Adjuvant therapy in pancreatic cancer

Postoperative Chemoradiotherapy of Pancreatic Cancer: What is the Appropriate Target Volume of Radiation Therapy?

Aims and Background

To evaluate the influence of radiation therapy target volume on the treatment outcome of adjuvant chemoradiotherapy for pancreatic cancer after curative resection.

Methods

Between February 1987 and July 2001, 70 patients treated with curative resection and adjuvant chemoradiotherapy for pancreatic adenocarcinoma were analyzed. There were 49 males and 21 females, with a median age of 57 years. Whipple's operation was performed in 44 patients, pylorus-preserving pancreaticoduodenectomy in 14, distal pancreatectomy in 9, and subtotal pancreatectomy in 3. Postoperative adjuvant radiotherapy was given up to 40 Gy at 2 Gy per fraction with a two-week planned rest. Intravenous 5-fluorouracil (500 mg/m2/day) was given on days 1 to 3 of each split course of radiotherapy. Until 1991, whole pancreas or preoperative tumor volume and retroperitoneal lymph nodes were irradiated (extended field, n = 14). Thereafter, the target volume included the retroperitoneal lymph nodes and the involved pancreatic resection margin (limited field, n = 56). The median follow-up period of all the patients was 16 months (range, 2-99).

Results

The overall 2- and 5-year survival rate of all patients was 29.7% and 14.0%, respectively. According to the radiotherapy target volume, the median survival time was 14 months in the extended field group and 16 months in the limited field group ( P = 0.65).

Conclusions

From the viewpoint of the target volume of radiotherapy, a limited field did not worsen the treatment outcome, although the survival rate was poor in both groups.

Helical tomotherapy with concurrent capecitabine for the treatment of inoperable pancreatic cancer

Background

Helical tomotherapy, an advanced intensity-modulated radiation therapy with integrated CT imaging, permits highly conformal irradiation with sparing of normal tissue. Capecitabine, a pro-drug of 5-FU that induces thymidine phosphorylase can achieve higher levels of intracellular 5-FU when administered concurrently with radiation. We evaluated the feasibility as well as the clinical outcome of concurrent administration of capecitabine with tomotherapy in patients with advanced pancreatic cancer.

Methods

Nineteen patients with advanced pancreatic cancer including primarily unresectable disease and recurrence after curative surgery were included in the study. Two planning target volumes (PTV) were entered: PTV1 is gross tumor volume; and PTV2, the volume of the draining lymph nodes. The total doses to target 1 and target 2 were 55 and 50 Gy, respectively. Capecitabine at 1600 mg/m²/day was administered on each day of irradiation.

Results

Twenty six measurable lesions were evaluated. Overall in-field response rate was 42.3%; partial responses were achieved in 53.3% of the pancreatic masses, 28.6% of distant metastatic lesions and 25.0% of regional lymph nodes. The median duration of follow-up after tomotherapy was 6.5 months. None of the lesions showed in-field progression. Treatment was well tolerated with only minor toxicities such as grade 1 nausea (one patient), grade 1 hand-foot syndrome (one patient) and grade 1/2 fatigue (three patients).

Conclusions

Helical tomotherapy with concurrent capecitabine is a feasible option without significant toxicities in patients with advanced pancreatic cancer. We achieved excellent conformal distribution of radiation doses and minimal treatment-related toxicities with promising target volume responses.

Heme oxygenase-1 and its metabolites affect pancreatic tumor growth in vivo

Background

Pancreatic cancer (PaCa) is a fatal human cancer due to its exceptional resistance to all current anticancer therapies. The cytoprotective enzyme heme oxygenase-1 (HO-1) is significantly overexpressed in PaCa and seems to play an important role in cancer resistance to anticancer treatment. The inhibition of HO-1 sensitized PaCa cells to chemo- and radiotherapy in vitro.

Therefore, we investigated the effects of HO-1 and its metabolites biliverdin, carbon monoxide and iron on PaCa cells.

PaCa cell lines with divergent HO-1 expression patterns were used in a murine orthotopic cancer model. HO-1 expression and activity was regulated by zinc (inhibition) and cobalt (induction) protoporphyrin. Furthermore, the influence of cellular HO-1 levels and its metabolites on effects of standard chemotherapy with gemcitabine was tested in vivo and in vitro.

