Number of examined lymph nodes and nodal status assessment in pancreaticoduodenectomy for pancreatic adenocarcinoma

The Association between Sampling and Survival in Patients with Pancreatic Ductal Adenocarcinoma Who Received Neoadjuvant Therapy and Pancreaticoduodenectomy

Adequate sampling is essential to an accurate pathologic evaluation of pancreatectomy specimens resected for pancreatic ductal adenocarcinoma (PDAC) after neoadjuvant therapy (NAT). However, limited data are available for the association between the sampling and survival in these patients. We examined the association of the entire submission of the tumor (ESOT) and the entire submission of the pancreas (ESOP) with disease-free survival (DFS) and overall survival (OS), as well as their correlations with clinicopathologic features, for 627 patients with PDAC who received NAT and pancreaticoduodenectomy. We demonstrated that both ESOT and ESOP were associated with lower ypT, less frequent perineural invasion, and better tumor response (p < 0.05). ESOP was also associated with a smaller tumor size (p < 0.001), more lymph nodes (p < 0.001), a lower ypN stage (p < 0.001), better differentiation (p = 0.02), and less frequent lymphovascular invasion (p = 0.009). However, since ESOP and ESOT were primarily conducted for cases with no grossly identifiable tumor or minimal residual carcinoma in initial sections, potential bias cannot be excluded. Both ESOT and ESOP were associated with less frequent recurrence/metastasis and better DFS and OS (p < 0.05) in the overall study population. ESOP was associated with better DFS and better OS in patients with ypT0/ypT1 or ypN0 tumors and better OS in patients with complete or near-complete response (p < 0.05). ESOT was associated with better OS in patients with ypT0/ypT1 or ypN0 tumors (p < 0.05). Both ESOT and ESOP were independent prognostic factors for OS according to multivariate survival analyses. Therefore, accurate pathologic evaluation using ESOP and ESOT is associated with the prognosis in PDAC patients with complete or near-complete pathologic response and ypT0/ypT1 tumor after NAT.

The impact of surgical-oncologic textbook outcome in patients with stage I to III pancreatic ductal adenocarcinoma: A cross-validation study of two national registries

BACKGROUND

Using national registries, we aimed to evaluate oncologic textbook outcomes in pancreatic ductal adenocarcinoma patients.

METHODS

Patients with stage I to III pancreatic ductal adenocarcinoma and surgical resection from 2010 to 2020 in the US and Germany were identified using the National Cancer Database and National Cancer Registries data. The surgical-oncologic textbook outcome was defined as complete oncologic resection with no residual tumor and ≥12 harvested lymph nodes. The composite endpoint was defined as surgical-oncologic textbook outcome and receipt of perioperative systemic and/or radiation therapy.

RESULTS

In total, 33,498 patients from the National Cancer Database and 14,589 patients from the National Cancer Registries were included. In the National Cancer Database, 28,931 (86%) patients had complete oncologic resection with no residual tumor, and 11,595 (79%) in the National Cancer Registries. 8,723 (26%) patients in the National Cancer Database and 556 (4%) in the National Cancer Registries had <12 lymph nodes harvested. The National Cancer Database shows 26,135 (78%) underwent perioperative therapy and 8,333 (57%) in the National Cancer Registries. Surgical-oncologic textbook outcome was achieved in 21,198 (63%) patients in the National Cancer Database and in 11,234 (77%) patients from the National Cancer Registries. 16,967 (50%) patients in the National Cancer Database and 7,878 (54%) patients in the National Cancer Registries had composite textbook outcome. Median overall survival in patients with composite textbook outcomes was 32 months in the National Cancer Database and 27 months in the National Cancer Registries (P < .001). In contrast, those with non-textbook outcomes had a median overall survival of 23 months in the National Cancer Database and 20 months in the National Cancer Registries (P < .001).

CONCLUSION

Surgical-oncologic textbook outcomes were achieved in > 50% of stage I to III pancreatic ductal adenocarcinoma for both the National Cancer Database and the National Cancer Registries. Failure to achieve textbook outcomes was associated with impaired survival across both registries.

Lymph node examination and survival in resected pancreatic ductal adenocarcinoma: retrospective study

BACKGROUND

The minimum number of examined lymph nodes (ELN) required for adequate staging and best prediction of survival has not been established in pancreatic ductal adenocarcinoma (PDAC). The aim of the study was to investigate the influence of ELN on staging and survival in PDAC.

METHODS

Patients undergoing partial or total pancreatectomy for PDAC at two European university hospitals between 2007 and 2018 were retrospectively reviewed. Multivariate Cox regression model and survival analyses were performed to verify adequate staging.

RESULTS

Overall 341 (73 per cent) patients showed lymph node metastasis (N1/N2), whereas 125 (27 per cent) patients had no lymph node involvement (N0). With increasing number of ELN, the proportion of positive lymph nodes increased. The minimum number of ELN needed to detect lymph node involvement was 21. In multivariate analysis, examination of <21 lymph nodes was a significant negative predictor for survival. Examination of ≥21 ELN reversed this effect and ruled out possible misclassification.

CONCLUSION

The number of ELN affects survival in PDAC. Possible misclassification was identified when <21 lymph nodes were examined. Therefore, at least 21 lymph nodes must be examined to avoid false lymph node classification in all types of resection.

Effect of adjuvant chemotherapy after pancreatectomy in patients with node-negative pancreatic cancer: target trial emulation

BACKGROUND

The effect of adjuvant therapy in node-negative pancreatic cancer is uncertain. The aim of this study was to estimate the effect of adjuvant chemotherapy on survival after surgery for pancreatic cancer in patients with node-negative (pN0) and node-positive (pN+) disease using target trial emulation.

METHODS

This was an observational cohort study emulating a hypothetical RCT by the clone-censor-weight approach using population-based Danish healthcare registries. The study included Danish patients undergoing curative-intent surgery for pancreatic cancer during 2008-2021, who were discharged alive no more than 4 weeks after surgery. At the time of discharge after surgery, the data for each patient were duplicated; one copy was assigned to the adjuvant chemotherapy strategy and the other to the no adjuvant chemotherapy strategy of the hypothetical trial. Copies were censored when the assigned treatment was no longer compatible with the observed treatment. To account for informative censoring, uncensored patients were weighted according to measured confounders. The primary outcomes were absolute difference in 2-year survival and median overall survival, comparing adjuvant with no adjuvant chemotherapy.

RESULTS

Some 424 patients with pN0 and 953 with pN+ disease were included. Of these, 62.0 and 74.6% respectively initiated adjuvant chemotherapy within the 8-week grace period. Among patients with pN0 tumours, the difference in 2-year survival between those with and without adjuvant therapy was -2.2 (95% c.i. -11.8 to 7.4)%. In those with pN+ disease, the difference in 2-year survival was 9.9 (1.6 to 18.1)%. Median overall survival was 24.9 (i.q.r. 12.8-49.4) and 15.0 (8.0-34.0) months for patients having adjuvant and no adjuvant therapy respectively.

