[Chemoradiation in pancreatic carcinoma]

Cryosurgery for pancreatic cancer

The procedure of pancreatic cryosurgery is performed with intraoperative or percutaneous approaches. Based on current data and our initial experience, cryoablation appears to be a feasible, potentially safe and promising option in patients with locally advanced and unresectable pancreatic cancer. It is suggested that there are almost no known contraindications to the use of cryosurgery for pancreatic cancer. For most patients with pancreatic cancer, cryosurgery can substitute conventional surgery.

Apoptosis and expression of the Bcl-2 family of proteins and P53 in human pancreatic ductal adenocarcinoma

OBJECTIVE

The purpose of this study was to clarify the association between P53 and the Bcl-2 family (Bcl-2, Bax, Bcl-xL, Bcl-xS) expression and apoptosis in pancreatic ductal adenocarcinoma (PDAC).

SUBJECTS AND METHODS

A total of 70 patients with PDAC were studied. The expression of P53 protein in PDAC was assessed using the immunohistochemical method, which categorized the PDAC patients into two groups: group 1: 36 cases with immunonegative P53(-), and group 2: 34 cases with immunopositive P53(+). The expression of Bcl-2, Bax, Bcl-xL, and Bcl-xS in the 70 PDAC cases was detected by immunohistochemical and Western blotting methods. The apoptotic index (AI) was also measured in these samples by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. The relation between P53 and the Bcl-2 protein family and apoptosis was then evaluated.

RESULTS

Bcl-2 and Bcl-xS expression was significantly associated with P53 (p < 0.05). No clear associations were found among P53, Bax and Bcl-xL expression (p > 0.05). The AI of groups 1 and 2 was 12.1 ± 2.47 and 8.1 ± 1.48, respectively (p = 0.023). There was no relationship between AI and Bcl-2, Bax, Bcl-xL and Bcl-xS expression (p > 0.05, respectively). Bcl-2/Bax ratio was significantly associated with AI (p < 0.01).

CONCLUSION

Bcl-2 and Bcl-xS represent significant anti- and proapoptotic proteins, respectively, modulated through a P53-dependent pathway in PDAC, and P53 modulated apoptosis mainly through Bcl-2/Bax ratio.

Inhibitory effect of Slug gene silencing with siRNA on pancreatic cancer

AIM: To study the effect on pancreatic cancer in rats of rAAV carrying Slug-siRNA to interfere Slug gene expression.

METHODS: A model of subcutaneous tumor was generated through injection of human pancreatic cancer cells BxPC-3 into the nude mice, two weeks later, the nude mice were divided into 3 groups randomly with 6 per group. A recombinant adeno-associated virus vector containing Slug-siRNA gene (rAAV-Slug-siRNA) was constructed. By continuous infusions over 14 d, in negative controls, 1 × 10⁹ puf (50 µL) rAAV-EGFP was injected, while in black controls, 50 µL normal saline was given, in experimental groups, 1 × 10⁹ puf (50 µL) rAAV2-EGFP-slug-siRNA was injected. The general condition, feeding, activities of the rats, and weight were observed. The growth curve of the rats was drawn. After 6 wk, the rats were killed with CO₂, and tumor tissues were cut off and weighed. The expression of Slug protein was detected using the IHC SP method, the apoptosis was detected by TUNEL, and the ultrastructure was detected with TEM.

RESULTS: In the beginning of 2 wk, not any apparent growth change was found in three groups. But 2 wk later, the tumor grew slowly in experimental groups than in negative controls and blank controls (P < 0.05). After treatment of 6 wk, the tumor weight in experimental groups was lower than in negative control group or than blank controls group (3.26 ± 0.48 g vs 7.56 ± 1.25 g, 7.50 ± 1.23 g, all P < 0.05). The AI was significant higher in experimental group than in the negative control group or blank control group (0.27 ± 0.06 vs 0.024 ± 0.01, 0.025 ± 0.01, all P < 0.05). The inhibitory rate was 71.4% in the experimental group, and 0.04% in the negative group, showing a significant difference (P < 0.01). Under TEM, the organelle had fuzzy structure, and karyopyknosis, chromatin margination was found in tumor cells in experimental group. The expression of Slug was down-regulated in experimental groups.

CONCLUSION: RNAi-mediated Slug gene with rAAV silencing could transfect to pancreatic cancer cells and silence Slug effectively and selectively, which results in the growth and proliferation inhibition in pancreatic cancer in vivo.

Chemoradioimmunotherapy with 5-fluorouracil, cisplatin and interferon-alpha in pancreatic and periampullary cancer: results of a feasibility study

BACKGROUND

Recent studies give rise to the hypothesis, that adjuvant chemoradioimmunotherapy with 5-fluorouracil (5-FU), cisplatin and interferon-alpha (IFN-alpha) might be a possible new treatment of pancreatic cancer in resected patients. We report the up-to-now experience at our institution.