Results

High HO-1 expression in PaCa cell lines was associated with increased chemoresistance in vitro. Chemoresistance to gemcitabine was increased during HO-1 induction in PaCa cells expressing low levels of HO-1. The inhibition of HO-1 activity in pancreatic tumors with high HO-1 boosted chemotherapeutic effects in vivo significantly. Furthermore, biliverdin and iron promoted PaCa resistance to chemotherapy. Consequently, specific iron chelation by desferrioxamine revealed profound anticancerous effects.

Conclusion

In summary, the inhibition of HO-1 and the chelation of iron in PaCa cells were associated with increased sensitivity and susceptibility of pancreatic tumors to chemotherapy in vivo. The metabolites biliverdin and iron seem to be involved in HO-1-mediated resistance to anticancer treatment. Therefore, HO-1 inhibition or direct interference with its metabolites may evolve new PaCa treatment strategies.

Role of epidermal growth factor gene in the development of pancreatic cancer and efficiency of inhibitors of this gene in the treatment of pancreatic carcinoma

The expression of epidermal growth factor receptors in normal and tumor cells of the pancreas, the type and incidence of EGFR gene polymorphism were studied. EGFR gene expression in pancreatic adenocarcinoma cells significantly surpassed that in normal pancreatic cells. On the other hand, AA genome and A allele polymorphism in the EGF gene nucleotide pair G-A 61 is a significant risk factor for pancreatic cancer. The effect of AG-1478 preparation (a new-generation inhibitor of EGFR) on apoptosis and cell proliferation in pancreatic cancer was evaluated. This preparation is not inferior to 5FU by its apoptotic effect and significantly reduces cell proliferation, its antiproliferative effect being 1.5 times higher than that of 5FU.

Effects of α-adrenoreceptor antagonists on apoptosis and proliferation of pancreatic cancer cells in vitro

AIM: To discuss the expression of α-adrenoreceptors in pancreatic cancer cell lines PC-2 and PC-3 and the effects of α₁- and α₂-adrenoreceptor antagonists, yohimbine and urapidil hydrochloride, on the cell lines in vitro.

METHODS: We cultured the human ductal pancreatic adenocarcinoma cell lines PC-2 and PC-3 and analyzed the mRNA expression of α₁- and α₂-adrenergic receptors by reverse transcription polymerase chain reaction (RT-PCR). The effects of yohimbine and urapidil hydrochloride on cell proliferation were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,4,-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected using the terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) assay and flow cytometry (FCM).

RESULTS: PC-2 expressed mRNA in α₁- and α₂-adrenoreceptors. MTT assays showed that urapidil hydrochloride had no effect on PC-3 cell lines. However, exposure to urapidil hydrochloride increased DNA synthesis in PC-2 cell lines as compared to the control group. PC-2 cell lines were sensitive to both drugs. The proliferation of the 2 cell lines was inhibited by yohimbine. Cell proliferation was inhibited by yohimbine via apoptosis induction.

CONCLUSION: The expression of α₁- and α₂-adrenoreceptors is different in PC-2 and PC-3 cell lines, which might be indicative of their different functions. The α₂-adrenoceptor antagonist, yohimbine, can inhibit the proliferation of both cell lines and induce their apoptosis, suggesting that yohimbine can be used as an anticancer drug for apoptosis of PC-2 and PC-3 cells.

Adjuvant chemoradiation for patients with adenocarcinoma of the pancreas: an expirence of single institute

Only a small percentage of patients with pancreatic cancer have limited disease suitable for curative resection. Even with surgery, patients often have poor long-term survival due to relapse of the disease. There are controversies about the adjuvant treatment of these patients. We reported the survival of resected pancreatic cancer from a single institute. About 128 consecutive patients who had complete resection of the pancreatic ductal adenocarcinoma were evaluated, retrospectively. Chemoradiotherapy (45 Gy plus 5-fluorouracil) was given to 63 patients. Fifty-five patients declined to take chemoradiotherapy or with poor performance status were observed without additional treatment. Eight patients took only chemotherapy and two patients took only radiotherapy. The median survival of chemoradiotherapy group was significantly higher than the observation group (13 months vs. 4 months, respectively; P < 0.001). In multivariate analyses the most important factors improving survival were the application of chemoradiation (P < 0.001), low-level serum LDH (P = 0.026), good performance status (P = 0.033) and low serum CA19-9 (P = 0.037). Although adjuvant chemoradiotherapy has a significant survival benefit when compared with the observation group, the survival data are still poor for pancreatic cancer. Therefore, we need more effective additional or adjuvant treatment modalities.

