Frozen section of the pancreatic neck margin in pancreatoduodenectomy for pancreatic adenocarcinoma is of limited utility

To Revise or Not Revise? Isolated Margin Positivity in Localized Pancreatic Ductal Adenocarcinoma

BACKGROUND

The study determined the proportion of patients with pancreatic adenocarcinoma (PDAC) who had margin-positive disease and no other adverse pathologic findings (APF) using institutional and administrative datasets.

METHODS

Patients with clinical stage I or II PDAC in the National Cancer Database (NCDB 2010-2020) and those who underwent pancreatectomy at the authors' institution (2010-2021) were identified. Isolated margin positivity (IMP) was defined as a positive surgical margin with no APF (negative nodes, no lymphovascular/perineural invasion).

RESULTS

The study included 225 patients from the authors' institution and 23,598 patients from the NCDB. The margin-positive rates were 21.8% and 20.3%, and the IMP rates were 0.4% and 0.5%, respectively. In the institutional cohort, 68.4% of the patients had recurrence, and most of the patients (65.6%) had distant recurrences. The median recurrence-free survival (RFS) was 63.3 months for no APF, not reached for IMP, 14.8 months for negative margins & 1 APF, 20.3 months for positive margins & 2 APFs, and 12.9 months with all APF positive. The patients in the NCDB with IMP had a lower median OS than the patients with no APF (20.5 vs 390 months), but a higher median OS than those with margin positivity plus 1 APF (20.5 vs 18.0 months) or all those with APF positivity (20.5 vs 15.4 months). Based on institutional rates of IMP, any margin positivity, neck margin positivity (NMP), and no APF, the fraction of patients who might benefit from neck margin revision was 1 in 100,000, and those likely to benefit from any margin revision was 1 in 18,500. In the NCDB, those estimated to derive potential benefit from margin revision was 1 in 25,000.

CONCLUSIONS

Isolated margin positivity in resected PDAC is rare, and most patients experience distant recurrence. Revision of IMP appears unlikely to confer benefit to most patients.

Systematic review of challenging issues in pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are a cystic precursor to pancreatic cancer. IPMNs deemed clinically to be at high-risk for malignant progression are frequently treated with surgical resection, and pathological examination of the pancreatectomy specimen is a key component of the clinical care of IPMN patients.

METHODS

Systematic literature reviews were conducted around eight topics of clinical relevance in the examination of pathological specimens in patients undergoing resection of IPMN.

RESULTS

This review provides updated perspectives on morphological subtyping of IPMNs, classification of intraductal oncocytic papillary neoplasms, nomenclature for high-grade dysplasia, assessment of T stage, distinction of carcinoma associated or concomitant with IPMN, role of molecular assessment of IPMN tissue, role of intraoperative assessment by frozen section, and preoperative evaluation of cyst fluid cytology.

CONCLUSIONS

This analysis provides the foundation for data-driven approaches to several challenging issues in the pathology of IPMNs.

Utility of intraoperative pathology consultations of whipple resection specimens and their impact on final margin status

The resection margin status is a significant surgical prognostic factor for the long-term outcomes of patients undergoing pancreaticoduodenectomy (Whipple procedure). As a result, surgeons frequently rely on intraoperative consults (IOCs) involving frozen sections to evaluate margin clearance during these resections. Nevertheless, the impact of this practice on final margin status and long-term outcomes remains a topic of debate. This study aimed to assess the impact of IOCs on the clearance rate of resection margins following Whipple procedure and distal pancreatectomy. A retrospective database review of all patients who underwent Whipple procedure or distal pancreatectomy at our institution between 2018 and 2020 was performed to evaluate the utility of IOCs by gastrointestinal surgeons and its correlation with final postoperative surgical margin status. A significant variation in the frequency of IOC requests for margins among surgeons was noted. However, the use of frozen section analysis for intraoperative margin assessment was not significantly associated with the clearance rate of final post-operative margins. More frequent use of IOC did not result in higher final margin clearance rate, an important prognostic factor following Whipple procedure.

