Early detection of cervical cancer with visual inspection methods: a summary of completed and on-going studies in India.

India is a high-risk country for cervical cancer which accounts a quarter (126,000 new cases, 71,000 deaths around 2,000) of the world burden. The age-standardized incidence rates range from 16-55 per 100,000 women in different regions with particularly high rates in rural areas. Control of cervical cancer by early detection and treatment is a priority of the National Cancer Control Programme of India. There are no organized cytology screening programmes in the country. The technical and financial constraints to organize cytology screening have encouraged the evaluation of visual inspection approaches as potential alternatives to cervical cytology in India. Four types of visual detection approaches for cervical neoplasia are investigated in India: a) naked eye inspection without acetic acid application, widely known as 'downstaging'; b) naked eye inspection after application of 3-5% acetic acid (VIA); c) VIA using magnification devices (VIAM); d) visual inspection after the application of Lugol's iodine (VILI). Downstaging has been shown to be poorly sensitive and specific to detect cervical neoplasia and is no longer considered as a suitable screening test for cervical cancer. VIA, VIAM and VILI are currently being investigated in multicentre cross-sectional studies (without verification bias), in which cytology and HPV testing are also simultaneously evaluated, and the results of these investigations will be available in 2003. These studies will provide valuable information on the average, comparative test performances in detecting high-grade cervical cancer precursors and cancer. Results from pooled analysis of data from two completed studies indicated an approximate sensitivity of 93.4% and specificity of 85.1% for VIA to detect CIN 2 or worse lesions; the corresponding figures for cytology were 72.1% and 91.6%. The efficacy of VIA in reducing incidence of an mortality from cervical cancer and its cost-effectiveness is currently being investigated in two cluster randomized controlled intervention trials in India. One of these studies is a 4-arm trial addressing the comparative efficacy of VIA, cytology and primary screening with HPV DNA testing. This trial will provide valuable information on comparative detection rates of CIN 2-3 lesions by the middle of 2003. The expected outcomes from the Indian studies will contribute valuable information for guiding the development of public health policies on cervical cancer prevention in countries with different levels of socio-economic and health services development and open up new avenues of research. This paper is available too at: http//www.insp.mx/salud/index.html.

Early detection of cervical cancer with visual inspection methods: a summary of completed and on-going studies in India

La India es un país de alto riesgo de cáncer cervical, donde se presentan cerca de la cuarta parte de los casos del total mundial (126 000 casos incidentes y 71 000 muertes durante 2000). La tasa de incidencia estandarizada por edad se encuentra en el rango de 16 a 55 por 100 000 mujeres en diferentes regiones con tasas particularmente altas en áreas rurales. El control del cáncer cervical por detección temprana y tratamiento es una prioridad del Programa Nacional de Control de Cáncer y, desafortunadamente, no hay programas organizados de tamizaje citológico en este país. La infraestructura técnica y financiera para organizar tamizaje en este tipo de cáncer, ha promovido la inspección visual como una potencial alternativa de la citología cervical en la India. Se investigan cuatro tipos de opciones de detección visual de neoplasia cervical: a) inspección a ojo desnudo sin la aplicación de ácido acético, opción ampliamente conocida como downstaging; b) inspección de ojo desnudo después de la aplicación de ácido acético de 3 a 5 por ciento (VIA); c) VIA usando un dispositivo de aumento (VIAM); d) inspección visual después de la aplicación de yodo-lugol (VILI). Se ha mostrado que el Downstaging ha sido pobremente sensible y específico para detectar neoplasia cervical y no es considerado ampliamente como una prueba de tamizaje conveniente para cáncer cervical. VIA, VIAM y VILI son frecuentemente investigados en estudios de corte transversal multicéntricos (sin verificación de sesgo), en los que se evalúan simultáneamente la citología y las pruebas del VPH; los resultados de esas investigaciones estarán disponibles próximamente. Estos estudios proveerán información valiosa sobre el desarrollo de pruebas comparativas para detectar lesiones de alto grado precursoras de neoplasia cervical, y cáncer invasor. Los resultados de los análisis de los datos de dos estudios previos indicaron una sensibilidad aproximada de 93.4 por ciento y una especificidad de 85.1 por ciento para VIA en la detección de CIN 2-3 o lesiones invasoras, comparadas con las de citología con 72.1 por ciento y 91.6 por ciento de sensibilidad y especificidad, respectivamente. La eficacia de VIA para la reducción de la incidencia y la mortalidad de cáncer cervical y su costo-efectividad están siendo actualmente investigadas en dos ensayos de intervención aleatorizados controlados en población de la India. Uno de esos estudios es un ensayo con cuatro brazos que establece la eficacia...