CONCLUSION

In a target trial emulation using observational data, adjuvant chemotherapy did not improve survival after surgery for node-negative pancreatic cancer.

The Impact of Medicaid Expansion on Early-Stage Pancreatic Adenocarcinoma at High- Versus Low-Volume Facilities

INTRODUCTION

While Medicaid Expansion (ME) has improved healthcare access, disparities in outcomes after volume-dependent surgical care persist. We sought to characterize the impact of ME on postoperative outcomes among patients undergoing resection for pancreatic ductal adenocarcinoma (PDAC) at high-volume (HVF) versus low-volume (LVF) facilities.

METHODS

Patients who underwent resection for PDAC were identified from the National Cancer Database (NCDB; 2011-2018). HVF was defined as ≥20 resections/year. Patients were divided into pre- and post-ME cohorts, and the primary outcome was textbook oncologic outcomes (TOO). Difference-in-difference (DID) analysis was used to assess changes in TOO achievement among patients living in ME versus non-ME states.

RESULTS

Among 33,764 patients who underwent resection of PDAC, 19.1% (n = 6461) were treated at HVF. Rates of TOO achievement were higher at HVF (HVF: 45.7% vs. LVF: 32.8%; p < 0.001). On multivariable analysis, undergoing surgery at HVF was associated with higher odds of achieving TOO (odds ratio [OR] 1.60, 95% confidence interval [CI] 1.49-1.72) and improved overall survival (OS) [hazard ratio (HR) 0.96, 95% CI 0.92-0.99]. Compared with patients living in non-ME states, individuals living in ME states were more likely to achieve TOO on adjusted DID analysis (5.4%, p = 0.041). Although rates of TOO achievement did not improve after ME at HVF (3.7%, p = 0.574), ME contributed to markedly higher rates of TOO among patients treated at LVF (6.7%, p = 0.022).

CONCLUSIONS

Although outcomes for PDAC remain volume-dependent, ME has contributed to significant improvement in TOO achievement among patients treated at LVF. These data highlight the impact of ME on reducing disparities in surgical outcomes relative to site of care.

A neoadjuvant therapy compatible prognostic staging for resected pancreatic ductal adenocarcinoma

OBJECTIVE

To improve prediction, the AJCC staging system was revised to be consistent with upfront surgery (UFS) and neoadjuvant therapy (NAT) for PDAC.

BACKGROUND

The AJCC staging system was designed for patients who have had UFS for PDAC, and it has limited predictive power for patients receiving NAT.

METHODS

We examined 146 PDAC patients who had resection after NAT and 1771 who had UFS at Changhai Hospital between 2012 and 2021. The clinicopathological factors were identified using Cox proportional regression analysis, and the Neoadjuvant Therapy Compatible Prognostic (NATCP) staging was developed based on these variables. Validation was carried out in the prospective NAT cohort and the SEER database. The staging approach was compared to the AJCC staging system regarding predictive accuracy.

RESULTS

The NAT cohort's multivariate analysis showed that tumor differentiation and the number of positive lymph nodes independently predicted OS. The NATCP staging simplified the AJCC stages, added tumor differentiation, and restaged the disease based on the Kaplan-Meier curve survival differences. The median OS for NATCP stages IA, IB, II, and III was 31.7 months, 25.0 months, and 15.8 months in the NAT cohort and 30.1 months, 22.8 months, 18.3 months, and 14.1 months in the UFS cohort. Compared to the AJCC staging method, the NATCP staging system performed better and was verified in the validation cohort.

CONCLUSIONS

Regardless of the use of NAT, NATCP staging demonstrated greater predictive abilities than the existing AJCC staging approach for resected PDAC and may facilitate clinical decision-making based on accurate prediction of patients' OS.

Integrated Pathologic Score Effectively Stratifies Patients With Pancreatic Ductal Adenocarcinoma Who Received Neoadjuvant Therapy and Pancreaticoduodenectomy

Neoadjuvant therapy is increasingly used to treat patients with pancreatic ductal adenocarcinoma (PDAC). Pathologic parameters of treated PDAC, including tumor (ypT) and lymph node (ypN) stage, and tumor response grading (TRG) are important prognostic factors in this group of patients. To our knowledge, a multifactorial prognostic score combining pathologic features including ypT, ypN, and TRG in treated PDAC patients has not been reported. Our cohort consisted of 398 PDAC patients who received neoadjuvant therapy and underwent pancreaticoduodenectomy at our institution. All pancreaticoduodenectomy specimens were grossly and microscopically evaluated using a standard protocol. The integrated pathologic score (IPS) was calculated as the sum of the scores for ypT, ypN, and TRG according to either the MD Anderson grading system (IPSMDA) or the College of American Pathologists (CAP) grading system (IPSCAP). The IPSMDA and IPSCAP were correlated with clinicopathologic parameters and patient survival. Using either IPSMDA or IPSCAP, PDAC patients were stratified into 3 distinct prognostic groups for both disease-free survival (DFS) ( P <0.001) and overall survival (OS) ( P <0.001). The IPSMDA and IPSCAP correlated with tumor differentiation, margin status, the American Joint Committee on Cancer (AJCC) stage, and tumor recurrence ( P <0.05). In multivariate analysis, IPSMDA, IPSCAP, margin status, and tumor differentiation were independent prognostic factors for both DFS ( P <0.05) and OS ( P <0.05). However, patients with AJCC stage IB, IIA, or IIB disease had no significant difference in either DFS or OS ( P >0.05). The IPS appears to provide improved prognostic information compared with AJCC staging for preoperatively treated patients with PDAC.

Higher Numbers of Examined Lymph Nodes Are Associated with Increased Survival in Resected, Treatment-Naïve, Node-Positive Esophageal, Gastric, Pancreatic, and Colon Cancers

BACKGROUND OR PURPOSE

The role of extended lymphadenectomy as part of resection for lymph node (LN)-positive gastrointestinal (GI) malignancies remains controversial with no clear clinical guidance. The purpose of this retrospective study is to determine whether the number of LNs examined as part of GI malignancy resections affects overall survival (OS) among patients with node-positive esophageal, gastric, pancreatic, and colon cancers.

METHODS

Participants with LN-positive GI cancers who were diagnosed between 2004 and 2015 and underwent oncologic resections were selected from National Cancer Database (NCDB). The primary predictor was the number of examined LNs categorized in tertiles. The effect on OS was measured by hazard ratio (HR) derived from multivariate Cox regression analyses.

