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Chokunonga E.,Zimbabwe National Cancer Registry
IARC scientific publications | Year: 2011

The Zimbabwe national cancer registry was established in 1985 as a population-based cancer registry covering Harare city. Cancer is not a notifiable disease, and registration of cases is done by active methods. The registry contributed data on randomly drawn sub-samples of Harare resident cases among 17 common cancer sites or types registered during 1993-1997 from black and white populations. Follow-up was carried out predominantly by active methods with median follow-up ranging from 1-54 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged from 20-100%; death certificate only (DCO) cases comprised 0-34%; 58-97% of total registered cases were included for survival analysis. Complete follow-up at five years ranged from 94-100%. Five-year age-standardized relative survival rates of selected cancers among both races combined were cervix (42%), breast (68%), Kaposi sarcoma (4%), liver (3%), oesophagus (12%), stomach (20%) and lung (14%). Survival was markedly higher among white than black populations for most cancers with adequate cases. Five-year relative survival by age group was fluctuating, with no definite pattern or trend. Source

Cheng M.L.,University of California at San Francisco | Zhang L.,University of California at San Francisco | Borok M.,Zimbabwe National Cancer Registry | Chokunonga E.,Zimbabwe National Cancer Registry | And 6 more authors.
Cancer Epidemiology | Year: 2015

The incidence of oesophageal cancer (OC) varies geographically, with more than 80% of cases and deaths worldwide occurring in developing countries. The aim of this study is to characterize the disease burden of OC in four urban populations in Eastern Africa, which may represent a previously undescribed high-incidence area. Data on all cases of OC diagnosed between 2004 and 2008 were obtained from four population-based cancer registries in: Blantyre, Malawi; Harare, Zimbabwe; Kampala, Uganda; and Nairobi, Kenya. Age-standardized incidence rates (ASRs) were calculated for each population, and descriptive statistics for incident cases were determined. In Blantyre, 351 male (59%) and 239 (41%) female cases were reported, with ASRs of 47.2 and 30.3. In Harare, 213 male (61%) and 134 (39%) female cases were reported, with ASRs of 33.4 and 25.3, respectively. In Kampala, 196 male (59%) and 137 female (41%) cases were reported, with ASRs of 36.7 and 24.8. In Nairobi, 323 male (57%) and 239 female (43%) cases were reported, with ASRs of 22.6 and 21.6. Median age at diagnosis was significantly different among the four populations, ranging from 50 years in Blantyre to 65 years in Harare (. p<. 0.0001). Except in Nairobi, incidence among males was significantly higher than among females (. p<. 0.01). Squamous cell OC was the predominant histologic subtype at all sites. ASRs at all four sites were remarkably higher than the mean worldwide ASR. Investigation to evaluate potential etiologic effects of dietary, lifestyle, environmental, and other factors impacting the incidence in this region is needed. © 2015 Elsevier Ltd. Source

Chokunonga E.,Zimbabwe National Cancer Registry | Windridge P.,Wolfson Institute of Preventive Medicine | Sasieni P.,Wolfson Institute of Preventive Medicine | Borok M.,Zimbabwe National Cancer Registry | Parkin D.M.,Wolfson Institute of Preventive Medicine
International Journal of Cancer | Year: 2016

Data from 20 years of cancer registration in Harare (Zimbabwe) are used to investigate the risk of cancer in the white population of the city (of European origin), relative to that in blacks (of African origin). In the absence of information on the respective populations-at-risk, we calculated odds of each major cancer among all cancers, and took the odds ratios of whites to blacks. Some major differences reflect obvious phenotypic differences (the very high incidence of skin cancer - melanoma and nonmelanoma - in the white population), whereas others (high rates of liver cancer, Kaposi sarcoma and conjunctival cancers in blacks) are the result of differences in exposure to infectious agents. Of particular interest are cancers related to lifestyle factors, and how the differences in risk are changing over time, as a result of evolving lifestyles. Thus, the high risk of cancers of the esophagus and cervix uteri in blacks (relative to whites) and colorectal cancers in whites show little change over time. Conversely, the odds of breast cancer, on average four times higher in whites than blacks, has shown a significant decrease in the differential over time. Cancer of the prostate, with the odds initially (1991-1997) 15% higher in whites had become 33% higher in blacks by 2004-2010. What's new? The risk of cancer frequently varies between ethnic groups, raising the question of how much those variations are due to inherent genetic differences versus environmental exposures. In this comparison of cancer risk among whites and blacks in Harare, Zimbabwe, over the period 1991-2010, both obvious and relatively obscure risk variations were identified. Prominent among the latter were changes in risk differential for certain cancers, including breast cancer, the incidence of which is rising in the black population. Changes in cancer risk differential likely are due in part to shifting lifestyle trends among white and black populations in Harare. © 2015 UICC. Source

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