Cancer in sub-Saharan Africa in 2020: a review of current estimates of the national burden, data gaps, and future needs.

BACKGROUND: With the cancer burden rising in sub-Saharan Africa, countries in the region need surveillance systems to measure the magnitude of the problem and monitor progress in cancer control planning. Based on the national estimates built from data provided by cancer registries in sub-Saharan Africa, we summarise key patterns of the regional burden and argue for investments in locally produced data. METHODS: To present national estimates of the cancer incidence and mortality burden in sub-Saharan Africa countries, new cancer cases and deaths were extracted from International Agency for Research on Cancers' GLOBOCAN database for the year 2020. Given weak vital statistics systems, almost all of the information on the cancer burden in sub-Saharan Africa was derived from population-based cancer registries. Of the 48 countries included in GLOBOCAN (national populations must be larger than 150 000 inhabitants in 2020), relatively recent cancer registry data (up to 2019) were directly used to produce national incidence estimates in 25 countries, while the absence of such data for 16 meant that estimates were based on data from neighbouring countries. Tables and figures present the estimated numbers of new cases and deaths, as well as age-standardised (incidence or mortality) rates per 100 000 person-years and the cumulative risk of developing or dying from cancer before the age of 75 years. FINDINGS: 801 392 new cancer cases and 520 158 cancer deaths were estimated to have occurred in sub-Saharan Africa in 2020. Cancers of the breast (129 400 female cases) and cervix (110 300 cases) were responsible for three in ten of the cancers diagnosed in both sexes. Breast and cervical cancer were the most common cancers, ranking first in 28 and 19 countries, respectively. In men, prostate cancer led in terms of incidence (77 300 cases), followed by liver cancer (24 700 cases) and colorectal cancer (23 400 cases). Prostate cancer was the leading incident cancer in men in 40 sub-Saharan Africa countries. The risk of a woman in sub-Saharan Africa developing cancer by the age of 75 years was 14·1%, with breast cancer (4·1%) and cervical cancer (3·5%) responsible for half of this risk. For men, the corresponding cumulative incidence was lower (12·2%), with prostate cancer responsible for a third of this risk (4·2%). Cervical cancer was the leading form of cancer death among women in 27 countries, followed by breast cancer (21 countries). Prostate cancer led as the most common type of cancer death in 26 countries, with liver cancer ranking second (11 countries). INTERPRETATION: The estimates indicate substantial geographical variations in the major cancers in sub-Saharan Africa. Rational cancer control planning requires capacity to be built for data production, analysis, and interpretation within the countries themselves. Cancer registries provide important information in this respect and should be prioritised for sustainable investment in the region. FUNDING: None.

Five ways to improve international comparisons of cancer survival: lessons learned from ICBP SURVMARK-2.

BACKGROUND: Comparisons of population-based cancer survival between countries are important to benchmark the overall effectiveness of cancer management. The International Cancer Benchmarking Partnership (ICBP) Survmark-2 study aims to compare survival in seven high-income countries across eight cancer sites and explore reasons for the observed differences. A critical aspect in ensuring comparability in the reported survival estimates are similarities in practice across cancer registries. While ICBP Survmark-2 has shown these differences are unlikely to explain the observed differences in cancer-specific survival between countries, it is important to keep in mind potential biases linked to registry practice and understand their likely impact. METHODS: Based on experiences gained within ICBP Survmark-2, we have developed a set of recommendations that seek to optimally harmonise cancer registry datasets to improve future benchmarking exercises. RESULTS: Our recommendations stem from considering the impact on cancer survival estimates in five key areas: (1) the completeness of the registry and the availability of registration sources; (2) the inclusion of death certification as a source of identifying cases; (3) the specification of the date of incidence; (4) the approach to handling multiple primary tumours and (5) the quality of linkage of cases to the deaths register. CONCLUSION: These recommendations seek to improve comparability whilst maintaining the opportunity to understand and act upon international variations in outcomes among cancer patients.

Population-based cancer staging for oesophageal, gastric, and pancreatic cancer 2012-2014: International Cancer Benchmarking Partnership SurvMark-2.