Resection margin status at the portomesenteric axis may not determine oncologic outcome after pancreaticoduodenectomy for lymph node-positive pancreatic ductal adenocarcinoma

BACKGROUND

Lymph node and resection margin status are associated with oncologic outcomes after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. However, surgical radicality at the portomesenteric axis in case of suspected infiltration remains controversial.

METHODS

Clinicopathological data of patients who underwent a partial or total pancreaticoduodenectomy for PDAC between 2012 to 2019 in 2 major hepato-pancreato-biliary centers in Germany and Switzerland were assessed. We evaluated the impact of positive resection margins at the vascular, parenchymal, and retropancreatic surfaces on overall survival in patients with and without lymph node involvement. Margin-positive vascular resection included both patients with positive margins at the vascular groove and the resected venous wall.

RESULTS

During the study period, 217 patients underwent partial/total pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. After excluding 7 patients suffering postoperative complications resulting in mortality within 90 days after surgery (3%), 169 patients had lymph node involvement (80%). In the entire study cohort, margin-positive resection (33%) was significantly associated with worse overall survival (3-year overall survival: margin-positive resection: 27% vs margin-negative resection: 43%, P = .014). Among patients with positive lymph nodes, margin-positive vascular resection (n = 48, 28%) was not significantly associated with impaired overall survival (3-year overall survival: margin-positive vascular resection: 28% vs margin-negative vascular resection: 36%, P = .065). On the contrary, margin-positive parenchymal resection (n = 7, 4%) (3-year overall survival: margin-positive parenchymal resection: 0% vs margin-negative parenchymal resection: 35%, P < .0001) and margin-positive retropancreatic resection (n = 21, 12%) (3-year overall survival: margin-positive retropancreatic resection: 6% vs margin-negative retropancreatic resection: 39%, P < .0001) significantly diminished overall survival in univariate and multivariate analysis in all patients. Among patients without lymph node involvement (n = 41, 20%), there were no margin-positive parenchymal or margin-positive retropancreatic resections. In contrast, only 5 patients had margin-positive vascular resection (12%), with overall survival compared to those with margin-negative vascular resection.

CONCLUSIONS

In patients with pancreatic ductal adenocarcinoma and lymph nodal positivity, resection status at the parenchymal and retropancreatic surface but probably not at the portal and/or superior mesenteric vein is a determinant of survival. Therefore, margin-negative resection should be pursued during pancreaticoduodenectomy. However, radical venous resection and/or reconstruction for suspected tumor infiltration may not be necessary for patients with intraoperatively detected lymph node metastases.

Assessment of Quality of Frozen Section Services at a Large Academic Hospital Before and After Relocation

OBJECTIVES

To determine outcomes following relocation of frozen section services (FSS) and the implementation of a dedicated gastrointestinal frozen service.

METHODS

We reviewed our FSS 6 months prior to and following FSS relocation. Satisfaction surveys were sent to surgeons and pathologists. Survey feedback resulted in a pilot of gastrointestinal subspecialist frozen section coverage.

RESULTS

There were 1,607 and 1,472 specimens from 667 and 602 patients pre- and post-FSS relocation, respectively. There was a decline in median specimen delivery time to pathology (12 vs 10 minutes, P < .001) and an increase in median time from receipt in pathology to intraoperative diagnosis (20 vs 22 minutes, P = .008) in cases with intrapathology consultation but no change without consultation (median, 19 minutes). Intrapathology consultation decreased from 19.7% (317/1,607) to 11.5% (169/1,472) (P < .001). Discordance rates between frozen section and permanent section remained low and similar (2.0% [33/1,607] vs 2.7% [40/1,472], P = .24). There was no significant change in discordance with dedicated gastrointestinal subspecialty frozen section interpretation.

