Esophageal cancer male to female incidence ratios in Africa: A systematic review and meta-analysis of geographic, time and age trends.

Esophageal squamous cell carcinoma (ESCC) remains the predominant histological subtype of esophageal cancer (EC) in many transitioning countries, with an enigmatic and geographically distinct etiology, and consistently elevated incidence rates in many Eastern and Southern African countries. To gain epidemiological insights into ESCC patterns across the continent, we conducted a systematic review and meta-analysis of male-to-female (M:F) sex ratios of EC age-standardised (world) incidence rates in Africa according to geography, time and age at diagnosis. Data from 197 populations in 36 countries were included in the analysis, based on data from cancer registries included in IARC's Cancer Incidence in Five Continents, Cancer in Africa and Cancer in Sub-Saharan Africa reports, alongside a systematic search of peer-reviewed literature. A consistent male excess in incidence rates overall (1.7; 95% CI: 1.4, 2.0), and in the high-risk Eastern (1.6; 95% CI: 1.4, 1.8) and Southern (1.8; 95% CI: 1.5, 2.0) African regions was observed. Within the latter two regions, there was a male excess evident in 30-39 year olds that was not observed in low-risk regions. Despite possible referral biases affecting the interpretability of the M:F ratios in place and time, the high degree of heterogeneity in ESCC incidence implies a large fraction of the disease is preventable, and directs research enquiries to elucidate early-age exposures among young men in Africa.

Tumor size and stage of breast cancer in Côte d'Ivoire and Republic of Congo - Results from population-based cancer registries.

PURPOSE: Breast cancer is now the leading female cancer in sub-Saharan Africa, but there is relatively little information on breast cancer characteristics from this region. We studied, on a population basis, the size and stage of female breast cancer at diagnosis in Côte d'Ivoire and Republic of Congo. METHODS: Data on tumor size and stage of breast cancer at diagnosis were collected by population-based cancer registries in Abidjan (the capital of Côte d'Ivoire; 141 cases) and Brazzaville (the capital of Republic of Congo; 139 cases) from a random group of female breast cancer cases that were diagnosed in 2008-2009 using the same protocol. RESULTS: The majority of breast cancers in both countries were advanced cancers. In Côte d'Ivoire, 68% of tumors were ≥5 cm in diameter and 74% of cancers were stage III or IV at diagnosis; the corresponding proportions in Republic of Congo were 63% and 81%. CONCLUSION: These results underscore the importance of increased awareness about early detection of breast cancer, as well as expansion of the capacity to provide appropriate diagnosis, treatment, and palliative care in sub-Saharan Africa.

Pooled analysis of the accuracy of five cervical cancer screening tests assessed in eleven studies in Africa and India.

Cervical cancer is the main cancer among women in sub-Saharan Africa, India and other parts of the developing world. Evaluation of screening performance of effective, feasible and affordable early detection and management methods is a public health priority. Five screening methods, naked eye visual inspection of the cervix uteri after application of diluted acetic acid (VIA), or Lugol's iodine (VILI) or with a magnifying device (VIAM), the Pap smear and human papillomavirus testing with the high-risk probe of the Hybrid Capture-2 assay (HC2), were evaluated in 11 studies in India and Africa. More than 58,000 women, aged 25-64 years, were tested with 2-5 screening tests and outcome verification was done on all women independent of the screen test results. The outcome was presence or absence of cervical intraepithelial neoplasia (CIN) of different degrees or invasive cervical cancer. Verification was based on colposcopy and histological interpretation of colposcopy-directed biopsies. Negative colposcopy was accepted as a truly negative outcome. VIA showed a sensitivity of 79% (95% CI 73-85%) and 83% (95% CI 77-89%), and a specificity of 85% (95% CI 81-89%) and 84% (95% CI 80-88%) for the outcomes CIN2+ or CIN3+, respectively. VILI was on average 10% more sensitive and equally specific. VIAM showed similar results as VIA. The Pap smear showed lowest sensitivity, even at the lowest cutoff of atypical squamous cells of undetermined significance (57%; 95% CI 38-76%) for CIN2+ but the specificity was rather high (93%; 95% CI 89-97%). The HC2-assay showed a sensitivity for CIN2+ of 62% (95% CI 56-68%) and a specificity of 94% (95% CI 92-95%). Substantial interstudy variation was observed in the accuracy of the visual screening methods. Accuracy of visual methods and cytology increased over time, whereas performance of HC2 was constant. Results of visual tests and colposcopy were highly correlated. This study was the largest ever done that evaluates the cross-sectional accuracy of screening tests for cervical cancer precursors in developing countries. The merit of the study was that all screened subjects were submitted to confirmatory investigations avoiding to verification bias. A major finding was the consistently higher sensitivity but equal specificity of VILI compared with VIA. Nevertheless, some caution is warranted in the interpretation of observed accuracy measures, since a certain degree of gold standard misclassification cannot be excluded. Because of the correlation between visual screening tests and colposcopy and a certain degree of over-diagnosis of apparent CIN2+ by study pathologists, it is possible that both sensitivity and specificity of VIA and VILI were overestimated. Gold standard verification error could also explain the surprisingly low sensitivity of HC2, which contrasts with findings from other studies.

Assessing the gain in diagnostic performance when two visual inspection methods are combined for cervical cancer prevention.

OBJECTIVES: The objectives of this study was to establish whether combined screening with visual inspection with acetic acid (VIA) and Lugol's iodine (VILI) improves detection of cervical intraepithelial neoplasia 2-3 (CIN 2-3) lesions and cancer beyond chance, compared with screening with VIA alone or VILI alone; and to estimate the extra number of false-positive (FP) results per additional disease case found with the combined test, and to estimate the additional costs involved. SETTING: Ten cross-sectional studies in Burkina Faso, Congo, Guinea, India, Mali and Niger, between 1999 and 2003. METHODS: Using a common protocol, health workers screened 56,147 women aged 25-65 years with VIA and VILI. All women underwent a colposcopy examination and biopsies were taken when necessary. The disease reference standard was histology or negative colposcopy. A positive result on the combined test was defined if either VIA or VILI were positive. The accuracy of the combined test compared with VIA alone or VILI alone was evaluated using likelihood ratios. RESULTS: The estimated sensitivity and specificity were 81.3% and 87.3%, respectively, for VIA; 91.5% and 86.9% for VILI; and 92.9% and 83.5% for the combined test. The ratio of the positive likelihood ratios of the combined test and VIA alone for CIN 2-3 lesions and cancer was 0.88 (95% confidense interval [CI]: 0.86-0.90), favouring use of VIA alone. The ratio of the negative likelihood ratios was 0.40 (95% CI: 0.37-0.47), favouring use of the combined test. Similar results were obtained when the combined test was compared with VILI alone. Assuming equivalent performance of VIA alone and the combined test with a disease prevalence of 2%, there will be about 16.0 (95% CI: 13.6-18.8) additional FPs for each additional true positive (TP) detected if the combined test is used. This number will be 121.1 (95% CI: 75.4-194.6) if VILI is considered as the single test. CONCLUSIONS: At the trade-off point between the combined test and VIA alone or VILI alone, given the numbers of additional FP results involved for each additional TP case of disease that were found, it would be more likely that settings already using VIA would advocate combined testing, and for settings using VILI to opt for the single test. The additional costs (per 1000 women) incurred with the combined test would be International 4117.68 dollars versus either of the tests above.