Cancer stage at diagnosis is important information for management and treatment of individual patients as well as in epidemiological studies to evaluate effectiveness of health care system in managing cancer patients. Population-based studies to examine international disparities on cancer survival by stage, however, has been challenging due to the lack of international standardization on recording stage information and variation in stage completeness across regions and countries. The International Cancer Benchmarking Partnership (ICBP) previously assessed the availability and comparability of staging information for colorectal, lung, female breast and ovarian cancers. Stage conversion algorithms were developed to aggregate and map all stage information into a single staging system to allow international comparison by stage at diagnosis. In this article, we developed stage conversion algorithms for three additional cancers, namely oesophageal, gastric and pancreatic cancers. We examined all stage information available, evaluated stage completeness, applied each stage conversion algorithm, and assessed the magnitude of misclassification using data from six Canadian cancer registries (Alberta, Manitoba, Newfoundland, Nova Scotia, Prince Edward Island and Saskatchewan). In addition, we discussed five recommendations for registries to improve international cancer survival comparison by stage: (a) improve collection and completeness of staging data; (b) promote a comparable definition for stage at diagnosis; (c) promote the use of a common stage classification system; (d) record versions of staging classifications and (e) use multiple data sources for valid staging data.

Essential TNM: a registry tool to reduce gaps in cancer staging information.

Accurate information on the extent of disease around the time of diagnosis is an important component of cancer care, in defining disease prognosis, and evaluating national and international cancer control policies. However, the collection of stage data by population-based cancer registries remains a challenge in both high-income and low and middle-income countries. We emphasise the lack of availability and comparability of staging information in many population-based cancer registries and propose Essential TNM, a simplified staging system for cancer registries when information on full Tumour, Node, Metastasis (TNM) is absent. Essential TNM aims at staging cancer in its most advanced disease form by summarising the extent of disease in the order of distant metastasis (M), regional lymph node involvement (N), and tumour size or extension, or both (T). Flowcharts and rules have been developed for coding these elements in breast, cervix, prostate, and colon cancers, and combining them into stage groups (I-IV) that correspond to those obtained by full TNM staging. Essential TNM is comparable to the Union for International Cancer Control TNM stage groups and is an alternative to providing staging information by the population-based cancer registries that complies with the objectives of the Global Initiative for Cancer Registry Development.

Survival from childhood cancers in Eastern Africa: A population-based registry study.

Cancers occurring in children in Africa are often underdiagnosed, or at best diagnosed late. As a result, survival is poor, even for cancers considered 'curable'. With limited population-level data, understanding the actual burden and survival from childhood cancers in Africa is difficult. In this study, we aimed at providing survival estimates for the most common types of cancers affecting children aged 0-14 years, in three population-based Eastern African registries; Harare, Zimbabwe (Kaposi sarcoma, Wilms tumour (WT), non-Hodgkin lymphoma (NHL), retinoblastoma, and acute lymphocytic leukaemia (ALL)), Kampala, Uganda (Burkitt lymphoma, Kaposi sarcoma, WT, and retinoblastoma), and Nairobi, Kenya (ALL, retinoblastoma, WT, Burkitt lymphoma, and Hodgkin lymphoma). We included cases diagnosed within the years 1998-2009 and followed up till the end of 2011. We estimated the observed and relative survival at 1, 3, and 5 years after diagnosis. We studied 627 individual patient records. Median follow-up ranged from 2.2 months for children with Kaposi sarcoma in Harare to 30.2 months for children with ALL in Nairobi. The proportion of children lost to follow-up was highest in the first year after diagnosis. In Harare and Kampala, the 5-year relative survival was <46% for all cancer types. The 5-year relative survival was best for children in Nairobi, though with wider confidence intervals. Survival from childhood cancers in Africa is still poor, even for cancers with good prognosis and potential for cure. Supporting cancer detection, treatment, and registration activities could help improve survival chances for children with cancers in Africa.

Long term effects of once-only flexible sigmoidoscopy screening after 17 years of follow-up: the UK Flexible Sigmoidoscopy Screening randomised controlled trial.