PATIENTS AND METHODS

Eleven patients with histological diagnosis of localized carcinoma of the pancreas (n=7) or periampullary (n=4) were prospectively analyzed. Four patients were deemed unresectable because of local invasion of adjacent organs (neoadjuvant setting) and seven patients underwent curative resection (adjuvant setting). Eight patients were classified as T3 carcinomas and three T4 carcinomas. Fifty-five per cent (6/11) of the patients presented with positive lymph node involvement. One histological Grade I, six Grade II and three Grade III were detected. External conformal irradiation to a total dose of 50.4 Gy with 1.8 Gy per day was delivered. All patients received a concomitant chemotherapy with continuous 5-FU 200 mg/m2 per day on 28 treatment days and intravenous bolus cisplatin 30 mg/m2 per week (Day 2, 9, 16, 23, 30). A recombinant r-IFN-alpha was administered on three days weekly during Week one to five of the radiotherapy course as subcutanous injections with 3*3 Mio. I.U. weekly.

RESULTS

The four-year overall survival rate for all patients was 55%. In the neoadjuvant group, three of four patients died due to progressive disease; in the adjuvant group, combined chemoradioimmunotherapy lead to controlled disease in five of seven patients. The overall toxicity was well-managed.

CONCLUSION

Our data strengthens the hypothesis of concomitant chemoradioimmunotherapy with 5-FU, IFN-alpha and cisplatin as a possible new treatment of pancreatic cancer in resected patients.

A pilot study on combination of cryosurgery and 125iodine seed implantation for treatment of locally advanced pancreatic cancer

AIM: To study the therapeutic value of combination of cryosurgery and ¹²⁵iodine seed implantation for locally advanced pancreatic cancer.

METHODS: Forty-nine patients with locally advanced pancreatic cancer (males 36, females 13), with a median age of 59 years, were enrolled in the study. Twelve patients had liver metastases. In all cases the tumors were considered unresectable after a comprehensive evaluation. Patients were treated with cryosurgery, which was performed intraoperatively or percutaneously under guidance of ultrasound and/or computed tomography (CT), and ¹²⁵iodine seed implantation, which was performed during cryosurgery or post-cryosurgery under guidance of ultrasound and/or CT. A few patients received regional celiac artery chemotherapy.

RESULTS: Thirteen patients received intraoperative cryosurgery and 36 received percutaneous cryosurgery. Some patients underwent repeat cryosurgery. ¹²⁵Iodine seed implantation was performed during freezing procedure in 35 patients and 3-9 d after cryosurgery in 14 cases. Twenty patients, 10 of whom had hepatic metastases received regional chemotherapy. At 3 mo after therapy, CT was repeated to estimate tumor response to therapy. Most patients showed varying degrees of tumor necrosis. Complete response (CR) of tumor was seen in 20.4% patients, partial response (PR), in 38.8%, stable disease (SD), in 30.6%, and progressive disease (PD), in 10.2%. Adverse effects associated with cryosurgery included upper abdomen pain and increased serum amylase. Acute pancreatitis was seen in 6 patients one of whom developed severe pancreatitis. All adverse effects were controlled by medical management with no poor outcome. There was no therapy-related mortality. During a median follow-up of 18 mo (range of 5-40), the median survival was 16.2 mo, with 26 patients (53.1%) surviving for 12 mo or more. Overall, the 6-, 12-, 24- and 36-mo survival rates were 94.9%, 63.1%, 22.8% and 9.5%, respectively. Eight patients had survival of 24 mo or more. The patient with the longest survival (40 mo) is still living without evidence of tumor recurrence.

CONCLUSION: Cryosurgery, which is far less invasive than conventional pancreatic resection, and is associated with a low rate of adverse effects, should be the treatment of choice for patients with locally advanced pancreatic cancer. ¹²⁵Iodine seed implantation can destroy the residual surviving cancer cells after cryosurgery. Hence, a combination of both modalities has a complementary effect.

Preoperative locoregional re-evaluation by endoscopic ultrasound in pancreatic ductal adenocarcinoma after neoadjuvant chemoradiation

INTRODUCTION

The accuracy of endoscopic ultrasound (EUS) for the diagnosis and staging of pancreatic ductal adenocarcinoma (PDA) has been confirmed. Chemo-radiotherpay (CRT) induces tumor changes which can limit the accuracy of EUS. The aim of our study was to analyze the efficacy of EUS following neoadjuvant CRT comparing findings with the pathology results.

PATIENTS AND METHODS

From November 1996 to October 2003, 45 patients with histologically proven and EUS-staged PDA were treated with neo-adjuvant CRT and radical surgery. All were restaged before surgery using both EUS and computed tomography. Fifteen patients were found to have developed distant metastases. Thirty patients finally underwent pancreaticoduodenectomy (N=24) or distal pancreatectomy (N=6).

RESULTS

Following CRT, tumor stage was correctly assessed in 12 patients (40%). The most frequent misinterpretation was overestimation of tumor size (N=13, 43.3%). Locoregional vascular invasion of veins was suspected by EUS in 13 patients (43.3%) but surgical findings and the histological examination were both negative. Node status was correctly assessed in 27 patients (90%) but nodal involvement was found on the histological specimen in only 3 patients.

CONCLUSION

Preoperative EUS after neoadjuvant CRT for PDA does not enable reliable definitive selection of patients for surgery, probably due to radiation-induced pancreatic changes.