Recent progress and limitations of chemotherapy for pancreatic and biliary tract cancers

The role of natural products versus miRNA in renal cell carcinoma: implications for disease mechanisms and diagnostic markers

Natural products are chemical compounds produced by living organisms. They are isolated and purified to determine their function and can potentially be used as therapeutic agents. The ability of some bioactive natural products to modify the course of cancer is fascinating and promising. In the past 50 years, there have been advancements in cancer therapy that have increased survival rates for localized tumors. However, there has been little progress in treating advanced renal cell carcinoma (RCC), which is resistant to radiation and chemotherapy. Oncogenes and tumor suppressors are two roles played by microRNAs (miRNAs). They are involved in important pathogenetic mechanisms like hypoxia and epithelial-mesenchymal transition (EMT); they control apoptosis, cell growth, migration, invasion, angiogenesis, and proliferation through target proteins involved in various signaling pathways. Depending on their expression pattern, miRNAs may identify certain subtypes of RCC or distinguish tumor tissue from healthy renal tissue. As diagnostic biomarkers of RCC, circulating miRNAs show promise. There is a correlation between the expression patterns of several miRNAs and the prognosis and diagnosis of patients with RCC. Potentially high-risk primary tumors may be identified by comparing original tumor tissue with metastases. Variations in miRNA expression between treatment-sensitive and therapy-resistant patients' tissues and serum allow for the estimation of responsiveness to target therapy. Our knowledge of miRNAs' function in RCC etiology has a tremendous uptick. Finding and validating their gene targets could have an immediate effect on creating anticancer treatments based on miRNAs. Several miRNAs have the potential to be used as biomarkers for diagnosis and prognosis. This review provides an in-depth analysis of the current knowledge regarding natural compounds and their modes of action in combating cancer. Also, this study aims to give information about the diagnostic and prognostic value of miRNAs as cancer biomarkers and their involvement in the pathogenesis of RCC.

Intestinal Flora in Chemotherapy Resistance of Biliary Pancreatic Cancer

Biliary pancreatic malignancy has an occultic onset, a high degree of malignancy, and a poor prognosis. Most clinical patients miss the opportunity for surgical resection of the tumor. Systemic chemotherapy is still one of the important methods for the treatment of biliary pancreatic malignancies. Many chemotherapy regimens are available, but their efficacy is not satisfactory, and the occurrence of chemotherapy resistance is a major reason leading to poor prognosis. With the advancement of studies on intestinal flora, it has been found that intestinal flora is correlated with and plays an important role in chemotherapy resistance. The application of probiotics and other ways to regulate intestinal flora can improve this problem. This paper aims to review and analyze the research progress of intestinal flora in the chemotherapy resistance of biliary pancreatic malignancies to provide new ideas for treatment.

Clinical outcomes after multiple self-expandable metallic stent placement using stent-in-stent technique for malignant gastric outlet obstruction

Self-expandable metallic stent (SEMS) placement is widely used for relieving symptoms in malignant gastric outlet obstruction (MGOO). This study aimed to evaluate the efficacy and safety of multiple gastroduodenal stent placement using the stent-in-stent technique and to identify factors predictive of stent patency.We retrospectively analyzed data from 170 patients with GOO receiving SEMS using the stent-in-stent technique between July 2006 and July 2018. Of these, 90 had been treated with SEMS placement for MGOO. Technical and clinical success rates were evaluated. Clinical outcomes and predictors of stent patency were also analyzed.Second SEMS placement was used in 34.4% of cases and 9.7% were treated with third SEMS placement because of prior stent dysfunction. Median stent patency time was 15.7 weeks for the first SEMS, 10.4 weeks for the second, and 11.3 weeks for the third. The technical and clinical success rates were 100% and 97.8% for the first SEMS, 100% and 90.3% for the second, respectively, and both 100% for the third. Multivariable analysis showed that use of covered SEMS and chemotherapy after first and second SEMS placement was significant predictors of stent patency. Serious complications such as bleeding or perforation did not occur in any patient.Second and third gastroduodenal SEMS placement using the stent-in-stent technique is safe and effective for management of first stent dysfunction in MGOO. Stent patency is significantly associated with the use of covered SEMS and chemotherapy after SEMS placement.

