A prospective randomized trial comparing standard pancreatoduodenectomy with pancreatoduodenectomy with extended lymphadenectomy in resectable pancreatic head adenocarcinoma

The Current Treatment Paradigm for Pancreatic Ductal Adenocarcinoma and Barriers to Therapeutic Efficacy

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, with a median survival time of 10-12 months. Clinically, these poor outcomes are attributed to several factors, including late stage at the time of diagnosis impeding resectability, as well as multi-drug resistance. Despite the high prevalence of drug-resistant phenotypes, nearly all patients are offered chemotherapy leading to modest improvements in postoperative survival. However, chemotherapy is all too often associated with toxicity, and many patients elect for palliative care. In cases of inoperable disease, cytotoxic therapies are less efficacious but still carry the same risk of serious adverse effects, and clinical outcomes remain particularly poor. Here we discuss the current state of pancreatic cancer therapy, both surgical and medical, and emerging factors limiting the efficacy of both. Combined, this review highlights an unmet clinical need to improve our understanding of the mechanisms underlying the poor therapeutic responses seen in patients with PDAC, in hopes of increasing drug efficacy, extending patient survival, and improving quality of life.

Complete circumferential lymphadenectomy around the superior mesenteric artery with preservation of nerve plexus reduces locoregional recurrence after pancreatoduodenectomy for resectable pancreatic ductal adenocarcinoma

BACKGROUND

Evaluation of recurrence pattern and risk factors for recurrence are essential for good rates of survival after upfront pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

This retrospective study included 167 consecutive patients who underwent upfront PD for resectable PDAC between 2000 and 2018. Postoperative recurrences were classified into three patterns according to initial recurrence site: isolated locoregional, isolated distant, and simultaneous locoregional and distant recurrences.

RESULTS

This study found 114 patients who developed postoperative recurrence (68.3%), including 37 patients with isolated locoregional recurrence (32.5%), 67 patients with isolated distant recurrence (58.8%), and 10 patients with simultaneous locoregional and distant recurrences (6.0%). When locoregional recurrence was classified based on the location of recurrent lesions, locoregional recurrence most commonly occurred around the superior mesenteric artery (SMA) (70.2%), followed by around the hepatic artery (25.5%) and in the paraaortic region (14.9%). Multivariate analyses showed that complete circumferential lymphadenectomy around the SMA, including not only the right side, but also the left side, was an independent factor for reduction of locoregional recurrence (P = 0.019, odds ratio [OR]: 2.217). Lymph node metastasis was an independent risk factor for both locoregional (P < 0.001, OR: 3.686) and distant recurrences (P < 0.001, OR: 4.315). Non-completion of postoperative adjuvant therapy was a risk factor for distant recurrence (P < 0.001, OR: 3.748).

CONCLUSION

Based on our data, complete circumferential lymphadenectomy around the SMA might contribute to local control, and multidisciplinary treatment including neoadjuvant therapy might be needed for resectable PDAC with high risk for recurrence.

Optimal Lymphadenectomy of the Mesopancreas Based on Fluorescence Imaging During Pancreaticoduodenectomy

BACKGROUND

Excision of the mesopancreas with lymphadenectomy is an important component of pancreatoduodenectomy. However, the optimal extent of lymphadenectomy remains unclear. Furthermore, accurate description of the mesopancreatic lymphatic pathways is difficult, probably because of the complex anatomy. Intestinal derotation simplifies the anatomy and facilitates both examination of lymphatic flow and the surgical procedure. The aim of this study was to evaluate lymphatic flow in the mesopancreas using indocyanine green fluorescence imaging with an intestinal derotation technique, and to clarify the optimal extent of mesopancreas excision and lymphadenectomy in pancreatoduodenectomy.

METHODS

Indocyanine green solution (2.5 × 10^-3 mg) was injected into the pancreatic head parenchyma. After intestinal derotation, the spread of indocyanine green was observed using near-infrared imaging.

RESULTS

Participants comprised 10 patients who underwent pancreatoduodenectomy for periampullary neoplasms. With indocyanine green fluorescence imaging, 9 of the 10 patients showed lymphatic flow from the pancreatic head to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery (but not via the second and more distant arteries), with eventual drainage into the paraaortic region.

CONCLUSIONS

Lymphatic pathways from the pancreatic head were connected to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery. Excision of the mesopancreas with the inferior pancreaticoduodenal artery and first jejunal artery while preserving the second or more distant arteries appears optimal in pancreatoduodenectomy for periampullary malignancies.

Practical significance of pancreatectomy with lymphadenectomy around the superior mesenteric artery for pancreatic cancer: comparison of prognosis after adjusting for major prognostic factors

INTRODUCTION

Although pancreatectomy with lymph node (LN) and nerve plexus dissection has usually been performed for pancreatic cancer, recent randomized controlled trials have questioned its survival benefits. However, superior mesenteric artery (SMA) LN dissection has still been included in standard treatment guidelines.

METHODS

A total of 94 patients who underwent pancreaticoduodenectomy for resectable pancreatic cancer without LN enlargement around the SMA on imaging were identified between 2008 and 2017. Disease-free survival (DFS), overall survival (OS), and complications were compared between those with LN and hemicircumferential nerve plexus dissection around the SMA (SMA ly+) and those without thorough LN and nerve plexus dissection around the SMA (SMA ly-) after adjusting for major prognostic factors.

RESULTS

A total of 78 and 16 patients with SMA ly+ and SMA ly- were identified, respectively. Our data demonstrated no difference in DFS and OS rates between both groups (P = 0.18 and 0.83, respectively). Patients with SMA ly+ had significantly more complications, particularly severe diarrhea, compared to those with SMA ly- (P = 0.001).

CONCLUSION

LN and nerve plexus dissection around the SMA did not prolong survival and significantly increased the frequency of severe diarrhea, suggesting that performing in all cases carries less practical significance.

Complete Lymphadenectomy Around the Entire Superior Mesenteric Artery Improves Survival in Artery-First Approach Pancreatoduodenectomy for T3 Pancreatic Ductal Adenocarcinoma

BACKGROUND

Artery-first approach pancreatoduodenectomy (AFA-PD) is an important technique for treating pancreatic ductal adenocarcinoma (PDAC). However, it remains unknown whether performing complete lymphadenectomy around the entire superior mesenteric artery (SMA) is associated with better outcomes. In this retrospective study, we aimed to investigate whether this approach improved overall and recurrence-free survival in patients with PDAC.

METHODS

We identified 88 patients with T3 PDAC who underwent PD at St. Marianna University School of Medicine, Kawasaki, Japan, between April 2005 and October 2017. Two groups were defined: an "AFA-PD group" (n = 45) who had undergone AFA-PD in addition to complete lymphadenectomy around the entire SMA, and a "conventional PD group" (n = 43) in whom complete lymphadenectomy had not been performed (conventional group). Univariate and multivariate survival analyses were performed to identify risk factors for overall and disease-free survival.

RESULTS

The AFA-PD group had a longer median survival time (40.3 vs. 22.6 months; p = 0.0140) and a higher 5-year survival rate (40.3% vs. 5.9%, p = 0.005) than the conventional PD group. Multivariate analysis showed that AFA-PD with complete lymphadenectomy around the entire SMA was an independent factor for improved overall survival (p = 0.022). Recurrences around the SMA were significantly less frequent in the AFA-PD group than in the conventional group (22.2% vs. 44.2%, p = 0.041).

