The prognostic influence of resection margin clearance following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma

Prognostic value of margin clearance in total and distal pancreatectomy specimens with pancreatic ductal adenocarcinoma in a Danish population-based nationwide study

BACKGROUND

The prognostic role of resection margin status following total (TP) and distal (DP) pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) is insufficiently evaluated. In Denmark, pancreatic surgery, including the postoperative pathological examination of the resection specimens, is confined to four centres, all reporting to the Danish Pancreatic Cancer Database (DPCD). In this Danish population-based nationwide study on TP and DP for PDAC from 2015-2019, based on data from DPCD, we evaluated whether there is a prognostically relevant minimum margin clearance definition and whether certain margins hold independent prognostic information.

METHODS

Clinical and pathological data were retrieved from DPCD and supplemented by review of pathology reports and re-microscopy, if needed. One of the study pathologists performed all re-microscopy. The prognostic significance of margin status was evaluated by dichotomisation of the TP cohort (n = 101) and the DP cohort (n = 90) into involved and uninvolved groups, using different clearance definitions (0.5 - ≥3.0 mm).

RESULTS

Following TP, direct involvement of the superior mesenteric artery (SMA) margin had independent prognostic value. When using a clearance definition of ≥ 0.5 or ≥ 1.5 mm for SMA, median survival for R0 versus R1 was 19 (95% CI 14-26) versus 10 (95% CI 5-20) months (p = 0.010), and 21 (95% CI 15-30) versus 10 (95% CI 8-19) months (p = 0.011), respectively. Overall margin status was not of significant prognostic importance following neither DP nor TP.

CONCLUSION

In this Danish population-based nationwide study, SMA margin involvement was a significant isolated prognostic factor following TP, whereas combined assessment of all circumferential margins did not hold statistically significant prognostic information. Following DP, resection margin status did not affect survival.

Prognostic importance of margin clearance in ampullary adenocarcinoma following pancreaticoduodenectomy in a Danish population-based nationwide study

BACKGROUND

In this Danish nationwide population-based study, we evaluated the prognostically relevant minimum tumour-free margin width following pancreaticoduodenectomy (PD) for ampullary adenocarcinoma (AAC) and evaluated whether certain margins hold independent prognostic information.

METHODS

We included 128 patients who underwent PD for AAC from 2015 to 2019. Clinical and pathological data including well-known prognostic factors were retrieved from the Danish Pancreatic Cancer Database. Missing data were obtained by review of pathology reports and re-microscopy of resection specimens. All PD specimens were examined using a standardised pathological protocol including multicolour inking, axial slicing and exact reporting of margin widths. The cohort was dichotomised into involved and uninvolved groups, using different margin clearance definitions (0.5-≥3.0 mm).

RESULTS

Following PD for AAC, margin clearance of ≥1 mm was independently associated with improved chance of survival compared with <1 mm (HR: 0.30, 95 % CI: 0.14-0.64 (p = 0.002)). Posterior and anterior margin widths were narrower compared with superior mesenteric artery and vein margins. Posterior margin and anterior surface had isolated prognostic significance in multivariable analysis.

CONCLUSION

Following PD for AAC, margin clearance of at least 1 mm is independently associated with improved survival. Our data further indicate that anterior surface and posterior margin hold particular prognostic value.

Perioperative NALIRIFOX in patients with resectable pancreatic ductal adenocarcinoma: The open-label, multicenter, phase II nITRO trial

BACKGROUND

Upfront surgery followed by postoperative treatment is a commonly adopted treatment for resectable pancreatic ductal adenocarcinoma (rPDAC). However, the risk of positive surgical margins, the poor recovery that often impairs postoperative treatments, and the risk of recurrence might limit the outcome of this strategy. This study evaluated the safety and the activity of liposomal irinotecan 50 mg/m2 + 5-fluorouracil 2400 mg/m2 + leucovorin 400 mg/m2 + oxaliplatin 60 mg/m2 (NALIRIFOX) in the perioperative treatment of patients with rPDAC.

METHODS

Eligible patients had a rPDAC with < 180° interface with major veins' wall. Patients received 3 cycles before and 3 cycles after resection with NALIRIFOX, days 1 and 15 of a 28-day cycle. The primary endpoint was the proportion of patients undergoing an R0 resection.

RESULTS

107 patients began preoperative treatment. Nine patients discontinued the treatment because of related or unrelated adverse events. Disease-control rate was 92.9%. 87 patients underwent surgical exploration, 11 had intraoperative evidence of metastatic disease, and 1 died for surgical complications. R0 resection rate was 65.3%. 49 patients completed the three postoperative cycles. The most common grade ≥ 3 adverse events were diarrhea and neutropenia. Median overall survival (OS) of ITT patients was 32.3 months (95% CI 27.8-44.3). Median disease-free and OS from surgery of resected patients were 19.3 (95% CI 12.6-34.1) and 40.3 months (95% CI 29-NA), respectively.

CONCLUSION

Perioperative NALIRIFOX was manageable and active, and deserves further investigation in randomized trials comparing it with standard upfront surgery followed by adjuvant therapy.

Prognosis of pancreaticoduodenectomy in octogenarians for pancreatic ductal adenocarcinoma with propensity score matched analysis

BACKGROUND

This retrospective study investigates factors affecting surgical and oncological outcome after performing pancreaticoduodenectomy in octogenarian patients diagnosed with pancreatic ductal adenocarcinoma.

METHODS

From January 2009 to December 2018, patients who underwent pancreaticoduodenectomy for pancreatic ductal adenocarcinoma were included. Data were analysed by comparing clinicopathological characteristics, complications, survival, recurrence, adjuvant treatment between octogenarians and the younger group. Propensity score matched analysis was performed due to the small size of the octogenarian group.

RESULTS

A total of 666 patients were included in this study and 24 (3.6%) were included in the octogenarian group. Short term complication rates (P = 0.119) and hospital stay (P = 0.839) did not differ between two groups. Overall survival between the two groups showed significant difference (<80 median 25 months versus ≥80 median 13 months, P = 0.045). However, after propensity score matched analysis, the two groups did not differ in overall survival (<80 median 18 months versus ≥80 median survival 16 months, P = 0.565) or disease-free survival (P = 0.471). Among the octogenarians, six patients survived longer than 24 months even without satisfying all favourable prognostic factors.

CONCLUSION

Considering the general condition of octogenarians diagnosed with pancreatic ductal adenocarcinoma, select patients should be treated more aggressively for the best chance of receiving curative treatment.

Prognostic significance of margin clearance in pancreaticoduodenectomy specimens with pancreatic ductal adenocarcinoma in a Danish population-based nationwide study

BACKGROUND

In this nationwide population-based cohort study, we investigated the overall minimum margin width that is independently associated with improved survival following pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) and evaluated whether certain margins or surfaces hold independent prognostic significance.

METHODS

Data from 367 patients who underwent PD for PDAC in the period 2015-2019 were retrieved from the Danish Pancreatic Cancer Database. Missing data were obtained by review of pathology reports and re-microscopy of resection specimens. Surgical specimens were evaluated using a standardised pathological protocol involving multicolour inking, axial slicing and exact reporting of circumferential margin clearances in 0.5 mm increments.

RESULTS

When categorised according to margin widths of <0.5, <1.0, <1.5, <2.0, <2.5 and <3.0 mm, R1 resections were detected in 34%, 57%, 75%, 78%, 86% and 87% of cases, respectively. In multivariable analyses, an overall margin clearance of ≥1.5 mm was associated with improved survival compared with a clearance of <1.5 mm (HR 0.70 95% CI 0.51-0.97 (p = 0.031)). When evaluating the margins separately, no margin had independent prognostic significance.

CONCLUSION

Margin clearance of at least 1.5 mm was independently associated with improved survival following PD for PDAC.

Necrosis as a strong independent prognostic factor required in the implementation of pathological reporting for pancreatic adenocarcinoma resection specimens

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is a major public health issue with an incidence/mortality ratio reaching 98 %. Only 15-20 % of patients with PDAC can undergo surgery. Following PDAC surgical resection, 80 % of patients will experience local or metastatic recurrence of this disease. pTNM staging is the gold standard for risk stratification but is not sufficient to recapitulate the prognosis. Several prognostic factors are known to impact survival after surgery when uncovered during pathological examination. However, necrosis has been poorly studied in pancreatic adenocarcinoma.

MATERIALS & METHODS

We retrieved clinical data and reviewed all tumor slides from patients who had a pancreatic surgery between January 2004 and December 2017, in the Hospices Civils de Lyon, to assess the presence of histopathological prognosis factors associated with poor prognosis.

