Cancer Incidence in Five Continents (CI5), a longstanding collaboration between the International Agency for Research on Cancer and the International Association of Cancer Registries, serves as a unique source of cancer incidence data from high‐quality population‐based cancer registries around the world. The recent publication of Volume X comprises cancer incidence data from 290 registries covering 424 populations in 68 countries for the registration period 2003–2007. In this article, we assess the status of population‐based cancer registries worldwide, describe the techniques used in CI5 to evaluate their quality and highlight the notable variation in the incidence rates of selected cancers contained within Volume X of CI5. We also discuss the Global Initiative for Cancer Registry Development as an international partnership that aims to reduce the disparities in availability of cancer incidence data for cancer control action, particularly in economically transitioning countries, already experiencing a rapid rise in the number of cancer patients annually.
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 CIN21 or CIN31, 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 CIN21 but the specificity was rather high (93%; 95% CI 89-97%). The HC2-assay showed a sensitivity for CIN21 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 CIN21 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. ' 2008 Wiley-Liss, Inc.Key words: cervical cancer; cervical intraepithelial neoplasia; screening methods; VIA; pap smear; HPV; developing countries Cervical cancer, an eminently preventable can...
HighlightsWe conducted a review and meta-analysis of esophageal cancer sex ratios in mainland Africa using data from 197 populations in 36 countries.We observed a consistent male excess in incidence rates overall and in the high-risk Eastern and Southern African regions.A male excess was evident in 30–39 year olds in high-risk Eastern and Southern African regions.Our findings suggest that a substantial fraction of the African EC burden could be avoided by targeting gender-specific exposures.
The exposure of the exocervix and/or the increased levels of estrogen and progesterone for more prolonged periods during pregnancy in multiparous women and the vulnerability of widowed/separated women in society might result in increased risk of cervical neoplasia more so among women exposed to HPV infection. High parity probably explains the persistently high rates of cervical cancer in sub-Saharan Africa.
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. 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 ) 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 versus either of the tests above. INTRODUCTION Cancer of the cervix uteri is the most common cancer among women in many developing countries, and 83% of all cases occur in the countries of the developing world.1 The highest incidence rates are observed in the developing world, such as in sub-Saharan Africa, Melanesia, Latin America and the Caribbean, south-central Asia, and south-east Asia.1 The usefulness of cervical cytology screening in reducing cervical cancer mortality is generally acknowledged in regions with well-organized programmes with quality assurance, but successful implementation is fraught with challenges in low-resource settings. Thus, simple and less expensive non-cytological methods of d...
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