Epidemiology of cancer

EPIDEMIOLOGY OF CANCER

2000 worldwide prevalence : > 22 million people, representing an increase of approximately 19% in incidence since 1990. Industrialized countries with the highest overall cancer rates are: USA, Italy, Australia, Germany, The Netherlands, Canada and France. Overall prevalence :

females :

males :

2003 worldwide incidence : 10 million people

2003 incidence rate in USA (rates are per 100,000 people)

prostate cancers 180.3
lung and bronchus cancers 83.5
colorectal cancers 64.5
urinary bladder cancers 36.1
non-Hodgkin's lymphoma (NHL) 23.7 (according to the American Cancer Society, the probability of NHL in a male from birth to 39 years of age is 0.14%, almost 5 times the probability of lung cancers (Cancer facts and figures 2005. Atlanta: American Cancer Society, 2005))
melanoma of the skin 20.2
leukemia 16.3
pancreas cancers 12.7

women

breast cancers 132.5
lung and bronchus cancers 49.2
colorectal cancers 46.6
non-Hodgkin's lymphoma (NHL) 15.4
ovarian cancers 14.2
pancreas cancers 9.9
uterine cervix cancers 9.9 (10,370 new cases and 3710 deaths in 2005 in USA - 11th most common cancer among women in the United States, second most common cancer in developing countries)
leukemia 9.6

variations in incidence (Italy, 1974 to 1983) :

expected 2020 incidence, based on current trends in smoking, diet and exercise : 15 million people (50% increase, partly because poor nations are adopting unhealthy Western habits)
wordwide deaths : 6 million people in 2003, 7.5 million people in 2005 (> 70% in low- and mediun-income countries). Cancer was responsible for 12% of all deaths worldwide in 2000. In industrialized countries > 20% of people will die from the disease, a rate more than twice as high as developing countries. In Britain there are 12% fewer cancer-related deaths than there were 30 years ago. The good news holds for a range of different cancers — the female death rate from breast cancers is down by 20%, and the male death rate from testicular cancer has fallen by 37%. Deaths from stomach cancer are down by about 50% in most of Europe.

uterine cervix cancers : 250,000 deaths in 2005 (80% of those cases were in developing countries)

2003 worldwide case-fatality ratio (CFR)

80% in developing countries
50% in rich nations

2003 death rate in USA (rates are per 100,000 people)

women

females :

males :

USA : death rates have decreased by 1.1% a year for all cancers since 1993.
Italy 1974 to 1983

India's first cancer atlas produced by the Indian Council of Medical Research since 1981 shows that parts of India have the world's highest incidence of cancers of the gall bladder, mouth, and lower pharynx, and there are pockets of stomach and thyroid cancer in the south of the country. The National Cancer Registry Programme in Bangalore used data from 105 hospitals and private clinics in 82 of the 593 districts in India to map the incidence of cancer, as part of a project funded by the WHO. The age adjusted incidence of gall bladder cancer in women in New Delhi is 10.6 per 100 000 of the population—the world's highest rate for women for this cancer. Districts in central, south, and northeast India had the world's highest incidence of cancers associated with tobacco, which is chewed as well as smoked in India. Aizawl district in the northeastern state of Mizoram has the world's highest incidence of cancers in men of the lower pharynx (11.5 per 100 000 people) and tongue (7.6 per 100 000 people). The district also has the country's highest rate of stomach cancer among men. The incidence of mouth cancer among men in Pondicherry was 8.9 per 100,000, one of the highest rates in the world for men. Rates of stomach cancer were high among men in Bangalore and Chennai. The survey also detected a belt of thyroid cancer in women in coastal districts of Kerala, Karnataka, and Goa. Lower pharynx cancer may be linked to tobacco use, but we're going to explore the genetic components of stomach cancer. The incidence atlas also confirmed earlier observations that breast cancer has replaced cervical cancer as the leading site of cancer among women in Indian cities and that lung cancer is the most common cancer in men in Calcutta, Mumbai, and New Delhi^ref
typical log-log curves show the rate of cancer at different ages, and plotting the slope of the rate curve at each point provides the age-specific acceleration of cancer. The decline in acceleration at later ages could be caused by the fact that individual cell lineages accumulate mutations, so that they need fewer steps to become tumorigenic. The number of lineages that are present in a tissue would affect this. If there were more lineages, only a few would become transformed, so most would have 0 mutations; however, if there were more lineages, more of these would have to undergo some of the steps towards cancer in order for the total incidence to be the same. The number of mutations in each lineage would therefore be higher, and there would be a corresponding decrease in acceleration. This mimics the situation in breast cancer , which could be explained by the tissue having fewer lineages ither because there are fewer stem cells than in other tissues or because precancerous lineages frequently expand at the expense of neighbouring lineages. The clonal expansion of a cell population could also influence the acceleration of cancer. For example, if the rate of expansion is slow, the rate at which a lineage acquires the next rate-limiting mutation would accelerate slowly over time, causing a peak of acceleration in midlife. The more rapid clonal expansion, the earlier the peak in acceleration. Also, as the size of the clone increases, the peak of acceleration increases, but only to a certain extent. When the number of cells reaches a certain size, the probability that a mutation will occur after a short time is so high that further clonal expansion can not further increase the rate. Finally, the number of rounds of clonal expansion could also affect the acceleration of cancer. When 3 rounds of clonal expansion occur - because different mutations cause waves of proliferation - the peak acceleration is greatly increased, and this could explain the high acceleration of cancer in midlife that is observed in prostate cancer.

rich nations have more cancer than poor ones, mostly because of tumors tied to bad habit

smoking
drinking
eating too much or the wrong kinds of foods
lack of exercise

although industrialization is suggested to be a major factor in the prevalence of cancer, the report reveals that the majority of investigative studies on occupational exposures and the risk of cancer were published between 1950 and 1975, adding that few occupational carcinogens have been identified in the last 25 years. This is a reflection of the shift to the right in social policy in all the major industrialized countries, as well as the complete prostration of the official labor movements, which have abandoned workers to being the guinea pigs for industrial poisoning.
globally, life expectancy has increased from 45 years in 1950 to 66 years in 2000, but the median age will have risen from 23.5 years in 1950 to 36.5 years in 2050. By 2050, more than 20% of the population will be 60 years and over, versus 10% in 2000. By comparison, the number of cancer deaths increased by 35% during the period 1985-1997.

Web resources : State Cancer Profiles at NCI