Design, synthesis, chemical characterization, biological evaluation, and docking study of new 1,3,4-oxadiazole homonucleoside analogs

Herein, we report the synthetic strategies and characterization of some novel 1,3,4-oxadiazole homonucleoside analogs that are relevant to potential antitumor and cytotoxic activities. The structure of all compounds is confirmed using various spectroscopic methods such as ¹H-NMR, ¹³C-NMR, HRMS, and FTIR. These compounds were evaluated against three human cancer cell lines (MCF-7, SKBR3, and HL60 Cell Line). Preliminary investigations showed that the cytotoxic activity was markedly dependent on the nucleobase. Introduction of 5-Iodouracil 4g and theobromine 6b proved to be extremely beneficial even they were more potent than the reference drug (DOX). Also, the synthesized compounds were tested for their antiviral activities against the human varicella-zoster virus (VZV). The product 4h was (6-azauracil derivative) more potent to the reference (acyclovir) against the deficient TK - VZV strain by about 2-fold. Finally, molecular docking suggested that the anticancer activities of compounds 6b and 4g mediated by inhibiting dual proteins EGFR/HER2 with low micromolar inhibition constant Ki range. The 1,3,4-oxadiazole homonucleosides showed a strong affinity to binding sites of target proteins by forming H-bond, carbon-hydrogen bond, Pi-anion, Pi-sulfur, Pi-sigma, alkyl, and Pi-alkyl interactions.

Graphene-Based Smart Platforms for Combined Cancer Therapy

The extensive research of graphene and its derivatives in biomedical applications during the past few years has witnessed its significance in the field of nanomedicine. Starting from simple drug delivery systems, the application of graphene and its derivatives has been extended to a versatile platform of multiple therapeutic modalities, including photothermal therapy, photodynamic therapy, magnetic hyperthermia therapy, and sonodynamic therapy. In addition to monotherapy, graphene-based materials are widely applied in combined therapies for enhanced anticancer activity and reduced side effects. In particular, graphene-based materials are often designed and fabricated as "smart" platforms for stimuli-responsive nanocarriers, whose therapeutic effects can be activated by the tumor microenvironment, such as acidic pH and elevated glutathione (termed as "endogenous stimuli"), or light, magnetic, or ultrasonic stimuli (termed as "exogenous stimuli"). Herein, the recent advances of smart graphene platforms for combined therapy applications are presented, starting with the principle for the design of graphene-based smart platforms in combined therapy applications. Next, recent advances of combined therapies contributed by graphene-based materials, including chemotherapy-based, photothermal-therapy-based, and ultrasound-therapy-based synergistic therapy, are outlined. In addition, current challenges and future prospects regarding this promising field are discussed.

Clinical outcomes of secondary gastroduodenal self-expandable metallic stent placement by stent-in-stent technique for malignant gastric outlet obstruction

BACKGROUND AND AIM

To evaluate the efficacy and safety of secondary gastroduodenal stent placement after first stent dysfunction for malignant gastric outlet obstruction.

METHODS

We conducted a retrospective analysis to investigate the efficacy and safety of secondary stent-in-stent gastroduodenal stent placement.

RESULTS

Among 260 patients who had been treated with first gastroduodenal stent placement for malignant gastric outlet obstruction, 29 patients (11.2%) were treated with secondary gastroduodenal stent placement because of first stent dysfunction. Pancreatic cancer was the major primary cancer (55.2%). A WallFlex duodenal stent was the most frequently inserted stent both as a first stent (75.9%) and as a secondary stent (62.1%). There were 22 patients (75.9%) that received gastroduodenal stents at the bending site (supraduodenal angle or infraduodenal angle). Technical and clinical success rates were 100% and 86.2%, respectively. Median eating period was 3.0 months, and median survival time was 3.5 months. As for related complications, gastrointestinal perforation, insufficient stent expansion, tumor ingrowth, tumor overgrowth, and cholangitis were experienced in 13.8% (four cases), 6.9% (two cases), 6.9% (two cases), 3.4% (one case), and 3.4% (one case), respectively.

CONCLUSION

Secondary gastroduodenal stent placement might be effective for managing first stent dysfunction in malignant gastric outlet obstruction. However, gastrointestinal perforation was the major complication.

Treatment outcomes of chemotherapy between unresectable and recurrent biliary tract cancer

AIM: To evaluate the differences in the treatment outcomes between the unresectable and recurrent biliary tract cancer patients who received chemotherapy.

METHODS: Patients who were treated with gemcitabine and S-1 combination therapy in the previous prospective studies were divided into groups of unresectable and recurrent cases. The tumor response, time-to-progression, overall survival, toxicity, and dose intensity were compared between these two groups.