RESULTS

514 patients with complete clinico-pathological description were included. Necrosis was found in 231 PDAC (44.9 %) and had an important impact on overall survival with a double risk of death when present in tumor samples (HR: 1.871, 95 % CI [1.523; 2.299], p < 0.001). When integrated in the multivariate model, necrosis is the only morphological aggressive feature to retain high statistical significance associated with the TNM staging but independently of it. This effect is independent of the preoperative treatment.

CONCLUSIONS

Despites improvement in treatment of PDAC, mortality rates remain relatively stable amongst the last years. There is a desperate need to better stratify patients. Here, we report the strong and prognostic impact of necrosis in surgical PDAC samples and encourage pathologists to report its presence in the future.

The Impact of Involved Resection Margin on Recurrence and Survival After Pancreaticoduodenectomy for Periampullary Carcinoma, with Emphasis on Pancreatic Head Carcinoma

BACKGROUND

The supposed adverse effect of involved resection margin during pancreaticoduodenectomy (PD) for periampullary carcinoma or pancreatic head carcinoma (CaP) on long-term oncological outcomes is still inconclusive.

METHODS

This is a retrospective study on periampullary carcinoma undergoing PD. Patients with R0 (margin clear) resection were compared to patients with R1 (microscopically directly involved margin) resection. Patients with gross involved margin (R2 resection) were excluded. Long-term oncological outcomes measured included incidence and site of recurrent disease, overall survival (OS) and disease-free survival (DFS). A subgroup analysis was made on patients with CaP.

RESULTS

Between January 2003 and December 2019, 203 PD were identified for present study. The incidence of R1 resection was common (12% in periampullary carcinoma and 20% in CaP). In periampullary carcinoma, R1 resection had greater proportion of CaP, lesser proportion of carcinoma of ampulla (CaA), more perineural invasion, more lymph node (LN) metastasis. R1 group had a shorter OS and DFS, but no difference in the incidence and site of recurrent disease. In the subgroup of CaP (91 patients), R1 group did not differ from R0 group except for more LN metastasis. There was no difference in incidence and site of recurrent disease, OS and DFS. On multivariable analysis, R1 resection was not an independent factor for OS and DFS for periampullary carcinoma or for CaP only.

CONCLUSION

Involved resection margin was not uncommon. It was not associated with higher incidence of recurrent disease including local recurrence, and was not an independent prognosticator for OS and DFS.

The Impact of Molecular Subtyping on Pathological Staging of Pancreatic Cancer

BACKGROUND

The long-term outcomes following surgical resection for pancreatic ductal adenocarcinoma (PDAC) remains poor, with only 20% of patients surviving 5 years after pancreatectomy. Patient selection for surgery remains suboptimal largely due to the absence of consideration of aggressive tumor biology.

OBJECTIVE

The aim of this study was to evaluate traditional staging criteria for PDAC in the setting of molecular subtypes.

METHODS

Clinicopathological data were obtained for 5 independent cohorts of consecutive unselected patients, totaling n = 1298, including n = 442 that underwent molecular subtyping. The main outcome measure was disease-specific survival following surgical resection for PDAC stratified according to the American Joint Commission for Cancer (TNM) staging criteria, margin status, and molecular subtype.

RESULTS

TNM staging criteria and margin status confers prognostic value only in tumors with classical pancreatic subtype. Patients with tumors that are of squamous subtype, have a poor outcome irrespective of favorable traditional pathological staging [hazard ratio (HR) 1.54, 95% confidence interval (CI) 1.04-2.28, P = 0.032]. Margin status has no impact on survival in the squamous subtype (16.0 vs 12.1 months, P = 0.374). There were no differences in molecular subtype or gene expression of tumors with positive resection margin status.

CONCLUSIONS

Aggressive tumor biology as measured by molecular subtype predicts poor outcome following pancreatectomy for PDAC and should be utilized to inform patient selection for surgery.

Prognostic Impact of Resection Margin Status on Distal Pancreatectomy for Ductal Adenocarcinoma

Pancreatic cancer is associated with a poor prognosis. While surgical resection is the only treatment option with curative intent, most patients die of locoregional and/or distant recurrence. The prognostic impact of the resection margin status has received much attention. However, the evidence is almost exclusively related to pancreatoduodenectomies, while corresponding data for distal pancreatectomy specimens are limited. The key data, such as the rate of microscopic margin involvement (“R1”), the site of margin involvement, and the impact of R1 on patient outcome, are divergent between studies and do not currently allow any general conclusions. The main reasons for the variability in the published data are the small size of the study cohorts and their heterogeneity, as well as the marked divergence in pathology examination practices. The latter is a consequence of the lack of concrete guidance, both for grossing and microscopic examination. The increasing administration of neoadjuvant chemo(radio)therapy introduces a further factor of uncertainty as the conventional definition of a tumour-free margin (“R0”) based on 1 mm clearance is inadequate for these specimens. This review discusses the published data regarding the prognostic impact of margin status in distal pancreatectomy specimens along with the challenges and uncertainties that are related to the assessment of the margins.

The Future Perspectives of Redefining the Resection Margin Status in Different Cancers of Pancreas

Background: The interest towards the assessment of circumferential resection margins(CRM) in pancreatic cancers has been evolving over last years. Whilst several studies investigated the influence of R1-resections on survival, not many studies evaluated the prognostic value of each resection margin. In this study, we examined the different resection margins to better understand their prognostic implications on overall survival. Methods: This prospective study included a cohort of patients who had pancreaticoduodenectomy for cancer purposes at our institution from 2008 till 2013. Median follow-up was 6 years. Involved margins in R1-resections were further classified into anatomical margins (anterior, posterior and circumferential margins) and surgical margins (vascular/medial margins and transection margins). Overall survival was assessed for each specific resection margin. Results: 134 patients were included with median age 66 years. R1-resection was done in 54% of patients(n=72/134). Median survival of R0-resection group was 6.3 years, compared to 1.9 years for R1-resection group(p-value 0.001). Vascular (surgical) margins had the lowest survival rate (1.7years) compared to anatomical margins (anterior, posterior and circumferential margins) with 3.6, 2.2 and 2.1 years respectively (p-value 0.02). On multivariate analysis; lymph node involvement and vascular resection were the only factors to correlate significantly with poor survival. Conclusion: Whilst the new pathological protocols advised to perform rigorous margin assessment of CRM, the prognostic value of each resection margin is still unclear. This study  showed variation of survival across different resection margins with inferiority towards vascular (surgical) margins. This supported the need of redefining R1-margins in the future pathological classifications according to their different prognostic impacts.

Pathology reporting of margin status in locally advanced pancreatic cancer: challenges and uncertainties

Chemo(radio)therapy is becoming the new standard for patients with locally advanced pancreatic cancer. In case of tumor regression on imaging, surgical resection can be undertaken, albeit often with the need for extended procedures. Reevaluation of the current routine pathology procedures is required to establish the appropriate histopathological approach of the resulting specimens. This review focusses on margin status, which is universally considered a core data item of the pathology report, of relevance to both the management of the individual patient and the evaluation of the result of surgery in this particular patient group. As explained in this review, due to the cytoreductive effect of neoadjuvant therapy, the conventional definition of a tumor-free margin ("R0") based on 1 mm clearance is not adequate. Furthermore, the complexity of many of the specimens following extended or multivisceral en bloc surgical resection make margin assessment challenging. These large specimens require extensive sampling, which is not always easily implemented in daily practice. At present, there is marked divergence in pathology practice, and consequently, neither the true R0-rate nor the exact prognostic effect of the margin status have been definitively established for resected locally advanced pancreatic cancer. A concerted effort towards uniform and optimal margin assessment is unfortunately still lacking.

Dataset for the reporting of carcinoma of the exocrine pancreas: recommendations from the International Collaboration on Cancer Reporting (ICCR)

BACKGROUND AND OBJECTIVES

Current guidelines for the pathology reporting on pancreatic cancer differ in certain aspects, resulting in divergent reporting practice and a lack of comparability of data. Here we report on a new international dataset for the pathology reporting of resection specimens with cancer of the exocrine pancreas (ductal adenocarcinoma and acinar cell carcinoma). The dataset was produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), a global alliance of major (inter-)national pathology and cancer organisations.

METHODS AND RESULTS

According to the ICCR's rigorous process for dataset development, an international expert panel consisting of pancreatic pathologists, a pancreatic surgeon and an oncologist produced a set of core and non-core data items based on a critical review and discussion of current evidence. Commentary was provided for each data item to explain the rationale for selecting it as a core or non-core element, its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. Following international public consultation, the document was finalised and ratified, and the dataset, which includes a synoptic reporting guide, was published on the ICCR website.

CONCLUSIONS

This first international dataset for cancer of the exocrine pancreas is intended to promote high quality, standardised pathology reporting. Its widespread adoption will improve consistency of reporting, facilitate multidisciplinary communication and enhance comparability of data, all of which will help to improve the management of pancreatic cancer patients.