BACKGROUND: Colorectal cancer is the third most common cancer worldwide. Previous analyses have only reported follow-up after flexible sigmoidoscopy for a maximum of 12 years. We aimed to examine colorectal cancer incidence and mortality after a single flexible sigmoidoscopy screening and 17 years of follow-up. METHODS: In this multicentre randomised trial (UK Flexible Sigmoidoscopy Screening Trial), done between Nov 14, 1994, and March 30, 1999, 170 432 eligible men and women, who had indicated on a previous questionnaire that they would probably attend screening if invited, were randomly assigned (1:2) to an intervention group (offered flexible sigmoidoscopy screening) or a control group (not contacted). Randomisation was done centrally in blocks of 12, and stratified by trial centre, general practice, and household type. The nature of the intervention did not allow the staff to be masked to arm of the trial; however, randomisation was done in batches so that the control group and participants not yet randomised were unaware of their allocation status. The primary outcomes were incidence and mortality of colorectal cancer. Hazard ratios (HRs) and 95% CIs for colorectal cancer incidence and mortality were estimated for intention-to-treat and per-protocol analyses. The trial is registered with ISRCTN, number 28352761. FINDINGS: Our cohort analysis included 170 034 people: 112 936 in the control group and 57 098 in the intervention group, 40 621 (71%) of whom were screened and 16 477 (29%) were not screened. During screening and a median of 17·1 years' follow-up, colorectal cancer was diagnosed in 1230 individuals in the intervention group and 3253 in the control group, and 353 individuals in the intervention group versus 996 individuals in the control group died from colorectal cancer. In intention-to-treat analyses, colorectal cancer incidence was reduced by 26% (HR 0·74 [95% CI 0·70-0·80]; p<0·0001) in the intervention group versus the control group and colorectal cancer mortality was reduced by 30% (0·70 [0·62-0·79]; p<0·0001) in the intervention group versus the control group. In per-protocol analyses, adjusted for non-compliance, colorectal cancer incidence and mortality were 35% (HR 0·65 [95% CI 0·59-0·71]) and 41% (0·59 [0·49-0·70]) lower in the screened group. INTERPRETATION: A single flexible sigmoidoscopy continues to provide substantial protection from colorectal cancer diagnosis and death, with protection lasting at least 17 years. FUNDING: National Institute for Health Research Efficacy and Mechanism Evaluation.

Three-year cancer incidence in Blantyre, Malawi (2008-2010).

In this paper, we present incidence rates of different cancers calculated for the population of Blantyre, Malawi for the period 2008-2010, using data from the Malawi Cancer Registry. Active methods were used for case finding, with standard checks for accuracy and validity performed in CanReg 4. During this 3-year period, a total of 3,711 cases were registered comprising 1,643 men (an estimated age-standardized incidence rate (ASR) of 169.8 per 100,000) and 2,068 women (ASR 238.7 per 105 ). Kaposi sarcoma (KS) was the most common cancer in men (40.5% of all cancers in men; ASR 54.0 per 105 ) while cervical cancer was the commonest in women (33.3%; ASR 88.6 per 105 ). The incidence rates for esophageal cancer remain one of the highest in the world (ASR 30.9 per 100,000 in men, 22.1 per 100,000 in women). Incidence of cancer of the prostate is relatively low in Blantyre (5.1%; ASR 16.4 per 105 ), compared with elsewhere in Africa. In childhood, the cancer spectrum is dominated by Burkitt lymphoma (32.5% ASR 90.9 per 106 ) followed by Wilms tumor (11.3%; ASR 35.9 per 106 ) and pediatric KS (11.0%; ASR 31.1 per 106 ). The overall percentage of cases with histological verification was 47.5%, a slight improvement from 42.4% in late 1990s also indicating successful case finding outside laboratories.

Black-white differences in cancer risk in Harare, Zimbabwe, during 1991-2010.

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.

Cancer registries in Africa 2014: A survey of operational features and uses in cancer control planning.

A questionnaire survey of all active population based cancer registries in sub-Saharan Africa obtained information on their characteristics (size, staffing, funding), methods of working, the nature of any links between registries and their respective Health Authorities (national and/or local), and the use of their data in research or cancer control planning. 23/25 registries (92%) responded. Sources of direct funding and estimated amounts from each source were established, and suggest that it is approximately US$8-9 per case registered. Almost half of the funding is used for routine data collection, processing and analysis. Staffing levels vary, partly as a function of the registry size (approximately one FTE per 300 cases registered). Most data collection is active, using multiple sources (median 10 per registry), and is largely paper-based (abstraction onto paper forms), although all use the computer system CanReg© for data entry, storage and analysis. Most reporting by the registries is remarkably timely, and in general, their results are widely used by health authorities and other stakeholders in planning and evaluating services, while research output is much more variable. These registries are the source of almost all the existing information on cancer incidence and mortality in sub-Saharan Africa, as published in IARC's "Globocan".

Trends in cancer incidence in rural Eastern Cape Province; South Africa, 1998-2012.

