Trends in the incidence of colorectal cancer in sub-Saharan Africa: A population-based registry study.

In sub-Saharan Africa, colorectal cancer (CRC) has historically been considered a rare disease, although some previous studies have suggested that the incidence is increasing. We examine time trends in the incidence of CRC using data from 12 population-based cancer registries in 11 countries of sub-Saharan Africa that were able to provide time series data for periods of 12 or more years, or with earlier data with which recent rates may be compared. Age-standardized incidence rates were highest in the higher-income countries, and were increasing in all of the populations studied, and these increases were statistically significant in all but three. Current evidence has suggested a link between the increased adoption of western lifestyle habits with colorectal cancer, and along with increasing urbanization of African populations, there is an increase in body weight, as well as evidence of increasing consumption of meat, sugars, and alcohol.

Trends in the incidence of ovarian cancer in sub-Saharan Africa.

Ovarian cancer (OC) is one of the commonest cancers of women in sub-Saharan Africa (SSA), although to date no data have been available on time trends in incidence to better understand the disease pattern in the region. We estimate time trends by histological subtype from 12 population-based cancer registries in 11 countries: Kenya (Nairobi), Mauritius, Seychelles, Uganda (Kampala), Congo (Brazzaville), Zimbabwe (Bulawayo and Harare), Cote d'Ivoire (Abidjan), The Gambia, Mali (Bamako), Nigeria (Ibadan) and South Africa (Eastern Cape). The selected registries were those that could provide consistent estimates of the incidence of ovarian cancer and with quality assessment for periods of 10 or more years. A total of 5423 cases of OC were included. Incidence rates have been increasing in all registries except Brazzaville, Congo, where a nonsignificant decline of 1% per year was seen. Statistically significant average annual increases were seen in Mauritius (2.5%), Bamako (5.3%), Ibadan (3.9%) and Eastern Cape (8%). Epithelial ovarian cancer was responsible for the increases observed in all registries. Statistically significant average annual percentage changes (AAPC) for epithelial OC were present in Bamako (AAPC = 5.9%), Ibadan (AAPC = 4.7%) and Eastern Cape (AAPC = 11.0%). Creating awareness among professionals of the growing importance of the disease is surely an important step to improving availability of, and access to, diagnosis and treatment of OC in SSA. Support must be given to the cancer registries to improve the availability of good-quality data on this important cancer.

Colorectal cancer survival in sub-Saharan Africa by age, stage at diagnosis and Human Development Index: A population-based registry study.

There are limited population-based survival data for colorectal cancer (CRC) in sub-Saharan Africa. Here, 1707 persons diagnosed with CRC from 2005 to 2015 were randomly selected from 13 population-based cancer registries operating in 11 countries in sub-Saharan Africa. Vital status was ascertained from medical charts or through next of kin. 1-, 3- and 5-year overall and relative survival rates for all registries and for each registry were calculated using the Kaplan-Meier estimator. Multivariable analysis was used to examine the associations of 5-year relative survival with age at diagnosis, stage and country-level Human Development Index (HDI). Observed survival for 1448 patients with CRC across all registries combined was 72.0% (95% CI 69.5-74.4%) at 1 year, 50.4% (95% CI 47.6-53.2%) at 3 years and 43.5% (95% CI 40.6-46.3%) at 5 years. We estimate that relative survival at 5 years in these registry populations is 48.2%. Factors associated with poorer survival included living in a country with lower HDI, late stage at diagnosis and younger or older age at diagnosis (<50 or ≥70 years). For example, the risk of death was 1.6 (95% CI 1.2-2.1) times higher for patients residing in medium-HDI and 2.7 (95% CI 2.2-3.4) times higher for patients residing in low-HDI compared to those residing in high-HDI countries. Survival for CRC remains low in sub-Saharan African countries, though estimates vary considerably by HDI. Strengthening health systems to ensure access to prevention, early diagnosis and appropriate treatment is critical in improving outcomes of CRC in the region.

Changes in the Incidence of Cancer in Bulawayo, Zimbabwe over a 50-Year Period.

