Radiotherapy in the treatment of pancreatic cancer

Analysis of long-term survivors after surgical resection for invasive pancreatic cancer

Pancreatic cancer remains a lethal disease. Although there are many reports on the survival rates of pancreatic cancer patients after surgical resection, the clinicopathological characteristics that influence long-term survival over 5 years remain controversial. Here, we clarify the favourable prognostic factors for long-term survival. One hundred and eighty-two patients with pancreatic cancer underwent surgical resections from 1981 to 1997 in our department. Among them, eight patients survived for at least 5 years after the surgery. The clinicopathological characteristics of the eight long-term survivors who underwent radical resections were studied retrospectively. R0 surgical resections, including five combined with portal vein resections (62.5%), were achieved in these eight patients. Negative invasions of the major regional artery (seven of eight, 87.5%) and to the extrapancreatic nerve plexus (seven of eight, 87.5%), and N0 or Nl lymph node metastasis (7 of 8, 87.5%) were detected as clinicopathological features of long-term survivors in our study. No exposure of carcinoma at the dissected surface and cut end (seven of eight, 87.5%) was characteristically confirmed by pathology. Portal vein invasion was seen in three of the eight patients (37.5%). For long-term survival in cases of pancreatic cancer, complete R0 resections should be performed and negative invasions in the major regional arteries and to the extrapancreatic plexus of the nerve were necessary. No invasion to the portal vein was not necessarily required if R0 was achieved by combined resection of the portal vein.

Pain management of patients with unresectable peripancreatic carcinoma

In patients with unresectable peripancreatic carcinoma, pain is generally treated with pain medication or with a celiac plexus blockade. Radiotherapy has also been reported to reduce pain. The efficacy of these treatment modalities is still under discussion. The aim of this study was to analyze the effects of the various types of pain management on patients who underwent palliative bypass surgery for unresectable peripancreatic carcinoma. During the period January 1995 to December 1998 a series of 98 patients underwent palliative bypass surgery, mostly for unresectable disease found during exploration. Patients were divided into three groups: palliative bypass surgery (BP), palliative bypass surgery with an intraoperative celiac plexus blockade (CPB), and palliative bypass surgery with or without celiac plexus blockade followed by high-dose conformal radiotherapy (RT). Radiotherapy was performed only in selected patients with locally advanced disease and without metastases, implying a better prognosis of the last group. The pain medication consumption, pain medication-free survival, hospital-free survival, and overall survival were analyzed. The preoperative consumption of pain medication was significantly higher in the CPB group than in the BP or RT group. The postoperative consumption of pain medication in the CPB, BP, and RT groups increased during follow-up from 15%, 17%, and 13% before surgery to 52%, 57%, and 46%, respectively, at three-fourths of the survival time (NS). This increase in consumption of pain medication was not different in the three groups. In the RT group the median pain medication-free survival was significantly longer than in the BP or CPB group (9.3 vs. 3.1 and 3.3 months; p = 0.02). The median hospital-free survival and median overall survival were significantly longer in the RT group than in the CPB group (10.3 vs. 6.8 months, p = 0.01; and 7.1 vs. 10.8 months, p = 0.01). Celiac plexus blockade as pain management did not result in an increase of the pain medication-free survival or overall survival. Therefore a positive effect of a celiac plexus blockade on pain could not be confirmed in the present study. Radiotherapy resulted in increased pain-medication survival, hospital-free survival, and overall survival compared to celiac plexus blockade. These effects are probably partly related to patient selection.

Combined effects of adeno-associated virus vector and a herpes simplex virus mutant as neoplastic therapy

BACKGROUND AND OBJECTIVES

Although surgical therapy for pancreatic cancer has not been successful, new gene therapies, such as adeno-associated virus (AAV) vectors hold promise for treating cancer. However, expression of AAV vectors alone is insufficient for adequate effects in vivo for cancer therapy. We describe a novel therapy using the combined herpes simplex virus-ICP6 deletion mutant (ICP6delta) and AAV vector.