Estimates of the worldwide mortality from 25 cancers in 1990.

We present here worldwide estimates of annual mortality from all cancers and for 25 specific cancer sites around 1990. Crude and age-standardised mortality rates and numbers of deaths were computed for 23 geographical areas. Of the estimated 5.2 million deaths from cancer (excluding non-melanoma skin cancer), 55% (2.8 million) occurred in developing countries. The sex ratio is 1.33 (M:F), greater than that of incidence (1.13) due to the more favourable prognosis of cancer in women. Lung cancer is still the most common cause of death from cancer worldwide with over 900,000 deaths per year, followed by gastric cancer with over 600,000 deaths and colorectal and liver cancers accounting for at least 400,000 deaths each. In men, deaths from liver cancer exceed those due to colo-rectal cancer by 38%. Over 300,000 deaths of women are attributed to breast cancer, which remains the leading cause of death from cancer in women, followed by cancers of the stomach and lung with 230,000 annual deaths each. In men, the risk of dying from cancer is highest in eastern Europe, with an age-standardised rate for all sites of 205 deaths per 100,000 population. Mortality rates in all other developed regions are around 180. The only developing area with an overall rate of the same magnitude as that in developed countries is southern Africa. All of eastern Asia, including China, has mortality rates above the world average, as do all developed countries. The region of highest risk among women is northern Europe (age-standardised rate = 125.4), followed by North America, southern Africa and tropical South America. Only south-central and western Asia (Indian subcontinent, central Asia and the middle-eastern countries) and Northern Africa are well below the world average of 90 deaths per 100,000 population annually. Our results indicate the potential impact of preventive practices. It is estimated that 20% of all cancer deaths (1 million) could be prevented by eliminating tobacco smoking. Infectious agents account for a further 16% of deaths.

Plantar melanoma: a case-control study in Paraguay.

In Paraguay, the plantar surface of the foot is the most common site for malignant melanoma, as it is in several other populations worldwide, most notably in those of African descent. Here, we report the results of the first case-control study of plantar melanoma, carried out in Paraguay. Sixty incident, histologically confirmed cases of plantar melanoma and 256 hospital controls were recruited in 11 hospitals throughout the country during 1988-93. Information was collected on general demographic, social, and lifestyle variables, on external exposures of feet (shoewear, work activities, injuries), and on some constitutional factors (skin, eye and hair color, and pigmented lesions of the feet). Few of the factors examined appeared to be associated with the risk of plantar melanoma. Adjusted for possible confounders, the strongest association was found for reported injuries (odds ratio [OR] = 40.9, 95 percent confidence interval [CI] = 14.8-112.7) and for occurrence of naevi on the soles (OR = 5.9, CI = 2.5-14.3). Walking barefoot did not seem to contribute to the risk although an outdoor workplace was associated with an increased melanoma occurrence (OR = 2.3, CI = 1.1-4.8). Future studies should be aware of problems of recall bias with respect to previous injuries, and ensure that evaluation of pigmentation of the sole is carried out blind to case/control status.

Case-control study of gastric cancer screening in Venezuela.

