Cancer survival in sub-Saharan Africa (SURVCAN-3): a population-based study.

BACKGROUND: The Cancer Survival in Africa, Asia, and South America project (SURVCAN-3) of the International Agency for Research on Cancer aims to fill gaps in the availability of population-level cancer survival estimates from countries in these regions. Here, we analysed survival for 18 cancers using data from member registries of the African Cancer Registry Network across 11 countries in sub-Saharan Africa. METHODS: We included data on patients diagnosed with 18 cancer types between Jan 1, 2005, and Dec 31, 2014, from 13 population-based cancer registries in Cotonou (Benin), Abidjan (CÔte d'Ivoire), Addis Ababa (Ethiopia), Eldoret and Nairobi (Kenya), Bamako (Mali), Mauritius, Namibia, Seychelles, Eastern Cape (South Africa), Kampala (Uganda), and Bulawayo and Harare (Zimbabwe). Patients were followed up until Dec 31, 2018. Patient-level data including cancer topography and morphology, age and date at diagnosis, vital status, and date of death (if applicable) were collected. The follow-up (survival) time was measured from the date of incidence until the date of last contact, the date of death, or until the end of the study, whichever occurred first. We estimated the 1-year, 3-year, and 5-year survival (observed, net, and age-standardised net survival) by sex, cancer type, registry, country, and human development index (HDI). 1-year and 3-year survival data were available for all registries and all cancer sites, whereas availability of 5-year survival data was slightly more variable; thus to provide medium-term survival prospects, we have focused on 3-year survival in the Results section. FINDINGS: 10 500 individuals from 13 population-based cancer registries in 11 countries were included in the survival analyses. 9177 (87·4%) of 10 500 cases were morphologically verified. Survival from cancers with a high burden and amenable to prevention was poor: the 3-year age-standardised net survival was 52·3% (95% CI 49·4-55·0) for cervical cancer, 18·1% (11·5-25·9) for liver cancer, and 32·4% (27·5-37·3) for lung cancer. Less than half of the included patients were alive 3 years after a cancer diagnosis for eight cancer types (oral cavity, oesophagus, stomach, larynx, lung, liver, non-Hodgkin lymphoma, and leukaemia). There were differences in survival for some cancers by sex: survival was longer for females with stomach or lung cancer than males with stomach or lung cancer, and longer for males with non-Hodgkin lymphomas than females with non-Hodgkin lymphomas. Survival did not differ by country-level HDI for cancers of the oral cavity, oesophagus, liver, thyroid, and for Hodgkin lymphoma. INTERPRETATION: For cancers for which population-level prevention strategies exist, and with relatively poor prognosis, these estimates highlight the urgent need to upscale population-level prevention activities in sub-Saharan Africa. These data are vital for providing the knowledge base for advocacy to improve access to prevention, diagnosis, and care for patients with cancers in sub-Saharan Africa. FUNDING: Vital Strategies, the Martin-Luther-University Halle-Wittenberg, and the International Agency for Research on Cancer. TRANSLATIONS: For the French and Portuguese translations of the abstract see Supplementary Materials section.

Impact of Hypertension on Left Ventricular Geometry and Diastolic Function in Africa: Results from the Population-Based TAnve Health (TAHES) Cohort Study.

High blood pressure leads to morphologic changes and functional alterations of the myocardial structure. Transthoracic echocardiography is of great clinical interest to evaluate these alterations, using reference values proposed by the American Society of Echocardiography/European Association of Cardiovascular Imaging, largely based on studies in Caucasian Whites. We aimed to assess the impact of hypertension on echocardiographic parameters in a sub-Saharan African community, using ethnic-specific reference values. This study is part of the TAnve HEalth Study, a population-based prospective cohort study initiated in 2015 in the district of Tanve, Republic of Benin. Hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg and/or currently taking antihypertensive medications. All participants had a transthoracic echocardiography. The patterns of diastolic dysfunction and left ventricular (LV) geometry were defined from 486 subjects in the cohort, free from cardiovascular disease, diabetes, and hypertension. Of all participants, 318 (65% women, median age 48 years) had hypertension. Systolic blood pressure correlated significantly (p <0.0001) with LV mass (r = 0.28), wall thickness (r = 0.25), isovolumic relaxation time (r = 0.27), E/A ratio (r = -0.35), lateral e' velocity (r= -0.41), and E/E' ratio (r = 0.39). Ventricular geometry was normal in only 22% of participants with hypertension when using the American Society of Echocardiography/European Association of Cardiovascular Imaging reference values, versus 69% with ethnic-specific reference ranges. The severity of hypertension was associated with ventricular geometry abnormalities. The prevalence of diastolic dysfunction was 14.5% (confidence interval 10.6% to 18.4%), including relaxation impairment (9%) and pseudonormal pattern (6%). Thus, correct assessment of the repercussions of hypertension on LV geometry in Black Africans requires ethnic-specific reference values.

Normal reference values of cardiac chamber sizes and functional parameters in a beninese community population: the TAHES study.