BACKGROUND: The cancer registry of Bulawayo (Zimbabwe) operated for 15 years in the preindependence period (1963-77), and was restarted in 2011. This allows comparison of incidence of cancers over a period of almost 50 years. METHODS: Age-standardized rates, with SEs, were calculated for 1963-1972 and 2011-2015. Detailed results are presented for those cancers for which there was a significant (P < 0.05) change in the rates between the two periods. RESULTS: There were declines in the rates of those cancers previously known to be common in East and Southern Africa (esophagus, liver, bladder), and the emergence of cancers associated with "westernization" of lifestyles (breast, prostate, large bowel). Cancers related to infection with HIV-AIDS (Kaposi sarcoma, non-Hodgkin lymphoma, eye cancers) have come to comprise a much larger proportion of the total burden, and cancer of the cervix (also AIDS-related) has shown a large increase in incidence-as elsewhere in sub-Saharan Africa (SSA). More surprising is the decline in cancer of the lung-formerly very high, but by 2011-2015, despite little change in the prevalence of smoking, rates were low-close to the average for SSA. This may relate, in part, to a decline in the numbers of miners, and ex-miners, residing in the city. CONCLUSIONS: The changes in incidence are largely explained by differences in past exposure to environmental risk factors. IMPACT: Few datasets from SSA can document temporal changes in the cancer epidemic on the continent. There are some anticipated observations, as well as unexpected findings meriting further investigation.

Cervical cancer survival in sub-Saharan Africa by age, stage at diagnosis and Human Development Index: A population-based registry study.

Cervical cancer is the leading cause of cancer death in African women. We sought to estimate population-based survival and evaluate excess hazards for mortality in African women with cervical cancer, examining the effects of country-level Human Development Index (HDI), age and stage at diagnosis. We selected a random sample of 2760 incident cervical cancer cases, diagnosed in 2005 to 2015 from 13 population-based cancer registries in 11 countries (Benin, Cote d'Ivoire, Ethiopia, Kenya, Mauritius, Mozambique, Namibia, Seychelles, South Africa, Uganda and Zimbabwe) through the African Cancer Registry Network. Of these, 2735 were included for survival analyses. The 1-, 3- and 5-year observed and relative survival were estimated by registry, stage and country-level HDI. We used flexible Poisson regression models to estimate the excess hazards for death adjusting for age, stage and HDI. Among patients with known stage, 65.8% were diagnosed with Stage III-IV disease. The 5-year relative survival for Stage I-II cervical cancer in high HDI registry areas was 67.5% (42.1-83.6) while it was much lower (42.2% [30.6-53.2]) for low HDI registry areas. Independent predictors of mortality were Stage III-IV disease, medium to low country-level HDI and age >65 years at cervical cancer diagnosis. The average relative survival from cervix cancer in the 11 countries was 69.8%, 44.5% and 33.1% at 1, 3 and 5 years, respectively. Factors contributing to the HDI (such as education and a country's financial resources) are critical for cervical cancer control in SSA and there is need to strengthen health systems with timely and appropriate prevention and treatment programmes.

Breast cancer survival in sub-Saharan Africa by age, stage at diagnosis and human development index: A population-based registry study.

Breast cancer is the leading cancer diagnosis and second most common cause of cancer deaths in sub-Saharan Africa (SSA). Yet, there are few population-level survival data from Africa and none on the survival differences by stage at diagnosis. Here, we estimate breast cancer survival within SSA by area, stage and country-level human development index (HDI). We obtained data on a random sample of 2,588 breast cancer incident cases, diagnosed in 2008-2015 from 14 population-based cancer registries in 12 countries (Benin, Cote d'Ivoire, Ethiopia, Kenya, Mali, Mauritius, Mozambique, Namibia, Seychelles, South Africa, Uganda and Zimbabwe) through the African Cancer Registry Network. Of these, 2,311 were included for survival analyses. The 1-, 3- and 5-year observed and relative survival (RS) were estimated by registry, stage and country-level HDI. We equally estimated the excess hazards adjusting for potential confounders. Among patients with known stage, 64.9% were diagnosed in late stages, with 18.4% being metastatic at diagnosis. The RS varied by registry, ranging from 21.6%(8.2-39.8) at Year 3 in Bulawayo to 84.5% (70.6-93.5) in Namibia. Patients diagnosed at early stages had a 3-year RS of 78% (71.6-83.3) in contrast to 40.3% (34.9-45.7) at advanced stages (III and IV). The overall RS at Year 1 was 86.1% (84.4-87.6), 65.8% (63.5-68.1) at Year 3 and 59.0% (56.3-61.6) at Year 5. Age at diagnosis was not independently associated with increased mortality risk after adjusting for the effect of stage and country-level HDI. In conclusion, downstaging breast cancer at diagnosis and improving access to quality care could be pivotal in improving breast cancer survival outcomes in Africa.