RESULTS

From 2004 to 2015, 1877, 10,086, 18,193, and 102,500 patients with LN-positive esophageal, gastric, pancreatic, and colon adenocarcinomas who did not receive neoadjuvant treatment and underwent oncologic tumor resection were registered in the NCDB. Using multivariate Cox proportional hazard modeling, greater LNs examined in surgically resected LN-positive GI cancers were found to be associated with increased OS for all histologies. This association was the strongest (as compared to the lowest tertile) for gastric cancer (middle tertile: HR = 0.91, 95% CI, 0.86-0.96, p = 0.001; highest tertile: HR = 0.73, 95% CI, 0.69-0.78, p < 0.001), followed by colon (highest tertile: HR = 0.86, 95% CI, 0.84-0.88, p < 0.001), esophageal (highest tertile: HR = 0.83, 95% CI, 0.72-0.95, p = 0.01), and pancreatic (highest tertile: HR = 0.93, 95% CI, 0.89-0.98, p = 0.002) cancers.

DISCUSSION AND CONCLUSION

In patients with surgically resected node-positive GI malignancies who did not receive neoadjuvant systemic therapy, a higher number of examined LNs is associated with increased OS. This association is the strongest for gastric cancer, followed by colon, esophageal, and pancreatic cancers respectively.

A Lymph Node Ratio Model for Prognosis of Patients with Pancreatic Neuroendocrine Tumors

The objective of this study was to determine the prognostic value of lymph node (LN) involvement and the LN ratio (LNR) and their effect on recurrence rates and survival in patients with pancreatic neuroendocrine tumors (PNETs) undergoing surgery. This single-center retrospective study reviewed the medical records of 95 consecutive patients diagnosed with PNETs who underwent surgery at our medical center between 1997 and 2017. The retrieved information included patient demographics, pathology reports, treatments, and oncological outcomes. Results: 95 consecutive potentially suitable patients were identified. The 78 patients with PNETs who underwent surgery and for whom there was adequate data were included in the analysis. Their mean ± standard deviation age at diagnosis was 57.4 ± 13.4 years (range 20-82), and there were 50 males (64%) and 28 females (36%). 23 patients (30%) had LN metastases (N1). The 2.5- and 5-year disease-free survival (DFS) rates for the entire cohort were 79.5% and 71.8%, respectively, and their 2- and 5-year overall survival (OS) rates were 85.9% and 82.1%, respectively. The optimal value of the LNR was 0.1603, which correlated with the outcome (2-year OS p = 0.002 HR = 13.4 and 5-year DFS p = 0.016 HR = 7.2, respectively, and 5-year OS and 5-year DFS p = 0.004 HR = 9 and p = 0.001 HR = 10.6, respectively). However, the multivariate analysis failed to show that the LNR was an independent prognostic factor in PNETs. Patients with PNETs grade and stage are known key prognostic factors influencing OS and DFS. According to our results, LNR failed to be an independent prognostic factor.

Nationwide Validation of the 8th American Joint Committee on Cancer TNM Staging System and Five Proposed Modifications for Resected Pancreatic Cancer

BACKGROUND

The prognostic value of four proposed modifications to the 8th American Joint Committee on Cancer (AJCC) TNM staging system has yet to be evaluated. This study aimed to validate five proposed modifications.

METHODS

Patients who underwent pancreatic ductal adenocarcinoma resection (2014-2016), as registered in the prospective Dutch Pancreatic Cancer Audit, were included. Stratification and prognostication of TNM staging systems were assessed using Kaplan-Meier curves, Cox proportional hazard analyses, and C-indices. A new modification was composed based on overall survival (OS).

RESULTS

Overall, 750 patients with a median OS of 18 months (interquartile range 10-32) were included. The 8th edition had an increased discriminative ability compared with the 7th edition {C-index 0.59 (95% confidence interval [CI] 0.56-0.61) vs. 0.56 (95% CI 0.54-0.58)}. Although the 8th edition showed a stepwise decrease in OS with increasing stage, no differences could be demonstrated between all substages; stage IIA vs. IB (hazard ratio [HR] 1.30, 95% CI 0.80-2.09; p  = 0.29) and stage IIB vs. IIA (HR 1.17, 95% CI 0.75-1.83; p  = 0.48). The four modifications showed comparable prognostic accuracy (C-index 0.59-0.60); however, OS did not differ between all modified TNM stages (ns). The new modification, migrating T3N1 patients to stage III, showed a C-index of 0.59, but did detect significant survival differences between all TNM stages (p  < 0.05).

CONCLUSIONS

The 8th TNM staging system still lacks prognostic value for some categories of patients, which was not clearly improved by four previously proposed modifications. The modification suggested in this study allows for better prognostication in patients with all stages of disease.

Prognostic relevance of the revised R status definition in pancreatic cancer: meta-analysis

BACKGROUND

The prognostic impact of margin status is reported with conflicting results after pancreatic cancer resection. While some studies validated an uninvolved resection margin (R0) 1 mm or more of tumour clearance, others have failed to show benefit. This systematic review and meta-analysis aimed to investigate the effects of margin definitions on median overall survival (OS).

METHODS

MEDLINE, Web of Science, and the Cochrane Central Register of Controlled Trials were searched for studies reporting associations between resection margins and OS between 2010 and 2021. Data regarding margin status (R0 circumferential resection margin (CRM) negative (CRM-), R0 CRM positive (CRM+), R0 direct, and R1 and OS were extracted. Hazard ratios (HRs) were pooled with a random-effects model. The risk of bias was evaluated with the Quality in Prognosis Studies (QUIPS) tool.

RESULTS

The full texts of 774 studies were screened. In total, 21 studies compromising 6056 patients were included in the final synthesis. In total, 188 (24 per cent) studies were excluded due to missing margin definitions. The R0 (CRM+) rate was 50 per cent (95 per cent confidence interval (c.i.) 0.40 to 0.61) and the R0 (CRM-) rate was 38 per cent (95 per cent c.i. 0.29 to 0.47). R0 (CRM-) resection was independently associated with improved OS compared to combined R1 and R0 (CRM+; HR 1.36, 95 per cent c.i. 1.23 to 1.56).

CONCLUSION

The revised R status was confirmed as an independent prognosticator compared to combined R0 (CRM+) and R1. The limited number of studies, non-standardized pathology protocols, and the varying number of margins assessed hamper comparability.

Surgery for pancreatic cancer: current controversies and challenges

Two areas that remain the focus of improvement in pancreatic cancer include high post-operative morbidity and inability to uniformly translate surgical success into long-term survival. This narrative review addresses specific aspects of pancreatic cancer surgery, including neoadjuvant therapy, vascular resections, extended pancreatectomy, extent of lymphadenectomy and current status of minimally invasive surgery. R0 resection confers longer disease-free survival and overall survival. Vascular and adjacent organ resections should be undertaken after neoadjuvant therapy, only if R0 resection can be ensured based on high-quality preoperative imaging, and that too, with acceptable post-operative morbidity. Extended lymphadenectomy does not offer any advantage over standard lymphadenectomy. Although minimally invasive distal pancreatectomies offers some short-term benefits over open distal pancreatectomy, safety remains a concern with minimally invasive pancreatoduodenectomy. Strict adherence to principles and judicious utilization of surgery within a multimodality framework is the way forward.