A screening programme for early gastric cancer was introduced in the state of Tachira, Venezuela, in 1980. Screening was performed by photofluorography, using two mobile units. The efficacy of this programme in reducing mortality from stomach cancer was evaluated by means of a case-control study. Cases were 241 individuals who died from stomach cancer in the period 1985-89. Ten live controls per case were drawn from the electoral rolls, matched by sex, age and residence. Exposure to the screening examination of cases and controls was assessed through individual linkage with the programme's centralised database. After the exclusion of examinations occurring within the 6 months preceding the case's diagnosis, the odds ratio (OR) of dying from stomach cancer for those screened was 1.26 (CI 0.83-1.91) and the OR in females was lower than in males: 0.77 (CI 0.33-1.78) and 1.52 (CI 0.94-2.47) respectively. Odds ratios associated with years since last test and number of tests did not differ significantly from 1. These results show the inefficacy of the programme in reducing mortality from gastric cancer in the area. In an attempt to determine whether this result was due to selection bias, an analysis restricted to subjects who had been screened at least once was performed. When examinations occurring after an index date at various intervals before the case's diagnosis were excluded, the screening test appeared to protect from death, although confidence intervals of the odds ratios are large, for example OR = 0.47 (CI 0.24-0.98) when excluding tests within 1 month.

Cancer risks among European migrants in São Paulo, Brazil.

Using both mortality and incidence data, cancer risk in Italian, Spanish and Portuguese migrants to São Paulo were compared with those in the Brazil-born population, and with those in their countries of origin. Italian and Spanish migrants show changes in cancer risks which are rather similar to those observed in migrants of the same origin in other parts of South America: they increase their rates of oropharyngeal, oesophageal, cervical and breast cancers and they decrease their rates of lung cancers. However, for cancer of the oesophagus, the changes are greater in São Paulo, where migrants acquire rates similar to those of the natives. For colon cancer, rates in Italian migrants decrease in the low risk area of São Paulo and increase in the high risk area of Argentina. Changes in Portuguese migrants are less evident: their rates of colorectal cancer remain high, and, as found for Japanese migrants in São Paulo, they also retain their higher risks of stomach cancer.

Education and mortality from cancer in São Paulo, Brazil.

This study investigated social class differentials in cancer mortality in São Paulo county, Brazil, for the period 1978 to 1982. A measure of socioeconomic status based on education was used, and cancer risk by level of education was estimated by a case-control approach in which other cancers were considered as controls. For most cancers, the socioeconomic differences in risk were similar to those found in western Europe and North America. For lung cancer, however, the highest risk was observed in men and women with the most education. Other cancers related to tobacco--cancer of the larynx, pharynx, and esophagus--showed a negative association with education. The differences between social classes in consumption habits of alcohol and maté and the use of black tobacco are probably responsible for these contrasting patterns. For breast and cervix uteri cancer the social class patterns were similar to those found in developed countries--a positive relationship for breast and a negative one for cervix uteri cancer. The magnitude of the differences observed between social classes for these cancers was frequently greater in South America than in the United States or western Europe.

Cancer in migrants to Argentina.

Mortality rates from different cancers in migrants to Argentina from 11 individual countries and 6 groups of countries were compared with those in the Argentina-born population and in their countries of origin. Almost all countries of origin had higher mortality rates from gastric cancer than Argentina, but the risk declines in migrants, and for European migrants becomes similar to that of the Argentina-born. In contrast, mortality from oesophageal cancer is significantly lower in European countries than in Argentina. For cancer of the colon and breast, most countries have lower mortality rates than the Argentina-born, the exceptions being Uruguay and Germany, and migrants demonstrate a convergence of risk towards that of Argentina-born. These results suggest that migrants to Argentina undergo changes in some environmental exposure, probably dietary, which give rise to substantial alterations in cancer risk within their lifespan.

Ethnicity and cancer risk in São Paulo, Brazil.

Data from the São Paulo Cancer Registry (Brazil) for the period 1969-1974 are used to investigate ethnic differentials in cancer risk. Risks for specific cancers were estimated for mulattos and blacks relative to whites, using a case-control approach with other cancers as controls. For both sexes, blacks and mulattos are at higher risk than whites for cancer of the esophagus, stomach, and liver and for myeloma; for prostate cancer in males; and for gall bladder, pancreas, and cervix uteri cancers in females. Blacks and mulattos are at lower risk than whites for cancer of the colon, lung, larynx (males only), bladder, bone, testis, breast, and corpus uteri and for melanoma and leukemia. Except for lung and colon cancers, for which life-style habits are the main risk factors, these ethnic differences are similar to those observed in the United States.

