Pancreatic surgery for adenocarcinoma

High-throughput sequencing of circRNAs reveals novel insights into mechanisms of nigericin in pancreatic cancer

BACKGROUND

Our previous study had proved that nigericin could reduce colorectal cancer cell proliferation in dose- and time-dependent manners by targeting Wnt/β-catenin signaling. To better elucidate its potential anti-cancer mechanism, two pancreatic cancer (PC) cell lines were exposed to increasing concentrations of nigericin for different time periods, and the high-throughput sequencing was performed to explore the circRNA expression profiles after nigericin exposure on pancreatic cancer (PC) cells.

RESULTS

In this study, a total of 183 common differentially expressed circRNAs were identified, and the reliability and validity of the sequencing data were verified by the PCR analysis. According to the parental genes of circRNAs, the GO analysis was performed to predict the most enriched terms in the biological process, cellular components and molecular functions. The KEGG analysis and pathway-pathway network exhibited the potential signal pathways and their regulatory relationships. Meanwhile, a potential competing endogenous RNA (ceRNA) mechanism through a circRNA-miRNA-mRNA network was applied to annotate potential functions of these common differentially expressed circRNAs, and these predicted miRNAs or mRNAs might be involved in nigericin damage.

CONCLUSIONS

By the bioinformatics method, our data will facilitate the understanding of nigericin in PC cells, and provide new insight into the molecular mechanism of nigericin toward cancer cells. This is the first report that discusses the potential functions of nigericin in cancers through the bioinformatics method. Our data will facilitate the understanding of nigericin-mediated anti-cancer mechanisms in PC.

Factors Predictive of Reoperation After Pancreaticoduodenectomy for Pancreatic Cancer

While mortality is low, morbidity remains high for patients undergoing pancreas resections, especially for those who return to the operating room (RTOR). The aim of this study is to identify risk factors for RTOR following pancreaticoduodenectomy (PD) for ductal adenocarcinoma. Logistic regression models were constructed using the 2014 and 2015 National Surgical Quality Improvement Program (NSQIP) Pancreas Targeted database. Preoperative and procedure-related risk factors predictive of RTOR for patients undergoing either classic or pylorus-preserving pancreaticoduodenectomy for pancreatic ductal adenocarcinoma (PDAC) were identified. A total of 1736 patients were included. Multivariable analysis of patients undergoing classic PD demonstrated that an abnormally low preoperative WBC count was significantly associated with RTOR (OR 2.78, 95% CI 1.27-6.06, p = 0.010). For patients who underwent pylorus-preserving PD, the wound classification (OR 3.99, 95% CI 1.75-9.11, p = 0.001) and arterial resection (OR 26.3, 95% CI 7.96-87.20, p < 0.001) were associated with a higher rate of RTOR. When analyzing both approaches (classic and pylorus-preserving PD) together, only isolated arterial (OR 9.98, 95% CI 3.81-26.18, p < 0.001) and isolated venous (OR 1.79, 95% CI 1.05-3.05, p = 0.032) resections were independently associated with RTOR. The results of our study demonstrate that few factors are predictive of RTOR. Knowledge of these few variables in combination with a focus on the components of medical care in the immediate postoperative period may help identify individuals at risk for RTOR and improve patient care.

Pancreatic Surgery in the Older Population: A Single Institution's Experience over Two Decades

Objectives. Surgery is the most effective treatment for pancreatic cancer. However, present literature varies on outcomes of curative pancreatic resection in the elderly. The objective of the study was to evaluate age as an independent risk factor for 90-day mortality and complications after pancreatic resection. Methods. Nine hundred twenty-nine consecutive patients underwent 934 pancreatic resections between March 1995 and July 2014 in a tertiary care center. Primary analyses focused on outcomes in terms of 90-day mortality and postoperative complications after pancreatic resection in these two age groups. Results. Even though patients aged 75 years or older had significantly more postoperative morbidities compared with the younger patient group, the age group was not associated with increased risk of 90-day mortality after pancreatic resection. Discussion. The study suggests that age alone should not preclude patients from undergoing curative pancreatic resection.

