Chemotherapy for advanced pancreatic cancer

Inhibiting DNA Polymerases as a Therapeutic Intervention against Cancer

Inhibiting DNA synthesis is an important therapeutic strategy that is widely used to treat a number of hyperproliferative diseases including viral infections, autoimmune disorders, and cancer. This chapter describes two major categories of therapeutic agents used to inhibit DNA synthesis. The first category includes purine and pyrmidine nucleoside analogs that directly inhibit DNA polymerase activity. The second category includes DNA damaging agents including cisplatin and chlorambucil that modify the composition and structure of the nucleic acid substrate to indirectly inhibit DNA synthesis. Special emphasis is placed on describing the molecular mechanisms of these inhibitory effects against chromosomal and mitochondrial DNA polymerases. Discussions are also provided on the mechanisms associated with resistance to these therapeutic agents. A primary focus is toward understanding the roles of specialized DNA polymerases that by-pass DNA lesions produced by DNA damaging agents. Finally, a section is provided that describes emerging areas in developing new therapeutic strategies targeting specialized DNA polymerases.

Gemcitabine and S-1 combination chemotherapy versus gemcitabine alone for locally advanced and metastatic pancreatic cancer: a meta-analysis of randomized controlled trials in Asia

INTRODUCTION

After decades of research, pancreatic cancer is still a devastating disease. The aim of this article was to assess the efficacy and safety of combination chemotherapy with gemcitabine (GEM) and S-1 (GS) therapy compared with GEM alone therapy in patients with locally advanced or metastatic pancreatic cancer.

METHODS

Relevant trials were identified by searching databases. Five trials were selected in this article. The indicators we used were overall response rate, disease control rate, 1-year survival rate and haematological toxicities.

RESULTS

Meta-analysis of the pooled data demonstrated that the overall response rate (risk ratio, RR = 2.52, 95% confidence interval, CI: 1.85-3.42, P < 0.00001) and disease control rate (RR = 1.24, 95% CI: 1.12-1.37, P < 0.0001) were significantly different for the GS and GEM alone chemotherapies. Among the group of patients, 43.4% in the GS group and 31.4% in the GEM group survived more than a year. According to this, patients who use the GS regiment may have a better prognosis than the GEM regiment (RR = 1.62, 95% CI: 1.12-2.33, P = 0.04). The combination chemotherapy with GEM and S-1 group had higher haematological toxicities including neutropaenia (RR = 1.58, 95% CI: 1.17-2.14, P = 0.003) and thrombocytopaenia (RR = 1.85, 95% CI: 1.28-2.67, P = 0.001). The incidence of anaemia was much the same in the two groups (RR = 1.22, 95% CI: 0.87-1.70, P = 0.24).

DISCUSSION

Overall response rate and disease control rate as well as 1-year survival rate in patients who received GS were superior to those treated with GEM alone. Combination chemotherapy with GEM and S-1 may offer greater benefits in the treatment of pancreatic cancer than GEM alone, although the GS group had higher haematological toxicities. Combination chemotherapy with GEM and S-1 might be an option of first-line chemotherapy for pancreatic cancer patients, at least in Asia. Mini Abstract: This systematic review analysing randomized controlled trials (RCTs) comparing S-1 combination chemotherapy versus GEM alone for locally advanced and metastatic pancreatic cancer demonstrated greater efficacy for S-1 combination in term of response, disease control and 1-year survival proportion.

A phase II study of capecitabine plus docetaxel in gemcitabine-pretreated metastatic pancreatic cancer patients: CapTere

PURPOSE

Docetaxel and capecitabine combination is synergistic in preclinical models. We investigated the efficacy and toxicity of this combination as second-line chemotherapy in patients with metastatic pancreatic adenocarcinoma (mPC), pretreated with gemcitabine-based chemotherapy.

METHODS

Eligible patients were treated with capecitabine 800 mg/m(2) orally PO bid on days 1-14 in combination with intravenous docetaxel 30 mg/m(2) on days 1 and 8 of each 21-day cycle. The primary end point was overall response rate. Using a three-stage sequential design, two interim analyses for early stopping due to lack of efficacy were planned and conducted after 13 and 26 patients were accrued. Secondary end points included time to treatment failure, progression-free survival (PFS), overall survival (OS) and 50 % drop in CA19-9 levels.

