FINE-NEEDLE ETHANOL INJECTION THERAPY FOR HUMAN PANCREATIC ADENOCARCINOMA SUBCUTANEOUSLY XENOGRAFTED IN NUDE-MICE

OBJECTIVE: To examine the effects of fine needle ethanol injections on human pancreatic adenocarcinoma subcutaneously xenografted in nude mi ce. METHODS: Thirty-six nude mice were inoculated with CAPAN-1-335 hum an pancreatic cancer cell line. Tumour volumes were calculated from se rial triaxial caliper measurements. On day 24, three sets of two group s of six mice each were formed based on the tumour volume achieved at that time so that groups from the same set had comparable tumour volum e. The first set of two groups was used as a feasibility study to dete rmine the amount of ethanol or saline which could be safely injected i nto nude mice. The second set was injected on day 24 and 28 with a vol ume of ethanol (group 3) or saline (group 4) equivalent to 25% of the tumour volume and was sacrificed on day 31. The tumours were excised f or histological analysis and nuclear magnetic resonance relaxation tim e measurements. The third set was injected four times (on day 24, 28, 31 and 35) with a similar volume of ethanol (group 5) or saline (group 6) and was observed for tumour growth curves and mice survival compar isons. RESULTS: On light microscopy, ethanol-injected tumours were mos tly necrotic with elongated and homogeneous cytoplasms and with conden sed and chromophilic nuclei. As a result of ethanol-induced tumour nec rosis, longitudinal (T1) and transverse (T2) relaxation times were sig nificantly shorter for ethanol-injected tumours (763+/-85 and 72+/-16 ms) compared with saline-injected ones (1147+/-75 and 122+/-11 ms). On day 42, the mean tumour volume in group 5 (392+/-366 mm3) was signifi cantly smaller than group 6 (1392+/-331 mm3). In group 5, tumour growt h was completely stopped from day 28 to 45 after which it started to e xpand again. In group 6, tumour growth was continuous until day 56 whe n it reached a plateau. Sixty days after the last injection, 50% of th e saline-injected mice were dead whereas all the ethanol-injected ones were still alive. CONCLUSIONS: This study shows that a series of fine needle ethanol injections had a significant effect on human pancreati c adenocarcinoma subcutaneously xenografted in nude mice.