CONCLUSIONS

AFA-PD with complete lymphadenectomy around the entire SMA can prevent recurrences around the SMA and may prolong overall survival in patients with PDAC.

Irreversible electroporation of locally advanced pancreatic cancer

Locally advanced pancreatic cancer (LAPC) constitutes approximately one-third of all pancreatic cancer, with standard of care inconsistently defined and achieving modest outcomes at best. While resection after downstaging offers the chance for cure, only a fraction of patients with LAPC become candidates for resection. Chemotherapy remains the mainstay of treatment for the remainder. In these patients, ablative therapy may be given for local control of the tumor. Irreversible electroporation (IRE) is an attractive ablative technique. IRE changes the permeability of tumor cell membranes to induce apoptosis. Unlike other ablative therapies, IRE causes little thermal injury to the target area, making it ideal for LAPC involving major vessels. Compared to systemic chemotherapy alone, IRE seems to offer some survival benefit. Although early studies reported notable morbidity and mortality rates, IRE presents opportunities for those who cannot undergo resection and who otherwise have limited options. Another role of IRE is to extend the margins of resected tumors when there is a concern for R1 resection. Perhaps most exciting, IRE is thought to have effects beyond local ablation. IRE has immunomodulatory effects, which may induce in vivo vaccination and may potentially synergize with immunotherapy. Through electrochemotherapy, IRE may enhance drug delivery to residual tumor cells. Ultimately the role of IRE in the treatment of LAPC still needs to be validated through well designed randomized trials. Investigations of its future possibilities are in the early stages. IRE offers the potential to provide more options to LAPC patients.

Extended lymph node resection versus standard resection for pancreatic and periampullary adenocarcinoma

BACKGROUND

Pancreatic and periampullary adenocarcinomas account for some of the most aggressive malignancies, and the leading causes of cancer-related mortalities. Partial pancreaticoduodenectomy (PD) with negative resection margins is the only potentially curative therapy. The high prevalence of lymph node metastases has led to the hypothesis that wider excision with the removal of more lymphatic tissue could result in an improvement of survival, and higher rates of negative resection margins.

OBJECTIVES

To compare overall survival following standard (SLA) versus extended lymph lymphadenectomy (ELA) for pancreatic head and periampullary adenocarcinoma. We also compared secondary outcomes, such as morbidity, mortality, and tumour involvement of the resection margins between the two procedures.

SEARCH METHODS

We searched CENTRAL, MEDLINE, PubMed, and Embase from 1973 to September 2020; we applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing PD with SLA versus PD with ELA, including participants with pancreatic head and periampullary adenocarcinoma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references and extracted data from study reports. We calculated pooled risk ratios (RR) for most binary outcomes except for postoperative mortality, for which we estimated a Peto odds ratio (Peto OR), and mean differences (MD) for continuous outcomes. We used a fixed-effect model in the absence of substantial heterogeneity (I² < 25%), and a random-effects model in cases of substantial heterogeneity (I² > 25%). Two review authors independently assessed risk of bias, and we used GRADE to assess the quality of the evidence for important outcomes.

MAIN RESULTS

We included seven studies with 843 participants (421 ELA and 422 SLA). All seven studies included Kaplan-Meier curves for overall survival. There was little or no difference in survival between groups (log hazard ratio (log HR) 0.12, 95% confidence interval (CI) -3.06 to 3.31; P = 0.94; seven studies, 843 participants; very low-quality evidence). There was little or no difference in postoperative mortality between the groups (Peto odds ratio (OR) 1.20, 95% CI 0.51 to 2.80; seven studies, 843 participants; low-quality evidence). Operating time was probably longer for ELA (mean difference (MD) 50.13 minutes, 95% CI 19.19 to 81.06 minutes; five studies, 670 participants; moderate-quality evidence). There was substantial heterogeneity between the studies (I² = 88%; P < 0.00001). There may have been more blood loss during ELA (MD 137.43 mL, 95% CI 11.55 to 263.30 mL; two studies, 463 participants; very low-quality evidence). There was substantial heterogeneity between the studies (I² = 81%, P = 0.02). There may have been more lymph nodes retrieved during ELA (MD 11.09 nodes, 95% CI 7.16 to 15.02; five studies, 670 participants; moderate-quality evidence). There was substantial heterogeneity between the studies (I² = 81%, P < 0.00001). There was little or no difference in the incidence of positive resection margins between groups (RR 0.81, 95% CI 0.58 to 1.13; six studies, 783 participants; very low-quality evidence).

AUTHORS' CONCLUSIONS

There is no evidence of an impact on survival with extended versus standard lymph node resection. However, the operating time may have been longer and blood loss greater in the extended resection group. In conclusion, current evidence neither supports nor refutes the effect of extended lymph lymphadenectomy in people with adenocarcinoma of the head of the pancreas.

Clinical Implication of Node-negative Resectable Pancreatic Cancer

BACKGROUND

Lymph node metastasis is one of the strongest prognostic factors of pancreatic cancer. However, the clinical implication of pathologically node-negative pancreatic cancer (pN0-PC) has not been fully investigated.

METHODS

Patients who underwent surgical resection for radiologically resectable pancreatic cancer between 2002 and 2018 were included in this study. A clinicopathological examination focusing on pN0-PC was performed.

RESULTS

Of all 533 patients, 155 (29.1%) were diagnosed with pN0-PC and 378 (70.9%) were diagnosed with node-positive pancreatic cancer (pN1/2-PC). The 5-year survival rates of patients with pN0-PC and pN1/2-PC were 57.1% and 25.0%, respectively (p < 0.001). A multivariate analysis revealed six prognostic factors in pN0-PC: age ≥ 70 years, nonadministration of adjuvant chemotherapy, anterior serosal invasion, nerve plexus invasion, and microscopic lymphatic and venous invasions. The 5-year survival rates of patients who had pN0-PC with 0-1 risk factor, with 2-3 risk factors, and with 4-6 risk factors were 87.6%, 47.9%, and 16.4%, respectively. Survival of patients who had pN0-PC with 4-6 risk factors was comparable to that of pN1/2 patients. The diagnostic capability of metastasis-negative lymph node was unsatisfactory, with a predictive value of < 43%.

CONCLUSIONS

Although the prognosis of patients with pN0-PC was better than that of patients with pN1/2-PC, it is not satisfactory. Survival of patients who had pN0-PC with 0-1 risk factors was extremely favorable; however, survival of patients who had pN0-PC with 4-6 risk factors was similar to those with pN1/2-PC.

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.

Multicenter randomized phase II trial of prophylactic right-half dissection of superior mesenteric artery nerve plexus in pancreatoduodenectomy for pancreatic head cancer

AIM

Right-half dissection of the superior mesenteric artery (SMA) nerve plexus in pancreatoduodenectomy for pancreatic cancer was initiated to accomplish R0 resection; however, subsequent refractory diarrhea was a major concern. This study aimed to evaluate the necessity of this technique.

METHODS

From April 2014 to June 2018, 74 patients with pancreatic head cancer were randomly allocated to either Group A, in which right-half dissection of the SMA nerve plexus was performed (n = 37), or Group B, in which total preservation of the nerve plexus was performed (n = 37). Short-term, long-term, and survival outcomes were prospectively compared between the groups.