Pathology of Treated Pancreatic Ductal Adenocarcinoma and Its Clinical Implications

CONTEXT.—

Preoperative neoadjuvant therapy has been increasingly used to treat patients with potentially resectable pancreatic ductal adenocarcinoma (PDAC). Neoadjuvant therapy often induces extensive fibrosis in tumor, adjacent pancreatic parenchyma, and peripancreatic tissue. Histopathologic evaluations and histologic tumor response grading (HTRG) of posttherapy pancreatectomy specimens are very difficult and challenging. Studies on prognostic significance of posttherapy pathologic staging, optimal system for HTRG, and other pathologic parameters in treated PDAC patients are limited.

OBJECTIVE.—

This review is to provide a timely update of the prognostic values of posttherapy pathologic staging, HTRG, and other pathologic parameters in PDAC patients who received neoadjuvant therapy and pancreas resection.

DATA SOURCES.—

Systemic review of major studies on pathologic evaluation and its clinicopathologic implications in treated PDAC patients.

CONCLUSIONS.—

Systemic pathologic examination, histologic tumor regression grading, pathologic evaluation of the margins, tumor involvement of superior mesenteric vein/portal vein, accurate pathologic staging, and reporting of posttherapy pancreatectomy specimens provide highly valuable prognostic information for postoperative patient care. Our findings suggest for the first time that tumor size of 1.0 cm, instead of 2.0 cm, is a better cutoff for ypT2 in PDAC patients. The newly proposed 3-tier MD Anderson HTRG system not only has proved to be an independent prognostic marker for PDAC patients who received neoadjuvant therapy and pancreatectomy, but also improves interobserver agreement among pathologists in evaluation of tumor response. This grading system should be considered in future editions of the College of American Pathologists protocol for PDAC.

Defining a minimum number of examined lymph nodes improves the prognostic value of lymphadenectomy in pancreas ductal adenocarcinoma

BACKGROUND

Lymph node (LN) metastasis is associated with decreased survival following resection for pancreatic ductal adenocarcinoma (PDAC). In N0 disease, increasing total evaluated LN (ELN) correlates with improved outcomes suggesting patients may be understaged when LNs are undersampled. We aim to assess the optimal number of examined lymph nodes (ELN) following pancreatectomy.

METHODS

Data from 1837 patients undergoing surgery were prospectively collected. The binomial probability law was utilized to analyze the minimum number of examined LNs (minELN) and accurately characterize each histopathologic stage. LN ratio (LNR) was compared to American Joint Committee on Cancer (AJCC) guidelines.

RESULTS

As ELN total increased, the likelihood of finding node positive disease increased. An evaluation based upon the binomial probability law suggested an optimal minELN of 12 for accurate AJCC N staging. As the number of ELNs increased, the discriminatory capacity of alternative strategies to characterize LN disease exceeded that offered by AJCC N stage.

CONCLUSION

This is the first study dedicated to optimizing histopathologic staging in PDAC using models of minELN informed by the binomial probability law. This study highlights two separate cutoffs for ELNs depending upon prognostic goal and validates that 12 LNs are adequate to determine AJCC N stage for the majority of patients.

Role of Node Dissection in Pancreatic Tumor Resection

BACKGROUND

Pancreatic cancer is a lethal disease, and, even with modern therapies, the mortality has not decreased significantly in decades. The prognostic importance of lymph node status is well defined; however, the role of extended lymphadenectomy to improve local recurrence and overall survival remains debated. Six randomized controlled trials have evaluated the extent of lymph node dissection in pancreaticoduodenectomy for pancreatic cancer.

OBJECTIVE

We sought to review the current literature to evaluate the role of lymphadenectomy in pancreatic cancer. The impact of each trial and its contribution to the literature is discussed.

CONCLUSIONS

Multiple randomized trials have failed to note an improvement in overall survival with extended lymphadenectomy for pancreatic cancer. Rather, extended lymphadenectomy was associated with increased morbidity, operating room time, and length of stay.

Impact of examined lymph node count on prognosis in patients with lymph node-negative pancreatic body/tail ductal adenocarcinoma

Background

Because the overall prognosis remains dismal for patients with resected pancreatic cancer (PC), we aimed to explore the prognostic impact of examined lymph node (ELN) count on lymph node (LN)-negative pancreatic body/tail ductal adenocarcinoma.

Methods

Patients' data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database (National Cancer Institute, USA) to investigate the relationship between ELN count and survival outcomes of LN-negative pancreatic body/tail ductal adenocarcinoma.

Results

A total of 700 patients were included, and the median number of ELNs was 11. The respective 1-, 3-, 5-year overall survival (OS) rates were 75.3%, 37.7%, 30.3%, and the 1-, 3-, 5-year cancer-specific survival (CSS) were 78.3%, 41.7%, 34.5%. The X-tile analysis showed that 14 was the most optimal cutoff for both OS and CSS. Kaplan-Meier survival analysis indicated that patients with ELNs >14 had better OS and CSS than ELNs ≤14. Multivariate Cox analysis showed ELNs ≤14 was an independent risk factor for both OS [hazard ratio (HR), 1.357; 95% confidence interval (CI), 1.080-1.704; P=0.009] and CSS (HR, 1.394; 95% CI, 1.092-1.778; P=0.008).

Conclusions

ELN count is associated with the survival rate in patients with LN-negative pancreatic body/tail ductal adenocarcinoma. Accurate nodal staging for these patients requires more than 14 ELNs.

Role of lymphadenectomy in resectable pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) remains one of the most devastating malignant diseases, predicted to become the second leading cause of cancer-related death by 2030. Despite advances in surgical techniques and in systemic therapy, the 5-year relative survival remains a grim 9% for all stages combined. The extent of lymphadenectomy has been discussed intensively for decades, given that even in early stages of PC, lymph node (LN) metastasis can be detected in approximately 80%.

PURPOSE

The primary objective of this review was to provide an overview of the current literature evaluating the role of lymphadenectomy in resected PC. For this, we evaluated randomized controlled studies (RCTs) assessing the impact of extent of lymphadenectomy on OS and studies evaluating the prognostic impact of anatomical site of LN metastasis and the impact of the number of resected LNs on OS.

CONCLUSIONS

Lymphadenectomy plays an essential part in the multimodal treatment algorithm of PC and is an additional therapeutic tool to increase the chance for surgical radicality and to ensure correct staging for optimal oncological therapy. Based on the literature from the last decades, standard lymphadenectomy with resection of at least ≥ 15 LNs is associated with an acceptable postoperative complication risk and should be recommended to obtain local radicality and accurate staging of the disease. Although radical surgery including appropriate lymphadenectomy of regional LNs remains the only chance for long-term tumor control, future studies specifically assessing the impact of neoadjuvant therapy on extraregional LNs are warranted.