RESULTS

Forty-three patients were evaluable for toxicity and 42 evaluable for response, at a median age of 64 years. The majority of patients (74 %) had ECOG PS 0-1. Six patients (14 %) achieved a partial tumor response, and stable disease for ≥2 cycles was observed in 59 % of patients (n = 25). Thirty-five percent (n = 11/31) of patients had a ≥50 % decrease in CA19-9 levels. The median PFS was 3.7 months (95 % CI 2.1-4.3 months), and the median OS was 5.3 months (95 % CI 4.3-8.6 months). Treatment was generally well tolerated. Grade 3 toxicity and grade 4 toxicity were seen in 45 and 5 % of patients, respectively. One patient had a potential treatment-related mortality.

CONCLUSIONS

The combination of capecitabine and docetaxel is active and well tolerated in mPC patients pretreated with gemcitabine-based therapy.

LY294002 enhances inhibitory effect of gemcitabine on proliferation of human pancreatic carcinoma PANC-1 cells

Phosphatidylinositide 3-kinase (PI3K)/protein kinase B (PKB, Akt) pathway plays a major role in proliferation and survival of many types of cells. The inhibitory effect of LY294002, widely applied as an inhibitor of PI3K, in combination with gemcitabine on proliferation of PANC-1 cells was investigated. The expression of PI3K, phosphorylated Akt (p-Akt) and multidrug-resistance like protein (MRP) in normal pancreas tissues, chronic pancreatitis tissues and pancreatic carcinoma tissues was detected. The effects of LY294002 combined with gemcitabine on proliferation of PANC-1 cells and protein levels of p-Akt and MRP were detected. The results showed that the positive expression rate of PI3K, p-Akt and MRP in pancreatic carcinoma tissues was significantly higher than that in normal pancreas tissues and chronic pancreatitis tissues (P<0.01 and P<0.05 respectively). LY294002 could effectively enhance the inhibitory effect of gemcitabine on proliferation of PANC-1 cells. Furthermore, Western blotting revealed that LY294002 combined with gemcitabine reduced the protein levels of p-Akt and MRP, which contributed to the inhibition of proliferation. It is concluded that LY294002 in combination with gemcitabine may represent an alternative therapy for pancreatic carcinoma.

Extended distal pancreatectomy with en bloc resection of the celiac axis for locally advanced pancreatic cancer: a case report and review of the literature

Due to a lack of early symptoms, pancreatic cancers of the body and tail are discovered mostly at advanced stages. These locally advanced cancers often involve the celiac axis or the common hepatic artery and are therefore declared unresectable. The extended distal pancreatectomy with en bloc resection of the celiac artery may offer a chance of complete resection. We present the case of a 48-year-old female with pancreatic body cancer invading the celiac axis. The patient underwent laparoscopy to exclude hepatic and peritoneal metastasis. Subsequently, a selective embolization of the common hepatic artery was performed to enlarge arterial flow to the hepatobiliary system and the stomach via the pancreatoduodenal arcades from the superior mesenteric artery. Fifteen days after embolization, the extended distal pancreatectomy with splenectomy and en bloc resection of the celiac axis was carried out. The postoperative course was uneventful, and complete tumor resection was achieved. This case report and a review of the literature show the feasibility and safety of the extended distal pancreatectomy with en bloc resection of the celiac axis. A preoperative embolization of the celiac axis may avoid ischemia-related complications of the stomach or the liver.

An oncolytic adenovirus defective in pRb-binding (dl922-947) can efficiently eliminate pancreatic cancer cells and tumors in vivo in combination with 5-FU or gemcitabine

Pancreatic adenocarcinoma has a poor prognosis and frequently develops resistance to standard chemotherapeutics. Oncolytic adenoviruses represent a promising approach to overcome treatment resistance. The replication-selective dl922-947 adenovirus, defective in pRb binding, targets cancers with deregulated cell cycle control, such as the majority of pancreatic tumors. Cell killing efficacy was higher for dl922-947 than for adenovirus type 5 (Ad5) and the clinically approved dl1520 in pancreatic cancer cells with K-ras, p16 and p53 mutations. Combinations of dl922-947 and 5-fluorouracil or gemcitabine (2'2'-difluoro-2-deoxytidine) resulted in strong synergistic cell killing in Suit-2 and the highly drug- and virus-resistant Hs766T cells. Viral uptake increased in response to drugs, but was independent of the expression levels of the viral attachment receptor coxsackie and adenovirus receptor (CAR), whereas expression levels of the internalization receptors α(v)β(3)- and α(v)β(5)-integrins were increased. Early viral E1A expression was potently induced with drugs contributing to the synergistic effects. The dl922-947 mutant was more efficacious than Ad5 in vivo in Hs766T and Suit-2 xenograft models. In combination with gemcitabine, median survival was further prolonged. We demonstrate that dl922-947 is highly efficacious in pancreatic cancers and conclude that oncolytic adenoviruses harboring the E1ACR2 deletion have great potential for development into future clinical candidates for pancreatic cancer.