There are few cancer trend data reported in sub-Saharan Africa notably due to the scarcity of population-based cancer registries (PBCRs). The Eastern Cape Province PBCR is amongst the few registries in sub-Saharan Africa that reports data for a rural population. Trends in cancer incidence are reported for the period 1998-2012. Registered cases, age-standardized rates (ASRs) and standardized rate ratios are presented for the most common cancers in both males and females in three periods (1998-2002, 2003-2007 and 2008-2012). In males, the most commonly diagnosed cancer during the 15 year period was cancer of the oesophagus; incidence rates showed a significant decline over the 15 year period, entirely due to a 30% decrease between 2003-2007 and 2008-2012, to an ASR of 23.2 per 100,000 population. This was followed by prostate cancer, the incidence of which was more than doubled to a level of 9.9/100,000. In women, cancer of the cervix uteri has become the most common malignancy, with a significant increase in incidence during the period to 29.0/100,000. Oesophageal cancer is second in frequency, with (as in males) a significant decline in the final 10 years to an incidence of 14.5/100,000 in 2008-2012. The incidence of breast cancer increased by 61%, although the absolute rate remains low (12.2/100,000). The incidence rates of colorectal cancer are low, and the increases in incidence, although relatively large (35% in men, 63% in women) were not statistically significant. Kaposi sarcoma showed a dramatic increase in incidence in both sexes (3.5-fold in men, 11-fold in women) although the incidence remains relatively low by southern African standards. Cancer prevention and control activities in the area need to be informed by these data and strengthened.

Global burden of cancer in 2008: a systematic analysis of disability-adjusted life-years in 12 world regions.

BACKGROUND: Country comparisons that consider the effect of fatal and non-fatal disease outcomes are needed for health-care planning. We calculated disability-adjusted life-years (DALYs) to estimate the global burden of cancer in 2008. METHODS: We used population-based data, mostly from cancer registries, for incidence, mortality, life expectancy, disease duration, and age at onset and death, alongside proportions of patients who were treated and living with sequelae or regarded as cured, to calculate years of life lost (YLLs) and years lived with disability (YLDs). We used YLLs and YLDs to derive DALYs for 27 sites of cancers in 184 countries in 12 world regions. Estimates were grouped into four categories based on a country's human development index (HDI). We applied zero discounting and uniform age weighting, and age-standardised rates to enable cross-country and regional comparisons. FINDINGS: Worldwide, an estimated 169·3 million years of healthy life were lost because of cancer in 2008. Colorectal, lung, breast, and prostate cancers were the main contributors to total DALYs in most world regions and caused 18-50% of the total cancer burden. We estimated an additional burden of 25% from infection-related cancers (liver, stomach, and cervical) in sub-Saharan Africa, and 27% in eastern Asia. We noted substantial global differences in the cancer profile of DALYs by country and region; however, YLLs were the most important component of DALYs in all countries and for all cancers, and contributed to more than 90% of the total burden. Nonetheless, low-resource settings had consistently higher YLLs (as a proportion of total DALYs) than did high-resource settings. INTERPRETATION: Age-adjusted DALYs lost from cancer are substantial, irrespective of world region. The consistently larger proportions of YLLs in low HDI than in high HDI countries indicate substantial inequalities in prognosis after diagnosis, related to degree of human development. Therefore, radical improvement in cancer care is needed in low-resource countries. FUNDING: Dutch Scientific Society, Erasmus University Rotterdam, and International Agency for research on Cancer.

Cancer burden in Africa and opportunities for prevention.

Cancer is an emerging public health problem in Africa. About 715,000 new cancer cases and 542,000 cancer deaths occurred in 2008 on the continent, with these numbers expected to double in the next 20 years simply because of the aging and growth of the population. Furthermore, cancers such as lung, female breast, and prostate cancers are diagnosed at much higher frequencies than in the past because of changes in lifestyle factors and detection practices associated with urbanization and economic development. Breast cancer in women and prostate cancer in men have now become the most commonly diagnosed cancers in many Sub-Saharan African countries, replacing cervical and liver cancers. In most African countries, cancer control programs and the provision of early detection and treatment services are limited despite this increasing burden. This paper reviews the current patterns of cancer in Africa and the opportunities for reducing the burden through the application of resource level interventions, including implementation of vaccinations for liver and cervical cancers, tobacco control policies for smoking-related cancers, and low-tech early detection methods for cervical cancer, as well as pain relief at the palliative stage of cancer.

Estimating and validating disability-adjusted life years at the global level: a methodological framework for cancer.