Role of lymphadenectomy, adjuvant chemotherapy, and treatment at high-volume centers in patients with resected pancreatic cancer-a distinct view on lymph node yield

PURPOSE

While the importance of lymphadenectomy is well-established for patients with resectable pancreatic cancer, its direct impact on survival in relation to other predictive factors is still ill-defined.

METHODS

The National Cancer Data Base 2006-2015 was queried for patients with resected pancreatic adenocarcinoma (stage IA-IIB). Patients were dichotomized into the following two groups, those with 1-14 resected lymph nodes and those with ≥ 15. Optimal number of resected lymph nodes and the effect of lymphadenectomy on survival were assessed using various statistical modeling techniques. Mediation analysis was performed to differentiate the direct and indirect effect of lymph node resection on survival.

RESULTS

A total of 21,912 patients were included; median age was 66 years (IQR 59-73), 48.9% were female. Median number of resected lymph nodes was 15 (IQR 10-22), 10,163 (46.4%) had 1-14 and 11,749 (53.6%) had ≥ 15 lymph nodes retrieved. Lymph node positivity increased by 4.1% per lymph node up to eight examined lymph nodes, and by 0.6% per lymph node above eight. Five-year overall survival was 17.9%. Overall survival was better in the ≥ 15 lymph node group (adjusted HR 0.91, CI 0.88-0.95, p < 0.001). On a continuous scale, survival improved with increasing LNs collected. Patients who underwent adjuvant chemotherapy and were treated at high-volume centers had improved overall survival compared with their counterparts (adjusted HR 0.59, CI 0.57-0.62, p < 0.001; adjusted HR 0.86, CI 0.83-0.89, p < 0.001, respectively). Mediation analysis revealed that lymphadenectomy had only 18% direct effect on improved overall survival, while 82% of its effect were mediated by other factors like treatment at high-volume hospitals and adjuvant chemotherapy.

DISCUSSION

While higher number of resected lymph nodes increases lymph node positivity and is associated with better overall survival, most of the observed survival benefit is mediated by chemotherapy and treatment at high-volume centers.

Prognostic impact of lymph node status in patients after total pancreatectomy for pancreatic ductal adenocarcinoma: A strobe-compliant study

The optimal number of examined lymph nodes (ELN) for staging and impact of nodal status on survival following total pancreatectomy (TP) for pancreatic ductal adenocarcinoma (PDAC) is unclear. The aim of this study was to evaluate the prognostic impact of different lymph node status after TP for PDAC.The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients who underwent TP for PDAC from 2004 to 2015. We calculated overall survival (OS) of these patients using Kaplan-Meier analysis and Cox proportional hazards model.Overall, 1291 patients were included in the study, with 869 node-positive patients (49.5%). A cut-off points analysis revealed that 19, 19, and 13 lymph nodes best discriminated OS for all patients, node-negative patients, and node-positive patients, respectively. Higher number of ELN than the corresponding cut-off points was an independent predictor for better prognosis [all patients: hazard ratios (HR) 0.786, P = .002; node-negative patients: HR 0.714, P = .043; node-positive patients: HR 0.678, P < .001]. For node-positive patients, 1 to 3 positive lymph nodes (PLN) correlated independently with better survival compared with those with 4 or more PLN (HR 1.433, P = .002). Moreover, when analyzed in node-positive patients with less than 13 ELN, neither the number of PLN nor lymph node ratio (LNR) was associated with survival. However, when limited node-positive patients with at least 13 ELN, univariate analyses showed that both the number of PLN and LNR were associated with survival, whereas multivariate analyses demonstrated that only number of PLN was consistently associated with survival (HR 1.556, P = .004).Evaluation at least 19 lymph nodes should be considered as quality metric of surgery in patients who underwent TP for PDAC. For node-negative patients, a minimal number of 19 lymph nodes is adequate to avoid stage migration. For node-positive patients, PLN is superior to LNR in predicting survival after TP, predominantly for those with high number of ELN.

Proposed Modification of the 8th Edition of the AJCC Staging System for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of this study was to improve the 8th edition (8th) of the American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

The new 8th AJCC staging system for PDAC was released in October, 2016, and will be applied in clinical practice in 2018.

METHODS

Two large cohorts were included in this analysis. One consisted of 45,856 PDAC patients in the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014), and the other consisted of 3166 PDAC patients in the Fudan University Shanghai Cancer Center (FUSCC) database (2005-2015).

RESULTS

Using the 8th AJCC staging system, the median overall survival of the patients in the same stage varied widely among the different substages. We proposed a modified staging system based on median OS in which we maintained the T, N, and M definitions, but regrouped the substages. In the SEER cohort, the concordance index was higher for local disease with the modified staging system [0.637; 95% confidence interval (CI) 0.631-0.642] than with the 8th AJCC staging system (0.620, 95% CI 0.615-0.626). Similar findings were also observed in the FUSCC cohort. In addition, we verified the reliability of the modified staging system in an analysis of patients with different examined lymph node counts (≥15 or 1-14).

CONCLUSIONS

The modified 8th AJCC staging system for PDAC proposed in this study provides improvements and may be evaluated for potential adoption in the next edition.

Survival, morbidity and mortality of pancreatic adenocarcinoma after pancreaticoduodenectomy with a total mesopancreas excision

INTRODUCTION

pancreatic adenocarcinoma is the most common malignancy in the periampullary region, with a five-year survival rate around 20%.

OBJECTIVE

the goal of our study was to determine the survival and safety data of a number of patients that underwent a cephalic duodenopancreatectomy (CDP) with total mesopancreas excision (TMPE).

MATERIAL AND METHODS

a prospective observational study was performed of 114 patients with pancreatic adenocarcinoma who underwent duodenopancreatectomy and TMPE over the period 2008-2017. Demographic variables, tumor stage, number of lymph nodes excised, lymph node ratio, R classification, the prognostic factor disease-free interval and survival were all assessed in a multivariate analysis.

RESULTS

complications were reported for 54 (47.3%) patients, of which 22 (19.3%) were categorized as serious. The mortality rate was 4.3% and the mean follow-up was 26.2 months. During this period, 73 (64%) patients relapsed after a mean interval of 40.9 months. The relapse pattern was mainly hepatic (26.3%), followed by local relapse (20%). Mean survival was 40.38 and actuarial survival was 26.6% at five years. Relapse-related factors included stage T3 or higher (RR 8.1 [1.1-61]) and an R1 resection (RR 13.4 [2.7-66.5]) and survival-related factors included an R1 resection (RR 10.7 [2.5-46.2]).