A meta-analysis of gemcitabine containing chemotherapy for locally advanced and metastatic pancreatic adenocarcinoma

BACKGROUND

The objectives of the present study are to investigate the efficacy and safety profile of gemcitabine-based combinations in the treatment of locally advanced and metastatic pancreatic adenocarcinoma (LA/MPC).

METHODS

We performed a computerized search using combinations of the following keywords: "chemotherapy", "gemcitabine", "trial", and "pancreatic cancer".

RESULTS

Thirty-five trials were included in the present analysis, with a total of 9,979 patients accrued. The analysis showed that the gemcitabine-based combination therapy was associated with significantly better overall survival (OS) (ORs, 1.15; p = 0.011), progression-free survival (PFS) (ORs, 1.27; p < 0.001), and overall response rate (ORR) (ORs, 1.58; p < 0.001) than gemcitabine monotherapy. Similar results were obtained when the gemcitabine-fluoropyrimidine combination was compared with gemcitabine, with the OS (ORs, 1.33; p = 0.007), PFS (ORs, 1.53; p < 0.001), and ORR (ORs 1.47, p = 0.03) being better in the case of the former. The OS (ORs, 1.33; p = 0.019), PFS (ORs, 1.38; p = 0.011), and one-year survival (ORs, 1.40; p = 0.04) achieved with the gemcitabine-oxaliplatin combination were significantly greater than those achieved with gemcitabine alone. However, no survival benefit (OS: ORs, 1.01, p = 0.93; PFS: ORs, 1.19, p = 0.17) was noted when the gemcitabine-cisplatin combination was compared to gemcitabine monotherapy. The combinations of gemcitabine and other cytotoxic agents also afforded disappointing results. Our analysis indicated that the ORR improved when patients were treated with the gemcitabine-camptothecin combination rather than gemcitabine alone (ORs, 2.03; p = 0.003); however, there were no differences in the OS (ORs, 1.03; p = 0.82) and PFS (ORs, 0.97; p = 0.78) in this case.

CONCLUSIONS

Gemcitabine in combination with capecitabine or oxaliplatin was associated with enhanced OS and ORR as compared with gemcitabine in monotherapy, which are likely to become the preferred standard first-line treatment of LA/MPC.

Irinotecan plus bolus/infusional 5-Fluorouracil and leucovorin in patients with pretreated advanced pancreatic carcinoma: a multicenter experience of the Gruppo Oncologico Italia Meridionale

BACKGROUND

Patients with advanced pancreatic cancer failing gemcitabine-based first-line chemotherapy are still in relatively good clinical conditions and may still require second-line chemotherapy, which is frequently administered in daily clinical practice given to without solid scientific support.

PATIENTS AND METHODS

A retrospective survey was carried out including 40 patients with stage III or IV gemcitabine-refractory pancreatic carcinoma. Patients received standard FOLFIRI regimen biweekly until progression or unacceptable toxicity. Response evaluation criteria in solid tumors and National Cancer Institute common toxicity criteria were employed respectively for response and toxicity assessment.

RESULTS

Six partial responses (15%) and 14 stabilizations of disease (35%) were recorded for a tumor growth control rate of 50%. The median time to progression was 3.7 (range, 1-6.5 months), and median overall survival was 6 months (range, 2-8.2 months). A stabilization of performance status and a subjective improvement of cancer-related symptoms were recorded in 21 patients (52.5%). No correlation has been found between length of time to progression during first-line chemotherapy and length of that reported in the second-line setting or objective response. Grade 3-4 diarrhea and mucositis was observed in 15% and 10% of cases, respectively.

CONCLUSIONS

Data presented in this article demonstrate that the second-line FOLFIRI regimen are able to induce an objective response in a relatively small fraction of patients with gemcitabine-refractory adenocarcinoma of the pancreas. The use of second-line chemotherapy should be carefully proposed to patients with good performance status or those who had a good response to first-line therapy.