Pancreatic malignancy in the backdrop of chronic pancreatitis: How much to push the boundaries to achieve R0 resection

Tumors of the body and tail of the pancreas are often more aggressive than tumors of the head and would have often undergone metastatic spread to other organs at the time of diagnosis. Most patients with carcinoma of the body and tail of the pancreas present at a late stage. Surgery is only indicated in those patients in whom there is no evidence of metastatic spread. Surgery is often not possible in cancers of the body and tail of the pancreas if the tumor invades celiac artery. Controversy exists regarding the margin status impact of microscopic resection margin involvement (R1) after pancreaticoduodenectomy (PD) for PDAC. There are reports indicating the rate of R1 resections increases significantly after PD if pathological examination is standardized. In this report, we present the case of a 56-year-old female who had undergone lateral pancreaticojejunostomy for chronic pancreatitis 8 years ago, but has now developed malignancy of the body and tail of the pancreas involving multiple organs. This patient underwent en bloc resection involving: 1. distal pancreatectomy with jejunal loop (lateral pancreaticojejunostomy) resection; 2. splenectomy; 3. left nephrectomy; 4. total gastrectomy; and 5. segmental colectomy with reconstruction by esophagojejunostomy, jejunojejunostomy, and colocolic anastomosis. The infrequent occurrence of tumor in the distal gland and advanced tumor stage at the time of diagnosis have both combined to produce therapeutic nihilism/dilemma in the minds of many surgeons. This report highlights the decision on how much to the push limits for multi-organ resection (en bloc resection with distal pancreatectomy, gastrectomy, splenectomy, colectomy, nephrectomy) with the intent of achieving R0 status in spite of the complexity of surgery in selected patients.

Contemporary Reappraisal of Intraoperative Neck Margin Assessment During Pancreaticoduodenectomy for Pancreatic Ductal Adenocarcinoma: A Review

Importance

Although margin-negative (R0) resection is the gold standard for surgical management of localized pancreatic ductal adenocarcinoma (PDAC), the question of how to manage the patient with a microscopically positive intraoperative neck margin (IONM) during pancreaticoduodenectomy remains controversial.

Observations

In the absence of randomized clinical trials, we critically evaluated high-quality retrospective studies examining the oncologic utility of re-resecting positive IONMs during pancreaticoduodenectomy for PDAC (2000-2019). Several studies have concluded that additional pancreatic resection to achieve an R0 margin in IONM-positive cases does not influence survival. The largest is a multi-institutional study of 1399 patients undergoing pancreaticoduodenectomy, which demonstrated that in comparison with patients undergoing R0 resection (n = 1196; median survival, 21 months), those with either final R1 resections (n = 131) or undergoing margin conversion from IONM-positive to R0 resection on permanent section (n = 72) demonstrated similar median survival times (13.7 and 11.9 months, respectively). Conversely, recent reports suggest that the conversion of IONM to R0 resection with additional resection or even total pancreatectomy may be associated with improved survival. The discordance between these conflicting studies could be explained in part by the influence of biologic and physiologic selection on the association of IONM re-resection and survival. Since most studies did not include patients receiving modern combination chemotherapy regimens, the intersection between margin status, tumor biology, and chemoresponsiveness remains unclear. Furthermore, there are no dedicated data to guide surgical management in IONM-positive pancreaticoduodenectomy for patients receiving neoadjuvant chemotherapy.

Conclusions and Relevance

Although data regarding the oncologic utility of additional resection to achieve a tumor-free margin following initial IONM positivity during pancreaticoduodenectomy for PDAC are conflicting, they suggest that IONM positivity may be a surrogate for biologic aggressiveness that is unlikely to be mitigated by the extent of surgical resection. The complex relationship between margin status and chemoresponsiveness warrants exploration in studies including patients receiving increasingly effective neoadjuvant chemotherapy.

The Role of Pathological Method and Clearance Definition for the Evaluation of Margin Status after Pancreatoduodenectomy for Periampullary Cancer. Results of a Multicenter Prospective Randomized Trial

BACKGROUND

There is extreme heterogeneity in the available literature on the determination of R1 resection rate after pancreatoduodenectomy (PD); consequently, its prognostic role is still debated. The aims of this multicenter randomized study were to evaluate the effect of sampling and clearance definition in determining R1 rate after PD for periampullary cancer and to assess the prognostic role of R1 resection.

METHODS

PD specimens were randomized to Leeds Pathology Protocol (LEEPP) (group A) or the conventional method adopted before the study (group B). R1 rate was determined by adopting 0- and 1-mm clearance; the association between R1, local recurrence (LR) and overall survival (OS) was also evaluated.

RESULTS

One-hundred-sixty-eight PD specimens were included. With 0 mm clearance, R1 rate was 26.2% and 20.2% for groups A and B, respectively; with 1 mm, R1 rate was 60.7% and 57.1%, respectively (p > 0.05). Only in group A was R1 found to be a significant prognostic factor: at 0 mm, median OS was 36 and 20 months for R0 and R1, respectively, while at 1 mm, median OS was not reached and 30 months. At multivariate analysis, R1 resection was found to be a significant prognostic factor independent of clearance definition only in the case of the adoption of LEEPP.

CONCLUSIONS

The 1 mm clearance is the most effective factor in determining the R1 rate after PD. However, the pathological method is crucial to accurately evaluate its prognostic role: only R1 resections obtained with the adoption of LEEPP seem to significantly affect prognosis.

Histopathological evaluation of resected intraductal papillary mucinous neoplasms reveals distinct patterns of invasion in associated carcinomas

Invasive intraductal papillary mucinous neoplasms (inv-IPMNs) have a better prognosis than regular pancreatic ductal adenocarcinoma (PDAC), but no association with status of surgical margins and microscopic infiltration patterns has previously been described. The aim of this study is to review patterns of invasion and the predictive value of clinical guidelines in terms of rates of resection of high-grade dysplasia (HGD) and cancer among intraductal papillary mucinous neoplasms (IPMNs). Consecutively, resected IPMNs between 2011 and 2017 were analyzed. Data were obtained from a prospectively maintained database. A total of 132 patients were identified. Out of these, 38 patients with inv-IPMNs, initially identified as solid lesions suspicious of cancer, were compared with a control group of 101 patients with ordinary PDAC. Lower rates of vascular invasion, perineural invasion, lymph node metastasis, advanced T stage, and R1 status were characteristic of the inv-IPMNs in addition to better overall survival (OS) for a low tumor stage. Furthermore, as novel findings, the PDACs presented with resection margin involvement of 3 or more positive margins (31.3% vs. 9.5%, p = 0.044), associated with poor OS. Of the patients presenting as pT3, the inv-IPMN less often invaded more than one extrapancreatic anatomical structure (40.1% vs. 63.9%, p = 0.03). Regarding the predictive value of clinical guidelines, the frequency of resected HGD in IPMNs with high-risk stigmata (n = 54) and IPMNs with worrisome features was 30.7%, and the frequency of invasive carcinoma was 5.7%. In conclusion, we report a low resection rate of high-risk IPMNs and present novel findings describing inv-IPMNs as a less infiltrative phenotype compared with regular PDAC.

Predictive factors for long-term survival after surgery for pancreatic ductal adenocarcinoma: Making a case for standardized reporting of the resection margin using certified cancer center data

Factors for overall survival after pancreatic ductal adenocarcinoma (PDAC) seem to be nodal status, chemotherapy administration, UICC staging, and resection margin. However, there is no consensus on the definition for tumor free resection margin. Therefore, univariate OS as well as multivariate long-term survival using cancer center data was analyzed with regards to two different resection margin definitions. Ninety-five patients met inclusion criteria (pancreatic head PDAC, R0/R1, no 30 days mortality). OS was analyzed in univariate analysis with respect to R-status, CRM (circumferential resection margin; positive: ≤1mm; negative: >1mm), nodal status, and chemotherapy administration. Long-term survival >36 months was modelled using multivariate logistic regression instead of Cox regression because the distribution function of the dependent data violated the requirements for the application of this test. Significant differences in OS were found regarding the R status (Median OS and 95%CI for R0: 29.8 months, 22.3–37.4; R1: 15.9 months, 9.2–22.7; p = 0.005), nodal status (pN0 = 34.7, 10.4–59.0; pN1 = 17.1, 11.5–22.8; p = 0.003), and chemotherapy (with CTx: 26.7, 20.4–33.0; without CTx: 9.7, 5.2–14.1; p < .001). OS according to CRM status differed on a clinically relevant level by about 12 months (CRM positive: 17.2 months, 11.5–23.0; CRM negative: 29.8 months, 18.6–41.1; p = 0.126). A multivariate model containing chemotherapy, nodal status, and CRM explained long-term survival (p = 0.008; correct prediction >70%). Chemotherapy, nodal status and resection margin according to UICC R status are univariate factors for OS after PDAC. In contrast, long-term survival seems to depend on wider resection margins than those used in UICC R classification. Therefore, standardized histopathological reporting (including resection margin size) should be agreed upon.

