Cancer incidence in older adults in selected regions of sub-Saharan Africa, 2008-2012.

Although the countries of Sub-Sharan Africa represent among the most rapidly growing and aging populations worldwide, no previous studies have examined the cancer patterns in older adults in the region as a means to inform cancer policies. Using data from Cancer Incidence in Five Continents, we describe recent patterns and trends in incidence rates for the major cancer sites in adults aged ≥60 years and in people aged 0-59 for comparison in four selected population-based cancer registries in Kenya (Nairobi), the Republic of South Africa (Eastern Cape Province), Uganda (Kyadondo country), and Zimbabwe (Harare blacks). Over the period 2008-2012, almost 9,000 new cancer cases were registered in older adults in the four populations, representing one-third of all cancer cases. Prostate and esophageal cancers were the leading cancer sites in older males, while breast, cervical and esophageal cancers were the most common among older females. Among younger people, Kaposi sarcoma and non-Hodgkin lymphoma were common. Over the past 20 years, incidence rates among older adults have increased in both sexes in Uganda and Zimbabwe while rates have stabilized among the younger age group. Among older adults, the largest rate increase was observed for breast cancer (estimated annual percentage change: 5% in each country) in females and for prostate cancer (6-7%) in males. Due to the specific needs of older adults, tailored considerations should be given to geriatric oncology when developing, funding and implementing national and regional cancer programmes.

Cancer risks in Nairobi (2000-2014) by ethnic group.

We investigated the ethnic differences in the risk of several cancers in the population of Nairobi, Kenya, using data from the Nairobi Cancer Registry. The registry records the variable "Tribe" for each case, a categorisation that includes, as well as 22 tribal groups, categories for Kenyans of European and of Asian origin, and non-Kenyan Africans. Tribes included in the final analysis were Kikuyu, Kamba, Kisii, Kalenjin, Luo, Luhya, Somalis, Asians, non-Kenyans, Caucasians, Other tribes and unknown. The largest group was taken as the reference category for the calculation of odds ratios; this was African Kenyans (for comparisons by race), and Kikuyus (the tribe with the largest numbers of cancer registrations (38% of the total)) for comparisons between the Kenyan tribes. P-values are obtained from the Wald test. Cancers that were more common among the white population than in black Kenyans were skin cancers and cancers of the bladder, while cancers that are more common in Kenyan Asians include colorectal, lung, breast, ovary, corpus uteri and non-Hodgkin lymphoma. Cancers that were less common among Asians and Caucasians were oesophagus, stomach and cervix cancer. Within the African population, there were marked differences in cancer risk by tribe. Among the tribes of Bantu ethnicity, the Kamba had higher risks of melanoma, Kaposi sarcoma, liver and cervix cancer, and lower risks of oesophagus, stomach, corpus uteri and nervous system cancers. Luo and Luhya had much higher odds of Kaposi sarcoma and Burkitt lymphoma.

Cancer incidence in Cotonou (Benin), 2014-2016: First results from the cancer Registry of Cotonou.

Incidence data from the population cancer registry of Cotonou (Benin) for the three year period 2014-2016 are presented. 1086 cancer cases were recorded, 608 cases (56.0%) in women (corresponding to an age standardized incidence rate (ASR) of 78.4 per 100,000) and 478 cases (44.0%) in men (ASR 91.8 per 100,000). Breast and cervical cancer accounted for 49.2% of all cancers in women. Breast cancer (ASR 22.6 per 100,000) was more common than cervical cancer (ASR 14.9 per 100,000) and the mean age of cases was lower. The incidence of prostate cancer (one quarter of all cancers in men), 30.5 per 100,000, was similar to that in other West African registries. Cancers of the liver and digestive tract were also relatively common in both sexes. These are the first data on cancer incidence in Benin, and will be invaluable for the development and evaluation of the National Cancer Control plan.

A case-control study of cancer of the uterine cervix in Uganda.

As part of an epidemiological study of cancer in Uganda, we investigated social, sexual and reproductive factors in relation to the risk of cancer of the uterine cervix. Patients with all cancer types or with benign tumours were recruited from hospitals in Kampala, Uganda, interviewed about various demographic and lifestyle factors and tested for antibodies against the human immunodeficiency virus-1 (HIV). The case-control study reported here involves 702 HIV-seronegative women, 343 of whom were diagnosed with cancer of the uterine cervix. Key findings were that the risk of cervical cancer increased linearly with the number of pregnancies [chi2(1)=44.7; P<0.0001]; a woman reporting having had 10 or more children had a roughly seven-fold increase in risk of the tumour as compared with women reporting fewer than four pregnancies (odds ratio=7.1; 95% confidence interval 3.8-13.2). The risk also varied inversely with age at first reported sexual intercourse [chi2(1)=8.4; P=0.004], perhaps reflecting an earlier age of infection with human papillomavirus, the main causal agent. These results are in line with those reported from studies in other countries.

Cancer of childhood in sub-Saharan Africa.

Measurement of incidence rates of childhood cancer in Africa is difficult. The study 'Cancer of Childhood in sub Saharan Africa' brings together results from 16 population-based registries which, as members of the African Cancer Registry Network (AFCRN), have been evaluated as achieving adequate coverage of their target population. The cancers are classified according to the third revision of the International Classification of Childhood Cancer (ICCC-3) and recorded rates in Africa are compared with those in childhood populations in the UK, France, and the USA. It is clear that, in many centres, lack of adequate diagnostic and treatment facilities leads to under-diagnosis (and enumeration) of leukaemias and brain cancers. However, for several childhood cancers, incidence rates in Africa are higher than those in high-income countries. This applies to infection-related cancers such as Kaposi sarcoma, Burkitt lymphoma, Hodgkin lymphoma and hepatocellular carcinoma, and also to two common embryonal cancers - retinoblastoma and nephroblastoma. These (and other) observations are unlikely to be artefact, and are of considerable interest when considering possible aetiological factors, including ethnic differences in risk (and hence genetic/familial antecedents). The data reported are the most extensive so far available on the incidence of cancer in sub Saharan Africa, and clearly indicate the need for more resources to be devoted to cancer registration, especially in the childhood age range, as part of an overall programme to improve the availability of diagnosis and treatment of this group of cancers, many of which have-potentially-an excellent prognosis.

An evaluation of the oral cancer control program in Cuba.

The Cuban oral cancer screening program, functioning since 1984, requires all subjects of > or = 15 years to have an annual oral visual inspection by dentists. It covered 12-26% of the target population annually. Less than 30% of the subjects with suspect lesions complied with referral. The program identified 16% of the 4,412 incident oral cancers in Cuba during 1984-1990. The proportion of stage I cases increased from 24% in 1983 to 49% in 1990, although staging information was available only for half of the cases. There was no change in oral cancer incidence and mortality in Cuba over the last decade that could be ascribed to the screening program.