CONCLUSIONS

Relocation of FSS and dedicated subspecialty interpretation may improve surgeon satisfaction but can also create workflow challenges. Pathology departments need to achieve a balance between satisfaction and adequacy to establish best frozen section coverage models.

[Better Therapy for Pancreatic Cancer through More Radical Surgery?]

Despite advances in the treatment of pancreatic cancer, the survival of affected patients remains limited. A more radical surgical therapy could help to improve the prognosis, in particular by reducing the local recurrence rate, which is around 45% in patients with resected pancreatic cancer. In addition, patients with oligometastatic pancreatic cancer could also benefit from a more radical indication for surgery.Based on an analysis of the literature, important principles of pancreatic cancer surgery were examined.Even if even more radical surgical approaches such as an "extended" lymphadenectomy or a standard complete pancreatectomy do not bring any survival advantage, complete resection of the tumour (R0), a thorough locoregional lymphadenectomy and an adequate radical dissection in the area of the peripancreatic vessels including periarterial nerve plexuses should be the standard of pancreatic carcinoma resections. Whenever necessary to achieve an R0 resection, resections of the pancreas have to be extended, as well as additional venous vascular resections and multivisceral resections had to be performed. Simultaneous arterial vascular resections as part of pancreatic resections as well as surgical resections in oligometastatic patients should, however, be reserved for selected patients. These aspects of the surgical technique in pancreatic carcinoma mentioned above must not be neglected from the point of view of an "existing limited prognosis". On the contrary, they form the absolutely necessary basis in order to achieve good survival results in combination with system therapy. However, it may always be necessary to adapt these standards according to the age, comorbidities and wishes of the patient.

Korean Surgical Practice Guideline for Pancreatic Cancer 2021: A summary of evidence-based surgical approaches

Pancreatic cancer is the eighth most common cancer and the fifth most common cause of cancer-related deaths in Korea. Despite the increasing incidence and high mortality rate of pancreatic cancer, there are no appropriate surgical practice guidelines for the current domestic medical situation. To enable standardization of management and facilitate improvements in surgical outcome, a total of 10 pancreatic surgical experts who are members of Korean Association of Hepato-Biliary-Pancreatic Surgery have developed new recommendations that integrate the most up-to-date, evidence-based research findings and expert opinions. This is an English version of the Korean Surgical Practice Guideline for Pancreatic Cancer 2021. This guideline includes 13 surgical questions and 15 statements. Due to the lack of high-level evidence, strong recommendation is almost impossible. However, we believe that this guideline will help surgeons understand the current status of evidence and suggest what to investigate further to establish more solid recommendations in the future.

Revision of Pancreatic Neck Margins Based on Intraoperative Frozen Section Analysis Is Associated With Improved Survival in Patients Undergoing Pancreatectomy for Ductal Adenocarcinoma

OBJECTIVE

To test the hypothesis that complete, tumor-free resection at the pancreatic neck, achieved either en-bloc or non-en-bloc (ie, revision based on intraoperative frozen section [FS] analysis), is associated with improved survival as compared with incomplete resection (IR) in pancreatic ductal adenocarcinoma.

SUMMARY BACKGROUND DATA

Given the likely systemic nature of pancreatic ductal adenocarcinoma, the oncologic benefit of achieving a histologically complete local resection, particularly through revision of a positive intraoperative FS at the pancreatic neck, remains controversial.

METHODS

Clinicopathologic and treatment data were reviewed for 986 consecutive patients with ductal adenocarcinoma at the head, neck, or uncinate process of the pancreas who underwent open pancreatectomy as well as intraoperative FS analysis between 1998 and 2012 at Massachusetts General Hospital and between 1998 and 2013 at the University of Verona. Overall survival (OS) and perioperative morbidity and mortality were compared across 3 groups: complete resection achieved en-bloc (CR-EB), complete resection achieved non-en-bloc (CR-NEB), and IR.