Tumour growth and resistance to gemcitabine of pancreatic cancer cells are decreased by AP-2alpha overexpression

Background:

Activator protein-2α (AP-2α) is a transcription factor that belongs to the family of AP-2 proteins that have essential roles in tumorigenesis. Indeed, AP-2α is considered as a tumour-suppressor gene in different tissues such as colonic, prostatic or breast epithelial cells. Moreover, AP-2α also participates in the control of colon and breast cancer cells sensitivity towards chemotherapeutic drugs. Despite its potential interest, very few data are available regarding the roles of AP-2α in pancreatic cancer.

Methods:

We have developed a stable pancreatic CAPAN-1 cell line overexpressing AP-2α. Consequences of overexpression were studied in terms of in vivo cell growth, gene expression, migration capacity and chemosensitivity.

Results:

In vivo tumour growth of CAPAN-1 cells overexpressing AP-2α was significantly decreased by comparison to control cells. An altered expression pattern of cell cycle-controlling factors (CDK-4, CDK-6, cyclin-G1, p27^kip1 and p57^kip2) was observed in AP-2α-overexpressing clones by microarrays and western blot analysis. Promoter activity and ChIP analysis indicated that AP-2α induces p27^kip1 protein levels by direct binding to and transactivation of its promoter. Moreover, AP-2α overexpression increased the chemosensitivity of CAPAN-1 cells to low doses of gemcitabine and reduced their in vitro migration capacity.

Conclusion:

Our data suggested that AP-2α overexpression could be exploited to decrease in vivo tumour growth of pancreatic cancer cells and to increase their sensitivity to gemcitabine.

Targeting the sphingolipid metabolism to defeat pancreatic cancer cell resistance to the chemotherapeutic gemcitabine drug

Defeating pancreatic cancer resistance to the chemotherapeutic drug gemcitabine remains a challenge to treat this deadly cancer. Targeting the sphingolipid metabolism for improving tumor chemosensitivity has recently emerged as a promising strategy. The fine balance between intracellular levels of the prosurvival sphingosine-1-phosphate (S1P) and the proapoptotic ceramide sphingolipids determines cell fate. Among enzymes that control this metabolism, sphingosine kinase-1 (SphK1), a tumor-associated protein overexpressed in many cancers, favors survival through S1P production, and inhibitors of SphK1 are used in ongoing clinical trials to sensitize epithelial ovarian and prostate cancer cells to various chemotherapeutic drugs. We here report that the cellular ceramide/S1P ratio is a critical biosensor for predicting pancreatic cancer cell sensitivity to gemcitabine. A low level of the ceramide/S1P ratio, associated with a high SphK1 activity, correlates with a robust intrinsic pancreatic cancer cell chemoresistance toward gemcitabine. Strikingly, increasing the ceramide/S1P ratio, by using pharmacologic (SphK1 inhibitor or ceramide analogue) or small interfering RNA-based approaches to up-regulate intracellular ceramide levels or reduce SphK1 activity, sensitized pancreatic cancer cells to gemcitabine. Conversely, decreasing the ceramide/S1P ratio, by up-regulating SphK1 activity, promoted gemcitabine resistance in these cells. Development of novel pharmacologic strategies targeting the sphingolipid metabolism might therefore represent an interesting promising approach, when combined with gemcitabine, to defeat pancreatic cancer chemoresistance to this drug.

CA 19-9 tumour-marker response to chemotherapy in patients with advanced pancreatic cancer enrolled in a randomised controlled trial

BACKGROUND

Several studies in patients undergoing chemotherapy for advanced pancreatic carcinoma have linked a decrease in the concentration of the tumour marker carbohydrate antigen (CA) 19-9 to lengthened survival. The aim of this study was to test the hypotheses that an early decrease in baseline serum CA 19-9 concentration (on day 42, after two cycles of chemotherapy) by at least 50% is associated with lengthened survival, and that a decrease in CA 19-9 concentration of at least 50% from the baseline concentration to the lowest value measured at any time during treatment (nadir) is of prognostic significance, enabling its use as a surrogate endpoint for survival.

METHODS

CA 19-9 serum concentration was measured at baseline and every 3 weeks thereafter in patients with histologically proven advanced pancreatic carcinoma enrolled in a randomised trial of gemcitabine versus gemcitabine plus capecitabine. Patients were excluded if baseline serum CA 19-9 concentration was below the upper limit of normal (ULN) in the laboratory or if this measurement was missing. Comparisons of survival between patients with and without a CA 19-9 response were corrected for the guarantee-time bias by the landmark method. The trial on which this study is based is registered on the clinical trials site of the US National Cancer Institute website http://www.clinicaltrials.gov/ct/show/NCT00030732.

