Laser therapy can worsen skin cancer: Study

London: Cancer patients should avoid low-level laser therapy (LLLT) to treat hair-loss and skin care, as a new study has found that over exposure to low-intensity lasers causes expansion of tumour cells.

Using a mouse model, Jan M. Bjordal from Bergen University College in Norway and his colleagues studied the effect of laser irradiation or the exposure to lasers on melanomas (cancerous tumours).

For their study, the team applied LLLT to cancer cultures and to mice injected with melanoma cells.

The team found that the treatment did not cause any significant changes in the cell cultures, however, direct irradiation of pain relieving, anti-inflammatory "cold laser", resulted in increased tumour growth in the mouse model of skin cancer.

"A high irradiance combined with high dose (of LLLT) can stimulate melanoma tumor growth with distinct histological features in vivo," said Bjordal.

"It is important that this contra-indication is implemented into clinical practice so that LLLT can remain a safe treatment," Bjordal writes in the open access journal "BMC Cancer".

LLLT was pioneered in the 1970s, when it was discovered that light from low-intensity lasers causes cells to proliferate more rapidly.