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.

Incidence of cancer in Nairobi, Kenya (2004-2008).

Cancer incidence rates are presented for the Nairobi Cancer Registry, a population-based cancer registry (PBCR) covering the population of the capital city of Kenya (3.2 million inhabitants in 2009). Case finding was by active methods, with standard and checks for accuracy and validity. During the period 2004-2008 a total of 8,982 cases were registered comprising 3,889 men (an age standardized incidence rate (ASR) of 161 per 100,000) and 5,093 women (ASR 231 per 1,00,000). Prostate cancer was the most common cancer in men (ASR 40.6 per 100,000) while breast cancer was the most common among women (ASR 51.7 per 100,000). Cervical cancer ranked the second most common cancer among women in Nairobi with an ASR of 46.1 per 100,000, somewhat lower than those of other registries in East Africa region. Breast and cervical cancers accounted for 44% of all cancers in women. Cancer of the oesophagus was common in both sexes, with a slight excess of cases in men (sex ratio 1.3). Unlike other regions in East Africa, the rate of Kaposi sarcoma was relatively low during the period (men 3.6/100,000; women 2.0/100,000). Although incidence rates cannot be calculated for the early years of the registry, the increase in relative frequency of prostate cancer and declines in frequency of Kaposi sarcoma may indicate underlying trends in the risk of these cancers.