RESULTS

The patient demographics, including the R0 resection rate, were not significantly different between the groups. Postoperative diarrhea occurred in 26 (70.3%) patients in Group A and 18 (48.6%) patients in Group B. There was a tendency for the development of severe diarrhea in Group A within 1 year postoperatively, and the frequency of diarrhea gradually decreased within 2 years, although that did not affect tolerance to adjuvant chemotherapy. There was no difference in either locoregional recurrence (27.0% vs 32.4%) or systemic recurrence (46.0% vs 46.0%). The median overall survival time in Groups A and B was 37.9 and 34.6 months, respectively (P = 0.77).

CONCLUSION

We did not demonstrate a clinical impact of right-half dissection of the SMA nerve plexus on locoregional recurrence or survival. Therefore, the prophylactic dissection of the SMA nerve plexus is unnecessary given that refractory diarrhea could be induced by this technique (UMIN000012241).

Essential updates 2018/2019: Current topics in the surgical treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is highly malignant. While cancers in other organs have shown clear improvements in 5-year survival, the 5-year survival rate of pancreatic cancer is approximately 10%. Early relapse and metastasis are not uncommon, making it difficult to achieve an acceptable prognosis even after complete surgical resection of the pancreas. Studies have been performed on various treatments to improve the prognosis of PDAC, and multidisciplinary approaches including non-surgical treatments have led to gradual improvement. In the present literature review, we have described the significance of anatomical and biological resectability criteria, the concept of R0 resection in surgical treatment, the feasibility of minimally invasive surgery, the remarkable development of perioperative chemotherapy, the effectiveness of conversion surgery for unresectable PDAC, and ongoing challenges in PDAC treatment. We also provide an essential update on these subjects by focusing on recent trends and topics.

En bloc proximal peri-mesenteric clearance for pancreatic head cancer surgery

The superior mesenteric artery (SMA) first approach and meso-pancreas excision (MPE) during pancreatoduodenectomy (PD) for pancreatic head cancer have been suggested for complete local tumor control, less operative blood loss, and early determination of resectability. However, SMA-first approach is merely a mode of approach and the concept of MPE has been challenged due to its anatomical obscurity. Dissection around proximal mesenteric vessels, superior mesenteric vein and SMA, is a critical procedure point for local tumor control as tumor infiltration is frequently observed both at the time of initial diagnosis and recurrence. The meso-pancreas, which encompasses the soft tissue between the uncinated process and SMA, does not include all the aforementioned points of proximal mesenteric areas. Therefore, the authors propose a new terminology named, “en bloc proximal peri-mesenteric clearance (PPMC)”, to describe the removal of all the lymph nodes including soft tissue around proximal mesenteric vessels, especially the SMA, to ensure complete local tumor control of pancreatic head cancer. The SMA-first approach applied either by the mesenteric approach or supra-colic approach can make this procedure more feasible. The extent of the circumferential dissection of the peri-SMA nerve plexus can be adjusted according to the primary disease. PPMC including the removal of all lymph nodes around the proximal SMA may be considered as a standard extent of PD for pancreatic head cancer.

Is Laparoscopic Pancreaticoduodenectomy Feasible for Pancreatic Ductal Adenocarcinoma?

Margin-negative radical pancreatectomy is the essential condition to obtain long-term survival of patients with pancreatic cancer. With the investigation for early diagnosis, introduction of potent chemotherapeutic agents, application of neoadjuvnat chemotherapy, advancement of open and laparoscopic surgical techniques, mature perioperative management, and patients' improved general conditions, survival of the resected pancreatic cancer is expected to be further improved. According to the literatures, laparoscopic pancreaticoduodenectomy (LPD) is also thought to be good alternative strategy in managing well-selected resectable pancreatic cancer. LPD with combined vascular resection is also feasible, but only expert surgeons should handle these challenging cases. LPD for pancreatic cancer should be determined based on surgeons' proficiency to fulfil the goals of the patient's safety and oncologic principles.

Pattern of local recurrence after curative resection in pancreatic ductal adenocarcinoma according to the initial location of the tumor

BACKGROUND/PURPOSE

The aim of the present study was to identify the types of recurrence in pancreatic ductal adenocarcinoma (PDAC) and discover the frequent location of the local recurrence.

METHODS

This study included 361 patients with PDAC who underwent curative-intent surgery between 2007-2014.

RESULTS

Among 361 patients, 75.1% (n = 271) developed recurrence during the follow-up period. The 5-year overall survival rate of recurred patients was 8.3%. The patterns of recurrence were classified as local (17.7%), systemic (62.0%), and loco-systemic (20.3%). According to the preoperative tumor locations, patients with uncinate and head cancer showed higher rates of local recurrence than those with body and tail cancer (47.8% vs 17.2%, P < .001). When comparing uncinate and head cancer only, patients with uncinate cancer had much more frequent local recurrence around the superior mesenteric artery/vein (M zone) than around the hepatoduodenal ligament/common hepatic artery (H zone). Patients with head cancer had a higher rate of local recurrence in the H zone (H zone vs M zone; 53.5% vs 81.4% in uncinate cancer, P = .001; 66.7% vs 44.4% in head cancer, P = .056).

CONCLUSION

Discovering the patterns of recurrence and frequent locations of recurrence may assist in local control as well as in the development of a customized individual approach for each patient.

Para-aortic lymph node metastasis detected intraoperatively by systematic frozen section examination in pancreatic head adenocarcinoma: is resection improving the prognosis?

BACKGROUND

This study aimed to evaluate the controversial benefit of a pancreaticoduodenectomy (PD) in patients with PALN metastasis intraoperatively detected by systematic frozen section examination in pancreatic adenocarcinoma.

METHODS

PALN intraoperative examination by frozen section was systematically performed from January 2006 to February 2018 prior to performing PD for pancreatic adenocarcinoma. Until June 2012, PALN + patients still underwent PD (PALN+/PD group) in the framework of a prospective study. Since July 2012, PALN+ was considered as contraindicating the planned PD (PALN+/No-PD group). Post-operative morbidity and survival were compared between these two groups.

RESULTS

Of the 32 PALN + patients intraoperatively detected, the first 13 underwent a PD, while the last 19 did not undergo resection. Seven patients (54%) among 13 PALN+/PD patients developed a post-operative complication against 3 (16%) among 19 PALN+/No-PD patients (p = 0.049). The median length of stay was 5 days longer for PALN+/PD patients (p = 0.001). The median survival did not differ between PALN+/No-PD and PALN+/PD groups (respectively 13.4 months (95%CI:7.6-19.3) and 11.5 months (95%CI:5.9-17.1), p = 0.471). No patient was alive 4 years after surgery in both the PALN+/No-PD or PALN+/PD groups.

CONCLUSION

In case of PALN detected intraoperatively in pancreatic adenocarcinoma, PD does not improve survival compared to current palliative treatment.

Risk Stratification for the Intensive Care Unit Following Pancreaticoduodenectomy

INTRODUCTION

In view of the limited capacities in intensive care units and the increasing economic burden, identification of risk factors could allow better and more efficient planning. Therefore, the aim of this study was to assess independent risk factors for the duration of intensive care unit stay after pancreatoduodenectomy (PD).

METHODS

147 patients who underwent pancreatoduodenectomy in the time period from 2013 to 2015 were identified from a prospective database and a retrospective analysis was performed. The primary endpoint was length of time spent in the ICU. A retrograde analysis was performed using univariate and multivariate regression analysis. All pre-, intra- and postoperative parameters were considered in the analysis.

