Cancer [antikvár]

The impact of cancer in a population is measured and clescribed by looking at a combination of three elements: (1) the number of new cases per year per 100,000 persons (incidence rate), (2) the number of deaths per 100,000 persons per year (mortality rate), and (3) a determination of the proportion of patients alive at somé point after their diagnosis of cancer (survival rate). Cancer occurs throughout the world, but the risk of cancer varies from region to region, suggesting geographic, environmental, and cultural implications. Cancer incidence is monitored by population-based tumor registries around the world. Not all countries maintain population-based tumor registries and in many countries, including the United States, these registries monitor considerably less than the entire population. Incidence data from existing populationbased registries from around the world are compiled by the International Agency for Research on Cancer (IARC), a part of the World Health Organization. The international incidence rates for the cancer sites presented in this section are taken from their publication, Cancer Incidence inFive Continents (CI5), Volume VI (Parkin, 1992). To make meaningful comparisons among different countries, the rates are age-adjusted to the world standard population. The effect of age-adjustment is to eliminate differences in rates when the population of one country has a different age distribution from that of another country. Many countries have vitai statistics departments which keep track of cancer deaths for the entire country, providing a broad base for comparing cancer mortality rates across countries. For many specific cancers, and for all cancers combined, there are wide variations in death rates among different counüies.