The National Cancer Registry of South Africa, which publishes pathology-based cancer incidence data, was first established in 1986. Some 36,000 new cases were recorded in South Africa that year, and the National Cancer Registry currently receives information about 60,000 new cases annually. The main objective of the Registry is to monitor cancer burden in South Africa and report cancer incidence for each year, stratified by sex, age, and population group, as well as time trends over the past 20 years.
Programs to control cancer need to be evaluated using accurate information on incidence, prevalence, and cancer patterns in different parts of the country. These parameters vary widely as a result of differences in access to health care, sociodemographics, lifestyle, and environmental factors.
Most currently available information on cancer incidence is derived from developed countries. With the technical assistance of the International Agency for Research on Cancer, the number of cancer registries in Africa has recently increased. The major challenge facing cancer registries in developing countries is the implementation of World Health Organization-recommended, population-based cancer registries, to obtain accurate data that will better inform government policy. An added challenge is the need to overcome financial constraints and limitations imposed by a lack of trained personnel, to ensure long-term sustainability.
South African Data
South Africa has a land area of 1.2 million km2, with the latest National Census (1996) estimating a population of 42 million inhabitants (75% black, 14% white, 8.6% mixed race, 2.4% Asian).
Cancer remains a major killer throughout the developed and developing world, including South Africa. Cancer incidence rates in South Africa are among the highest reported in Africa. According to the latest 2002 data from the National Cancer Registry, South African males have an overall age standardized incidence rate of cancer of 135.89 per 100,000 and a lifetime risk of developing cancer of 1 in 7, whereas South African females have an age standardized incidence rate of 115.53 per 100,000 and an lifetime risk of developing cancer of 1 in 8.
In 2002, 28,126 males developed cancer; cancers of the prostate (1 in 23), unknown primary site (1 in 64), lung (1 in 71), esophagus (1 in 91), colon/rectum (1 in 99), and bladder (1 in 109) predominated. The same year, 28,430 women were diagnosed with cancer, with cancer of the breast (1 in 29) and cancer of the uterine cervix (1 in 36) predominating; cancers of an unknown primary site (1 in 91), corpus uteri (1 in 148), colon/rectum (1 in 158), and esophagus (1 in 199) followed.
Toward A More Accurate Picture
In South Africa, lung cancer remains a growing health problem in both sexes. Although lung cancer risk in males (lifetime risk of 1 in 71) far exceeds that in females (lifetime risk of 1 in 233), the long-term effects of smoking will result in increasing incidence of lung cancer in females as well as males for years to come. It will be decades before recent antismoking drives and legislation will reduce these figures.
Some cancers are suboptimally reported because of a lack of tissue diagnoses. An important example is hepatocellular carcinoma, which is diagnosed clinically and by blood tests (alpha-fetoprotein)—without tissue diagnosis—but still remains among the top 15 most common cancers. Approximately 700,000 new cases yearly are diagnosed worldwide, especially in southern Africa and the Far East, which are endemic for hepatitis B virus. Future population-based registries, as well as better cancer diagnoses, especially in rural areas, will give us a more accurate picture of this usually fatal malignancy, as well as other pathologically underdiagnosed cancers.
In considering cancers associated with HIV/AIDS, Kaposi’s sarcoma was the third most common cancer in South African males and females aged 15 to 29 years, comprising approximately 9% of all cancers in this group. Contrary to most cancers where the age standardized incidence rate peaks at older ages, the rate for Kaposi’s sarcoma showed a bimodal pattern in most racial groups, with the highest peaks at ages 25 to 29 in women and 35 to 39 in men.
Conclusions
Monitoring cancer incidence is important in detecting changes in cancer patterns that might occur as a result of environmental conditions or in association with other diseases (for example, HIV/AIDS). Such records are also essential for the detection of new cancers, and to measure effectiveness of cancer control programs.
Future legislation in South Africa will make cancer a reportable disease by both pathologists and clinicians, enhancing the existing pathology-based registry while developing population-based registries. ■
Financial Disclosure: Dr. Vorobiof and Dr. Ruff reported no potential conflicts of interest.
Dr. Vorobiof is Oncology Director of the Sandton Oncology Centre, Johannesburg, South Africa, and a member of The ASCO Post’s International Editorial Board. Dr. Ruff is Professor of Medical Oncology at the University of the Witwatersrand, Faculty of Health Sciences, Johannesburg.