METHODS

We investigated ICP6delta and AAV regarding kinetics and dose-response relationships of LacZ expression in vitro. We studied the expression of LacZ in vivo using subcutaneous pancreatic cancer tumors (SW1990) in nude mice.

RESULTS

In vitro, ICP6delta enhanced the expression of AAV; 24 hr following inoculation there was more expression with AAV plus ICP6delta than with AAV plus KOS, and a multiplicity of infection (MOI) of 0.5 was the optimal titer of ICP6delta to support maximal expression of AAV. In vivo, there was much higher expression of LacZ in mice injected with AAV-LacZ plus ICP6A than with AAV-LacZ alone.

CONCLUSIONS

ICP6delta enhances expression of AAV-vector in vitro and in vivo. These results suggested that combined therapy have potential for human cancer.

Intraperitoneal delivery of hrR3 and ganciclovir prolongs survival in mice with disseminated pancreatic cancer

BACKGROUND AND OBJECTIVES; Intraperitoneal dissemination of pancreatic cancer is associated with a poor prognosis. Surgical resection does not prolong survival. Here we describe a novel approach to this difficult clinical problem consisting of intraperitoneal delivery of the herpes simplex virus (HSV) vector (hrR3) to mice with peritoneal dissemination of the pancreatic cancer cells.

METHODS

The human pancreatic cancer cell line (SW1990) was implanted into the abdominal cavity of nude mice. Fifteen days later, the abdominal neoplasm was treated by intraperitoneal injection of the replication-conditional HSV vector (hrR3). The mutant lacks the ribonucleotide reductase gene, but contains an intact HSV-tk gene. Beginning 5 days after vector injection, mice were treated with a 14-day course of ganciclovir.

RESULTS

Long-term survival (150 days) was seen in 70% of mice receiving hrR3 and ganciclovir, 40% of mice receiving hrR3 alone, and 0% of untreated mice. No vector-related mortality was observed. X-Gal tissue staining revealed blue-stained cells only in tumor nodules, not in normal organs.

CONCLUSIONS

Intraperitoneal delivery of hrR3 and ganciclovir improves survival in this murine model of peritoneal dissemination of pancreatic cancer. The ability of hrR3 to replicate only in rapidly dividing cells makes this virus an attractive vector for gene therapy of cancer.

Gene therapy for peritoneal dissemination of pancreatic cancer by liposome-mediated transfer of herpes simplex virus thymidine kinase gene

Peritoneal dissemination is one of the most common complications of the malignancies of the digestive system, such as gastric or pancreatic cancers. Yet, no effective therapy has been established so far to alleviate this devastating and often fatal end-stage condition. Here we describe a novel approach of intraperitoneal (i.p.) lipofection of a suicidal gene to the pancreatic cancer cells in a mouse peritoneal dissemination model. A human pancreatic cancer cell line, PSN-1, was inoculated into the peritoneal cavity of nude mice. Eight days later, a herpes simplex virus thymidine kinase (HSV-TK) gene expression plasmid under a potent hybrid promoter CAG was injected as a DNA-lipopolyamine complex. Ganciclovir (GCV) was then administered for 8 days, and the mice were examined for tumor development at the 24th day after the tumor inoculation. Although all 24 control mice showed macroscopic peritoneal dissemination and solid tumors on the pancreas, 8 of the 14 mice treated with HSV-TK and GCV were free of tumors, and only a few small tumors were observed in the remaining 6 mice. Treatment-related toxicity was not observed. The semiquantitative reverse transcription polymerase chain reaction (RT-PCR) analysis suggested that the HSV-TK transgene was expressed in about 10% of tumor cells but not in the normal pancreas or in the small intestine. When the lacZ gene was transduced in place of the HSV-TK gene, the blue-stained cells were identified only in tumor nodules and not in normal organs. This preclinical study suggests the therapeutic feasibility of the i.p. lipofection-based suicidal gene/prodrug strategy for peritoneal dissemination of pancreatic cancer.