BACKGROUND: Disability-adjusted life years (DALYs) link data on disease occurrence to health outcomes, and they are a useful aid in establishing country-specific agendas regarding cancer control. The variables required to compute DALYs are however multiple and not readily available in many countries. We propose a methodology that derives global DALYs and validate variables and DALYs based on data from various cancer registries. METHODS: We estimated DALYs for four countries (Norway, Bulgaria, India and Uganda) within each category of the human development index (HDI). The following sources (indicators) were used: Globocan2008 (incidence and mortality), various cancer registries (proportion cured, proportion treated and duration of disease), treatment guidelines (duration of treatment), specific burden of disease studies (sequelae and disability weights), alongside expert opinion. We obtained country-specific population estimates and identified resource levels using the HDI, DALYs are computed as the sum of years of life lost and years lived with disabilities. RESULTS: Using mortality:incidence ratios to estimate country-specific survival, and by applying the human development index we derived country-specific estimates of the proportion cured and the proportion treated. The fit between the estimates and observed data from the cancer registries was relatively good. The final DALY estimates were similar to those computed using observed values in Norway, and in WHO's earlier global burden of disease study. Marked cross-country differences in the patterns of DALYs by cancer sites were observed. In Norway and Bulgaria, breast, colorectal, prostate and lung cancer were the main contributors to DALYs, representing 54% and 45%, respectively, of the totals. These cancers contributed only 27% and 18%, respectively, of total DALYs in India and Uganda. CONCLUSIONS: Our approach resulted in a series of variables that can be used to estimate country-specific DALYs, enabling global estimates of DALYs and international comparisons that support priorities in cancer control.

A way to explore the existence of "immortals" in cancer registry data - An illustration using data from ICBP SURVMARK-2.

BACKGROUND: Accurately recorded vital status of individuals is essential when estimating cancer patient survival. When deaths are ascertained by linkage with vital statistics registers, some may be missed, and such individuals will wrongly appear to be long-term survivors, and survival will be overestimated. Interval-specific relative survival that levels off above one indicates that the survival among the cancer patients is better than expected, which could be due to the presence of immortals. METHODS: We included colon cancer cases diagnosed in 1995-1999 within the 19 jurisdictions in seven countries participating in ICBP SURVMARK-2, with follow-up information available until end-2015. Interval-specific relative survival was estimated for each year following diagnosis, by country and age group at diagnosis. RESULTS: The interval-specific relative survival levels off at 1 for all countries and age groups, with two exceptions: for the age group diagnosed at age 75 years and above in Ireland, and, to a lesser extent, in New Zealand. CONCLUSION: Overall, a subset of immortals are not apparent in the early years within the ICBP SURVMARK-2 study, except for possibly in Ireland. We suggest this approach as one strategy of exploring the existence of immortals, and to be part of routine checks of cancer registry data.

The cancer burden in the United Kingdom in 2007 due to radiotherapy.

The number of long-term cancer survivors in the general population of the UK is substantial and increasing rapidly. Many cancer survivors have been treated with radiotherapy but the likely number of radiotherapy-related second cancers has not previously been estimated. We used estimates of the numbers of cancer survivors in the UK at the beginning of 2007, in conjunction with estimates of the relative risk of a second primary cancer associated with previous radiotherapy from the United States Surveillance Epidemiology and End Results (SEER) programme, to estimate the numbers of incident cancers in the UK in 2007 that were associated with radiotherapy for a previous cancer and that may have been caused by it. We estimated that 1,346 cases of cancer, or about 0.45% of the 298,000 new cancers registered in the UK in 2007, were associated with radiotherapy for a previous cancer. The largest numbers of radiotherapy-related second cancers were lung cancer (23.7% of the total), oesophageal cancer (13.3%), and female breast cancer (10.6%); 54% of radiotherapy-related second cancers were in individuals aged 75 or over. The highest percentages of second cancers related to radiotherapy were among survivors of Hodgkin's disease and cancers of the oral cavity and pharynx and cervix uteri; over 15% of second cancers among these survivors were associated with radiotherapy for the first cancer. These calculations, which involve a number of assumptions and approximations, provide a reasonable, if conservative, estimate of the fraction of incident cancers in the UK that are attributable to past radiation therapy.

Risk factors for breast cancer among Filipino women in Manila.