Alterations in Tumor DNA Are Related to Short Postoperative Survival in Patients Resected for Pancreatic Carcinoma Aimed at Cure

OBJECTIVES

Pancreatic ductal adenocarcinomas (PDACs) are found in more than 85% of patients with pancreatic cancer and with 5-year survival of less than 10%. Effective treatment may be radical surgery, which is hampered by rapid relapse. Therefore, our aim was to compare DNA sequence alterations in patients with short and long survival to evaluate if confirmed DNA alterations predict short postoperative survival.

METHODS

DNA was extracted from tumor tissue from 59 PDAC patients, analyzed for KRAS mutations, and hybridized to 180 K CGH + SNP microarrays and 450 K methylation arrays. Analyses were based on postoperative survival where less than 12 months was considered to be short survival and more than 18 months was considered long survival.

RESULTS

Ninety-three percent of the patients had KRAS mutations in tumor DNA. Great heterogeneity of whole genome DNA sequence alterations were observed among chromosomes within the patient materials. Specific DNA sequence alterations did not directly predict postoperative survival, although short survivors had significantly more and larger DNA amplifications (P < 0.006). Amplifications on chromosome 11 and 21 and deletions on chromosome 2 predicted short postoperative survival (P < 0.03). DNA methylation was not related to survival.

CONCLUSIONS

Highly variable genetic differences among DNA regions in PDAC tumors were demonstrated. Postoperative short survival was related to tumor sequence DNA alterations on chromosome 2, 11, and 21.

Anatomical, Physiological, and Molecular Imaging for Pancreatic Cancer: Current Clinical Use and Future Implications

Pancreatic adenocarcinoma is one of the deadliest human malignancies. Early detection is difficult and effective treatment is limited. Verifying the presence of micrometastatic dissemination and vessel invasion remains elusive, limiting radiological staging once this diagnosis is made. Diagnostic imaging provides independent tools to evaluate and characterize the biologic behavior of pancreatic cancer. Conventional anatomic imaging alone with either CT or MRI yields useful information on organ involvement but is limited in providing molecular and physiological information. Molecular imaging techniques such as PET or MRS provide information on metabolic and signaling pathways. Advanced MR sequences that target physiological parameters expand imaging options to characterize these tumors. By considering the parametric data from these three imaging approaches (anatomic, molecular, and physiological) we can better define specific tumor signatures. Such parametric characterization can provide insight into tumor metabolism, cellular density, protein expression, focal perfusion, and vascular permeability of these tumors. Radiogenomics research has already demonstrated ability to obtain information about cancer's genotype and phenotype; this is without invasive procedures or surgery. Further advances in these areas of experimental imaging hold promise to enable future clinical advances in detection and therapy of pancreatic cancer.

Pancreatic adenocarcinoma with venous involvement: is up-front synchronous portal-superior mesenteric vein resection still justified? A survey of the Association Française de Chirurgie

BACKGROUND

Venous resection (VR) during pancreatectomy has been reported to neither increase mortality nor morbidity and to provide similar survival outcomes in same stage tumors. However, controversy remains regarding the indications for up-front surgery according to the degree of venous involvement.

METHODS

From 2004 to 2009, 1,399 patients included in a French multicenter survey underwent pancreaticoduodenectomy or total pancreatectomy for pancreatic adenocarcinoma, either without VR (997 standard resections [SR]) or with VR (402 patients; 29 %). Postoperative and long-term outcomes were compared in both groups.

RESULTS

VR was associated with the following factors: larger tumors (p < 0.001), poorly differentiated tumors (p = 0.004), higher numbers of positive lymph nodes (p = 0.042), and positive resection margins (R1; p < 0.001). Overall, VR increased neither postoperative morbidity nor postoperative mortality (5 vs. 3 % in SR patients; p = 0.16). The median and 3-year survival rates in VR patients versus SR patients were 21 months and 31 % vs. 29 months and 44 %, respectively (p = 0.0002). In the entire cohort, multivariate analysis identified VR as a significant poor prognostic factor for long-term survival (hazard ratio [HR] 1.75, 95 % confidence interval [CI] 1.28-2.40; p = 0.0005). In the VR patients, lymph node ratio, whatever the cutoff (<0.3: p = 0.093; ≥ 0.3: p = 0.0098), R1 resection (p = 0.010), and segmental resection (p = 0.016) were independent risk factors; neoadjuvant treatment (HR 0.52, 95 % CI 0.29-0.94; p = 0.031) and adjuvant treatment (HR 0.55, 95 % CI 0.35-0.85; p = 0.006) were significantly associated with improved long-term survival.