Intraoperative and postoperative radiotherapy in pancreatic cancer

In the 1985-1994 period, 101 patients underwent resection for ductal pancreatic adenocarcinoma. In 27 patients, the resection was not associated with adjuvant therapies, whereas in 74 patients, it was. Intraoperative radiation therapy (IORT) was performed in 54 patients. Operative mortality and morbidity were similar in patients undergoing IORT (1.8 and 29.6%) to those undergoing resection alone (2.1 and 27.6%). Median survival of the IORT group was 17 vs 14 mo of the non-IORT group (irrespective of postoperative treatments) (ns); the local recurrence rates were 38 and 54%, respectively. The group of 74 patients undergoing adjuvant therapies had a greater survival than 27 patients with no adjuvant treatment, both at the univariate (p < 0.01) and the multivariate analyses (p < 0.05) (covariates tumor stage and radicality). The subgroup of patients undergoing only radiotherapy (RT) and/or chemotherapy (CT) did not show significantly better survival than patients with no additional therapies, whereas the group of patients undergoing IORT + CT + RT showed a significantly better survival (p < 0.05). In conclusion, adjuvant therapies seem to improve survival in patients undergoing resection for pancreatic cancer.

Recurrence after resection for ductal adenocarcinoma of the pancreas

We analyzed the pattern of failure and clinicopathologic factors influencing the disease-free survival of 78 patients who died after macroscopic curative resection for pancreatic cancer. Local recurrence was a component of failure in 56 patients (71.8%) and hepatic recurrence in 48 (61.5%), both accounting for 97% of the total recurrence rate. About 95% of recurrences occurred by 24 months after operation. Median disease-free survival time was 8 months, and cumulative 1-, 3-, and 5-year actuarial disease-free survival rates were 66%, 7%, and 3%, respectively. Multivariate analysis showed that tumor grade (p = 0.04), microscopic radicality of resection (p = 0.04), lymph node status (p = 0.01), and size of the tumor (p = 0.005) were independent predictors of disease-free survival. Patterns of failure and disease-free survival were not statistically influenced by the type of surgical procedure performed. Median survival time from the detection of recurrence until death was 7 months for local recurrence versus 3 months for hepatic or local plus hepatic recurrence (p < 0.05). From our experience and the data collected from the literature, it appears that surgery alone is an inadequate treatment for cure in patients with pancreatic carcinoma. Effective adjuvant therapies are needed to improve locoregional control of pancreatic cancer after surgical resection.

Combined modality treatment with accelerated radiotherapy and chemotherapy in patients with locally advanced inoperable carcinoma of the pancreas: results of a feasibility study

Between July 1990 and September 1993, 32 patients with locally advanced irresectable adenocarcinoma of the pancreas, histologically proven by laparotomy, were involved in our study. Patients were treated with hyperfractionated, accelerated radiotherapy and simultaneous application of 5-fluorouracil and folinic acid. Chemotherapy was given on days 1,2 and 3. Determination of the target volume for radiotherapy was carried out by computerized axial tomography. The total tumour dose of 44.8 Gy was applied relative to the 90% isodose in two daily fractions of 1.6 Gy, resulting in ten fractions per week. On the first three days of radiotherapy, 600 mg m-3 of 5-fluorouracil and 300 mg m-3 of folinic acid were given i.v. According to response, chemotherapy was repeated in 4-week intervals. The median survival time for all patients was 12.7 months, compared with 3-7 months after palliative surgery (historical control). The median progression-free interval was 6.6 months. Toxicity and therapy-induced morbidity were recorded according to WHO criteria. Nausea and vomiting of WHO grade I and II occurred in 72.1% and of grade III and IV in 27.9% of the patients. WHO grade I and II diarrhoea was seen in 11 patients. The overall incidence of leucopenia and thrombocytopenia was 37.4%; severe side-effects (WHO III-IV) occurred in 9.3% of all patients. One patient experienced a severe mucositis (WHO III). This combined modality treatment consisting of accelerated hyperfractionated radiotherapy and chemotherapy turned out to be feasible for patients with locally advanced, irresectable pancreatic cancer. The therapy could be applied in a short period of time, approximately half the time used in conventional therapy schemes.