1: Med Hypotheses. 1980 Dec;6(12):1315-25. |
Feedback in cancer.
Zajicek G.
The theory presented regards cancer as a systemic disease initiated by
carcinogens, and neoplasia as the organism's main defence against it.
Carcinogens are assumed to destroy a vital substance "A" which is
replenished by a second, "B", produced by neoplastic stem cells.
Cancer progression is manifested by a gradual deterioration of the
"A" producing machinery accompanied by a compensatory proliferation
of neoplastic "B" producing stem cells whose size is therefore
closely regulated so as to meet the organism's demands. Any stem cell pool
reduction leading to a loss of "A" or "B" is followed by a
proliferation of the remaining stem cells to replenish the loss. Such may be
observed in chronic lymphoblastic leukemia maintaining a nearly constant
elevated peripheral lymphoblast count. Following selective lymphoblast
destruction the count is rapidly replenished to its pretreatment level. The same
mechanism is assumed to explain the detrimental effect of some surgical
interventions on cancer patients. Neoplastic progression is postulated to a
obey a "stem cell conservation" principle which when violated is
followed either by a stem cell replenishment or aggrevates the patient's
conditions. This conservation law introduces a new definition of
carcinogenesis: Any process reducing the "A" or "B"
producing machinery is regarded as a carcinogen. A definition embracing,
surgical extirpation of normal or neoplastic stem cells or cell destruction by
irradiation, chemotherapy or chemical carcinogens.
PMID: 7219237 [PubMed - indexed for MEDLINE]