RESULTS

The CR-EB cohort comprised 749 (76%) patients, CR-NEB 159 patients (16%), and IR 78 patients (8%). Other than a higher incidence of vascular resection among CR-NEB and IR patients, no demographic, pathologic (eg, tumor grade, lymph node positivity, superior mesenteric artery involvement), or treatment factors (eg, neoadjuvant and adjuvant therapy use) differed between the groups. Median OS was significantly higher in patients with CR-EB (28 mo, P = 0.01) and CR-NEB resections (24 mo, P = 0.02) as compared with patients with IR resections (19 mo). After adjusting for clinicopathologic and treatment characteristics, CR-EB and CR-NEB margin status were found to be independent predictors of improved OS (relative to IR, CR-EB hazard ratio [HR] 0.65, 95% confidence interval [CI] 0.49-0.86; CR-NEB HR 0.69, 95% CI 0.50-0.96). There were no intergroup differences in perioperative morbidity and mortality, including rates of pancreatic fistula.

CONCLUSIONS

For patients with ductal adenocarcinoma at the head, neck, or uncinate process of the pancreas undergoing pancreatectomy, complete tumor extirpation via either en-bloc or non-en-bloc complete resection based on FS analysis is associated with improved OS, without an associated increased perioperative morbidity or mortality.

Indications to total pancreatectomy for positive neck margin after partial pancreatectomy: a review of a slippery ground

The extension of a partial pancreatectomy up to total pancreatectomy because of positive neck margin examined at intraoperative frozen section (IFS) analysis is an accepted procedure in modern pancreatic surgery with good accuracy. The goal of this practice is to improve the rate of radical (R0) resection in malignant tumors, mainly pancreatic ductal adenocarcinoma (PDAC), and to completely resect pre-invasive neoplasms such as intraductal papillary mucinous neoplasms (IPMNs). In the setting of IPMNs there is a consensus for pancreatic re-resection when high-grade dysplasia and invasive cancer are present at the neck margin. The presence of denudation is another indication for further resection in IPMNs. The role of IFS analysis in the management of pancreatic cancer is more debated. The presence of a positive intraoperative transection margin can be considered the surrogate of a biologically aggressive disease associated with a poorer prognosis. There are conflicting data regarding possible advantages of pancreatic re-resection up to total pancreatectomy, and the lack of randomized trials comparing different strategies does not offer a definitive answer. The goal of this review is to provide an up-to-date overview of the role IFS analysis of pancreatic margin and of pancreatic re-resection up to total pancreatectomy considering different pancreatic tumors.

The Impact of Intraoperative Frozen Section on Resection Margin Status and Survival of Patients Underwent Pancreatoduodenectomy for Distal Cholangiocarcinoma

Background

Intraoperative frozen section (FS) is broadly used during pancreaticoduodenectomy (PD) to ensure a negative margin status, but its survival benefits on obtaining a secondary R0 resection for distal cholangiocarcinoma (dCCA) is controversial and unclear.

Methods

Clinical data of 107 patients who underwent PD for dCCA was retrospectively collected and divided into different groups based on use of FS (FS and non-FS groups) and status of resection margin (pR0, sR0 and R1 groups), and clinical parameters and survival of patients were compared and analyzed accordingly.

Results

There were 50 patients in FS group with a median survival of 28 months, 57 patients in non-FS group with a median survival of 27 months. There was no statistical difference between the two groups with Kaplan-Meier survival analysis (P = 0.347). There were 98 patients in R0 group (88 in pR0 and 10 in sR0) and nine patients in R1 group, with a median survival of 29 months and 22 months respectively, which showed a better survival in R0 group than in R1 group (P = 0.006). Survival analyses between subgroups revealed difference between pR0 and R1 group (P = 0.005), while no statistical difference concerning pR0 vs. sR0 (P = 0.211) and sR0 vs. R1 groups (P = 0.262). Multivariate Cox regression analysis revealed resection margin status, pre-operative biliary drainage and lymph node invasion to be independent prognostic factors for dCCA patients.