FINDINGS

247 of 319 randomised patients were assessable for analysis of baseline serum CA 19-9 concentration, and, of these, 175 patients were assessable for tumour-marker response to treatment. Median overall survival for patients with a baseline CA 19-9 concentration equal to or above the median value (ie, 59xULN) was 5.8 months (95% CI 5.1-7.0), which was significantly shorter than that for patients with baseline concentrations below the median value (10.3 months [95% CI 8.6-12.8], p<0.0001). An early decrease in CA 19-9 concentration of at least 50% after two cycles of chemotherapy was not associated with a longer overall survival compared with patients who did not have a decrease of at least 50% (median 10.1 months [9.2-12.7] vs 8.6 months [6.9-11.2], p=0.53; hazard ratio for death 1.11 [0.81-1.52]). Furthermore, a decrease in CA 19-9 concentration of at least 50% reached at the CA 19-9 nadir concentration was not associated with a longer overall survival compared with those patients who did not have a decrease of at least 50% (median 7.8 months [6.5.10.1] vs 6.7 months [5.5-9.8], p=0.74; 0.95 [0.69-1.31]) after adjusting for the guarantee-time bias.

INTERPRETATION

Pretreatment serum CA 19-9 concentration is an independent prognostic factor for survival, but a decrease in concentration during chemotherapy is not significantly associated with lengthened survival compared with those who did not have a corresponding decrease. Our data suggest that CA 19-9 response during chemotherapy is not a valid surrogate endpoint for survival in clinical trials.

Second-line chemotherapy in advanced pancreatic carcinoma: a multicenter survey of the Gruppo Oncologico Italia Meridionale on the activity and safety of the FOLFOX4 regimen in clinical practice

BACKGROUND

In daily clinical practice second-line chemotherapy (SLCT) is frequently given to patients with advanced pancreatic cancer failing gemcitabine-based first-line chemotherapy without solid scientific support.

PATIENTS AND METHODS

A retrospective survey was carried out including 42 patients. Patients received standard FOLFOX4 regimen biweekly until progression or unacceptable toxicity.

RESULTS

Six partial responses (14%) and 16 stabilizations (38%) were recorded for a tumor growth control rate of 57%. The median time to progression (TtP) was 4 months (range 1-7 months), and median overall survival (OS) was 6.7 months (range 2-9 months). A stabilization of performance status (PS) and a subjective improvement of cancer-related symptoms were recorded in 27 patients.

CONCLUSIONS

Data presented in this paper support the use of FOLFOX4 regimen in the second-line treatment of adenocarcinoma of the pancreas patients. The use of SLCT, however, should be carefully proposed to patients with good PS or those who had a good response to first-line therapy.

Clinical roles of increased populations of Foxp3+CD4+ T cells in peripheral blood from advanced pancreatic cancer patients

OBJECTIVES

Further metastasis should be avoided in pancreatic cancer (PC) patients for effective surgical treatment. Regulatory T cells (Foxp3CD4 T cells including CD4CD25 T cells and CD4CD25 T cells) play important roles in tumor immunity. This study aimed to investigate whether regulatory T cells participate in metastasis.

METHODS

Peripheral blood was withdrawn from PC patients, as well as healthy volunteer donors as controls. The peripheral blood mononuclear cells (PBMCs) were subjected to FACScan analysis after labeling with anti-CD4, anti-CD25, and anti-Foxp3 antibodies. Tumor markers, including DUPAN2 and CA19-9, surface markers, such as the CD4/CD8 ratio, and the CD57 cell population were assessed. Clinical stages were classified according to the TNM classification.

RESULTS

The Foxp3CD4 T-cell population among the PBMCs was significantly increased in PC patients (8.10% +/- 4.65%) compared with healthy donors (2.47 +/- 0.78%) (P < 0.001). No significant relationships existed for the tumor markers, CD4/CD8 ratio, and CD57 cells. However, a significant correlation was found between Foxp3CD4 T cells among the PBMCs and the TNM stage (P < 0.05).

CONCLUSIONS

Foxp3CD4 T cells are good markers for metastasis detection in PC patients and more accurate than other conventional tumor markers, especially at advanced stages of the disease.