Antitumor effect induced by dendritic cell (DC)-based immunotherapy against peritoneal dissemination of the hamster pancreatic cancer.

Establishing a method to control peritoneal dissemination is one of the most pressing issues in the postsurgical treatment of pancreatic cancer. In the present study, we investigated the effect of dendritic cell (DC)-based immunotherapy on peritoneal disseminations of hamster pancreatic cancer cells, PGHAM-1. After the orthotopically inoculation of 2 x 10(6) PGHAM-1 cells, DC pulsed with PGHAM-1-derived tumor lysates, DC alone or PBS as a vehicle was injected intraperitoneally (i.p.) three times at weekly intervals. The group treated with DC or DC+lysate was found to have smaller disseminated tumors than the vehicle-treated. In addition, mean survival time in the DC+lysate groups was significantly longer than the PBS group. These findings suggested that DC-based immunotherapy might be efficient for the treatment of peritoneal disseminations of the pancreatic cancer.