Conclusions

Intraoperative FS should be recommended as it significantly increased the rate of R0 resection, which was positively related to a better survival. A primary R0 resection should also be encouraged and if not, a secondary R0 could be considered at the discretion of surgeons as it showed similar survival with primary R0 resection.

A Critical Assessment of Postneoadjuvant Therapy Pancreatic Cancer Regression Grading Schemes With a Proposal for a Novel Approach

Currently, there is no consensus on the optimal tumor response score (TRS) system to assess regression in pancreatic cancers resected after neoadjuvant therapy. We developed a novel TRS (Royal North Shore [RNS] system) based on estimating the percentage of tumor bed occupied by viable cancer and categorized into 3 tiers: grade 1 (≤10%), grade 2 (11% to 75%), and grade 3 (>75%). We assessed 147 resected carcinomas with this and other TRS systems (College of American Pathologists [CAP], MD Anderson Cancer Center [MDACC], and Evans). The 3-tiered RNS system predicted median survival after surgery for grades 1, 2, and 3 of 54, 23, and 9 months, respectively (P<0.05). The CAP, MDACC, and Evans systems also predicted survival (P<0.05) but less consistently. The median survival for MDACC and CAP grade 0 (complete regression) was less than MDACC grade 1 and CAP grades 1 and 2. There was no difference in survival between CAP grades 2 and 3 (P=0.960), Evans grades 1 and 2a (P=0.395), and Evans grades 2a and 2b (P=0.587). Interobserver concordance was weak for CAP (κ=0.431), moderate for MDACC (κ=0.691), minimal for Evans (κ=0.307), and moderate to strong for RNS (κ=0.632 to 0.84). Of age, sex, size, stage, grade, perineural and vascular invasion, extrapancreatic extension, margin status, and RNS score, only RNS score, vascular invasion, and extrapancreatic extension predicted survival in univariate analysis. Only extrapancreatic extension (P=0.034) and RNS score (P<0.0001) remained significant in multivariate analysis. We conclude that the RNS system is a reproducible and powerful predictor of survival after resection for pancreatic cancers treated with neoadjuvant therapy and should be investigated in larger cohorts.

Pancreatic Frozen Section Guides Operative Management With Few Deferrals and Errors

CONTEXT.—

Pancreatic adenocarcinoma is the third leading cause of cancer death in the United States. Surgery remains the mainstay of treatment, and frozen section analysis is used to confirm diagnosis and determine resectability and margin status.

OBJECTIVE.—

To evaluate use and accuracy of frozen section and how diagnosis impacts surgical procedure.

DESIGN.—

We reviewed patients with planned pancreatic resections between January 2014 and March 2019 with at least 1 frozen section. Pathology reports including frozen sections, preoperative cytology, and operative notes were reviewed. Frozen sections were categorized by margin, primary pancreatic diagnosis, metastasis, or vascular resectability. The deferral and error rates and surgeons' response were noted.

RESULTS.—

We identified 898 planned pancreatic resections and 221 frozen sections that were performed on 152 cases for 102 margins, 94 metastatic lesions, 20 primary diagnoses, and 5 to confirm vascular resectability. The diagnosis was deferred to permanent sections in 13 of 152 cases (8.6%) on 16 of 221 frozen sections (7.2%): 6 for metastasis, 8 for margins, and 2 for primary diagnosis. Discrepancies/errors were identified in 4 of 152 cases (2.6%) and 4 of 221 frozen sections (1.8%). Surgeon's response was different than expected in 8 of 221 frozen sections (3.6%), but their actions were explained by other intraoperative findings in 6 of 8.

CONCLUSIONS.—

Frozen section remains an important diagnostic tool used primarily for evaluation of margins and metastasis during pancreatectomy. In most cases, a definitive diagnosis is rendered, with occasional deferrals and few errors. Intraoperative findings explain most cases where surgeons act differently than expected based on frozen section diagnosis.