RESULTS

The median time spent in the intensive care unit (ICU) is one day. The univariate analysis demonstrated increased pack years, cerebrovascular events, anticoagulation, elevated creatinine and CA 19-9 as preoperative risk factors. In multivariate analysis, antihypertensive medication (AHT; OR 2.46; 95% CI 1.57 - 3.87; p = 0.05), operation time (OR 1.01; 95% CI 1.00 - 1.01; p = 0.03), extended LAD (OR 5.46; 95% CI 2.77 - 10.75; p = 0.01) and severe PPH (OR 4.01; 95% CI 2.07 - 7.76; p = 0.04) are significant risk factors for longer ICU stay.

DISCUSSION

Patients with cardiovascular risk factors and elevated preoperative creatinine level are at greater risk for a prolonged ICU stay. Risk and benefit of an extended LAD should be weighed during the operation. Median duration on ICU/IMC after PD is one day or less for patients without risk factors. Whether routine monitoring in the ICU/IMC after PD is necessary must be clarified in further studies.

Pancreatic body and tail cancer and favorable metastatic lymph node behavior on the left edge of the aorta

BACKGROUND

Lymph node (LN) metastasis in pancreatic body-tail cancer is a poor prognostic factor and the optimal LN dissection area for distal pancreatectomy (DP) remains unclear. Lymphatic flow from the tumors is thought to depend on the tumor sites. We examined LN metastasis frequency based on tumor site and recurrent patterns post-DP.

METHODS

With a retrospective, single institutional study, we examined 100 patients who underwent DP as an upfront surgery for pancreatic cancer over 17 years. Tumor sites were classified as tumor confined to pancreatic body (and neck) (Pb(n)); and pancreatic tail (Pt). We compared metastatic LN and recurrence patterns based on tumor site. The median overall survival (OS) and disease-free survival (DFS) were analyzed.

RESULTS

LN metastasis occurred in 59/100 (59.0%), with 23 and 25 tumors located in the Pb(n), and Pt, respectively. Those with the tumor in Pt had metastases to #10, #11d/p, and #18 LN mainly. However, the patients with the Pb(n) tumor had metastases to #8a/p, #11p, and #14p/d LN. There was no metastasis to #10 and #11d LN. The OS and DFS were 34 and 15 months, respectively. No significant difference was found in the OS, DFS, and recurrence patterns based on tumor sites.

CONCLUSION

Differences in metastatic LN sites were observed in pancreatic body-tail cancer when tumors were confined to the left or right of the left aortic edge. Although it is necessary to validate this finding with a large-scale study, organ-preserving DP might be a treatment option for selected patients depending on the tumor sites.

Meta-analysis and trial sequential analysis of randomised controlled trials comparing standard versus extended lymphadenectomy in pancreatoduodenectomy for adenocarcinoma of the head of pancreas

PURPOSE

To compare baseline demographics, operative, and survival outcomes of randomised controlled trials (RCTs) comparing standard lymphadenectomy versus extended lymphadenectomy in patients undergoing pancreaticoduodenectomy for pancreatic head cancer METHODS: In compliance with PRISMA standards we performed a meta-analysis of baseline demographics, operative, and survival outcomes of RCTs comparing standard lymphadenectomy versus extended lymphadenectomy in patients undergoing pancreaticoduodenectomy for pancreatic head cancer. The uncertainties associated with varying follow-up periods among the included studies were resolved by analysis of time-to-event outcomes. Moreover, we performed trial sequential analysis (TSA) to determine whether the available evidence is conclusive and to assess the risk of type 1 or type 2 errors.

RESULTS

Overall, 724 patients from 5 RCTs were included. The included populations were comparable in terms of baseline characteristics. There was no difference between standard and extended lymphadenectomy in terms of pancreatic fistula (OR 0.64, P = 0.11), delayed gastric emptying (OR 0.68, P = 0.40), bile leak (OR 0.33, P = 0.06), wound infection (OR 0.53, P = 0.06), abscess (OR 0.83, P = 0.63), total complications (OR 0.73, P = 0.27), postoperative mortality (OR 1.01, P = 0.85), and overall survival (HR 1.10, P = 0.46). TSA suggested that meta-analysis was conclusive with low risk of type 2 error. The results remained consistent through subgroup analyses based on lymph node positive or negative status and studies from the West and East.

CONCLUSIONS

Robust evidence from randomised controlled trials (Level 1) suggests no difference in postoperative and survival outcomes between standard and extended lymphadenectomy in patients undergoing pancreaticoduodenectomy for pancreatic head cancer. The findings were consistent in patients with positive and negative lymph node status and in studies from the West or East.

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.

Mesopancreas level 3 dissection in robotic pancreaticoduodenectomy

BACKGROUND

There are no reports of performing mesopancreas dissections in robotic pancreaticoduodenectomy. This study evaluated the feasibility and justification for mesopancreas level 3 dissection in robotic pancreaticoduodenectomy.

METHODS

Surgical outcomes after robotic pancreaticoduodenectomy and open pancreaticoduodenectomy were evaluated and compared.

RESULTS

There were 289 robotic pancreaticoduodenectomy and 162 open pancreaticoduodenectomy patients included in the study. Postoperative diarrhea occurred in 34.5% of mesopancreas level 3 dissection cases and was higher than in levels 2 and 1 dissection cases, P < .001. Blood loss in the robotic pancreaticoduodenectomy group was higher for mesopancreas level 3 dissection, with a median loss of 263 mL (P = .015). The rate of R0 resection with margin >1 mm was higher for mesopancreas level 3 dissection (93.8%) than for level 2 dissection (72.2%) (P < .001). The lymph node yield was higher for mesopancreas level 3 dissection in robotic pancreaticoduodenectomy; the median lymph node yield was 21 for level 3, 18 for level 2, and 14 for level 1 (P < .001). Compared with mesopancreas levels 1 and 2 dissections in the robotic pancreaticoduodenectomy groups, level 3 dissection did not show increased surgical mortality or postoperative complications, including postoperative pancreatic fistula, delayed gastric emptying, postpancreatectomy hemorrhage, chyle leakage, bile leakage, or wound infection. Compared with open pancreaticoduodenectomy, mesopancreas level 3 dissection in robotic pancreaticoduodenectomy had less blood loss, no delayed gastric emptying, and lower chyle leakage.

CONCLUSION

Mesopancreas level 3 dissection in robotic pancreaticoduodenectomy is feasible without compromising surgical safety. Therefore, robotic pancreaticoduodenectomy can be recommended as a safe alternative to open pancreaticoduodenectomy for mesopancreas level 3 dissection.

Reconsidering the Optimal Regional Lymph Node Station According to Tumor Location for Pancreatic Cancer

BACKGROUND

A consensus regarding the optimal extent of lymph node dissection for pancreatic cancer has not yet been achieved. The purpose of this study was to evaluate the efficacy of lymph node dissection according to the location for pancreatic cancer.

METHODS

A total of 495 patients diagnosed with invasive ductal carcinoma of the pancreas who had undergone a pancreatectomy between October 2002 and December 2015 were analyzed. The efficacy index (EI) was calculated for each lymph node station via multiplication of the frequency of metastasis to the station and the 5-year survival rate of the patients with metastasis to that station.