Geographical patterns of cancer mortality in Argentina.

Mortality rates in 1980, for the major cancer sites, are presented for Argentina as a whole, and for the 22 provinces, the capital city, and the southern territories. In comparison with other countries, national mortality rates are high for oesophageal cancer and cancer of the larynx, and moderately elevated for cancers of the lung, colon, breast, and bladder in males. The rates of tobacco-related cancers (lung, bladder and larynx) were much higher in males than females, and in males showed similar geographical patterns. In females, breast cancer rates by province showed a positive correlation with those for cancer of the colon, and a negative correlation with cervical cancer. There were marked geographical variations, quite different in the two sexes, in the mortality from oesophageal cancer. It is suggested that, although some of these variations within Argentina may be related to ethnic differences and patterns of migration from neighbouring countries, for the majority the explanations must lie in different exposures to environmental of lifestyle factors, such as diet.

Cancer in migrants to Uruguay.

Mortality rates from different cancers in the principal groups of migrants to Uruguay are compared with those in their countries of origin (Argentina, Brazil, Italy and Spain) and in the Uruguay-born population. Oesophageal cancer is very common in Uruguay and European-born populations, initially at low risk, appear to acquire rather higher rates after migration. For most migrants, the mortality from cancers of the breast, colon-rectum, corpus uteri and prostate is closer to the moderately elevated rates of Uruguay than those in their countries of origin. The results suggest that migrants to Uruguay undergo changes in some important environmental exposures, probably dietary, which give rise to substantial alterations in cancer risk within their lifespan.

Cancer in Costa Rica.

Data from the national tumor registry of Costa Rica for the years 1979-1983 have been used to calculate incidence rates for the major cancer sites by age, sex, urban-rural residence, and geographic region. Recent trends in mortality rates are also presented. Results are compared with data from elsewhere in Latin America, U.S.A., Europe, and Japan. Stomach cancer is the most frequent neoplasm in Costa Rica; although rates are declining, they are second only to those observed in Japan. There are marked variations in risk by region, suggesting important environmental influences in etiology. The cervix is the major female site; rates are declining in young women, probably due to the introduction of screening programs, although these do not seem to account for the geographic variations in invasive cancer incidence. Breast and prostate cancer show moderate rates, while those for colon and rectum cancer are low; increases in mortality rates for these sites are small, and involve mainly the older age groups. In contrast, rates of lung cancer are increasing dramatically in both sexes. In the childhood age group, very high incidence rates are observed for two neoplasms: Hodgkin's disease and acute lymphocytic leukemia.

Estimates of the worldwide frequency of twelve major cancers.

PIP: By examination of incidence, mortality, and relative frequency data, an estimate has been made of the number of cancer cases in 12 common sites and of all cancers that occurred in 1975 and in the 24 areas of the world for which the UN publishes population data. While several cancers are of importance in localized areas or regions; e.g., cancer of the larynx, these are infrequent on the world level and are not included here. While the relative importance of the selected sites varies from 1 area to another, on a global basis, the 1st 6 ranking cancer sites in males are lings, stomach, colon/rectum, mouth/pharynx, prostate, and esophagus; in females, they are breast, cervix uteri, stomach, colon/rectum, lung, and mouth/pharynx. Cancers of these sites, together with leukemias and cancers of the liver, bladder, and lymphatic tissues, account for 75% of the estimated 5.9 million cancers that occurred in 1975. When the 2 sexes are combined, stomach cancers are in 1st rank, followed closely by lung; it is suggested that, given current trends, their rank order will soon be reversed. There are clear opportunities for cancer prevention by controlling tobacco smoking, reducing infection by hepatitis B virus, and curbing the excessive intake of alcohol. The increasing adoption of high fat diets may lead to more cancers of the large bowel, breast, and prostate.^ieng