Is the Use of Intraoperative Frozen Section During Pancreaticoduodenectomy Justified?

BACKGROUND

Intraoperative frozen section (IFS) is routinely utilized by many surgeons during pancreaticoduodenectomy. However, its utility has not been rigorously studied.

METHODS

Patients who underwent pancreaticoduodenectomy between 2006 and 2015 were identified from institutional data. Measures of diagnostic accuracy of frozen section and multivariate logistic regression are reported.

RESULTS

The cohort included 1076 patients. Of resected specimens, 73.3% were malignant. IFS and final pathologic review (the gold standard) were discrepant for (1) pathologic diagnosis or (2) resection margin status in 5.3% and 3.3% of cases. The sensitivity, specificity, and accuracy of IFS for histologic determination of malignancy were 97.2%, 95.3%, and 96.7% respectively. For resection margins, they were 92.3%, 99.3%, and 96.8%, respectively. Positive bile duct and neck margins were revised intraoperatively 62% and 65% of the time, respectively; positive uncinate margins were never resected but led surgeons to avoid revision of a second positive margin in 13% of cases (4.2% of all PDA). Operative changes were rarely noted in the presence of benign disease (n = 11, 1.0%); conversion to total pancreatectomy based on positive margins was performed in just 13 cases (1.2%). Upon multivariable analysis, a positive neck margin proved to be the greatest predictor for a revised resection margin (AOR 16.9 [4.8-59.8]), whereas a positive uncinate margin or a diagnosis of chronic pancreatitis was protective against IFS-driven operative changes (AOR 0.25 [0.09-0.73]; AOR 0.16 [0.13-0.19]).

CONCLUSIONS

IFS is highly accurate and guides reresection of margins. However, selective omission of IFS may be justified for cases where benign disease is suspected.

Improved survival after pancreatic re-resection of positive neck margin in pancreatic cancer patients. A systematic review and network meta-analysis

The oncological benefit of achieving a negative pancreatic neck margin through re-resection after a positive frozen section (FS) is debated. Aim of this network meta-analysis is to evaluate the survival benefit of re-resection after intraoperative FS neck margin examination following pancreatectomy for ductal adenocarcinoma. A systematic search of studies comparing different strategies for the management of positive FS was performed. Patients were classified in three groups based on FS and permanent section (PS): Group A (FS-, PS-R0), Group B (FS+, PS-R0), Group C (FS±, PS-R1). A frequent random-effects network-meta-analysis was made reporting the surface under the cumulative ranking (SUCRA). Primary endpoint was overall survival (OS). Secondary endpoints were pathological outcomes. Seven retrospectives studies with 4205 patients were included and 99.1% of the pancreatic resections were pancreatoduodenectomies. Group A had the highest probability of better OS (SUCRA = 90%), compared to Group B (SUCRA = 48.7%) and Group C, which was the worst prognostic scenario (SUCRA = 11.3%). Group B had still a probability of longer OS compared to Group C (SUCRA = 48.7% vs 11.3%). Pathological features were more favourable in Group A, with the highest SUCRA for T1-T2 tumors (92.6%), N0 status (89.4%), absence of perineural invasion (92.3%). Heterogeneity was low (τ-value <0.1) for OS, and moderate (τ-values: 0.1-0.6) for pT, pN, and perineural invasion. In conclusion, negative neck margin after primary resection (FS negative) or re-resection of a positive FS was associated with improved survival compared with PS-R1. However, any intraoperative positive FS can be considered as a prognostic factor associated with a more aggressive disease.

Detailed Analysis of Margin Positivity and the Site of Local Recurrence After Pancreaticoduodenectomy

BACKGROUND

The association between a positive surgical margin and local recurrence after resection of pancreatic adenocarcinoma (PDAC) has been reported. Assessment of the location of the a positive margin and the specific site of local recurrence has not been well described.