Neoadjuvant chemoradiation is associated with decreased lymph node ratio in borderline resectable pancreatic cancer: A propensity score matched analysis

BACKGROUND

Lymph node ratio (LNR) and margin status have prognostic significance in pancreatic cancer. Herein we examined the pathologic and clinical outcomes in patients with borderline resectable pancreatic cancer (BRPC) following neoadjuvant therapy (NAT) and pancreaticoduodenectomy.

METHODS

Patients who underwent treatment between January 1, 2012 and June 30, 2017 were included. Sequential patients in the BRPC group were compared to a propensity score matched cohort of patients with radiographically resectable pancreatic cancer who underwent upfront surgical resection. The BRPC group was also compared to sequential patients with radiographically resectable pancreatic cancer who required vein resection (VR) during upfront surgery.

RESULTS

There were 50 patients in the BRPC group, 50 patients in the matched control group, and 38 patients in the VR group. Negative margins (R0) were seen in 72%, 64%, and 34% of the BRPC, control, and VR groups, respectively (P = 0.521 for BRPC vs. control; P = 0.002 for BRPC vs. VR), with 24% of the BRPC group requiring a vascular resection. Nodal stage was N0 in 64%, 20%, and 18% of the BRPC, control, and VR groups, respectively (P < 0.001 for BRPC vs. control or VR). When nodal status was stratified into four groups (N0, or LNR ≤ 0.2, 0.2-0.4, ≥ 0.4), the BRPC group had a more favorable distribution (P < 0.001). The median overall survival were 28.8, 38.6, and 19.0 months for the BRPC, control, and VR groups, respectively (log-rank P = 0.096).

CONCLUSIONS

NAT in BRPC was associated with more R0 and N0 resections and lower LNR compared to patients undergoing upfront resection for resectable disease.

In the Era of the Leeds Protocol: A Systematic Review and A Meta-Analysis on the Effect of Resection Margins on Survival Among Pancreatic Ductal Adenocarcinoma Patients

BACKGROUND AND AIMS

A positive resection margin is considered to be a factor associated with poor prognosis after pancreatic ductal adenocarcinoma resection. However, analysis of the resection margin is dependent on the pathological slicing technique. The aim of this systematic review and meta-analysis was to study the impact of resection margin on the survival of pancreatic ductal adenocarcinoma patients whose specimens were analyzed using the axial slicing technique.

MATERIAL AND METHODS

A systematic search in the PubMed, Cochrane, and Embase datasets covering the time period from November 2006 to January 2019 was performed. Only studies with axial slicing technique (Leeds Pathology Protocol or Royal College of Pathology Protocol) were included in the final database. Meta-analysis between the marginal distance and survival was performed with the Inverse Variance Method in RevMan.

RESULTS

The systematic search resulted in nine studies meeting the inclusion criteria. The median survival for a resection margin 0 mm ranged from 12.3 to 23.4 months, for resection margin <0.5 mm 16 months, for resection margin <1 mm ranged from 11 to 27.5 months, for resection margin <1.5 mm ranged from 16.9 to 21.2 months, and for resection margin >2 mm ranged from 53.9 to 63.1 months. Five studies were eligible for meta-analysis. The pooled multivariable hazard ratio favored resection margin ⩾1 mm (hazard ratio: 1.32 and 95% confidence interval: 1.03-1.68, p = 0.03).

CONCLUSION

Resection margins ⩾1 mm seem to lead to better survival in pancreatic ductal adenocarcinoma patients than resection margin <1 mm. However, there is not enough data to evaluate the effect of oncologic therapy or to analyze the impact of other resection margin distances on survival.

Recurrence patterns of pancreatic cancer after pancreatoduodenectomy: systematic review and a single-centre retrospective study

BACKGROUND

Positive margins in pancreatoduodenectomy (PD) for pancreatic cancer, specifically the superior mesenteric artery (SMA) margin, are associated with worse outcomes. Local therapies targeting these margins could impact on recurrence. This study analysed recurrence-patterns to identify whether strategies to control local disease could have a meaningful impact.

METHODS

(I) Systematic review to define recurrence patterns and resection margin status. (II) Additional retrospective study of PD performed at our centre.

RESULTS

In the systematic review, 23/617 evaluated studies were included (n = 3815). Local recurrence was observed in 7-69%. SMA margin (6 studies) was positive in 15-35%. In the retrospective study (n = 204), local recurrence was more frequently observed with a positive SMA margin (66 vs.45%; p = 0.005). Furthermore, in a multivariate cox-proportional hazard model, only a positive SMA margin was associated with disease recurrence (HR 1.615; 95%CI 1.127-2.315; p = 0.009). Interestingly, median overall survival was 20 months and similar for patients who developed local only, metastases only or simultaneous recurrence (p = 0.124).

CONCLUSION

Local recurrence of pancreatic cancer is common and associated with similar mortality rates as those who present with simultaneous or metastatic recurrence. Involvement of the SMA margin is an independent predictor for disease progression and should be the target of future adjuvant local therapies.

Pancreatoduodenectomy with venous resection for ductal adenocarcinoma rarely achieves complete (R0) resection

BACKGROUND

Pancreatoduodenectomy with venous resection is considered standard of care for patients with tumour involvement of the superior mesenteric/portal vein (SMV/PV) and deemed justified if an R0-resection can be achieved. The aim of this study was to provide a detailed pathology assessment of the site and extent of margin involvement in specimens resulting from pancreatoduodenectomy with venous resection.

METHODS

Retrospective observational study including patients undergoing pancreatoduodenectomy with or without venous resection for pancreatic ductal adenocarcinoma between 2015 and 2017. Detailed histopathological mapping of the tumour and its relationship to the margins was undertaken.

RESULTS

98 patients met the inclusion criteria. An R0-resection, based on 1 mm clearance, was achieved in 16 of 73 patients without venous resection and in 1 of 25 patients with venous resection (p = 0.063). The surface of the SMV-groove was the most frequently involved margin (23 of 25 patients with venous resection, 37 of 73 patients without venous resection; p < 0.001). The broad invasive tumour front as well as the absence of peripancreatic fat at the SMV-groove were the reasons for these findings.

CONLUSION

An R0-resection following pancreatoduodenectomy with venous resection for ductal adenocarcinoma can rarely be achieved due to microscopical involvement of the SMV-groove.

Positive Resection Margins Detected by Standardized Study of a Pancreaticoduodenectomy Sample: Is There Any Real Impact on Long-term Survival?

INTRODUCTION

The pathological evaluation of pancreaticoduodenectomy (PD) samples and the impact of R1 resections on survival has recently been questioned. This study evaluates the introduction of a standardized pathology study protocol (PSP) and the prognosis of R1 resections after long-term follow-up.

METHODS

We reviewed data from a prospectively maintained database regarding 109 periampullary tumors treated by PD from 2005 to 2013. The results of the introduction of a PSP were analysed, and the recurrence rate (RR), disease-free survival (DFS) and overall survival (OS) of the R1 resections were evaluated for each positive margin.

RESULTS

The PD specimens of periampullary tumors analyzed by PSP showed a higher rate of isolated lymph nodes (17 vs. 8; P=.003), N+ (60% vs. 31%; P<.001), microvascular invasion (67% vs. 34%; P=.001) and R1 resections (42% vs. 18%; P=.010). Pancreatic adenocarcinomas with R1 resection in the PSP group were compared with R0, presenting higher percentages of vascular resections (P=.033), N+ (P=.029), lymphatic and perineural invasion (P=.047; P=.029), higher RR (P=.026), lower DFS (P=.016) and lower OS (P=.025). Invasion of the medial margin correlated with a worse prognosis.

CONCLUSIONS

Our series shows an increase in R1 resection after the introduction of a PSP. Infiltration of the medial margin seems to be associated with a higher RR and a decrease in DFS and OS.

Clinical impact of additional therapy for residual pancreatic cancer

PURPOSE

This study aimed to explore the prognostic significance of the resection margin (R) status of pancreatic ductal adenocarcinoma (PDAC) patients receiving neoadjuvant therapy (NAT) or adjuvant chemotherapy (AC).

METHODS

We retrospectively reviewed 427 consecutive patients, and the overall survival (OS) and disease-free survival (DFS) were analyzed based on the R status by a propensity score analysis (PSA).

