[Experimental study on tumor metastasis after treatment by hematoporphyrin derivative and laser].

The purpose of the present experiment is to observe whether metastasis will develop after the tumor is treated by hematoporphyrin derivative (HPD) and pulse laser. Mouse transplantable forestomach carcinoma (FC) was used of which the spontaneous metastasis rate was 33% to 83%. 179 inbred "615" mice were divided into six groups for repeated experiments. The first repeated experiment included three groups: group 1, pulse laser with HPD; group 2, continuous laser with HPD; group 3, control. The second repeated experiment also included three groups: group 4, pulse laser without HPD; group 5, pulse laser with HPD and group 6, control. On day 5 after FC transplantation, the animals of group 1, 2 and 5 were injected intraperitoneally with HPD (50mg/kg) and then group 1, 2, 4 and 5 were treated with laser on day 7. From group 1, 2 and 3, 10 animals were sacrificed on day 12 and the rest animals on day 16. The lymph nodes and lungs of all animals were taken out for gross and histological examination. It was found that the tumor metastasis rates of the six groups were: group 1, 32.3% (10/31); group 2, 21.8% (7/32); group 3, 38.1% (8/22); group 4, 64.0% (16/25); group 5, 74.1% (20/27) and group 6, 83.3% (35/42). It shows that laser does not increase the incidence of tumor metastasis.