METHODS

A prospectively maintained database was queried for patients who underwent R0/R1 pancreaticoduodenectomy for PDAC between 2000 and 2015. The pancreatic, posterior, gastric/duodenal, anterior peritoneal, and bile duct margins were routinely assessed. Postoperative imaging was reviewed for the site of first recurrence, and local recurrence was defined as recurrence located in the remnant pancreas, surgical bed, or retroperitoneal site outside the surgical bed.

RESULTS

During the study period, 891 patients underwent pancreaticoduodenectomy, and 390 patients had an initial local recurrence with or without distant metastases. The 5-year cumulative incidence of local recurrence by site included the remnant pancreas (4%; 95% confidence interval [CI], 3-5%), the surgical bed (35%; 95% CI, 32-39%), and other regional retroperitoneal site (4%; 95% CI, 3-6%). In the univariate analysis, positive posterior margin (hazard ratio [HR], 1.50; 95% CI, 1.17-1.91; p = 0.001) and positive lymph nodes (HR, 1.36; 95% CI, 1.06-1.75; p = 0.017) were associated with surgical bed recurrence, and in the multivariate analysis, positive posterior margin remained significant (HR, 1.40; 95% CI, 1.09-1.81; p = 0.009). An isolated local recurrence was found in 197 patients, and a positive posterior margin was associated with surgical bed recurrence in this subgroup (HR, 1.51; 95% CI, 1.08-2.10; p = 0.016).

CONCLUSION

In this study, the primary association between site of margin positivity and site of local recurrence was between the posterior margin and surgical bed recurrence. Given this association and the limited ability to modify this margin intraoperatively, preoperative assessment should be emphasized.

Impact of intraoperative margin clearance on survival following pancreatoduodenectomy for pancreatic cancer: a systematic review and meta-analysis

The use of intraoperative margin revision to achieve margin clearance in patients undergoing pancreatoduodenectomy for pancreatic cancer is controversial. We performed a systematic review and meta-analysis to summarize the evidence of intraoperative margin revisions of the pancreatic neck and its impact on overall survival (OS). Nine studies with 4501 patients were included. Patient cohort was stratified in an R0R0-group (negative margin on frozen and permanent section), R1R0-group (revised positive margin on frozen section which turned negative on permanent section), and R1R1-group (positive margin on frozen and permanent section despite margin revision). OS was higher in the R1R0-group (HR 0.83, 95% CI 0.72-0.96, P = 0.01) compared to the R1R1-group but lower compared to the R0R0-group (HR 1.20; 95% CI 1.05-1.37, P = 0.008), respectively. Subgroup analyses on the use of different margin clearance definitions confirmed an OS benefit in the R1R0-group compared to the R1R1-group (HR 0.81; 95% CI 0.65-0.99, P = 0.04). In conclusion, intraoperative margin clearance of the pancreatic neck margin is associated with improved OS while residual tumor indicates aggressive tumor biology. Consensus definitions on margin terminologies, clearance, and surgical techniques are required.

Margin-Positive Pancreatic Ductal Adenocarcinoma during Pancreaticoduodenectomy: Additional Resection Does Not Improve Survival

BACKGROUND

The impact of resecting positive margins during pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDA) remains debated. Additionally, the survival benefit of resecting multiple positive margins is unknown.

METHODS

We identified patients with PDA who underwent PD from 2006 to 2015. Pancreatic neck, bile duct, and uncinate frozen section margins were assessed before and after resection of positive margins. Survival curves were compared with log-rank tests. Multivariable Cox regression assessed the effect of margin status on overall survival.

RESULTS

Of 501 patients identified, 17.3%, 5.3%, and 19.7% had an initially positive uncinate, bile duct, or neck margin, respectively. Among initially positive bile duct and neck margins, 77.8% and 67.0% were resected, respectively. Although median survival was decreased among patients with any positive margins (15.6 vs. 20.9 months; p = 0.006), it was similar among patients with positive bile duct or neck margins with or without R1 to R0 resection (17.0 vs. 15.6 months; p = 0.20). Median survival with and without positive uncinate margins was 13.8 vs. 19.7 months (p = 0.04). Uncinate margins were never resected. Resection of additional margins when the uncinate was concurrently positive was not associated with improved survival (p = 0.37). Patients with positive margins who received adjuvant therapy had improved survival, regardless of margin resection (p = 0.03). Adjuvant therapy was independently protective against death (hazard ratio 0.6, 95% CI 0.5-0.7).