Reported ranges of normal values for echocardiographic measurements are mostly issued from studies performed in Caucasians. This study is a part of TAHES, a population-based prospective cohort study in Benin and aims to establish normal reference values for echocardiographic cardiac chambers dimensions and Doppler parameters in a Sub-Saharan African population. We included 486 healthy (non-diabetic, non-obese and normotensive) individuals (202 men and 284 women, age 37[30-47] years, BSA 1.58 (1.47-1.67) m2). End-diastolic interventricular septal wall thickness, left ventricular (LV) internal diameter, posterior wall thicknesses, and systolic LV internal diameter were respectively at 10[9-12], 45[43-49], 9[8-11], 29[26-34] mm for male and 9[7-10], 43[41-46], 8[7-], 29[27-32] mm for females. LV mass was significantly greater in males even after normalization for the body surface area (98[85-117] vs. 82[71-96] g/m2). Upper limits of BSA-indexed LV mass were 145 g/m2 for males and 124 g/m2 for females. The allometric exponent that described the LV mass-Height relationship were 2.5 in both sexes but 1.2 for males and 1.8 for females separately. E-wave velocity was 0.79 [0.65-0.90] cm/sec in males and 0.88 [0.78-0.99]cm/sec in females (p < 0.0001) but without significant gender differences in E/A ratio (limits: 0.75 and 2.1). The e'-wave velocity (lower limit = 8 cm/sec) decreased and E/e' ratio (Upper limit = 9) increased with aging. Upper limit of BSA-indexed left atrium volume was 38 mL/m2 for both sexes. In conclusion, normal values from a general population in West Africa differ from those established in Caucasian populations with greater LV mass and wall thicknesses.

Normal limits of electrocardiogram in Africans and their consequences on the prevalence of left ventricular hypertrophy in hypertensive individuals: Insights from the TAHES study.

AIMS: To determine normal limits for major ECG variables, and the electrocardiographic impact of hypertension, in a rural sub-Saharan African setting. METHODS: This cross-sectional study included adults aged ≥25 years from Tanvè Health Study (TAHES) cohort. ECG were recorded at rest at 25 mm/s using a standard 12­lead device. Wave amplitudes and durations were measured. Corrected QT interval (QTc) was calculated using Bazett's formula. Sokolow-Lyon, Cornell and Peguero-Lo Presti criteria were determined to assess left ventricular hypertrophy (LVH). RESULTS: ECG was recorded among 997 out of 1407 TAHES participants. After exclusion of subjects with hypertension or diabetes, normal limits, defined as the 2nd and 98th percentiles, were evaluated in 622 healthy participants (median: 37 years; 60.1% women). The following limits were established in men (women): heart rate: 50 to 100 (55 to 102) beats/min, P wave duration: 80 to 120 (80 to 120) ms, PR interval: 120 to 200 (120 to 200) ms, QTc: 315 to 470 (323 to 465) ms, QRS duration: 50 to 120 (50 to 110) ms. Upper limits (in millimeter) for the Sokolow-Lyon, Cornell and Peguero-Lo Presti for men (women) were 47 (38), 30 (22) and 39 (30), respectively, all above current reference limits. The prevalence of LVH in hypertensive subjects according to these criteria were lower than those estimated according to current LVH criteria. CONCLUSION: The normal limits of ECG variables determined in this African population differ from those in Caucasians, indicating that ethnicity must be considered in ECG interpretation.

Prevalence of sleep-disordered breathing in an African general population: The Benin Society and Sleep (BeSAS) study.

BACKGROUND: Data on the prevalence of sleep-disordered breathing (SDB) in the African general population are scarce, and a better understanding is urgently needed. Our study aimed to objectively determine the prevalence of, and factors associated with, SDB in a large sample in Benin, west Africa. METHODS: In the Benin Society and Sleep (BeSAS) cross-sectional study, participants aged 25 years and older were recruited from both urban and rural areas. Rural participants were recruited from Tanve, a village located 200 km north of Cotonou, and urban participants were recruited from Cotonou. The participants underwent respiratory polygraphy at home using a type-3 device that measures airflow through a nasal pressure sensor, respiratory effort (thoracic movement), and pulse oximetry. Clinical and morphometric data were also collected. SDB severity categories were defined according to the apnoea-hypopnoea index (AHI), with mild-to-severe SDB (AHI ≥5/h), moderate-to-severe SDB (AHI ≥15/h), and severe SDB (AHI ≥30/h). FINDINGS: The study was completed from April 4, 2018 to Jan 15, 2021. Of 2909 participants recruited in the BeSAS study, 2168 (74·5%) underwent respiratory polygraphy. For the 1810 participants with complete polygraphic data (mean age 46 years, SD 15; 1163 [64·2%] women), the prevalence of mild-to-severe SDB (AHI ≥5/h) was 43·2% (95% CI 40·9-45·5), of moderate-to-severe SDB (AHI ≥15/h) was 11·6% (10·2-13·1), and of severe SDB (AHI ≥30/h) was 2·7% (2·0-3·5). Factors independently associated with SDB were advanced age, male sex, large neck circumference, abdominal obesity, overweight or obesity, and snoring. After multivariable adjustment, severe SDB was independently associated with hypertension in women (odds ratio 3·99, 95% CI 1·04-15·33; ptrend=0·044), but not in men (odds ratio 0·67, 0·22-2·05; Ptrend=0·63). INTERPRETATION: The BeSAS study provides the first large-scale objective evaluation of SDB prevalence and associated factors in Africa. The high prevalence of SDB identified should stimulate the development of public health policies to prevent and treat this condition in African countries. FUNDING: Ligue Pulmonaire Vaudoise, Switzerland.