RESULTS: Response rate of the recurrent group was higher than that of the unresectable group (40.0% vs 25.5%; P = 0.34). Median time-to-progression of the recurrent and unresectable groups were 8.7 mo (95%CI), 1.2 mo, not reached) and 5.7 mo (95%CI: 4.0-7.0 mo), respectively (P = 0.14). Median overall survival of the recurrent and the unresectable groups were 16.1 mo (95%CI: 2.0 mo-not reached) and 9.6 mo (95%CI: 7.1-11.7 mo), respectively (P = 0.10). Dose intensities were significantly lower in the recurrent groups (gemcitabine: recurrent group 83.5% vs unresectable group 96.8%; P < 0.01, S-1: Recurrent group 75.9% vs unresectable group 91.8%; P < 0.01). Neutropenia occurred more frequently in recurrent group (recurrent group 90% vs unresectable group 55%; P = 0.04).

CONCLUSION: Not only the efficacy but also the toxicity and dose intensity were significantly different between unresectable and recurrent biliary tract cancer.

A novel, fully covered laser-cut nitinol stent with antimigration properties for nonresectable distal malignant biliary obstruction: a multicenter feasibility study

BACKGROUND/AIMS

Stent migration occurs frequently, but the prevention of complications resulting from covered self-expandable metal stents (C-SEMSs) remains unresolved. We prospectively assessed a newly developed C-SEMS, a modified covered Zeo stent (m-CZS), in terms of its antimigration effect.

METHODS

Between February 2010 and January 2011, an m-CZS was inserted into 42 patients (31 initial drainage cases and 11 reintervention cases) at a tertiary referral center and three affiliated hospitals. The laser-cut stent was flared for 1.5 cm at both ends, with a 1 cm raised bank located 1 cm in from each flared end. The main outcome of this study was the rate of stent migration, and secondary outcomes were the rate of recurrent biliary obstruction (RBO), the time to RBO, the frequencies of complications, and overall survival.

RESULTS

Of the 31 patients with initial drainage, stent migration occurred in four (12.9%, 95% confidence interval, 5.1% to 29.0%), with a mean time of 131 days. RBO occurred in 18 (58%), with a median time to RBO of 107 days. Following previous C-SEMS migration, seven of 10 patients (70%) did not experience m-CZS migration until death.

CONCLUSIONS

m-CZSs with antimigration properties effectively, although not completely, prevented stent migration after stent insertion.

A retrospective study of gemcitabine and cisplatin combination therapy as second-line treatment for advanced biliary tract cancer

BACKGROUND

To evaluate the treatment outcome of gemcitabine and cisplatin combination therapy as second-line treatment for advanced biliary tract cancer.

PATIENTS AND METHODS

Patients with advanced biliary tract cancer who were refractory to gemcitabine-based first-line chemotherapy were treated with gemcitabine and cisplatin combination therapy. Gemcitabine (1,000 mg/m(2)) and cisplatin (25 mg/m(2)) were administered intravenously on days 1 and 8, repeated every 3 weeks.

RESULTS

Sixty patients were included. The tumor response and disease control rates were 1.7 and 58.3%, respectively. The median overall survival and time to progression were 6.7 months (95% CI 4.9-8.1) and 3.5 months (95% CI 2.5-5.0), respectively. Grade 3/4 toxicities included leucopenia (20%), neutropenia (25%), anemia (23%), thrombocytopenia (17%), nausea (2%), anorexia (2%), and liver dysfunction (2%).

CONCLUSIONS

Gemcitabine and cisplatin combination therapy showed moderate efficacy and safety as second-line treatment for advanced biliary tract cancer that is refractory to gemcitabine-based first-line chemotherapy.

Current status of chemotherapy for the treatment of advanced biliary tract cancer

Chemotherapy is indispensable for the treatment of advanced biliary tract cancer. Recently, reports regarding first-line chemotherapy have increased, and first-line chemotherapy treatment has become gradually more sophisticated. Gemcitabine and cisplatin combination therapy (or gemcitabine and oxaliplatin combination therapy) have become the standard of care for advanced biliary tract cancer. Oral fluoropyrimidines have also been shown to have good antitumor effects. Gemcitabine, platinum compounds, and oral fluoropyrimidines are now considered key drugs for the treatment of advanced biliary tract cancer. Several clinical trials using molecular targeted agents are also ongoing. Combination therapy using cytotoxic agents and molecular-targeted agents has been evaluated widely. However, reports regarding second-line chemotherapy remain limited, and it has not yet been clarified whether second-line chemotherapy can improve the prognosis of advanced biliary tract cancer. Thus, there is an urgent need to establish second-line standard chemotherapy treatment for advanced biliary tract cancer. Several problems exist when assessing the results of previous reports concerning advanced biliary tract cancer. In the present review, the current status of the treatment of advanced biliary tract cancer is summarized, and several associated problems are indicated. These problems should be solved to achieve more sophisticated treatment of advanced biliary tract cancer.