Age-adjusted incidence rates of breast cancer vary greatly worldwide with highest rates found in the typically 'westernised' countries of North America and Europe. Much lower rates are observed in Asian and African populations but an exception to this has been reported for the Manila Cancer Registry in the Philippines. The reason for this high rate is unknown but may be associated with the change in lifestyle that has occurred in urban Manila since the 1960s. In 1995, a randomised controlled trial was set up in Manila to evaluate the feasibility of a screening intervention by clinical breast examination as an alternative to mammography. The cohort of 151,168 women was followed-up to 2001 for cancer incidence and a nested case-control study carried out. This aimed to evaluate the increase in breast cancer risk associated with known risk factors. Increased risks were seen for a high level of education (OR = 1.9 95%CI 1.1-3.3 for education stopped at > or =13 versus <13 years), nulliparity (OR = 5.0 95% CI 2.5-10.0 for nulliparity versus five or more children), and late age at first birth (OR = 3.3 95% CI 1.3-8.3 for age > or =30 versus <20 years). We found no association with excess body weight, height, use of exogenous hormones or alcohol consumption. From this study, the recognised "classical" risk factors do not fully explain the high breast cancer incidence in Metro Manila, especially when compared to other urban Asian populations. We conclude that it is too simplistic to ascribe the high risk to 'westernisation'.

Can different definitions of date of cancer incidence explain observed international variation in cancer survival? An ICBP SURVMARK-2 study.

BACKGROUND: Differences in registration practices across population-based cancer registries may contribute to international variation in survival estimates. In particular, there are variations in recorded date of incidence (DOI) as cancer registries have access to different sources of information and use different rules to determine an official DOI. This study investigates the impact of different DOI rules on cancer survival estimates. MATERIALS AND METHODS: Detailed data on dates of pathological confirmation and hospital admittance were collected from three registries participating in the ICBP SURVMARK-2 project (England, Northern Ireland and Norway). Multiple dates of incidence were determined for each cancer patient diagnosed during 2010-2014 by applying three sets of rules that prioritize either: a) histological date, b) hospital admittance date or c) the earliest date recorded. For each set of rules and registry, 1- and 5-year net survival were estimated for eight cancer sites (oesophagus, stomach, colon, rectum, liver, pancreas, lung and ovary). RESULTS: The mean difference between different DOIs within a country and cancer site ranged from 0.1-23 days. The variation in 1- and 5-year net survival using different DOIs were generally small for all registries and cancer sites. Only for liver and pancreatic cancer in Norway and ovarian cancer in England, were larger 1-year survival differences, of 2-3 % found. CONCLUSION: In the ongoing discussion of the comparability of survival estimates across registry populations, the use of different DOI definitions can be considered to have a very limited impact.

Essential TNM: Evaluation of a Training Exercise in Sub-Saharan Africa.

Information on cancer stage at diagnosis is largely missing or poorly documented among population-based cancer registries in sub-Saharan Africa (SSA). In an early field trial of Essential TNM staging, it was observed that some training was needed to enable cancer registrars to abstract the correct TNM from case records. In November 2018, the Addis Ababa City Cancer Registry hosted a training course attended by 17 participants from 16 cancer registries in SSA. The participants were asked to stage 16 cancer cases (from anonymized photocopies of case records obtained from the Global Initiative for Cancer Registry Development) before and after the training. The discrepancy of the stages from before and after were scored and compared. Results showed that there was a substantial improvement in the participants' performance after the training. The application of the Essential TNM staging system, with training in its use, would allow cancer registrars in SSA to abstract cancer stage at diagnosis in a clinically recognized format, which is crucial for cancer control and public health care policy making.

The global burden of urinary bladder cancer.

Statistics on the incidence of bladder cancer are particularly hard to interpret, because of changing classification, variations in counting of multiple cancers in the same individual and, most importantly, the variable inclusion of non-invasive cancers in different data sets. Mortality statistics are almost certainly more comparable, but as indirect estimators of disease risk, require some cautious interpretation, because of differing survival between populations, and over time. Cancer of the bladder is estimated to be the ninth most common cause of cancer worldwide (357 000 cases in 2002) and the 13th most numerous cause of death from cancer (145 000 deaths). Rates in males are three to four times those in females. Incidence rates are high in many southern and eastern European countries, in parts of Africa and the Middle East, and in North America. The highest estimated mortality is in Egypt, where rates are more than three times greater than the highest rates in Europe and eight times those in the USA. In the USA, the incidence in whites is higher than in blacks. In general, in Western countries, incidence rates have been rising, but the increase has slowed or stopped in many. Mortality rates are, for the most part, decreasing. Trends are more variable in developing countries. To some extent, the geography and time trends are related to prevalence of known risk factors, especially exposure to tobacco (responsible for almost one-third of bladder cancer deaths) and, in some specific areas, schistosomiasis.