  Understanding the untreated tumor growth kinetics and its intrinsic findings
is interesting and intriguing. The aim of this study is to propose an
approximate analytical expression that allows to simulate changes in surface
charge density changes at cancer-surrounding healthy tissue interface during
the untreated solid tumor growth. For this, the Gompertz and Poisson equations
are used. Simulations reveal that the unperturbed solid tumor growth is closely
related to changes in the surface charge density over time between the tumor
and the surrounding healthy tissue. Furthermore, the unperturbed solid tumor
growth is governed by temporal changes in this surface charge density. It is
concluded that graphic strategies corroborate the correspondence between the
electrical and physiological parameters in the untreated cancer, which may have
an essential role in its growth, progression, metastasis and protection against
immune system attack and anti-cancer therapies. In addition, the knowledge of
surface charge density changes at cancer-surrounding healthy tissue interface
may be relevant when redesigning the molecules in chemotherapy and
immunotherapy taking into account their polarities. This can also be true in
the design of completely novel therapies.