CONCLUSION

TMPE ensures an adequate lymphadenectomy and lymph node ratio according to reported standards. The survival of patients that have undergone surgery for pancreatic adenocarcinoma in our institution is 68.4% at one year and 26.6% at five years. An R1 resection is the primary factor for both relapse and survival.

Does Neoadjuvant Chemotherapy Change the Role of Regional Lymphadenectomy in Pancreatic Cancer Survival?

OBJECTIVES

The objective of this study was to evaluate the role of lymph node (LN) dissection and staging in outcomes of patients with pancreatic adenocarcinoma (PDAC) who underwent neoadjuvant chemotherapy (NAC).

METHODS

National Cancer Database was queried for patients with stages I to III PDAC diagnosed between 2004 and 2014. Overall survival (OS) was derived from Kaplan-Meier methods, and Cox-regression model was used to evaluate associations between the number of LN examined, number of positive nodes, and LN ratio with OS.

RESULTS

A total 35,599 patients were included, 3395 (9%) underwent NAC, 19,865 (56%) received adjuvant chemotherapy (AC), and 12,299 (35%) underwent surgery alone. Cox-regression showed superior OS in NAC compared with AC and surgery alone (26 vs 23 vs 14 months, P < 0.001). Minimum number of LN examined affecting OS was 8 LNs in NAC (23.8 vs 26.6 months, P = 0.029), and 12 LNs in AC group (22 vs 23.1 months, P = 0.028). Lymph node ratio cutoff of greater than 0.2 was associated with decreased OS (19.4 vs 24.4 months, P < 0.001).

CONCLUSIONS

Neoadjuvant chemotherapy is associated with improved survival in PDAC. Lymph node yield remains a significant prognostic factor after NAC, whereas the minimum number of harvested LNs associated with sufficient staging and survival is decreased.

Determining the optimal number of examined lymph nodes for accurate staging of pancreatic cancer: An analysis using the nodal staging score model

INTRODUCTION

The aim of this study was to determine the optimal number of examined lymph nodes (ELNs) for accurate staging of pancreatic cancer using the nodal staging score model.

MATERIALS AND METHODS

Clinicopathological data for patients with resected pancreatic cancer were collected from SEER database (development cohort [DC]) and Fudan University Shanghai Cancer Center database (validation cohort [VC]). Multivariable models were constructed to assess how the number of ELNs was associated with stage migration and overall survival (OS). Using the β-binomial distribution, we developed a nodal staging score model from the DC and tested it with the VC.

RESULTS

Both cohorts exhibited significant proportional increases from node-negative to node-positive disease (DC: odds ratio [OR], 1.047; P < 0.001; VC: OR, 1.035; P < 0.001) and improved OS (DC: hazard ratio [HR], 0.982; P < 0.001; VC: HR, 0.979; P < 0.001) as ELNs increased. Nodal staging scores escalated separately as ELNs increased for different tumor (T) stages, with plateaus at 16, 21, and 23 LNs (cut-offs) for T1, T2, and T3 tumors, respectively. Multivariable analysis indicated that examining more LNs than the corresponding cut-off value was a significant survival predictor (DC: HR, 0.813; P < 0.001; VC: HR, 0.696; P = 0.028).

CONCLUSION

The optimal number of ELNs for adequate staging of pancreatic cancer was related to T stage. We recommend examining at least 16, 21, and 23 LNs for T1, T2, and T3 tumors, respectively, as a nodal staging quality measure for both surgery and pathological analysis.

How to Reliably Assess Nodal Status in Distal Pancreatectomy for Adenocarcinoma

OBJECTIVES

The optimal number of lymph nodes that need to be analyzed to reliably assess nodal status in distal pancreatectomy for adenocarcinoma is still unknown.

METHODS

Two hundred seventy-eight patients who underwent distal pancreatectomy for adenocarcinoma were retrieved from a retrospective French nationwide database. The relations between the number of analyzed lymph nodes and the nodal status of the tumor were studied. The beta-binomial law was used to estimate the probability of being truly node negative depending on the number of analyzed lymph nodes. Cox proportional hazard model was used for the survival analysis.

RESULTS

The median number of analyzed lymph nodes was 15. There was a positive correlation between the number of positive lymph nodes and the number of lymph nodes analyzed. The curve reached a plateau at approximately 25 lymph nodes. The beta binomial model demonstrated that an analysis of 21 negative lymph nodes shows a probability to be truly N0 at 95%. N+ status was associated with survival, but the number of lymph node analyzed was not.

CONCLUSION

At least 21 lymph nodes should be analyzed to ensure a reliable assessment of the nodal status, but this number may be hard to reach in distal pancreatectomy.

Extensive lymph node dissection during pancreaticoduodenectomy: a risk factor for hepatic steatosis?

PURPOSE

The first reports of hepatic steatosis following pancreaticoduodenectomy (PD) were published several years ago; however, clear risk factors remain to be identified. Therefore, the aim of this study was to identify the risk factors for hepatic steatosis post-PD.

METHODS

We studied 90 patients who had undergone PD between September 2005 and January 2015. The inclusion criteria were as follows: available unenhanced CT within one month before PD and at least one unenhanced CT acquisition between PD and chemotherapy initiation. Using scanners, we studied the liver and spleen density as well as the surface areas of visceral (VF) and subcutaneous fat (SCF). These variables were previously identified by univariate and multivariate analyses.

RESULTS

Hepatic steatosis occurred in 25.6% of patients at 45.2 days, on average, post-PD. Among the patients with hepatic steatosis, the average liver density was 52 HU before PD and 15.1 HU post-PD (p < 0.001). The Patients with hepatic steatosis lost more VF (mean, 28 vs. 11 cm²) and SCF (28.8 vs. 13.7 cm²) (p < 0.01 and p = 0.01, respectively). Portal vein resection and extensive lymph node dissection were independent risk factors in the multivariate analysis (odds ratio [OR] 5.29, p = 0.009; OR 3.38, p = 0.04, respectively).

CONCLUSION

Portal vein resection and extensive lymph node dissection are independent risk factors for post-PD hepatic steatosis.

Increased pancreatic cancer survival with greater lymph node retrieval in the National Cancer Data Base

BACKGROUND

We evaluated the role of lymph node (LN) retrieval in pancreatic adenocarcinoma (PA) patients undergoing pancreaticoduodenectomy (PD).

METHODS

We utilized the National Cancer Data Base; Cox regression models and logistic regression models were used for statistical evaluation.

RESULTS

We evaluated 26,792 patients with PA who underwent PD. The mean LN retrieved in LN(-) patients was 10.8 vs 14.4 for LN(+) patients (P < 0.0001). Greater LN retrieval is an independent predictor of a negative microscopic margin and decreased length of stay. The median survival of LN(-) patients exceeded that of LN(+) patients (24.5 vs 15.1 months, P < 0.0001). Increasing LN retrieval is a significant predictor of survival in all patients, and in LN(-) patients. The relationship of increased LN retrieval and enhanced survival is a nearly linear trend.