RESULTS

For pancreatic head (Ph) tumors, mesocolon lymph nodes had a high EI, although not regional. For pancreatic body (Pb) tumors, peri-Ph lymph nodes had a high EI, although not regional. For pancreatic tail (Pt) tumors, lymph nodes along the celiac axis and common hepatic artery had a zero EI, although regional. When the Ph was segmented into the pancreatic neck (Ph-neck), uncinate process (Ph-up), and periampullary regions, hepatoduodenal ligament lymph nodes had a zero EI for Ph-up, although regional; the mesojejunum lymph node also had a zero EI, even for Ph-up, regardless of a high incidence of metastasis. Regarding lymph node recurrence after surgery, recurrence was most frequently found at the peri-Ph lymph node (12%) in patients with Pb tumors who had undergone a distal pancreatectomy.

CONCLUSIONS

The optimal extent of lymph node dissection should be estimated in regard to the tumor location.

The Cancer of the Bladder Risk Assessment (COBRA) score for estimating cancer-specific survival after radical cystectomy: external validation in a large bi-institutional cohort

OBJECTIVE

To perform an external validation of the Cancer of the Bladder Risk Assessment (COBRA) score for estimating cancer-specific survival (CSS) after radical cystectomy (RC) in a large bi-institutional cohort of patients.

PATIENTS AND METHODS

Patients treated with RC and lymph node dissection (LND) between May 1996 and July 2017 were retrieved from the RC databases of Leuven and Turin. Collected variables were age at RC, tumour stage, lymph node (LN) density, neoadjuvant chemotherapy, the extent of LND, and nodal stage. The primary outcome was CSS visualised using Kaplan-Meier plots. Cox proportional hazard models were used to assess the impact of variables on CSS. We performed a pairwise comparison between the COBRA score levels using a log-rank test corrected by Bonferroni, and developed a simplified COBRA score with three risk categories. To compare models, we assessed concordance indices (C-indices), receiver operating characteristic curves with area under the curve (AUC), calibration plots, and decision curve analysis (DCA). Finally, we compared both COBRA and simplified COBRA models with the established American Joint Committee on Cancer (AJCC) model.

RESULTS

A total of 812 patients were included. All COBRA score variables had a significant impact on CSS in a Cox proportional hazard model. However, pairwise comparison of the COBRA subscores could not differentiate significantly between all COBRA score levels. Based on these findings, we developed a simplified COBRA score by introducing three categories within the following COBRA score ranges: low- (0-1) vs intermediate- (2-4) vs high-risk (5-7). A pairwise comparison could discriminate significantly between all COBRA risk categories. When finally comparing COBRA and simplified COBRA models with the AJCC model, AJCC performed better than both. C-indices, AUCs, calibration plots and DCA for AJCC were all better compared with the original and simplified COBRA models.

CONCLUSION

We performed an external validation of the COBRA score in a large bi-institutional cohort. We observed that several risk groups had overlapping CSS, demonstrating suboptimal performance of the COBRA score. Therefore, we constructed a simplified model with three COBRA score risk categories. This model resulted in demarcated risk groups with non-overlapping CSS and good predictive accuracy. However, both COBRA score models were outperformed by the AJCC staging system. Therefore, we conclude that the AJCC staging system should remain the current standard for stratifying patients after RC for CSS.

The Necessity of Dissection of No. 14 Lymph Nodes to Patients With Pancreatic Ductal Adenocarcinoma Based on the Embryonic Development of the Head of the Pancreas

Objectives: Pancreaticoduodenectomy (PD) followed by lymphadenectomy is performed for patients with pancreatic ductal adenocarcinoma (PDAC) located in the head of the pancreas. Because the head of the pancreas could be divided into dorsal or ventral primordium in relation to embryonic development, the metastasis of lymph node (LN) may differ. In this retrospective study, we evaluated the impact of extended or standard LN dissection for PDAC located in ventral or dorsal primordia of the pancreatic head.

Methods: From February 2016 to November 2018, 178 patients who underwent PD for PDAC were enrolled at the Pancreatic Disease Center, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University. According to the tumor location and the range of LN dissection, all patients were divided into three groups: ventral primordium with extended lymphadenectomy (VE group), ventral primordium with standard lymphadenectomy (VS group), and dorsal primordium with extended lymphadenectomy (DE group). Clinical and pathological features were retrospectively analyzed as were the long-term survival outcomes.

Results: More patients in the VE group were detected with metastasis in the lymph nodes around the superior mesenteric artery (LN14) than those in the DE group (LN along the right side of the superior mesenteric artery, LN14ab): 22.9 vs. 5.9%, p = 0.005; (LN along the left side of the superior mesenteric artery, LN14cd): 10.0 vs. 0.0%, p = 0.022. LN14 was involved in more patients in the VE group than in the VS group (22.9 vs. 5.0%, p = 0.015). For IIb-stage patients in the VE group, the overall survival time (18.3 vs. 9.3 months, p < 0.001) and disease-free survival time (12.2 vs. 5.1 months, p = 0.045) were longer in those with LN14cd (–) than those with LN14cd (+).

Conclusion: This study suggested that patients with PDAC located in the ventral head of the pancreas had higher risk of LN14 involvement compared with those at dorsal. Thus, a thorough dissection of LN14 in PDAC located in the ventral head of the pancreas is recommended to optimize the regional extended lymphadenectomy.

Identification and Validation of Circulating Micrornas as Prognostic Biomarkers in Pancreatic Ductal Adenocarcinoma Patients Undergoing Surgical Resection

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal and aggressive cancers with a less than 6% five-year survival rate. Circulating microRNAs (miRNAs) are emerging as a useful tool for non-invasive diagnosis and prognosis estimation in the various cancer types, including PDAC. Our study aimed to evaluate whether miRNAs in the pre-operative blood plasma specimen have the potential to predict the prognosis of PDAC patients. In total, 112 PDAC patients planned for surgical resection were enrolled in our prospective study. To identify prognostic miRNAs, we used small RNA sequencing in 24 plasma samples of PDAC patients with poor prognosis (overall survival (OS) < 16 months) and 24 plasma samples of PDAC patients with a good prognosis (OS > 20 months). qPCR validation of selected miRNA candidates was performed in the independent cohort of PDAC patients (n = 64). In the discovery phase of the study, we identified 44 miRNAs with significantly different levels in the plasma samples of the group of good and poor prognosis patients. Among these miRNAs, 23 showed lower levels, and 21 showed higher levels in plasma specimens from PDAC patients with poor prognosis. Eleven miRNAs were selected for the validation, but only miR-99a-5p and miR-365a-3p were confirmed to have significantly lower levels and miR-200c-3p higher levels in plasma samples of poor prognosis cases. Using the combination of these 3-miRNA levels, we were able to identify the patients with poor prognosis with sensitivity 85% and specificity 80% (Area Under the Curve = 0.890). Overall, 3-miRNA prognostic score associated with OS was identified in the pre-operative blood plasma samples of PDAC patients undergoing surgical resection. Following further independent validations, the detection of these miRNA may enable identification of PDAC patients who have no survival benefit from the surgical treatment, which is associated with the high morbidity rates.