RESULTS

The R0 ratio of the NAT (+) group was significantly higher than that of the NAT (-) group (97.2% vs. 69.6%, P < 0.0001). Local recurrence was well controlled in the NAT (+) group compared to the NAT (-) group (15.3% vs. 34.1%, P = 0.0013). The PSA revealed no significant survival difference between R0 and R1 resection among those treated with AC (median survival time [MST]: 43.0 vs. 33.3 months, matching hazard ratio [HR]: 1.212, P = 0.5708). Furthermore, the DFS in R0 and R1 resection followed by AC was identical (MST: 20.6 vs. 17.7 months, matching HR: 1.020, P = 0.9482).

CONCLUSIONS

NAT was a significant predictor of R0 resection. When patients completed AC, there were no marked differences in the OS or DFS between R0 and R1 resection. Our results demonstrated that the clinical impact of the R1 status has waned in the current era of PDAC management.

Preoperative Clinical and Computed Tomography (CT)-Based Nomogram to Predict Oncologic Outcomes in Patients with Pancreatic Head Cancer Resected with Curative Intent: A Retrospective Study

Background: Currently, proposed nomograms are mainly based on post-operative histopathology. The purpose of this study was to identify preoperative computed tomography (CT) and clinical information that allow prediction of disease-free (DFS) and overall survival (OS) of patients surgically treated for pancreatic head cancer. Methods: A total of 136 patients who underwent curative-intent surgery were retrospectively reviewed. Based on results from multivariate Cox regression analysis, a prediction model was constructed with preoperative CT features and clinical information. Overall performance of the nomogram was calculated by Harrell’s C-index. Results: Symptoms at diagnosis, preoperative serum CA 19-9 ≥ 34 U/mL, and four imaging features (necrosis (DFS, P = 0.066; OS, P = 0.002), possible venous invasion (DFS, P = 0.150, OS, P = 0.055), suspected metastatic regional lymph node (DFS, P = 0.001; OS, P = 0.099), and associated pancreatitis or pseudocyst (DFS, P = 0.013; OS, P = 0.041)) were included to build the nomogram. The c-statistics for the discrimination power of the proposed nomogram was 0.6496 for DFS and 0.6746 for OS. Conclusion: A nomogram derived from preoperative CT and clinical information could estimate the risk of recurrence and all-cause death after curative-intent surgery for radiologically resectable pancreatic head cancer.

R0 Versus R1 Resection Matters after Pancreaticoduodenectomy, and Less after Distal or Total Pancreatectomy for Pancreatic Cancer

OBJECTIVE

The aim of this study was to decipher the true importance of R0 versus R1 resection for survival in pancreatic ductal adenocarcinoma (PDAC).

SUMMARY OF BACKGROUND DATA

PDAC is characterized by poor survival, even after curative resection. In many studies, R0 versus R1 does not result in different prognosis and does not affect the postoperative management.

METHODS

Pubmed, Embase, and Cochrane databases were screened for prognostic studies on the association between resection status and survival. Hazard ratios (HRs) were pooled in a meta-analysis. Furthermore, our prospective database was retrospectively screened for curative PDAC resections according to inclusion criteria (n = 254 patients) between July 2007 and October 2014.

RESULTS

In the meta-analysis, R1 was associated with a decreased overall survival [HR 1.45 (95% confidence interval, 95% CI 1.37-1.52)] and disease-free survival [HR 1.44 (1.30-1.59)] in PDAC when compared with R0. Importantly, this effect held true only for pancreatic head resection both in the meta-analysis [R0 ≥0 mm: HR 1.21 (1.05-1.39) vs R0 ≥1 mm: HR 1.66 (1.46-1.89)] and in our cohort (R0 ≥0 mm: 31.8 vs 14.5 months, P < 0.001; R0 ≥1 mm, 41.2 vs 16.8 months; P < 0.001). Moreover, R1 resections were associated with advanced tumor disease, that is, larger tumor size, lymph node metastases, and extended resections. Multivariable Cox proportional hazard model suggested G3, pN1, tumor size, and R1 (0 mm/1 mm) as independent predictors of overall survival.

CONCLUSION

Resection margin is not a valid prognostic marker in publications before 2010 due to heterogeneity of cohorts and lack of standardized histopathological examination. Within standardized pathology protocols, R-status' prognostic validity may be primarily confined to pancreatic head cancers.

Validation of the American Joint Committee on Cancer 8th edition staging system for the pancreatic ductal adenocarcinoma

BACKGROUND & AIMS

The American Joint Commission on Cancer (AJCC) 8th edition staging system for pancreatic ductal adenocarcinoma (PDA) contains several significant changes. This study aimed to validate the AJCC 8th edition staging system of PDA.

METHODS

We analyzed patients with resected PDA between 2001 and 2017 using the Korean Pancreatic Cancer (K-PaC) registry. Overall survival (OS) was estimated using the Kaplan-Meier survival curves and compared via the log-rank test.

RESULTS

In total, 701 resected PDA patients were identified. During a median follow-up of 24.5 months, the median OS was 21.7 months. Meanwhile, the median OS of each stage according to the AJCC 8th edition was 73.5 months (stage IA), 41.9 months (stage IB), 24.2 months (stage IIA), 18.3 months (stage IIB), and 16.8 months (stage III). However, the new N-category (pN1 vs. pN2) did not subdivide prognosis, although the lymph node ratio (i.e., the ratio of the number of LN involved to the number of examined LN) did. Although pT3 and pN2 belong under stage III, pN2 has a significantly longer median OS than pT3 (16.9 months vs 11.2 months; p < 0.01).

CONCLUSION

The AJCC 8th edition staging system appropriately stratifies the prognosis of PDA patients. However, the cutoff of the N-category is not statistically valid, and the new stage III includes a heterogeneous category (pN2 and pT4). Therefore, we propose that stage III be divided into stage IIIA (Tany N2 M0) and stage IIIB (T4 Nany M0).

Can post-hoc video review of robotic pancreaticoduodenectomy predict portal/superior mesenteric vein margin status in pancreatic adenocarcinoma?

BACKGROUND

Achieving margin negative resection is a significant determinant of outcome in pancreatic adenocarcinoma (PDA). However, because of the fibrotic nature of PDA, it can be difficult to discriminate fibrosis from active disease intra-operatively. We sought to determine if post-hoc video review of robotic pancreatico-duodenectomy (RPD) could predict the portal/superior mesenteric vein (PV/SMV) margin status on final pathology.

METHODS

Experienced pancreatic surgeons, blinded to patient and operative variables, reviewed the PV/SMV margin for available RPD videos of consecutive PDA patients from 9/2012 through 6/2017.

RESULTS

107 RPD videos were reviewed. Of 76 patients (71%) predicted to have a negative vein margin on video review, 20 patients (26%) had a pathologic positive margin. 25 of 31 patients (81%) predicted to have positive margin on video review were positive on pathology. The specificity of video prediction was 90.3% with a sensitivity of 55.6% and an accuracy of 75.7%.

CONCLUSION

Post-hoc video review prediction is unable to reliably predict a positive (R1) margin at the portal vein/SMV, suggesting that intra-operative clinical assessment may be suboptimal in determining the need for more extensive resections.

Margin status and long-term prognosis of primary pancreatic neuroendocrine tumor after curative resection: Results from the US Neuroendocrine Tumor Study Group

BACKGROUND

The impact of margin status on resection of primary pancreatic neuroendocrine tumors has been poorly defined. The objectives of the present study were to determine the impact of margin status on long-term survival of patients with pancreatic neuroendocrine tumors after curative resection and evaluate the impact of reresection to obtain a microscopically negative margin.

METHODS

Patients who underwent curative-intent resection for pancreatic neuroendocrine tumors between 2000 and 2016 were identified at 8 hepatobiliary centers. Overall and recurrence-free survival were analyzed relative to surgical margin status using univariable and multivariable analyses.

RESULTS

Among 1,020 patients, 866 (84.9%) had an R0 (>1 mm margin) resection, whereas 154 (15.1%) had an R1 (≤1 mm margin) resection. R1 resection was associated with a worse recurrence-free survival (10-year recurrence-free survival, R1 47.3% vs R0 62.8%, hazard ratio 1.8, 95% confidence interval 1.2-2.7, P = .002); residual tumor at either the transection margin (R1t) or the mobilization margin (R1m) was associated with increased recurrence versus R0 (R1t versus R0: hazard ratio 1.8, 95% confidence interval 1.0-3.0, P = .033; R1m versus R0: hazard ratio 1.3, 95% confidence interval 1.0-1.7, P = .060). In contrast, margin status was not associated with overall survival (10-year overall survival, R1 71.1% vs R0 71.8%, P = .392). Intraoperatively, 539 (53.6%) patients had frozen section evaluation of the surgical margin; 49 (9.1%) patients had a positive margin on frozen section analysis; 38 of the 49 patients (77.6%) had reresection, and a final R0 (secondary R0) margin was achieved in 30 patients (78.9%). Extending resection to achieve an R0 status remained associated with worse overall survival (hazard ratio 3.1, 95% confidence interval 1.6-6.2, P = .001) and recurrence-free survival (hazard ratio 2.6, 95% confidence interval 1.4-5.0, P = .004) compared with primary R0 resection. On multivariable analyses, tumor-specific factors, such as cellular differentiation, perineural invasion, Ki-67 index, and major vascular invasion, rather than surgical margin, were associated with long-term outcomes.