CONCLUSIONS

Long-term survival after pancreatectomy was significantly altered when up-front VR was performed. Neoadjuvant treatment may be a better strategy than up-front resection in patients with preoperative suspicion of venous involvement.

Duodenum-preserving total and partial pancreatic head resection for benign tumors--systematic review and meta-analysis

BACKGROUND

Potential benefits of local extirpation of benign pancreatic head tumors are tissue conservation of pancreas, stomach, duodenum and common bile duct (CBD) and maintenance of pancreatic functions.

METHODS

Medline/PubMed, Embase and Cochrane Library databases were searched to identify studies applying duodenum-preserving total or partial pancreatic-head resection (DPPHRt/p) and reporting short- and long-term outcomes. Twenty-four studies, including 416 patients who underwent DPPHRt/p, were identified for systematic analysis. The meta-analysis was based on 10 prospective controlled and 4 retrospective controlled cohort studies, comparing 293 DPPHRt/p resections with 372 pancreato-duodenectomies (PD).

RESULTS, SYSTEMATIC ANALYSIS

Of 416 patients, 75.7% underwent total and 24.3% partial head resection, while 47.1% included segmentectomy of duodenum and CBD. The most common pathology was cystic neoplasm (65.8%) and endocrine tumors (13.4%). The frequencies of severe postoperative complications of 8.8%, pancreatic fistula of 19.2%, re-operation of 1.7% and hospital mortality of 0.48%, indicate a low level of early post-operative complications.

META-ANALYSIS

DPPHRt/p significantly preserved the level of exocrine (IV = -0.67, 95% CI -0.98 to -0.35, p = 0.0001) and endocrine (IV = 18.20, fixed, 95% CI -0.92 to 25.48, p = 0.0001) pancreatic functions compared to PD when the pre- and postoperative functional status in both groups are analyzed. There were no significant differences between DPPHRt/p and PD in frequency of pancreatic fistula, delayed gastric emptying or hospital mortality.

CONCLUSION

DPPHRt/p for benign neoplasms and neuro-endocrine tumors of the pancreatic head is associated with a low level of early-postoperative complications and a better conservation of exocrine and endocrine functions.

Neoadjuvant therapy for non-metastatic pancreatic ductal adenocarcinoma

Treatment of pancreatic cancer is increasingly multimodal, with patients receiving chemotherapy, radiation, and surgical extirpation in hope of long-term cure. There is ongoing debate over the timing, sequence, and necessity of these treatments as they pertain to the spectrum of local-regional disease. Current guidelines support a neoadjuvant strategy in patients with locally advanced and borderline resectable disease. Although there is currently no high-level evidence to recommend neoadjuvant therapy for all patients, there are data to suggest that wider application of neoadjuvant therapy may be beneficial. Random-assignment prospective trials are ongoing. In this review we examine the literature addressing a neoadjuvant approach to potentially resectable, borderline resectable, and locally advanced pancreatic cancer and highlight the outcomes of preoperative emergence of latent metastatic disease, attempted resection rates, margin negative resection rates, and pathologic response to treatment.

Phase II trial of vatalanib in patients with advanced or metastatic pancreatic adenocarcinoma after first-line gemcitabine therapy (PCRT O4-001)

PURPOSE

Vatalanib (PTK 787/ZK22584) is an oral poly-tyrosine kinase inhibitor with strong affinity for platelet-derived growth factor and vascular endothelial growth factor (VEGF) receptors. We conducted an open-label, phase II multicenter therapeutic trial investigating the efficacy and tolerability of vatalanib in patients with metastatic or advanced pancreatic cancer who failed first-line gemcitabine-based therapy.

METHODS

Vatalanib treatment consisted of a twice daily oral dosing using a "ramp-up schedule," beginning with 250 mg bid during week 1,500 mg bid during week 2, and 750 mg bid on week three and thereafter. The primary objective of this study was to evaluate the 6-month survival rate.

RESULTS

Sixty-seven patients were enrolled. The median age was 64, and 66% (N = 43) had only one prior regimen. Common grade 3/4 adverse events included hypertension (20%; N = 13), fatigue (17%; N = 11), abdominal pain (17%; N = 11), and elevated alkaline phosphatase (15%; N = 10). Among the 65 evaluable patients, the 6-month survival rate was 29% (95% CI 18-41%) and the median progression-free survival was 2 months. Fifteen patients survived 6 months or more. Two patients had objective partial responses, and 28% of patients had stable disease. Changes in biomarkers including soluble VEGF and vascular endothelial growth factor receptor did not correlate with response to drug.