Three-dimensional remnant pancreatic volume ratio indicates postoperative pancreatic exocrine insufficiency in pancreatic cancer patients after distal pancreatectomy

BACKGROUND

Pancreatectomy may cause serious pancreatic exocrine insufficiency (PEI), which can lead to some nutritional problems, including new-onset diabetes mellitus (DM) or non-alcoholic fatty liver disease (NAFLD). Recent studies have reported that remnant pancreatic volume (RPV) significantly influences postoperative PEI. However, the specific correlation between RPV and postoperative PEI remains unclear. Here, we compare various pre-, peri-, and postoperative risk factors in a retrospective cohort to address whether preoperatively measured RPV is a predictor of postoperative PEI in pancreatic cancer patients after distal pancreatectomy (DP).

METHODS

Sixty-one pancreatic cancer patients who underwent DP were retrospectively enrolled. Pancreatic volume was measured using preoperative 3D images, which simulated the actual intraoperative pancreatic parenchymal volume. We obtained the 3D-measured RPV and resected pancreatic volume. We calculated the ratio of the RPV to the total pancreatic volume and then divided the cohort into high- and low-RPV ratio groups based on a cut-off value (>0.35, n = 37 and ≤ 0.35, n = 24). Using multivariate analysis, the RPV ratio as well as pre-, peri- and postoperative PEI risk factors were independently assessed.

RESULTS

The multivariate analysis revealed that a low RPV ratio (odds ratio [OR], 5.911; p = 0.001), a hard pancreatic texture (OR, 3.313; p = 0.023) and TNM stage III/IV (OR, 3.515; p = 0.031) were strong predictors of the incidence of PEI.

CONCLUSIONS

The present study indicates that the RPV ratio is an additional useful predictor of postoperative nutrition status in pancreatic cancer patients.

Clinical Characteristics and Overall Survival in Patients with Anaplastic Pancreatic Cancer

Anaplastic pancreatic cancer (APC) is a rare undifferentiated variant of pancreatic ductal adenocarcinoma with poor overall survival (OS). The aim of this study was to evaluate the clinical outcomes of APC compared with differentiated pancreatic ductal adenocarcinoma. We conducted a retrospective review of all patients treated at the Mayo Clinic with pathologically confirmed APC from 1987 to 2011. After matching with control subjects with pancreatic ductal adenocarcinoma, OS was evaluated using Kaplan-Meier estimates and log-rank test. Sixteen patients were identified with APC (56.3% male, median age 57 years). Ten patients underwent exploration of whom eight underwent pancreatectomy. Perioperative morbidity was 60 per cent with no mortality. The median OS was 12.8 months. However, patients with APC who underwent resection had longer OS compared with those who were not resected, 34.1 versus 3.3 months ( P = 0.001). After matching age, sex, tumor stage, and year of operation, the median OS was similar between patients with APC and those with ductal adenocarcinoma treated with pancreatic resection, 44.1 versus 39.9 months, ( P = 0.763). Overall survival for APC is poor; however, when resected, survival is similar to differentiated pancreatic ductal adenocarcinoma.

Margin Status Impacts Survival after Pancreaticoduodenectomy but Negative Margins Should Not be Pursued

Negative margins are the goal with pancreaticoduodenectomy for pancreatic adenocarcinoma. Thereby, margins are assessed intraoperatively with frozen section analysis and negative margins are pursued. This study was undertaken to determine the impact of margin status with pancreaticoduodenectomy for pancreatic adenocarcinoma and the value of extending resections to achieve negative margins. The intraoperative frozen section analysis and final margins for 448 patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma were assessed and their impact on survival was determined. Median data are presented. Two hundred ninety-eight (67%) patients had negative margins (R0), an additional 110 (25%) patients had microscopically positive and macroscopically negative margins (R1), and an additional 40 (9%) patients had initially positive microscopic margins, which became negative with further resection (R1 å R0). R0 resections were more likely to have smaller tumors, earlier T grade, earlier N grade, lower American Joint Committee on Cancer stage, and less frequent extrapancreatic extension ( P ≤ 0.03 for each). Survival was better with R0 resections than R1 resections (20 vs 12 months, P < 0.001); extending resections to achieve negative margins (i.e., R1 ! R0) did not improve survival beyond R1 resections (14 vs 12 months, P = 0.19). Survival after pancreaticoduodenectomy is disappointing. Patients with initial negative margins do best. Positive microscopic margins reflect more aggressive tumor-specific factors and lead to abbreviated survival even with extended resections to achieve negative margins (i.e., R1 ! R0). With an initial positive margin, pursuing negative margins does not improve survival and, thereby, negative margins should not be “chased.”

Regional pancreatoduodenectomy versus standard pancreatoduodenectomy with portal vein resection for pancreatic ductal adenocarcinoma with portal vein invasion

Background

Pancreatoduodenectomy (PD) with portal vein resection (PVR) is a standard operation for pancreatic ductal adenocarcinoma (PDAC) with portal vein (PV) invasion, but positive margin rates remain high. It was hypothesized that regional pancreatoduodenectomy (RPD), in which soft tissue around the PV is resected en bloc, could enhance oncological clearance and survival.

Methods

This retrospective study included consecutive patients who underwent PD with PVR between January 2005 and December 2016 in a single high‐volume centre. In standard PD (SPD) with PVR, the PV was skeletonized and the surrounding soft tissue dissected. In RPD, the retropancreatic segment of the PV was resected en bloc with its surrounding soft tissue. The extent of lymphadenectomy was similar between the procedures.

Results

A total of 268 patients were included (177 SPD, 91 RPD). Tumours were more often resectable in patients undergoing SPD (60·5 per cent versus 38 per cent in those having RPD; P = 0·014), and consequently they received neoadjuvant therapy less often (7·9 versus 25 per cent respectively; P < 0·001). R0 resection was achieved in 73 patients (80 per cent) in the RPD group, compared with 117 (66·1 per cent) of those in the SPD group (P = 0·016), although perioperative outcomes were comparable between the groups. Median recurrence‐free (RFS) and overall (OS) survival were 17 and 32 months respectively in patients who had RPD, compared with 11 and 21 months in those who had SPD (RFS: P = 0·003; OS: P = 0·004).

Conclusion

RPD is as safe and feasible as SPD, and may increase the survival of patients with PDAC with PV invasion.

Precise anatomical resection based on structures of nerve and fibrous tissue around the superior mesenteric artery for mesopancreas dissection in pancreaticoduodenectomy for pancreatic cancer

BACKGROUND

The aim of the present study was to investigate the feasibility of resection based on the nerve and fibrous tissue (NFT) structures around the superior mesenteric artery (SMA) for resectable pancreatic adenocarcinoma (R-PDAC) patients.

METHODS

NFTs around the SMA were classified into four "intensive NTFs area" with spreading the NFTs around the SMA and three SMA nerve plexus regions without branching nerves according to autopsy findings. Complete dissection of four "intensive NTFs areas" was performed by pre-exposing three SMA nerve plexus regions without branching nerves as "dissection-guiding points" with SMA nerve plexus preservation (NFT-based resection). Among 157 R-PDAC patients undergoing pancreaticoduodenectomy, surgical outcomes of 78 patients with NFT-based resection were compared with 59 patients with half-SMA nerve plexus dissection and 20 patients without NFTs dissection.

RESULTS

In the NFT-based resection group, 76.5% had tumor involvement and metastasis in each intensive NTFs area. Operative time, blood loss, and postoperative diarrhea rate were significantly lower in NFT-based resection than in half-SMA nerve plexus group (321 vs 390 min; P < .01, 228 vs 550 mL; P < .01, 5.1% vs 15.3%; P = .04, respectively). R0 rate and median overall survival significantly improved in NFT-based resection than in non-NFT dissection group (93.6% vs 65.0%; P < .01, 49.6 vs 23.6 months, P = .01).

