Can laser cause cancer/tumors/malignancies, or accelerate their growth?
The simple answer to this is “no!”. All available research to date indicates that laser irradiation either has no effect on cancerous tissues or, in the case of small tumors, a positive effect (i.e. it can reduce the tumor size). Laser tends to act only upon cells in which normal function is compromised, not on those with normal or ‘super-normal’ function. Tumor cells do not have compromised function, but are effectively ‘over-functioning’, and both in vitro and in vivo research has shown that laser has no effect on those cells (in other words, it doesn’t speed up the rate of tumor growth). In fact, some in vivo research has shown that if tumorous tissues are irradiated with laser energy, small tumors can actually be reduced or caused to disappear completely (likely due to enhanced function of surrounding, compromised, tissues as well as the systemic effects generated by laser irradiation), whereas tumors over a certain size were completely unaffected. McGuff et al showed as far back a
