Addis Ababa Cancer Registry (AACR) has collected data on the population of Addis Ababa City Administration. The population is entirely urban, but with diverse ethnic and religious composition. In Addis Ababa, cancer care is provided in three major hospitals,and twelve private facilities. In most cases, a cancer diagnosis was confirmed through pathologic examination of a biopsy specimen, whereas in others it was through clinical, laboratory and imaging modalities. TASH provides the bulk of cancer care, both for Addis Ababa residents and nationally. Albeit provision of care in public hospitals and private facilities is irrespective of geographic location, the AACR unit collects data on patients with cancer only for residents of the city. In the computation of incidence, only patients with cancer from Addis Ababa were inclu

The AACR unit has three full-time employees and has trained 20 contact persons in each health institution delivering cancer diagnostic/treatment services. The contact persons collect data on patients with cancer (for all ages) daily from inpatient and outpatient departments, including pathology units, using a standardized format developed by the International Agency for Research on Cancer.8 Cases identified in each unit are reported weekly to the AACR unit. AACR staff regularly supervises the contact persons to make sure all cases are registered and to verify data quality. When the contact persons leave the facility, AACR staff provides training to a substitute contact person. Duplicate entries are identified and corrected based on demographic data and patient phone number. On the basis of the topography (site of origin of a cancer) and tumor morphology (type of cancerous cell), each case was coded into a coding schema from the full International Classification of Diseases for Oncology, 3rd edition (ICD-O-3).8 Once a data set had been converted into ICD-O-3, it was checked for consistency by code verification (sex and ICD-O-3 topography and morphology) and consistency between items (age v incidence dates, sex v site, sex v histology, age v site, site vhistology). The registry uses CanReg5 system for data entry, analysis, quality control, and management. Completeness and Data Quality

In assessing cancer incidence, completeness of registration (the extent to which all incident cases in the population are included in the registry) is a vital factor. We assessed completeness using the following indices: stability of incidence rates over time, proportion of cases microscopically verified, and proportion of unknown basis of diagnosis. We could not use mortality-to-incidence ratios, because accurate data on cancer mortality were lacking.Crude and Age-Standardized Incidence Rates

We calculated incidence of a specific cancer by 5-year age category and sex. The crude incidence rate (CIR) is the rate at which new cases occur in a population during a specific period. CIR is classically expressed as the average number of cases occurring per 100,000 population. It relates to each population as a whole and is influenced by the age structure of each population.

The age-standardized incidence rate (ASIR) is a summary of the individual age-specific rates using an external population called a standard population. This is the incidence that would be observed if the population had the age structure of the standard population and corresponds to the CIR in the standard population. Similar to CIR, ASIR is expressed as the number of new cases per 100,000 population (details are provided in the Data Supplement). We used the 1960 world population for age standardization.Data on the population distribution of Ethiopia and Addis Ababa were obtained from the United Nations Population Division and the Central Statistics Agency of Ethiopia. We estimated, nationally, the expected number of cases and the corresponding 95% CIs on the basis of the average incidence for each specific cancer over the 4-year period 2015 to 2018 from AACR data. Using data available for breast cancer cases only, we also assessed stage of the disease at the initial presentation.

Over the 2013 to 2018 period, 5,920 and 2,619 cancer cases were identified in women and men, respectively; 275 were pediatric cancer cases. Of 8,539 total cases, 89% were microscopically verified (cytology/histology examination), and 11% were verified by clinical and other laboratory investigations. None of the cases had an unknown basis of diagnosis. Comparison of incidence rates for the five commonest tumors in women and men is presented in the Data Supplement.

Source : W.H.O for East-Africa


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