CONCLUSION

NFT-based resection may become a novel method for R-PDAC patients.

Early recurrence detected by 18F-FDG PET/CT in patients with resected pancreatic ductal adenocarcinoma

F-fluoro-2-deoxy-D-glucose positron emission tomography integrated with computed tomography (F-FDG PET/CT) has been proved to be practical in detecting occult malignant lesions. However, the evidence of its utility in detecting early recurrence after resection of pancreatic ductal adenocarcinoma (PDAC) is lacking. Therefore, the primary aim of the present study is to evaluate the diagnostic value of F-FDG PET/CT in the early postoperative period after radical resection of PDAC.This retrospective study included 32 patients who had F-FDG PET/CT scan within 6 months after radical resection of PDAC between January 2010 and December 2018.In total, 10 positive PET results were found at surgical margins of remnant pancreas, 12 at locoregional lymph nodes, 5 at distant areas, with the corresponding mean maximum standard uptake value (SUVmax) of 5.8 ± 1.1, 5.9 ± 0.9, and 6.4 ± 0.7, respectively. The median follow-up time was 23.5 months (range: 8-75 months), and the median survival time was 39.5 months (95% confidence interval: 14.6-64.4 months) for the entire cohort. Patients with positive PET findings at either locoregional lymph nodes or distant areas obtained significantly poorer overall survival (OS) than those without increased FDG uptake at the corresponding areas (P = .003 and P < .001, respectively). Whereas comparisons of OS between patients with or without increased FDG uptake at the surgical margin of remnant pancreas presented no statistically difference (P = .742).The early application of F-FDG PET/CT after radical resection of PDAC could stratify the prognosis of patients well by detecting occult early recurrence at locoregional lymph nodes and distant areas efficiently.

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.

A nomogram to preoperatively predict 1-year disease-specific survival in resected pancreatic cancer following neoadjuvant chemoradiation therapy

OBJECTIVE

This study aimed to develop a nomogram to predict the 1-year survival of patients with pancreatic cancer who underwent pancreatectomy following neoadjuvant treatment with preoperatively detectable clinical parameters. Extended pancreatectomy is necessary to achieve complete tumor removal in borderline resectable and locally advanced pancreatic cancer. However, it increases postoperative morbidity and mortality rates, and should be balanced with potential benefit of long-term survival.

METHODS

The medical records of patients who underwent pancreatectomy following neoadjuvant treatment from January 2005 to December 2016 at Severance Hospital were retrospectively reviewed. Medical records were collected from five international institutions from Japan and Singapore for external validation.

RESULTS

A total of 113 patients were enrolled. The nomogram for predicting 1-year disease-specific survival was created based on 5 clinically detectable preoperative parameters as follows: age (year), symptom (no/yes), tumor size at initial diagnostic stage (cm), preoperative serum carbohydrate antigen (CA) 19-9 level after neoadjuvant treatment (<34/≥34 U/mL), and planned surgery [pancreaticoduodenectomy (PD) (pylorus-preserving PD)/distal pancreatectomy (DP)/total pancreatectomy]. Model performance was assessed for discrimination and calibration. The calibration plot showed good agreement between actual and predicted survival probabilities; the the Greenwood-Nam-D'Agostino (GND) goodness-of-fit test showed that the model was well calibrated (χ2=8.24, P=0.5099). A total of 84 patients were used for external validation. When correlating actual disease-specific survival and calculated 1-year disease-specific survival, there were significance differences according to the calculated probability of 1-year survival among the three groups (P=0.044).

CONCLUSIONS

The developed nomogram had quite acceptable accuracy and clinical feasibility in the decision-making process for the management of pancreatic cancer.

Oncologic Impact of Local Recurrence in Resected Pancreatic Cancer and Topographic Preference in Local Recurrence Patterns According to Tumor Location

OBJECTIVES

The objective of this study was to investigate the pattern and the oncologic impact of local recurrence after surgical resection of pancreatic cancer.

METHODS

From July 1992 to December 2016, 388 patients who underwent curative-intent surgery for pancreatic ductal adenocarcinoma were retrospectively reviewed.

RESULTS

At a median follow-up of 29.0 months, 286 (73.7%) of the 367 patients experienced recurrence, and the 5-year overall survival rate was 31.3%. The first recurrence pattern was local in 83 patients (22.0%), systemic in 152 patients (40.2%), and locosystemic in 51 patients (13.5%). There was no difference in overall survival between the patients who had either local or systemic recurrence (P > 0.05). Remnant pancreas, common hepatic artery, celiac trunk, and para-aortic area were the common local recurrence sites in both head and body/tail cancer. However, the superior mesenteric artery (P = 0.050) and portal vein (P = 0.001) were more frequent local recurrence sites for a head tumor, and the surgical bed was a common recurrence site for body/tail tumor (P < 0.001).

CONCLUSIONS

Our study shows the importance of local recurrence on overall survival and that preferred sites of local recurrence according to tumor location are predictable.

Efficacy of extended versus standard lymphadenectomy in pancreatoduodenectomy for pancreatic head adenocarcinoma. An update meta-analysis

BACKGROUND

Surgical resection is the only possible cure for pancreatic cancer, it remains controversial whether extend lymphadenectomy in pancreatoduodenectomy (EPD) is better than standard lymphadenectomy in pancreatoduodenectomy (SPD). The aim of this study was to compare the efficacy of EPD with SPD for pancreatic head adenocarcinoma.

METHODS

A specific search of online databases including PubMed, Web of Science, Embase, and Cochrane library was conducted from January 1990 to October 2018. Relative perioperative outcomes were synthesized. Single-arm meta-analysis was also performed.

RESULTS

A total of eight studies involving 687 (342 vs 345) patients were included for analysis in our study. The number of lymph nodes harvested [24.54 vs 13.29; weighted mean difference (WMD) -10.69, P = 0.000], operative time (469.84 min vs 354.85 min; WMD -99.09, P = 0.000), and diarrhea (postoperative three months) [45.1% vs 18.2%; odds radio (OR) 0.20, P = 0.014] were significantly higher in patients who underwent EPD than SPD. The perioperative complications (35% vs 28.8%; OR 0.79, P = 0.186), tumor size (3.27 cm vs 3.248 cm; WMD -0.11, P = 0.256), lymph node metastasis (66% vs 55.9%; OR 0.71, P = 0.105), and positive margin (10.4% vs 11.3%; OR 1.28, P = 0.392) were no significant differences between EPD group and SPD group. Extended lymphadenectomy in pancreatoduodenectomy dose not contribute to the overall survival of patients with adenocarcinoma of the pancreatic head [hazard ratio (HR) 0.95; 95% CI 0.78-1.15; P = 0.61].

CONCLUSION

The update meta-analysis shows that EPD failed to improve the overall survival, may even lead to increased morbidity.