CONCLUSION

Margin status was not associated with long-term survival. The reresection of an initially positive surgical margin to achieve a negative margin did not improve the outcome of patients with pancreatic neuroendocrine tumors. Parenchymal-sparing pancreatic procedures for pancreatic neuroendocrine tumors may be appropriate when feasible.

Can we predict long-term survival in resectable pancreatic ductal adenocarcinoma?

Objective

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive tumour associated with poor 5-year survival. We aimed to determine factors which differentiate short and long-term survivors and identify a prognostic biomarker.

Methods

Over a ten-year period, patients with resected PDAC who developed disease recurrence within 12 months (Group I) and those who had no disease recurrence for 24 months (Group II) were identified. Clinicopathological data was analysed. Ion Torrent high-throughput sequencing on DNA extracted from FFPE tumour samples was used to identify mutations. Additionally, peripheral blood samples were analysed for variants in cell-free DNA, circulating tumour cells (CTCs), and microRNAs.

Results

Multivariable analysis of clinicopathological factors showed that a positive medial resection margin was significantly associated with short disease-free survival (p = 0.007). Group I patients (n = 21) had a higher frequency of the KRAS mutant mean variant allele (16.93% ± 11.04) compared to those in Group II (n = 13; 7.55% ± 5.76, p = 0.0078). Group I patients also trended towards having a KRAS c.35G>A p.Gly12Asp mutation in addition to variants in other genes, such as TP53, CDKN2A, and SMAD4. Mutational status of cell-free DNA, and number of CTCs, was not found to be useful in this study. A circulating miRNA (hsa-miR-548ah-5p) was found to be significantly differentially expressed.

Conclusions

Medial resection margin status and the frequency of KRAS mutation in the tumour tissue are independent prognostic indicators for resectable PDAC. Circulating miRNA hsa-miR-548ah-5p has the potential to be used as a prognostic biomarker.

Clinical significance of revised microscopic positive resection margin status in ductal adenocarcinoma of pancreatic head

Purpose

Recent studies have suggested microscopic positive resection margin should be revised according to the presence of tumor cells within 1mm of the margin surface in resected specimens of pancreatic cancer. However, the clinical meaning of this revised margin status for R1 resection margin was not fully clarified.

Methods

From July 2012 to December 2014, the medical records of 194 consecutive patients who underwent pancreaticoduodenectomy for ductal adenocarcinoma of the pancreatic head were analyzed retrospectively. They were divided into 3 groups on margin status; revised microscopic negative margin (rR0) – tumor exists more than 1 mm from surgical margin, revised microscopic positive margin (rR1) – tumor present within less than 1 mm from surgical margin, classic microscopic positive margin (cR1) – tumor is exposed to surgical margin.

Results

There were 76 rR0 (39.2%), 100 rR1 (51.5%), and 18 cR1 (9.3%). There was significant difference in disease-free survival rates between cR1 vs. rR1 (8.4 months vs. 24.0 months, P = 0.013). Margin status correlated with local recurrence rate (17.1% in rR0, 26.0% in rR1, and 44.4% in cR1, P = 0.048). There is significant difference in recurrence at tumor bed (11.8% in rR0 vs. 23.0 in rR1, P = 0.050). Of rR1, adjuvant treatment was found to be an independent risk factor for local recurrence (hazard ratio, 0.297; 95% confidence interval, 0.127–0.693, P = 0.005).

Conclusion

Revised R1 resection margin (rR1) affects recurrence at the tumor bed. Adjuvant treatment significantly reduced local recurrence of rR1. Accordingly, adjuvant chemoradiation for rR1 group should be taken into account.

Fluorescent humanized anti-CEA antibody specifically labels metastatic pancreatic cancer in a patient-derived orthotopic xenograft (PDOX) mouse model

Pancreatic cancer is a highly lethal disease in part due to incomplete tumor resection. Targeting by tumor-specific antibodies conjugated with a fluorescent label can result in selective labeling of cancer in vivo for surgical navigation. In the present study, we describe a patient-derived orthotopic xenograft model of pancreatic cancer that recapitulated the disease on a gross and microscopic level, along with physiologic clinical manifestations. We additionally show that the use of an anti-CEA antibody conjugated to the near-infrared (NIR) fluorescent dye, IRDye800CW, can selectively highlight the pancreatic cancer and its metastases in this model with a tumor-to-background ratio of 3.5 (SEM 0.9). The present results demonstrate the clinical potential of this labeling technique for fluorescence-guided surgery of pancreatic cancer.

Validation of at least 1 mm as cut-off for resection margins for pancreatic adenocarcinoma of the body and tail

BACKGROUND

The definition of resection margin (R) status in pancreatic cancer is under debate. Although a margin of at least 1 mm is an independent predictor of survival after resection for pancreatic head cancer, its relevance to pancreatic body and tail cancers remains unclear. This study aimed to validate R status based on a 1-mm tumour-free margin as a prognostic factor for resected adenocarcinoma involving the pancreatic body and tail.

METHODS

Patients who underwent distal or total pancreatectomy for adenocarcinomas of the pancreatic body and tail between January 2006 and December 2014 were identified from a prospective database. Resection margins were evaluated using a predefined cut-off of 1 mm. Rates of R0, R1 with invasion within 1 mm of the margin (R1 less than 1 mm), and R1 with direct invasion of the resection margin (R1 direct) were determined, and overall survival in each group assessed by Kaplan-Meier analysis. Univariable and multivariable Cox regression analyses were performed to identify predictors of survival.

RESULTS

R0 resection was achieved in 107 (23·5 per cent) and R1 in 348 (76·5 per cent) of 455 patients. Among R1 resections, invasion within 1 mm of the margin was found in 104 (22·9 per cent) and direct invasion in 244 (53·6 per cent). The R0 rate was 28·9 per cent after distal and 18·6 per cent after total pancreatectomy. In the total cohort, median survival times for patients with R0, R1 (less than 1 mm) and R1 (direct) status were 62·4, 24·6 and 17·2 months respectively, with 5-year survival rates of 52·6, 16·8 and 13·0 per cent (P < 0·001). In patients who received adjuvant chemotherapy, respective median survival times were 68·6, 32·8 and 21·4 months, with 5-year survival rates of 56, 22 and 16·0 per cent (P < 0·001). In multivariable analysis, R status was independently associated with survival.

CONCLUSION

A cut-off of at least 1 mm for evaluation of resection margins is an independent determinant of survival after resection of adenocarcinomas of the pancreatic body and tail.

Meta-analysis of an artery-first approach versus standard pancreatoduodenectomy on perioperative outcomes and survival

Background

The aim of this systematic review and meta-analysis was to evaluate perioperative outcomes and survival in patients undergoing an artery-first approach to pancreatoduodenectomy in comparison with those having standard pancreatoduodenectomy.

Methods

A systematic search of PubMed, MEDLINE, Embase and the Cochrane Database of Systematic Reviews was performed in accordance with PRISMA guidelines. Comparative studies including patients who underwent artery-first pancreatoduodenectomy and standard pancreatoduodenectomy were analysed.

Results

Seventeen studies were included in the final analysis. There were 16 retrospective cohort or case–control studies and one RCT. A total of 1472 patients were included in the meta-analysis, of whom 771 underwent artery-first pancreatoduodenectomy and 701 had standard pancreatoduodenectomy. Intraoperative blood loss (mean difference –389 ml; P &lt; 0·001) and the proportion of patients requiring intraoperative transfusion (10·6 per cent (54 of 508) versus 40·1 per cent (186 of 464); P &lt; 0·001) were significantly lower in the artery-first group. Although rates of perioperative mortality were comparable between the two groups, perioperative morbidity (35·5 per cent (263 of 741) versus 44·3 per cent (277 of 625); P = 0·002), and the incidence of grade B/C pancreatic fistula (7·4 per cent (26 of 353) versus 12·8 per cent (42 of 327); P = 0·031) were significantly lower in the artery-first group. The R0 resection rate (75·8 per cent (269 of 355) versus 67·0 per cent (280 of 418); P &lt; 0·001) and overall survival (hazard ratio 0·72, 95 per cent c.i. 0·60 to 0·87; P &lt; 0·001) were significantly higher in the artery-first group.

Conclusion

The artery-first approach to pancreatoduodenectomy may be associated with improved perioperative outcomes and survival.

