes for cervical cancer, based on exfoliative cervical cytology, are known to be effective at reducing the incidence of invasive cervical cancer and mortality from the disease. HPV testing should not replace cervical cytology as the first-line approach in screening for cervical cancer, as HPV testing is not sufficiently reliable and some cancers are not associated with HPV infection. Even though there are many unanswered questions about the validity of HPV tests, it is timely to consider whether HPV testing might improve the management of the substantial number of women whose smears are neither clearly normal nor abnormal, but are described as atypical, suspicious or mildly dyskaryotic. The efficacy and costs of incorporating HPV testing into a cervical cancer screening programme need to be evaluated in controlled trials.

  • Sex hormones and cancer.

    3 July 2018

    There are few instances in which a clear effect of hormones on cancer risk is known and in which the effects of those hormones on the cells concerned are also known. The best examples are the relationships between sex hormones and cancer in women. The effects of sex hormones both on the risk for endometrial cancer and on the cells of the endometrium are well understood, and the evidence strongly suggests that hormones act by altering the rate of cell division. The same mechanism may explain the relationships between sex hormones and the risk for breast cancer, but our understanding of cancers at this site is incomplete. Less still is known about the mechanisms of the effects of sex hormones on other hormone-related cancers, such as those of the ovary and cervix. Most sex hormones are not genotoxic.

  • Epidemiology of Kaposi's sarcoma.

    3 July 2018

    The AIDS epidemic drew attention to KS, a previously rare and little studied condition. The epidemiological evidence summarized here strongly suggests that the disease is caused by a transmissible agent, in addition to HIV. Sexual contact is the most important mode of transmission of the agent, although transmission by blood and perinatally may also occur (Beral et al, 1990).