  In 2015 in the United States 612,000 persons died from cancer whereas only
470 died from tuberculosis (TB), a disease which was the main cause of death
around 1900. How can one explain such a key discrepancy in treatment progress?
A statistical comparison between TB and cancer will give some clues. However,
TB and cancer also share several important features. Both TB and cancer can
affect several organs, e.g. lungs, brain, bones, intestines, skin. What in
cancer is called malignant neoplasm (tumor) is called granuloma in TB. By
isolating malignant cells (versus bacteria) from the rest of the body, such
clusters protect the host's organism but at the same time they are "secure
beachheads" from where malignant cells (versus infected macrophages) can wander
off to new locations. Thus, metastatic tumors have a TB parallel in the form of
secondary granulomas. In order to investigate more closely this parallel we use
the age-specific response of organs. Called spectrometric analysis in a
previous paper (Berrut et al. 2017), this method provides information about how
fast tumors develop and how serious they become. A convenient characterization
of the response to TB of organ j is given by the following (age-dependent)
death ratio: Tj(t)=(death by TB of type j)/(all TB deaths) The development of
cancer tumors can be described by a similar function Cj(t). We compare the
organs' responses in all cases for which specific death data are available. It
appears that for the same organ Tj(t) is similar in shape to Cj(t). For
instance, with regard to brain tumors, both TB and cancer mortality peak around
the age of 10. Such observations may bring to light vulnerabilities in the way
the immune system provides protection to various organs.