Clinical monitoring of innate cellular immunity of monocytes/macrophages by tumor necrosis factor alpha productivity in whole blood stimulated by lipopolysaccharide in patients with pancreatic cancer

OBJECTIVE

The aim of this study was to evaluate the tumor necrosis factor alpha (TNF-alpha) releasing capacity in whole blood stimulated by lipopolysaccharide (LPS) in patients with pancreatic cancer during the perioperative period, and before and after chemotherapy.

METHODS

The current study involved a total of 39 patients with pancreatic cancer (PC), who were further divided into a PC-Op group (n = 16, underwent pancreatectomy) and a PC-chemo group (n = 23, received chemotherapy). The control groups consisted of patients with hepatocellular carcinoma (n = 27, HCC group) and with benign diseases (n = 15, control group). Serial changes in TNF-alpha in whole blood stimulated by LPS were compared in various clinical settings.

RESULTS

Preoperative TNF-alpha levels in the PC-Op group were significantly lower than those in the HCC and control groups (P = 0.034). The TNF-alpha variable surgical index (s-index) was defined as the ratio of the preoperative TNF-alpha level to postoperative level in the PC-Op and HCC groups. Although the TNF-alpha s-index in the PC-Op group was significantly decreased on postoperative day 1 and recovered on postoperative day 3 (P < 0.002), there were no significant changes in the TNF-alpha s-index in the HCC group. The TNF-alpha variable chemotherapeutic index (c-index) was defined as the ratio of the TNF-alpha level before to that after chemotherapy in the PC-chemo group. The TNF-alpha c-index in all 7 patients was reduced to less than 0.3 until leukopenia appeared. Patients who had an increase in TNF-alpha production (TNF-alpha c-index >1.0) on day 3 or 7 after chemotherapy had significantly better cumulative survival than those with no increase (P < 0.033).

CONCLUSIONS

TNF-alpha production stimulated by LPS in the whole blood of patients with pancreatic cancer was low. Surgical stress and depressed immunocompetence might induce such profound decreases. A method of assessing the capability of leukocytes, particularly macrophages, to produce TNF-alpha could be useful for prognostis and for monitoring immunocompetence in patients with pancreatic cancer who have undergone chemotherapy.

Regional perfusion chemotherapy via arterial chemotherapy pump after extended resection for pancreatic cancer

AIM: To improve the survival rate of pancreatic cancer patients after extended pancreatectomy.

METHODS: The clinical data of pancreatic cancer patients were reviewed after extended pancreatectomy, without adjuvant therapy (control group, n = 27) or with 5-fluorouracil (5-FU) regional perfusion via arterial chemotherapy pump (5-FU group, n = 30), and the prognosis of the two groups were compared.

RESULTS: The survival rate in 5-FU group (median survival time = 16 mo) was significantly better than that in control group (median survival time = 12 mo) (P<0.05, Kaplan-Meier survival analysis, Log rank test); The 2-, 3-year cumulative survival rates in 5-FU group were 37% and 26% respectively, significantly better than those in the control group (15% and 5% respectively) (P < 0.05, x² test); The cumulative rate of death by hepatic metastasis alone in 5-FU group was significantly lower than that in control group (P < 0.05, Log rank test); The WHO grade toxicities of 5-FU group generally were WHO Ⅰ and Ⅱ, and no WHO Ⅳ toxic events were observed.

CONCLUSION: 5-FU regional perfusion chemotherapy via arterial chemotherapy pump after extended resection for pancreatic cancer can reduce the hepatic metastasis with relatively mild toxicities and increase the survival rate of the patients.

Intensity modulated radiation therapy and chemotherapy for locally advanced pancreatic cancer: Results of feasibility study

AIM: To explore whether intensity modulated radiation therapy (IMRT) in combination with chemotherapy could increase radiation dose to gross tumor volume without severe acute radiation related toxicity by decreasing the dose to the surrounding normal tissue in patients with locally advanced pancreatic cancer.

