Toward general prophylactic cancer vaccination.

It is well established that chronic infections can lead to cancer. Almost unknown is that, in contrast, acute brief viral and bacterial infections may have beneficial effects in cases of established neoplastic disease, while exposure to pathogenic products by infection, vaccination, and inhalation can cause prophylactic effects. In the following I will align evidence from case studies of spontaneous regression and from epidemiological studies with recent immunology to conclude that pathogenic substances belonging to the group of "pathogen-associated molecular patterns" can trigger the innate immune system to establish anti-neoplastic immune responses. A better understanding of the protective role of the innate immune system might leverage considerable prophylactic potential.