Treatment of human pancreatic tumors xenografted in nude mice by chemotherapy combined with pulsed electric fields.

Cancer of the pancreas is currently the fifth leading cause of cancer related deaths with a five year survival of less than 1% In the United States (1). It is one of the most difficult cancers to treat, since it is hard to detect in the early stages. The patients remain asymptomatic until late in the course of the disease. An excellent review of pancreatic carcinoma has appeared (2). Despite the progress made in our understanding of the biology of this cancer (3), the final outcome for this disease has remained extremely poor. Conventional chemotherapeutic agents have not been very effective for human pancreatic adenocarcinoma (4). Use of intratumoral chemotherapy in combination with monoclonal antibodies have been reported to produce better response rate and also reduced toxicity (5,6). Smith and colleagues (7) have recently shown that an injectable gel with a sustained release profile can inhibit tumor growth in vivo in human pancreatic cancer xenografts. This was demonstrated in nude mice with BxPC-3 xenografts using fluorouracil, cisplatin, and doxorubicin with a consequent size reduction of the tumors between 72% and 79%, compared to the controls at day 28 after the first treatment. Although these figures are impressive, by any standard, no cure was reported.