Local radicality and survival outcome of pancreatic cancer surgery

Pancreatic cancer remains a therapeutic challenge. Surgical resection in combination with systemic chemotherapy is the only option promising long-term survival and potential cure. However, only about 20% of patients are diagnosed with tumors that are still in a resectable stage. Even after potentially curative resection and modern regimens for adjuvant chemotherapy, the majority of patients develop local and systemic recurrence resulting in median overall survival times of 28-54 months. The predominance of systemic recurrence and its impact on survival may lead to the assumption that surgical radicality and local control play only minor roles in the treatment of pancreatic cancer. This review provides an overview of the recent literature on surgical radicality and survival outcome in pancreatic cancer. The current evidence on the extent of lymphadenectomy, the prognostic impact of the extent of lymph node involvement, and the impact of the resection margin status on postresection survival are reviewed. Data from recent studies performed in the context of modern surgery and adjuvant therapy provide good evidence of a considerable impact of local radicality on survival after pancreatic cancer surgery. Surgical techniques that have been developed to refine oncological resections and to increase local control as well as resectability are highlighted. These techniques include artery-first approaches, level-3 dissection with removal of the periarterial nerve plexus, the triangle operation, and extended resections. Local radicality and quality of surgical resection remain among the most important parameters that determine the chances for survival in patients with non-metastatic pancreatic cancer.

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.

Optimal Extent of Superior Mesenteric Artery Dissection during Pancreaticoduodenectomy for Pancreatic Cancer: Balancing Surgical and Oncological Safety

BACKGROUND

We describe the short- and long-term outcomes for PDAC patients after tailored mesopancreas dissection using supracolic artery-first approach followed by adjuvant therapy.

METHODS

This study analyzed 233 consecutive patients who underwent artery-first pancreaticoduodenectomy for PDAC. Dissection extent for the superior mesenteric artery (SMA) was categorized into three levels: level 2 (LV2) including regional lymph nodes, level 3 (LV3) with hemicircumferential nerve plexus dissection, and extended-level 3 (E-LV3) including borderline resectable cases for the SMA. All clinical, pathological, and survival outcomes were reviewed.

RESULTS

LV2/3/E-LV3 dissection was performed in 77/115/41 patients. The short-term outcomes were similar among groups without mortality. Although postoperative diarrhea requiring opioids was significantly more frequent in the E-LV3 group (76%) than other groups (vs. LV2 (21%), P < .0001; vs. LV3 (34%), P < .0001; LV2 vs. LV3, P = 0.20), most cases of diarrhea were well controlled. Adjuvant chemotherapy was introduced similarly among groups (LV2, 76%; LV3, 81%; E-LV3, 88%, P = 0.29). The 3- and 5-year overall survival rates in the LV2/3/E-LV3 groups were 42/33/42% and 27/22/26%, respectively, showing no significant difference among groups.

DISCUSSION

Our tailored dissection and preemptive use of opioid antidiarrheal effectively prevents intractable diarrhea, increasing the success of adjuvant chemotherapy.

Detection of visually occult metastatic lymph nodes using molecularly targeted fluorescent imaging during surgical resection of pancreatic cancer

BACKGROUND

Although most patients with PDAC experience distant failure after resection, a significant portion still present with local recurrence. Intraoperative fluorescent imaging can potentially facilitate the visualization of involved peritumoral LNs and guide the locoregional extent of nodal dissection. Here, the efficacy of targeted intraoperative fluorescent imaging was examined in the detection of metastatic lymph nodes (LNs) during resection of pancreatic ductal adenocarcinoma (PDAC).

METHODS

A dose-escalation prospective study was performed to assess feasibility of tumor detection within peripancreatic LNs using cetuximab-IRDye800 in PDAC patients. Fluorescent imaging of dissected LNs was analyzed ex vivo macroscopically and microscopically and fluorescence was correlated with histopathology.

RESULTS

A total of 144 LNs (72 in the low-dose and 72 in the high-dose cohort) were evaluated. Detection of metastatic LNs by fluorescence was better in the low-dose (50 mg) cohort, where sensitivity and specificity was 100% and 78% macroscopically, and 91% and 66% microscopically. More importantly, this method was able to detect occult foci of tumor (measuring < 5 mm) with a sensitivity of 88% (15/17 LNs).

CONCLUSION

This study provides proof of concept that intraoperative fluorescent imaging with cetuximab-IRDye800 can facilitate the detection of peripancreatic lymph nodes often containing subclinical foci of disease.

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.

Hydroxychavicol from Piper betle induces apoptosis, cell cycle arrest, and inhibits epithelial-mesenchymal transition in pancreatic cancer cells

Pancreatic cancer is a major cause of cancer-related mortality around the world. Currently, options for diagnosis and treatment are extremely limited, which culminates in a very high mortality rate. Intensive research spanning more than four decades has met several roadblocks in terms of improvement in overall survival. In this study, we have evaluated the effect of Hydroxychavicol (HC), a naturally occurring and abundantly isolatable allylarene from Piper betle leaves on pancreatic cancer cells. Our investigation reveals that HC inhibits proliferation and epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. HC induces DNA damage, as evidenced by γ-H2AX, 53BP1 induction and comet assay, which further results in mitotic catastrophe and apoptosis. The apoptosis induced by HC is JNK pathway-dependent and caspase-mediated. HC also inhibits migration and invasion of pancreatic cancer cells via a generalized repression of genes involved in EMT. A quantitative real time PCR-based array revealed at least 14 different genes to be differentially expressed upon HC treatment in pancreatic cancer cells. These results show significant potential of HC as an anticancer agent against pancreatic cancer.

Body weight loss after surgery affects the continuity of adjuvant chemotherapy for pancreatic cancer

BACKGROUND

Postoperative chemotherapy is beneficial for many pancreatic cancer patients. However, some patients require dose reduction or the discontinuation of adjuvant chemotherapy because of adverse treatment-related effects. In this study, we aimed to evaluate two main outcomes. First, we evaluated the clinicopathological factors affecting patient disease-free survival (DFS) and overall survival (OS) following upfront surgery. Second, we evaluated the factors that influence the continuity of adjuvant chemotherapy.

METHODS

Fifty-four patients with resected pancreatic cancer were enrolled. First, we evaluated the clinicopathological factors affecting postoperative survival using the Kaplan-Meier method and Cox regression method. Next, factors affecting the continuity of adjuvant chemotherapy were analyzed using multiple logistic regression analysis.

RESULTS

Univariate and multivariate analyses revealed that positive LN metastasis (HR (95% CI) 6.329 (2.381-16.95); p < 0.001) and relative dose intensity (RDI) < 80% for adjuvant chemotherapy (HR (95% CI) 5.154 (1.761-15.15); p = 0.003) were independent predictive factors for DFS. Regarding OS, extended dissection of the nerve plexus around the superior mesenteric artery (SMA) (HR (95% CI) 4.504 (1.721-11.76); p = 0.002), positive microscopic surgical margin (HR (95% CI) 5.565 (1.724-17.96); p = 0.004), and adjuvant chemotherapy of RDI < 80% (HR (95% CI) 3.534 (1.135-2.667); p = 0.029) were also independent predictive factors. Moreover, the level of RDI significantly correlated with DFS and OS. Multiple logistic regression analysis revealed that low RDI was significantly associated with postoperative body weight loss (BWL) ≥ 10%.

CONCLUSIONS

The following factors were significantly associated with poor survival: extended dissection of the nerve plexus around the SMA, lymph node metastasis, residual tumor, and RDI of the adjuvant chemotherapy. Patient's prognosis with adjuvant chemotherapy of RDI < 80% was worse. BWL ≥10% was the most important factor affecting the continuity of adjuvant chemotherapy. Perioperative nutritional intervention is necessary for patients who receive adjuvant chemotherapy for advanced pancreatic cancer.