Outcomes of endoscopic pyloric stenting in malignant gastric outlet obstruction: a retrospective study

Background

Up to 30% of patients with pancreatic cancer and more than 50% of patients with gastric cancer already have incurable disease, with distressing symptoms of gastric outlet obstruction at the time of presentation which require effective palliation. We decided to test the clinical outcomes of endoscopic stent placement in malignant gastric outlet obstruction.

Methods

In a retrospective single institution-based study, the charts of patients who had self-expandable metal stents placed to alleviate malignant gastric outlet obstruction were reviewed. Charts were reviewed to assess improvement in oral intake according to the Gastric Outlet Obstruction Scoring System (GOOSS), and in order to also evaluate technical success and complications of the procedure.

Results

69 patients with successful stent placement were retrospectively evaluated. Within 7 and 28 days after stent placement respectively, 85.5% and 80% benefited from stent insertion, with an increase in the GOOSS score of > 1. Resumption of soft or low residue diet (GOOSS 2-3) was achieved in 53.6% at day 7 and in 62% of patients at day 28, respectively. Of the patients achieving a GOOSS score of 2-3, 17.3% remained on a soft or low residue diet at 24 weeks or at last follow up, while 46% died. Stent related adverse events occurred in 10 patients (14%), including stent blockade in 7 and stent migration in 3 patients.

Conclusion

Endoscopic enteral stenting promptly increases oral intake in the majority of patients with malignant gastric outlet obstruction and is a safe procedure with a low rate of serious complications.

Chemotherapy for the biliary tract cancers: moving toward improved survival time

BACKGROUND

The biliary tract carcinomas rank fifth in incidence among all gastrointestinal tumours. This group of tumours includes both cholangiocarcinoma and gallbladder carcinoma. Although surgery represents the main therapeutic option for these patients, both radiotherapy and chemotherapy could be used in a multidisciplinary approach. Several studies are currently available on the use of chemotherapy, including 5-fluorouracil, mitomycin C, methotrexate, doxorubicin and cisplatin or newer anticancer molecules, such as gemcitabine, capecitabine, oxaliplatin and irinotecan. However, the small sample size of most of these studies prevents generalization.

DISCUSSION

We reviewed the available data on both chemotherapy and targeted therapies for biliary carcinoma. By using conventional chemotherapy, a response rate ranging from 10% to 40% has been reported. Although encouraging data emerged with the use of targeted therapies, further efforts are needed to improve treatment options for patients with biliary tract cancer.

Improvement of prognosis for unresectable biliary tract cancer

AIM: To evaluate the chemotherapeutic outcomes and confirm the recent improvement of prognosis for unresectable biliary tract cancer.

METHODS: A total of 186 consecutive patients with unresectable biliary tract cancer, who had been treated with chemotherapy between 2000 and 2009 at five institutions in Japan, were retrospectively analyzed. These patients were divided into three groups based on the year beginning chemotherapy: Group A (2000-2003), Group B (2004-2006), and Group C (2007-2009). The data were fixed at the end of December 2011. Overall survival and time-to-progression were analyzed and compared chronologically.

RESULTS: No patient characteristics were significantly different among the three groups. The gallbladder was involved in about half of the patients in each group, and metastatic biliary tract cancer was present in three quarters of the enrollees. In Group A, 5-fluorouracil-based chemotherapies were primarily selected as first-line chemotherapy, and only 24% were treated with second-line chemotherapy. In Group B, gemcitabine or S-1 monotherapy was mainly introduced as first-line chemotherapy, and 51% of the patients who were refractory to first-line chemotherapy were treated with second-line chemotherapy mainly with monotherapy. In Group C, the combination therapy with gemcitabine and S-1 was mainly chosen as first-line chemotherapy, and 53% of the patients refractory to first-line chemotherapy were treated with second-line chemotherapy mainly with combination therapy. The median time-to-progressions were 4.4 mo, 3.5 mo and 5.9 mo in Groups A, B and C, respectively (4.4 mo vs 3.5 mo vs 5.9 mo, P < 0.01). The median overall survivals were 7.1, 7.3, and 11.7 mo in Groups A, B and C (7.1 mo vs 7.3 mo vs 11.7 mo, P = 0.03). Induction rates of all three drugs (gemcitabine, platinum analogs, and fluoropyrimidine) in Groups A, B and C were 4%, 2% and 27% (4% vs 2% vs 27%, P < 0.01).