METHODS: Twenty-one patients with locally advanced pancreatic cancer were evaluated in this clinical trial. Patients would receive the dose of IMRT from 21 Gy to 30 Gy in 7 to 10 fractions within two weeks after conventional radiotherapy of 30 Gy in 15 fractions over 3 wk. The total escalation tumor dose would be 51, 54, 57, 60 Gy, respectively. 5-fluororacil (5-FU) or gemcitabine was given concurrently with radiotherapy during the treatment course.

RESULTS: Sixteen patients who had completed the radiotherapy plan with doses of 51 Gy (3 cases), 54 Gy (3 cases), 57 Gy (3 cases) and 60 Gy (7 cases) were included for evaluation. The median levels of CA19-9 prior to and after radiotherapy were 716 U/mL and 255 U/mL respectively (P < 0.001) in 13 patients who demonstrated high levels of CA19-9 before radiotherapy. Fourteen patients who suffered from pain could reduce at least 1/3-1/2 amount of analgesic intake and 5 among these patients got complete relief of pain. Ten patients improved in Karnofsky performance status (KPS). The median follow-up period was 8 mo and one-year survival rate was 35%. No patient suffered more than grade III acute toxicities induced by radiotherapy.

CONCLUSION: Sixty Gy in 25 fractions over 5 wk with late course IMRT technique combined with concurrent 5-FU chemotherapy can provide a definitely palliative benefit with tolerable acute radiation related toxicity for patients with advanced pancreatic cancer.

Correlation of CT enhancement, tumor angiogenesis and pathologic grading of pancreatic carcinoma

AIM: To study the correlation between pancreatic phase CT enhancement, intratumor microvessel density (MVD) and pathologic grading of pancreatic carcinoma and to evaluate the relationship between the degrees of CT enhancement and malignancy of pancreatic carcinoma.

METHODS: Thirty four patients with pancreatic carcinoma underwent CT scanning before resection. The enhancement degrees and forms of tumor were observed in pancreatic phase. The operative sample was stained with HE and CD34 marked by immunohistochemistry. MVD and histopathological grades of pancreatic carcinoma were examined. CT enhancement of the tumor, MVD counting in hot spot areas of neoplastic parenchymal cells and pathological grades of pancreatic carcinoma were comparatively analyzed.

RESULTS: Highly differentiated pancreatic adenocarcinoma was identified in 16 patients, moderately-differentiated tumor in 7 and poorly-differentiated in 11. Isodensity CT enhancement was demonstrated in 13 cases, slightly low density enhancement in 9, slightly low density enhancement with small cystic lesions in 9 and slightly low density enhancement with large cystic lesions in 3. The counting of MVD with CD34 marked by immunohistochemistry in hot spot areas of neoplastic parenchyma cells was small in 10 cases, medium in 16 and large in 8. The pathological grades correlated well with CT enhancement of the tumor (r = 0.7857, P < 0.001) and with MVD counting of tumor (r = 0.3613, P < 0.05). The CT enhancement of tumor correlated with MVD(r = 0.6768, P < 0.001).

CONCLUSION: There is an obvious and significant correlation between CT enhancement, pathological grades and MVD number in the hot spot areas of tumor. The extent of CT enhancement is inversely proportional to the malignant degree of pancreatic carcinoma, and to the MVD number in the hot spot areas of neoplastic parenchyma. The MVD in the hot spot areas of neoplastic parenchyma cells can also reflect the prognosis of the patients, and is directly proportional to the malignant degree of pancreatic carcinoma.

The feasibility and safety of immunotherapy with dendritic cells loaded with CEA mRNA following neoadjuvant chemoradiotherapy and resection of pancreatic cancer

BACKGROUND

Resected pancreatic cancer has a high risk of recurrence and mortality despite the the use of chemoradiotherapy. Because pancreatic cancers express tumor antigens such as carcinoembryonic antigen (CEA), it may be possible to immunize patients to induce tumor antigen-specific immune responses. We hypothesize that high-frequency tumor antigen-specific immune responses will reduce recurrence and increase survival. Autologous dendritic cells (DCs) loaded with tumor antigens are particularly potent at inducing tumor antigen-specific immune responses.