CONCLUSIONS

Rather than demonstrating an inflection point that defines the extent of adequate lymphadenectomy, this dataset demonstrates an incremental relationship between LN retrieval and survival.

Evolution and impact of lymph node dissection during pancreaticoduodenectomy for pancreatic cancer

BACKGROUND

Insufficient examination of lymph nodes after pancreaticoduodenectomy can lead some pancreatic cancer patients with N1 disease to be misclassified as N0. We examined trends in lymph node dissection throughout time and investigated how these changes affect lymph node status and its prognostic value.

METHODS

The National Cancer Data Base was queried for patients with nonmetastatic pancreatic adenocarcinoma (2004-2013) who underwent classic pancreaticoduodenectomy with antrectomy. Logistic regression was performed for odds of node positivity. Kaplan-Meier curves and Cox proportional hazards models were used to assess the impact of lymph node status on overall survival for patients diagnosed during 2-year intervals from 2004-2012.

RESULTS

Median number of examined lymph nodes was 10 (interquartile range 6-15) in 2004 vs 17 (interquartile range 12-24) in 2013. Number of lymph nodes examined was a significant predictor of N1 disease (P < .0001), with a plateau at 30 nodes. N1 disease increased from 64.4% to 68.0% (P < .0001). Survival for both N1 and N0 subgroups improved. In successive multivariate models, N0 versus N1 status was consistently protective for overall survival (P < .0001), but there was no change in the magnitude of its hazard ratio over time (overall hazard ratio 0.691; 95% confidence interval 0.660-0.723).

CONCLUSION

Contemporary patients have an adequate number of nodes examined during standard pancreaticoduodenectomy. This, along with rising rates of N1 cancer detection and improved survival for both node-positive and node-negative patients, suggest more accurate classification of lymph node status. However, no increased benefit is achieved beyond 30 nodes. Overall, lymph node status remains a strong prognosticator for overall survival.

Metabolomics approaches in pancreatic adenocarcinoma: tumor metabolism profiling predicts clinical outcome of patients

BACKGROUND

Pancreatic adenocarcinomas (PAs) have very poor prognoses even when surgery is possible. Currently, there are no tissular biomarkers to predict long-term survival in patients with PA. The aims of this study were to (1) describe the metabolome of pancreatic parenchyma (PP) and PA, (2) determine the impact of neoadjuvant chemotherapy on PP and PA, and (3) find tissue metabolic biomarkers associated with long-term survivors, using metabolomics analysis.

METHODS

1H high-resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy using intact tissues was applied to analyze metabolites in PP tissue samples (n = 17) and intact tumor samples (n = 106), obtained from 106 patients undergoing surgical resection for PA.

RESULTS

An orthogonal partial least square-discriminant analysis (OPLS-DA) showed a clear distinction between PP and PA. Higher concentrations of myo-inositol and glycerol were shown in PP, whereas higher levels of glucose, ascorbate, ethanolamine, lactate, and taurine were revealed in PA. Among those metabolites, one of them was particularly obvious in the distinction between long-term and short-term survivors. A high ethanolamine level was associated with worse survival. The impact of neoadjuvant chemotherapy was higher on PA than on PP.

CONCLUSIONS

This study shows that HRMAS NMR spectroscopy using intact tissue provides important and solid information in the characterization of PA. Metabolomics profiling can also predict long-term survival: the assessment of ethanolamine concentration can be clinically relevant as a single metabolic biomarker. This information can be obtained in 20 min, during surgery, to distinguish long-term from short-term survival.

Validation of the American Joint Commission on Cancer (AJCC) 8th Edition Staging System for Patients with Pancreatic Adenocarcinoma: A Surveillance, Epidemiology and End Results (SEER) Analysis

BACKGROUND

The 8th edition of the AJCC staging system for pancreatic cancer incorporated several significant changes. This study sought to evaluate this staging system and assess its strengths and weaknesses relative to the 7th edition AJCC staging system.

METHODS

Using the Surveillance, Epidemiology and End Results (SEER) database (2004-2013), 8960 patients undergoing surgical resection for non-metastatic pancreatic adenocarcinoma were identified. Overall survival was estimated using the Kaplan-Meier method and compared using log-rank tests. Concordance indices (c-index) were calculated to evaluate the discriminatory power of both staging systems. The Cox proportional hazards model was used to determine the impact of T and N classification on overall survival.

RESULTS

The c-index for the AJCC 8th staging system [0.60; 95% confidence interval (CI), 0.59-0.61] was comparable with that for the 7th edition AJCC staging system (0.59; 95% CI, 0.58-0.60). Stratified analyses for each N classification system demonstrated a diminishing impact of T classification on overall survival with increasing nodal involvement. The corresponding c-indices were 0.58 (95% CI, 0.55-0.60) for N0, 0.53 (95% CI, 0.51-0.55) for N1, and 0.53 (95% CI, 0.50-0.56) for N2 classification.

CONCLUSION

This is the first large-scale validation of the AJCC 8th edition staging system for pancreatic cancer. The revised system provides discrimination similar to that of the 7th-edition system. However, the 8th-edition system allows for finer stratification of patients with resected tumors according to extent of nodal involvement.

Number of evaluated lymph nodes and positive lymph nodes, lymph node ratio, and log odds evaluation in early-stage pancreatic ductal adenocarcinoma: numerology or valid indicators of patient outcome?

BACKGROUND

We evaluated the prognostic significance and universal validity of the total number of evaluated lymph nodes (ELN), number of positive lymph nodes (PLN), lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS) in a relatively large and homogenous cohort of surgically treated pancreatic ductal adenocarcinoma (PDAC) patients.

METHODS

Prospectively accrued data were retrospectively analyzed for 282 PDAC patients who had pancreaticoduodenectomy (PD) at our institution. Long-term survival was analyzed according to the ELN, PLN, LNR, and LODDS.

RESULTS

Of these patients, 168 patients (59.5 %) had LN metastasis (N1). Mean ELN and PLN were 13.5 and 1.6, respectively. LN positivity correlated with a greater number of evaluated lymph nodes; positive lymph nodes were identified in 61.4 % of the patients with ELN ≥ 13 compared with 44.9 % of the patients with ELN < 13 (p = 0.014). Median overall survival (OS) and 5-year OS rate were higher in N0 than in N1 patients, 22.4 vs. 18.7 months and 35 vs. 11 %, respectively (p = 0.008). Mean LNR was 0.12; 91 patients (54.1 %) had LNR < 0.3. Among the N1 patients, median OS was comparable in those with LNR ≥ 0.3 vs. LNR < 0.3 (16.7 vs. 14.1 months, p = 0.950). Neither LODDS nor various ELN and PLN cutoff values provided more discriminative information within the group of N1 patients.