CONCLUSION: The prognosis of unresectable biliary tract cancer has improved recently. Using three effective drugs (gemcitabine, platinum analogs, and fluoropyrimidine) may improve the prognosis of this cancer.

Japanese multicenter estimation of WallFlex duodenal stent for unresectable malignant gastric outlet obstruction

AIM

This retrospective study estimated the efficacy and safety of the WallFlex duodenal stent for malignant gastric outlet obstruction (GOO) in Japan.

METHODS

Forty-two consecutive patients with symptomatic malignant GOO were treated using WallFlex duodenal stents between January 2010 and October 2010.

RESULTS

The technical and clinical success rates were 100% and 83.3%, respectively.The median gastric outlet obstruction scoring system increased significantly, from 0 to 2, after stent placement (P < 0.01).The median survival time was 3.3 months (95% confidence interval (CI), 1.8-6.0 months), and the median eating period was 3.0 months (95% CI, 1.1-4.3 months). Re-intervention was required in 11 patients (26.2%). The complication rate was 26.2%. The major complication was stent occlusion (23.8%) by tumor ingrowth, which occurred in nine (21.4%) patients, and tumor overgrowth, which occurred in one (2.4%) patient. Stentmigration, perforation, and food impaction without stent occlusion were not observed.The median survival time of the patients with stent occlusion was 11.7 months (95% CI, 2.2 months - not reached), and the median stent patency of these patients was 4.0 months (95% CI, 0.8-4.7 months).These patients were successfully treated with additional stent insertion using a stent-in-stent procedure.

CONCLUSION

Duodenal stent placement using a WallFlex duodenal stent was safe and effective for managing malignant GOO.This stent is an uncovered metallic stent, and the major problem was stent occlusion due to tumor ingrowth. However, the occluded stent could be corrected by inserting an additional duodenal stent.

Predictive factors of solid food intake in patients with malignant gastric outlet obstruction receiving self-expandable metallic stents for palliation

AIM

As for self-expandable metallic stents (SEMS) for malignant gastric outlet obstruction (GOO), some predictive factors of stent patency have been reported, although re-canalization of GOO by SEMS does not necessarily lead to favorable food intake. Therefore, we analyzed the predictive factors of oral food intake following SEMS placement.

METHODS

A total of 97 consecutive patients in whom SEMS were placed for malignant GOO in five hospitals were included in this retrospective study. Clinical outcomes and predictive factors influencing solid food intake were analyzed.

RESULTS

The technical and clinical success rates were 97.9% and 87.6%, respectively. The mean gastric outlet obstruction scoring system (GOOSS) improved from 0.39 to 2.24 after SEMS placement (P<0.01). The median eating period was 2.1 months (95% CI, 1.1-3.0 months), and the median survival time was 3.1 months (95% CI, 2.0-4.2 months). A Karnofsky performance status of ≤ 50 (odds ratio, 3.65; 95% CI, 1.17-13.1; P=0.03) and ascites (odds ratio, 3.28; 95% CI, 1.23-9.05; P=0.02) were identified as statistically significant independent poor predictive factors of solid food intake.

CONCLUSION

SEMS is an effective treatment for patients with malignant GOO. Ascites and a poor performance status were poor predictive factors of solid food intake.

Combinational therapy: new hope for pancreatic cancer?

Pancreatic cancer is a devastating disease with a low overall survival rate. Chemotherapy is the most common treatment for patients presenting with advanced pancreatic cancer. Gemcitabine achieves a modest improvement in overall survival and is the gold standard for advanced pancreatic cancer treatment. Capecitabine and S-1, derivatives of 5-fluorouracil (5-FU), offers minimal clinical benefits. Folfirinox represents a new and aggressive regimen that might benefit patients of metastatic pancreatic cancer with good performance status. Other chemotherapy drugs such as platinums and irinotecan do not provide significant improvement in overall survival, but have been used as part of combinational therapies. Comparing to systemically delivered chemotherapy, regional intra-arterial chemotherapy achieves higher local drug concentration in tumors with lower systemic drug toxicity, and may serve as a better treatment regimen. Although there have been progress made in chemotherapeutic strategies against pancreatic cancer, the overall survival is not significantly improved in the last decade. Recently, development of chemotherapy in combination with molecular targeted therapies holds great promise in pancreatic cancer treatment, especially in patients with metastatic disease. Growing bodies of preclinical and clinical evidences indicate that the combination of conventional modalities with specific molecular targeted therapy increase the efficacy of the monotherapy without an increase in toxicity. In this review, we summarized the current regimens of chemotherapy and molecular targeted therapy for advanced pancreatic cancer and highlighted the novel combinational treatments tested in recent clinical trials.