CONCLUSION

Vatalanib was well tolerated as a second-line therapy and resulted in favorable 6-month survival rate in patients with metastatic pancreatic cancer, compared with historic controls.

Pancreaticoduodenectomy for pancreatic ductal adenocarcinoma: a French multicentre prospective evaluation of resection margins in 150 evaluable specimens

OBJECTIVES

This study aimed to determine the impact of a standardized pathological protocol on resection margin status after pancreaticoduodenectomy (PD) for ductal adenocarcinoma.

METHODS

A total of 150 patients operated during 2008-2010 were included in a prospective multicentre study using a 'quality protocol'. Multicolour inking by the surgeon identified three resection margins: the portal vein-superior mesenteric vein margin (PV-SMVm) or mesenterico-portal vein groove; the superior mesenteric artery margin (SMAm), and the posterior margin. Resection margins were stratified by 0.5-mm increments (range: 0-2.0 mm). Pancreatic neck, bile duct and intestinal margins were also analysed. Correlations between histopathological factors and survival in the 0-mm resection margin group were analysed.

RESULTS

Thirty-six patients (24%) had a PV-SMV resection (PV-SMVR). An analysis of resections categorized according to margin distances of 0 mm, <1.0 mm, <1.5 mm and <2.0 mm confirmed R1 resections in 35 (23%), 91 (61%), 94 (63%) and 107 (71%) patients, respectively. The most frequently invaded resection margin was the PV-SMVm (35% of all patients) and PV-SMVR was the only factor correlated with a higher risk for at least one 0-mm positive resection margin on multivariate analysis (P < 0.001). Two-year progression-free survival (PFS) and median PFS time in patients with R0 and R1 resections (at 0 mm), respectively, were 42.0% and 26.5%, and 19.5 months and 10.5 months, respectively (P = 0.02). A positive PV-SMVm and SMAm had significant impact on PFS, whereas a positive posterior margin had no impact.

CONCLUSIONS

Pancreaticoduodenectomy requiring PV-SMVR was associated with a higher risk for R1 resection. The standardization of histopathological analysis has a clinically relevant impact on PFS data.

Outcomes of pancreaticoduodenectomy for pancreatic malignancy in octogenarians: an American College of Surgeons National Surgical Quality Improvement Program analysis

BACKGROUND

Most series analyzing outcomes of pancreaticoduodenectomy in octogenarians are limited by a small sample size. The investigators used the American College of Surgeons National Surgical Quality Improvement Program database for an analysis of the impact of advanced age on outcomes after pancreatic cancer surgery.

METHODS

The National Surgical Quality Improvement Program database from 2005 to 2010 was accessed to study the outcomes of 475 pancreaticoduodenectomies performed in patients ≥80 years of age compared with 4,102 patients <80 years of age using chi-square and Student's t tests. A multivariate logistic regression was used to analyze factors associated with 30-day mortality and the occurrence of major complications.

RESULTS

Octogenarians had significantly more preoperative comorbidities compared with patients <80 years of age. On multivariate analysis, age ≥80 years was associated with an increased likelihood of experiencing 30-day mortality and major complications compared with patients <80 years of age. On subgroup analysis, septuagenarians had a similar odds ratio of experiencing mortality or complications compared with octogenarians, whereas patients <70 years of age were at lower risk.

CONCLUSIONS

Although octogenarians have an increased risk for mortality and major complications compared with patients <80 years of age, on subgroup analysis, they do not differ from septuagenarians.

Evolution and dynamics of pancreatic cancer progression

Efficient metastasis is believed as the result of multiple genetic, epigenetic and/or post-translational events in the lifetime of a carcinoma. At the genetic level, these events may be categorized into those that occur during carcinogenesis, and those that occur during subclonal evolution. This review summarizes current knowledge of the genetics of pancreatic cancer from its initiation within a normal cell until the time that is has disseminated to distant organs, many features of which can be extrapolated to other solid tumor types. The implications of these findings to personalize genome analyses of an individual patient's tumor are also discussed.