FAQ - Cancer, Tumors and Malignancies

QUESTION: 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 as 1964, in what is probably the first ever academic paper discussing laser biostimulation, that "Laser energy has a selective effect on certain malignant tumours, resulting in their progressive regression and ultimate dissolution." 'The Laser Treatment of Experimental Malignant Tumours' Journal of the Canadian Medical Association, Nov 21, 1964, Vol.91 No.21.

The Swedish Laser-Medical Society has the following to say on the subject:

There are many people that don't know so much about lasers – some believe that a laser emits some kind of mystical "radiation". Yes, radiation (e.g. X-ray or gamma) can be dangerous and can even cause cancer, but can the light from a therapeutic laser cause cancer? No, definitely not. (See the section "Contraindications" on page 22). No mutational effects have been observed from light with wavelengths above 600 nm at the doses that are used in laser therapy. But what happens if you happen to treat someone who already has cancer without knowing about it? Can the growth of a tumour be stimulated by laser light? The answer is no; The effects of laser light in cancer cells in vitro have been studied, and it has been established that it is possible to stimulate the cancer cells' growth with the help of particular doses of laser light. However, conditions are different for a cancer that is growing inside a living being (this is called in vivo) to what is true for treating a cell culture (in vitro).

In trials using rats, with transplanted tumors of different sizes, it has been observed that small tumors that have been treated with lasers can be made to shrink and even completely disappear; this is due to the laser stimulating the local immune system more than the tumor. However, for tumors above a certain size the immune system boosting effect of the laser treatment was not enough to stop them growing. The situation is equivalent to that of bacteria cultures. These can, in culture, be stimulated by the right doses of laser light, while a bacterial infection in an individual, where there is also an immune system, heals more quickly when laser treatment is carried out in the correct manner. It is important that there is a diagnosis before you start laser therapy – an undiagnosed pain could be due to cancer...

Excerpt from 'Lasers That Heal' by Lars Hode, The Swedish Laser-Medical Society and Irradia Education, p16.

So, although caution is recommended and accurate diagnosis is essential, the application of laser therapy can neither cause nor accelerate tumor growth.

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