Clinical impact of margin status on survival and recurrence pattern after curative-intent surgery for pancreatic cancer

BACKGROUND/OBJECTIVE

The definition of R0 resection for invasive pancreatic ductal carcinoma (IPDC) is important. However, there are different definitions among several countries in the world.

METHODS

From 2001 to 2015, 100 consecutive patients with IPDC who underwent pancreatic resection in our hospital were enrolled. We compared survival and recurrence patterns between the R0 group and R1 group based on the UICC (Union for International Cancer Control) classification (current-R0 vs. current-R1) and based on our revised classification, which defines R0 as a surgical margin of >1 mm (revised-R0 vs. revised-R1).

RESULTS

The 100 patients comprised 58 males and 42 females, and their median age was 70 [32-87]. There were 84 patients in the current-R0 group and 43 in the revised-R0 group. There was no difference in overall survival (OS) or recurrence-free survival (RFS) between the current-R0 group and current-R1 group. However, there was a tendency toward a higher OS rate in the revised-R0 than revised-R1 group (log-rank p = 0.065), and RFS was significantly better in the revised-R0 than revised-R1 group (log-rank p = 0.002). There was no significant difference in the recurrence patterns between the current-R0 and current-R1 groups. In contrast, the local recurrence rate was significantly lower in the revised-R0 than revised-R1 group (21% vs. 42%, respectively; p = 0.026).

CONCLUSION

The revised classification of surgical resection may be more useful than the current UICC classification for prediction of prognosis and local recurrence of IPDC.

The role of irreversible electroporation (IRE) for locally advanced pancreatic cancer: a systematic review of safety and efficacy

OBJECTIVES

Irreversible electroporation (IRE) is a new modality for tumor ablation. Electrodes are placed around the tumor, and a pulsed, direct current with a field strength of 2000 V/cm is delivered. The direct current drives cells into apoptosis and cell death without causing significant heating of the tissues, which spares the extracellular matrix and proteins. The purpose of this review was to evaluate current experience of IRE for the ablation of pancreatic cancer.

MATERIAL AND METHODS

We searched PubMed for all studies of IRE in human pancreatic cancer in English reporting at least 10 patients.

RESULTS

The search yielded 10 studies, comprising a total of 446 patients. Percutaneous IRE was done in 142 patients, while 304 patients were treated during laparotomy. Tumor sizes ranged from median 2.8 to 4.5 cm. Post-procedural complications occurred in 35% of patients, most of them were less severe. Nine patients (2.0%) died after the procedure. The technical success rate was 85-100%. The median recurrence-free survival was 2.7-12.4 months after IRE treatment. The median overall survival was 7-23 months postoperatively. The longest overall survival was noted when IRE was used in conjunction with pancreatic resection.

CONCLUSIONS

IRE seems feasible and safe with a low post-procedural mortality. Further efforts are needed to address patient selection and efficacy of IRE, as well as the use of IRE for 'margin accentuation' during surgical resection.

Resectable pancreatic head adenocarcinoma: Is R0 resection an illusion? Genetic evaluation of venous resection margin affirmed unrecognized disease

PURPOSE

To assess the K-ras gene mutation in the histologically negative venous margin of a pancreaticoduodenectomy (PD) specimen and its impact on survival.

METHOD

From 2007 to 2010, 22 patients underwent R0 PD for resecable pancreatic adenocarcinoma. All specimens were stained and the portal vein (PV) bed was identified by blue ink; a 2mm³ sample (including the blue ink) was cut from a microscopic free-tumor block. DNA was extracted and assessed by quantitative real time polymerase chain reaction to detect the K-ras gene mutation. Twelve specimens (55%) (kras+ group) were identified with a K-ras mutation in the venous margin resection, and 10 specimens (kras- group) did not have K-ras mutation detected in the venous margin resection.

RESULTS

The two groups were comparable. Overall 3years survival of patients of kras+ group versus patients of kras- group was 0 and 17% (P=0.03), respectively. Median survival time of patients of kras+ group versus patients of kras- group was 16months vs 25months (P=0.04; 95% confidence interval [1,11-1,88]), respectively.

CONCLUSION

Genetic evaluation of venous resection margin affirmed unrecognized disease with strong impact on survival in more than 50% of patients with histologically R0 resection.

A margin distance analysis of the impact of adjuvant chemoradiation on survival after pancreatoduodenectomy for pancreatic adenocarcinoma

BACKGROUND

The role of adjuvant chemoradiotherapy (CRT) following pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PDA) remains controversial. Recent data suggest that increased margin clearance (MC: distance between tumor and cut surface) is associated with improved survival after PD, but the role of adjuvant CRT in patients with known MC is undefined. We sought to delineate the impact of adjuvant CRT on survival based on MC following PD.

METHODS

Patients who underwent PD for PDA between 2002 and 2014 were retrospectively stratified into three groups based on MC: 0 mm, ≤1 mm, and >1 mm. The impact of CRT on survival in each MC group was determined by univariate and multivariate analysis.

RESULTS

Three hundred and ten patients with known MC were analyzed (0 mm =67, ≤1 mm =113, and >1 mm =130). Increasing MC was independently associated with improved OS (≤1 mm, HR 0.66, 95% CI 0.46-0.96, P=0.03; >1 mm, HR 0.51, 95% CI 0.35-0.75, P=0.001; compared to 0 mm). Adjuvant CRT was administered to 62 patients (20%). On margin-stratified multivariate analysis, adjuvant CRT was independently associated with increased OS in patients with ≤1 mm margins (HR 0.36; 95% CI 0.18-0.69, P=0.002) but not for 0 mm and >1 mm margins.

CONCLUSIONS

This analysis suggests that the benefit of adjuvant CRT may be restricted to patients with ≤1 mm MC after PD for pancreatic cancer.

The role of induction chemotherapy + chemoradiotherapy in localised pancreatic cancer: initial experience in Scotland

BACKGROUND

Despite being relatively rare pancreatic cancer is one of the highest causes of death. Even within the potentially resectable group outcomes are poor. We present our initial experiences utilising a neoadjuvant approach to localised pancreatic cancer, evaluating survival, response rates and tolerability.

METHODS

This was a retrospective analysis of a prospectively maintained database. Patients from 2012 to 2015 referred to a busy regional Hepato-Pancreatic Biliary (HPB) MDT were included. Patients were classified according to respectability criteria (utilising NCCN guidelines) and a treatment plan agreed. Systemic therapy with either FOLFIRINOX or Gem/Cap was delivered followed by chemoradiotherapy if disease remained localised. Toxicity, response, pathological outcomes and survival were all recorded.

RESULTS

A total of 85 patients were included in the study: 45 had initially resectable disease; 19 required a response for resection and 21 had locally advanced inoperable disease; 34 patients underwent resection. The median survival for the potentially resectable group was 22.2 months while for those undergoing resection it was 37 months.

CONCLUSIONS

We have demonstrated that a neoadjuvant approach is deliverable and tolerable. In addition we have demonstrated impressive survival results in patients undergoing resection with no detriment in outcome for those not proceeding to surgery.

Impact of Intraoperative Re-resection to Achieve R0 Status on Survival in Patients With Pancreatic Cancer: A Single-center Experience With 483 Patients

OBJECTIVE

The aim of this study was to test the hypothesis that intraoperative frozen section (FS) and re-resection results to achieve R0 status are associated with different long-term outcomes in pancreatic cancer patients.

BACKGROUND

Recent data have challenged the survival benefit of additional resection in patients with pancreatic cancer in case of positive FS to achieve clear pathological section (PS).

METHODS

Patients who underwent surgery for exocrine pancreatic malignancy with curative intent were identified from a prospective database. Data were stratified by resection margin (group I: FS-R0 → PS-R0; group II: FS-R1 → PS-R0; group III: FS-R1 → PS-R1). Associations with survival were analyzed by univariate and multivariate analyses.

RESULTS

A total of 483 patients met the inclusion criteria. Of these, 61 patients were excluded due to R2 or Rx status. Three hundred seventeen (75%) patients were allocated to margin group I, 32 (8%) to group II, and 73 (17%) to group III. Median overall survival in group I, II, and III was 29, 36, and 12 months (P < 0.001). There was no significant difference in survival between patients in Group I and II (P = 0.849), whereas patients in group III had significantly poorer outcome than group I (P < 0.001) and II (P = 0.039). The prognostic value of margin group status was confirmed on multivariate analysis (hazard ratio = 1.694, 95% confidence interval 1.175-2.442).

CONCLUSIONS

FS analysis with intraoperative re-resection should be performed routinely in patients undergoing pancreatic cancer surgery with the aim to achieve a R0 resection.

Pancreatic Cancer Surgery: The New R-status Counts

OBJECTIVE

To assess the relevance of resection margin status for survival outcome after resection and adjuvant therapy for pancreatic cancer.