CONCLUSIONS

Our data confirms that lymph node positivity strongly reflects PDAC biology and thus patient outcome. While a higher number of evaluated lymph nodes may provide a more accurate nodal staging, it does not have any prognostic value among N1 patients. Similarly, PLN, LNR, and LODDS had limited prognostic relevance.

The role of lymph nodes in predicting the prognosis of ampullary carcinoma after curative resection

BACKGROUND

Lymph node involvement is one of the well-demonstrated prognostic factors in ampullary carcinoma. The aim of this study is to clarify the role of lymph nodes in predicting the survival outcome of ampullary carcinoma.

METHODS

A cohort of consecutive curative pancreaticoduodenectomies for ampullary carcinoma from 1999 to 2014 was retrospectively analyzed. The effect of node-associated variables, including lymph node status, positive lymph node number, total harvested lymph node (THLN) number, and lymph node ratio (LNR) was examined using univariate and multivariate analyses for survival outcome prediction.

RESULTS

In 194 evaluable patients, univariate analysis demonstrated that stage, cell differentiation, perineural invasion, and nodal status were significant conventional prognostic factors. Concerning the node-associated variables, positive nodal status, positive lymph node number≥2, THLN number<14, and LNR≥0.15 were significantly associated with poorer survival outcomes, with a 5-year survival rate of 20.3, 38.9, 25.4, and 18%, respectively. By multivariate analysis, nodal status and THLN number were two independent predictors of survival. The most favorable 5-year survival rate was 84.4% in patients with negative nodal involvement and THLN number≥14, compared with the poorest 5-year survival rate of 16.1% in those with positive nodal status and THLN number<14.

CONCLUSIONS

Tumor biology reflected by lymph node status is the most important independent prognostic factor; nevertheless, surgical radicality based on THLN number also plays a significant role in the survival outcome for patients with ampullary carcinoma after curative pancreaticoduodenectomy.

Extent of lymphadenectomy to associate with pancreaticoduodenectomy in patients with pancreatic head cancer for better tumor staging

OBJECTIVES

To define the extent of lymphadenectomy to associate with surgery for pancreatic head cancer.

BACKGROUND

Pancreaticoduodenectomy with extended lymphadenectomy fails to prolong patient survival.

METHODS

Prospective randomized and nonrandomized controlled trials (RCTs and NRCTs), meta-analyses, retrospective reviews, consensus conferences and pre- and intraoperative diagnoses of lymph node (LN) metastases were retrieved. Standard and extended lymphadenectomies were reviewed, including their effects on postoperative complications, mortality rate and long-term survival. The minimum total number of LN examined (TNLE) for adequate tumor staging, and the incidence of metastasis to each LN station were also considered. A pros and cons analysis was performed on the removal of each LN station.

RESULTS

Eleven retrospective studies (2514 patients), five prospective NRCTs (545 patients), and five prospective RCTs (586 patients) described different lymphadenectomies, which obtained similar long-term results. Five meta-analyses showed they did not influence long-term survival. However, N status is an important component of tumor staging. The recommended minimum TNLE is 15. The percent incidence of metastasis to each LN station was calculated considering at least 385 and up to 3725 patients. Preoperative imaging and intraoperative exploration frequently fail to identify metastatic nodes. A pros and cons analysis suggests that lymph node status is better established removing the following LN stations: 6, 8a-p, 12a-b-c, 13a-b, 14a-b-c-d, 16b1, 17a-b. Metastasis to 16b1 LNs significantly worsens prognosis. Their removal and frozen section examination, before proceeding with resection, may contraindicate resection.

CONCLUSION

A standard lymphadenectomy demands an adequate TNLE and removal of the LN stations metastasizing more frequently, without increasing the surgical risk.

Mesopancreas: A boundless structure, namely the rationale for dissection of the paraaortic area in pancreaticoduodenectomy for pancreatic head carcinoma

This review highlights the rationale for dissection of the 16a2 and 16b1 paraaortic area during pancreaticoduodenectomy (PD) for carcinoma of the head of the pancreas. Recent advances in surgical anatomy of the mesopancreas indicate that the retropancreatic area is not a single entity with well defined boundaries but an anatomical site of embryological fusion of peritoneal layers, and that continuity exists between the neuro lymphovascular adipose tissues of the retropancreatic and paraaortic areas. Recent advances in surgical pathology and oncology indicate that, in pancreatic head carcinoma, the mesopancreatic resection margin is the primary site for R1 resection, and that epithelial-mesenchymal transition-related processes involved in tumor progression may impact on the prevalence of R1 resection or local recurrence rates after R0 surgery. These concepts imply that mesopancreas resection during PD for pancreatic head carcinoma should be extended to the paraaortic area in order to maximize retropancreatic clearance and minimize the likelihood of an R1 resection or the persistence of residual tumor cells after R0 resection. In PD for pancreatic head carcinoma, the rationale for dissection of the paraaortic area is to control the spread of the tumor cells along the mesopancreatic resection margin, rather than to control or stage the nodal spread. Although mesopancreatic resection cannot be considered “complete” or “en bloc”, it should be “extended as far as possible” or be “maximal”, including dissection of 16a2 and 16b1 paraaortic areas.

Factors influencing survival after pancreatoduodenectomy for ductal adenocarcinoma depend on patients' age

BACKGROUND

It is supposed that a prolonged lifetime will be associated with increased incidence of PDAC among the elderly. Some studies show a tendency toward decreased survival in the elderly patients following pancreatoduodenectomy for PDAC. The aim of this study was to evaluate factors, influencing survival following pancreatoduodenectomy for PDAC in different age groups.

METHODS

Data of 251 patients after pancreatoduodenectomy for PDAC between 1999 and 2012 were analyzed. The Kaplan-Meier method and log-rank test were used to calculate survival and to compare differences between groups. The Cox proportional hazard model was applied to indentify independent prognosticators.

RESULTS

The overall median survival was 14.9 months. Postoperative morbidity was 25.5% with a 5.1% mortality rate. No significant differences in the overall morbidity (22.4 vs. 29.6%) or mortality (2.8 vs. 8.3%) rates were observed between different patients' age groups (<70 years and >70 years). Multivariate analysis revealed R1 resection (HR 1.76) and poor tumor differentiation (G3-G4) (HR 1.48) were independent negative factors for survival in patients <70 years. Lymph-node metastases (N1) - HR 4.89 and perineural invasion - HR 2.73 were independent prognosticators in the elderly.

CONCLUSIONS

Our study highlighted different factors influencing long-term survival after pancreatoduodenectomy: R1 resection and poor tumor differentiation (G3-G4) were independent negative factors for survival in patients <70 years, while perineural invasion and lymph-node metastases result in worse survival among the elderly.