METHODS

Three patients with resected pancreatic adenocarcinoma following neoadjuvant chemoradiotherapy received autologous, monocyte-derived DCs loaded with the mRNA encoding CEA monthly for 6 mo.

RESULTS

It was feasible to generate an adequate number of DC from these patients and to cryopreserve them for repeated use. The DC demonstrated the typical immature phenotype. The immunizations were well-tolerated without evidence of adverse events. All three developed injection site reactivity. All three are alive without evidence of disease at more than 2 1/2 yr from the original diagnosis.

CONCLUSION

The postoperative period following neoadjuvant chemoradiotherapy and pancreaticoduodenectomy for pancreatic cancer is an ideal environment to test novel immune-based therapies. DC-based immunotherapy in this setting is safe and feasible and may lead to prolonged survival.

Effect of ribozymes on inhibiting expression of HBV mRNA in HepG2 cells

AIM: To study the activity of ribozymes with multiple cleavage sites and mutated ribozymes on expression of HBV mRNA in HepG2 cells.

METHODS: The triple ribozymes and two cis-ribozymes or two mutated ribozymes were inserted, respectively, into five kinds of eukaryotic plasmids, which were cotransfected into the HepG2 cells with p1.2Ⅱplasmid carring genome of adv-subtype HBV. Cleavage effect of ribozymes on HBeAg and HBcAg were detected by ELISA and laser confocal imaging technique.

RESULTS: The transfected HepG2 cells expressed the expected ribozyme and muta-ribozyme. Intracellular level of HBeAg was surpressed variably with variety of ribozymes. The ribozyme plasmid with tRNA promoter demonstrated the highest inhibitory rate at 81% for suppression HBeAg expression.

CONCLUSION: The ribozymes exert varied inhibitory effect on the expression of HBV in HepG2 cells depending on kinds of eukaryotic expressing plasmids.

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Localization of TRAIL/TRAILR in fetal pancreas

AIM: To observe the localization of TRAIL/TRAIR (DR4, DR5, DcR1, DcR2) in the fetal pancreas.

METHODS: Fetal pancreas of 32 wk of pregnancy were obtained from induced abortions, embedded in paraffin, and 4-μm sections were prepared. The localization of TRAIL/TRAILR in fetal pancreas was investigated by fluorescence immunohistochemical method combined with laser scanning confocal microscopy.

RESULTS: TRAIL immunoreactive cells were mainly located on the periphery of the pancreas islets. There were a few DcR1 and DcR2 positive cells whereas there were no immunoreactive cells of DR4 and DR5 in the pancreas islets. In the acini and the ducts of the exocrine pancreas there were no TRAIL/TRAILR immunoreactive cells.

CONCLUSION: This study not only describes the distribution of TRAIL/TRAILR in the fetal pancreas, but also provides a morphological basis for deducing the function of TRAIL/TRAILR in pancreas, suggesting that in normal pancreatic islets, the pancreatic cells are resistant towards apoptosis too.

K-ras gene mutation in the diagnosis of ultrasound guided fine-needle biopsy of pancreatic masses

AIM: To investigate the utility of K-ras mutation analysis of ultrasound guided fine-needle aspirate biopsy of pancreatic masses.

METHODS: Sixty-six ultrasound guided fine-needle biopsies were evaluated by cytology, histology and K-ras mutation. The mutation at codon 12 of the K-ras oncogene was detected by artificial restriction fragment length polymorphisms using BstN I approach.

RESULTS: The presence of malignant cells was reported in 40 of 54 pancreatic carcinomas and K-ras mutations were detected in 45 of the 54 FNABs of pancreatic carcinomas. The sensitivity of cytology and K-ras mutation were 74% and 83%, respectively. The speciality of cytology and K-ras mutation were both 100%. The sensitivity and speciality of K-ras mutation combined with cytology were 83% and 100%, respectively.

CONCLUSION: High diagnostic accuracy with acceptable discomfort of FNAB make it useful in diagnosis of pancreatic carcinoma. Ultrasound guided fine-needle biopsy is a safe and feasible method for diagnosing pancreatic cancer. Pancreatic carcinoma has the highest K-ras mutation rate among all solid tumors. The mutation rate of K-ras is about 80%-100%. The usage of mutation of codon 12 of K-ras oncogene combined with cytology is a good alternative for evaluation of pancreatic masses.