br are for the registration
are for the registration states Bur . After 1930 the data cover the whole country (except Alaska and Hawaii until statehood). 1850–1899: Statistique
Fig. 3a. Successive lines of defense of a human organism against ‘‘intruders’’, TB mycobacteria or cancer cells. The distinction between phase (2) and (3) would correspond to HIV versus AIDS or latent TB versus developing TB. 90% of TB infected persons remain without symptoms. Antibody fight intruders by marking them for destruction by macrophages. In a general way Trichostatin A (TSA) are foreign or abnormal bodies; for instance in the case of breast cancer, the cancer antigen CA 15.3 are proteins released by cancer cells; for healthy persons the concentration of CA 15.3 is low but not zero for it is thought that this protein is also produced (albeit in small quantity) by normal breast cells.
in contact with the mycobacteria through vaccination (although these are of course in attenuated form). For cancer, the occurrence of cancer cases in early childhood suggests that organisms come in contact with abnormal cells soon after birth. Statistically, this phase is described by the incidence rate which is the number of cases divided by the population. Fig. 3b shows that, averaged over age, control is lost in about 1000 cases per 100,000 for cancer as compared to only 3.3 cases per 100,000 for TB. It is mostly in this phase that the battle against cancer is lost.
In short for cancer the incidence rate is much larger than for TB especially in old age.
(2) In the second phase the number of intruders continues to grow until eventually this increase leads to death. Statistically, this phase is described by the case-fatality ratio which is the probability of death for a person who was diagnosed with the disease. It is given by the death rate divided by the incidence rate. Fig. 3c shows that for cancer the case-fatality ratio is moderately larger than for TB.
P. Richmond and B.M. Roehner / Physica A xxx (xxxx) xxx 5
Fig. 3b,c. Comparison of the incidence rate and case fatality ratio for TB and cancer. (b) The incidence rate is the ratio: persons diagnosed with the disease divided by population. (c) The case fatality ratio is the ratio: deaths caused by the disease divided by persons diagnosed with the disease; it is given by the death rate divided by the incidence rate. It represents the probability of death for a person who is known to be ill in the respective age interval. The fact that both the incidence rate and the case fatality ratio increase with age shows that as they age organisms becomes less and less able to fight the disease successfully. More precisely, for TB it is the fatality ratio which increases fastest with age, whereas for cancer it is the incidence rate which shows the largest increase.
Taken together the curves in Fig. 3b,c show that it is the weakness of the first and second line of defense against cancer which is the main factor in the huge difference seen in Fig. 1a.
The graphs of Fig. 3b,c can be further illustrated by the following facts.
• Fig. 3c shows that for cancer the case-fatality ratio is of the order of 30%.3 This is a proportion which is higher than for most infectious diseases. Thus, for measles in the outbreak of 1989–1991 in California and New York it was less than 1%. As a more significant comparison, the case fatality ratio of TB for South African HIV-infested persons is about 20% . Moreover, for most infectious diseases the case-fatality ratio decreases with age whereas for cancer it increases with age.4
• In an epidemic usually only a small proportion of the population is infected by the pathogens (in the sense of producing antibodies). On the contrary, the production of abnormal cells occurs in all organisms which means that the theoretical infection rate is 100%.
• With respect to infectious diseases any population comprises two components: (i) the susceptibles that is to say the persons who are not immunized and (ii) those who are immunized. The proportion of the second group increases with age. On the contrary, for cancer nobody seems to be immune.