BACKGROUND

The definitions for R0 and R1 margin status after resection for pancreatic cancer are controversial. The strict definition of R0 requiring a 1 mm tumor-free margin is not commonly accepted. Reported R0/R1 rates and associated survival are highly heterogeneous.

METHODS

A standardized protocol with rigorous assessment of circumferential margins and the R0 definition with a 1 mm free margin were introduced into clinical routine in 2005. From a prospective database, patients undergoing pancreatoduodenectomy for pancreatic adenocarcinoma between January 1, 2006 and December 12, 2012 were identified. The rates of R0 (≥1 mm margin), R1 (<1 mm clearance), and R1 (direct margin involvement) status and associated survival were assessed by uni- and multivariable analyses.

RESULTS

Of 561 patients included, 112 patients (20.0%) had R0 and 449 patients (80.0%) had R1 resections, including 123 (21.9%) R1 (≤1 mm) and 326 (58.1%) R1 (direct) resections. A total of 438 (85.9%) received adjuvant therapy. With R0, R1 (<1 mm), and R1 (direct) status the median survival times and 5-year survival rates were 41.6, 27.5, and 23.4 months; and 37.7%, 30.1%, and 20.3%, respectively (P < 0.0001). By multivariable analysis, margin status was confirmed to be independently associated with survival.

CONCLUSIONS

In the context of adjuvant therapy, the resection margin status remains an important independent determinant of postresection survival. R0/R1 resection rates and associated survival vary significantly with the definitions used. An international consensus is urgently needed to achieve comparability with respect to studies and protocols on patients with adjuvant therapy.

Actual long-term outcome of T1 and T2 pancreatic ductal adenocarcinoma after surgical resection

BACKGROUND

The prognosis for patients with pancreatic cancer is extremely poor. The diagnosis of pancreatic ductal adenocarcinoma at an early stage is uncommon. The purpose of this study was to analyze the clinicopathological characteristics of patients with pathologically proven pancreatic ductal adenocarcinoma following surgical resection and their actual 5 year survival rates, especially for those with T1 and T2 early stage cancer.

METHODS

Retrospective analysis was performed for 433 patients with pancreatic ductal adenocarcinoma who underwent resection at Samsung medical center between May 1995 and December 2010. The actual 5 year survival rates and prognostic factors were analyzed.

RESULTS

Multivariate analysis showed that positive resection margin, poor differentiation, large tumor size, large amount of blood loss, and T3/T4 were independent prognostic factors on overall survival. The median survival for T1/T2 stage was 71.7 months compared to 16.1 months for those with T3/T4 stage. The actual 5 year survival rates for T1/T2 and T3/T4 stages were 66.7% and 18.4%, respectively.

CONCLUSIONS

T stage is one of the strongest independent prognostic factor for overall survival of patients with pancreatic cancer. T1/T2 pancreatic ductal adenocarcinoma showed good survival outcome. Therefore, additional efforts are needed to improve the screening for early detection.

[Robot-assisted pancreatic resection]

Although robot-assisted pancreatic surgery has been considered critically in the past, it is nowadays an established standard technique in some centers, for distal pancreatectomy and pancreatic head resection. Compared with the laparoscopic approach, the use of robot-assisted surgery seems to be advantageous for acquiring the skills for pancreatic, bile duct and vascular anastomoses during pancreatic head resection and total pancreatectomy. On the other hand, the use of the robot is associated with increased costs and only highly effective and professional robotic programs in centers for pancreatic surgery will achieve top surgical and oncological quality, acceptable operation times and a reduction in duration of hospital stay. Moreover, new technologies, such as intraoperative fluorescence guidance and augmented reality will define additional indications for robot-assisted pancreatic surgery.

Multimodal treatment of resectable pancreatic ductal adenocarcinoma

After a timing preoperative staging, treatment of resectable pancreatic adenocarcinoma (PDAC) includes surgery and adjuvant therapies, the former representing the initial therapeutic option and the latter aiming to reduce the incidence of both distant metastases (chemotherapy) and locoregional failures (chemoradiotherapy). Herein, we provide a critical overview on the role of multimodal treatment in PDAC and on new opportunities related to current more active poli-chemotherapy regimens, targeted therapies, and the more recent immunotherapy approaches. Moreover, an analysis of pathological markers and clinical features able to help clinicians in the selection of the best therapeutic strategy will be discussed. Lastly, the role of neoadjuvant treatment of initially resectable disease will be considered mostly in patients whose malignancy shows morphological but not clinical or biological criteria of resectability. Depending on the results of these investigational studies, today a multidisciplinary approach can offer the best address therapy for these patients.

The impact of margin status determined by the one-millimeter rule on tumor recurrence and survival following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma

PURPOSE

The tumor-node-metastasis (TNM) classification defines R1 as the presence of tumor cells at the resection margin, while the current Royal College of Pathologists guidelines for pancreaticoduodenectomy specimens regard the presence of tumor cells within 1 mm from the resection margin as R1 (the "1-mm rule"). The aims of this study were to investigate the resection margin status of pancreatic head cancer retrospectively according to both the TNM and 1-mm rule classifications, and to evaluate the postoperative survival and tumor recurrence patterns.

METHODS

A total of 117 patients with pancreatic head cancer were the subjects of this study.

RESULTS

R1^{1-mm rule} resection was associated with a significantly worse disease-free survival (DFS) than R0^{1-mm rule} resection (p = 0.0259), while R1^TNM had no impact on DFS. R1^{1-mm rule} resection margin status correlated with the incidence of tumor recurrence in the liver (p = 0.0483). In a multivariate analysis, R1^{1-mm rule} resection was the independent variable for predicting poor DFS (hazard ratio 1.71; p = 0.0289).

CONCLUSIONS

R1 resection margin status determined by the 1-mm rule may be an independent indicator for predicting disease recurrence, especially liver metastasis. These results may be useful for selecting the appropriate adjuvant therapy protocol and conducting strict surveillance in PDAC patients.

Impact of Resection Margin Distance on Survival of Pancreatic Cancer: A Systematic Review and Meta-Analysis

Purpose

While curative resection is the only chance of cure in pancreatic cancer, controversies exist about the impact of surgical margin status on survival. Non-standardized pathologic report and different criteria on the R1 status made it difficult to implicate adjuvant therapy after resection based on the margin status. We evaluated the influence of resection margins on survival by meta-analysis.

Materials and Methods

We thoroughly searched electronic databases of PubMed, EMBASE, and Cochrane Library. We included studies reporting survival outcomes with different margin status: involved margin (R0 mm), margin clearance with ≤ 1 mm (R0-1 mm), and margin with > 1 mm (R>1 mm). Hazard ratio (HR) for overall survival was extracted, and a random-effects model was used for pooled analysis.

Results

A total of eight retrospective studies involving 1,932 patients were included. Pooled HR for overall survival showed that patients with R>1 mm had reduced risk of death than those with R0-1 mm (HR, 0.74; 95% confidence interval [CI], 0.61 to 0.88; p=0.001). In addition, patients with R0-1 mm had reduced risk of death than those with R0 mm (HR, 0.81; 95% CI, 0.72 to 0.91; p < 0.001). There was no heterogeneity between the included studies (I² index, 42% and 0%; p=0.10 and p=0.82, respectively).

Conclusion

Our results suggest that stratification of the patients based on margin status is warranted in the clinical trials assessing the role of adjuvant treatment for pancreatic cancer.

Redefining the R1 resection in patients with pancreatic ductal adenocarcinoma

Most cases of pancreatic ductal adenocarcinoma (PDAC) are lethal. Margin-negative surgical resection is a mainstay of treatment and the only chance of a cure. Differences in pathological reporting, surgical technique, definitions of resection margin, and group stratification all affect outcome analyses. Furthermore, there are controversial issues influencing the clinical interpretation of resection margin after pancreatectomy. There is no standardized definition of margin involvement in resected specimens of PDAC. The non-standardized pathologic approach explains the wide range of positive resection margin rates (13-71%) that have previously been reported. A standardized pathologic evaluation needs to be developed for proper assessment of resection margin after oncologic pancreatectomy. This manuscript reviews the current controversial issues in assessing resection margin in order to enhance understanding of the current status and potential role of pathological evaluation in patients with PDAC.

Re-evaluation of classical prognostic factors in resectable ductal adenocarcinoma of the pancreas

Pancreatic ductal adenocarcinoma carries a poor prognosis with annual deaths almost matching the reported incidence rates. Surgical resection offers the only potential cure. Yet, even among patients that undergo tumor resection, recurrence rates are high and long-term survival is scarce. Various tumor-related factors have been identified as predictors of survival after potentially curative resection. These factors include tumor size, lymph node disease, tumor grade, vascular invasion, perineural invasion and surgical resection margin. This article will re-evaluate the importance of these factors based on recent publications on the topic, with potential implications for treatment and outcome in patients with pancreatic cancer.