CONCLUSIONS

Positive PD margins at any position are associated with reduced overall survival; however, resection of additional margins may not improve survival, particularly with concurrently positive uncinate margins. Adjuvant chemotherapy improves survival with positive margins, regardless of resection.

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.

Revision of Surgical Margin under Frozen Section to Achieve R0 Status on Survival in Patients with Pancreatic Cancer

OBJECTIVE

The aim is to investigate whether additional resection based on intraoperative frozen section (FS) to a secondary R0(s) status are associated with different long-term survivals in pancreatic cancer patients, comparing to those with R1 or primary R0(p) status.

METHODS

A systematic literature search (PubMed, Embase, Science Citation Index, Springer-Link, and Cochrane Central Register of Controlled Trials) was performed to identify all studies published up to June 2017. Survivals of patients undergoing pancreatic surgery according to the results of FS and re-resection were pooled for analysis.

RESULTS

Five cohort studies were qualified for inclusion in this review with a total of 2980 patients. Long-term survival outcomes favored R0(p) resection as compared to R0(s) resection (HR = 1.58, 95%CI 1.24-2.01, P = 0.0002, I² = 58%). No significant difference was observed for patients with or without additional resection at the time of surgery when positive FS was detected (HR = 0.98, 95CI% 0.65-1.47, P = 0.91, I² = 81%).

CONCLUSIONS

The present study did not support the concept of achieving an R0 resection by intraoperative re-resection would benefit the patient's survival. R1 margin at the time of surgery is more like a marker of aggressive tumor biology. Future well-designed randomized controlled trials are needed to confirm the conclusion.

Intra-Operative Frozen Section Histology of the Pancreatic Resection Margins and Clinical Outcome of Patients with Adenocarcinoma of the Head of the Pancreas Undergoing Pancreaticoduodenectomy

BACKGROUND The aim of this study was to compare the clinical outcome in patients with pancreatic ductal adenocarcinoma who underwent frozen section and paraffin section histology of the surgical resection margins during pancreaticoduodenectomy. MATERIAL AND METHODS Frozen section and routine paraffin section histopathology were performed using the following categories: R0 (no tumor cells at the surgical resection margin), R1 (tumor cells at, or within 1 mm, of the surgical resection margin), and R2 (tumor seen macroscopically at the surgical resection margin). R1 and R2 patients underwent additional resection to achieve R0. RESULTS Of 346 patients who underwent pancreaticoduodenectomy, frozen section histology showed positive resection margins in 22 patients (9.2%) and paraffin section histology was positive in 20 patients (8.4%). The OS was nine months in frozen section-positive patients and 20 months in frozen section-negative patients (p=0.001). The OS rates were significantly different between the paraffin section-positive and paraffin section-negative patients (11 months vs. 21 months) (p=0.001). Univariate and multivariate analysis showed that increased tumor size, high tumor grade, lymph node metastases, a positive superior mesenteric artery and retroperitoneal margin, and a positive resection margin on frozen section were significantly correlated with reduced OS (p<0.05). Twenty-two patients with positive resection margins on frozen section histology underwent further resection; R0 was achieved in 14 patients, with no significant difference in OS. CONCLUSIONS For patients who underwent pancreaticoduodenectomy for pancreatic carcinoma with positive resection margins on frozen section, further surgical resection to achieve R0 had no significant positive impact on OS.

Neoadjuvant therapy affects margins and margins affect all: perioperative and survival outcomes in resected pancreatic adenocarcinoma

BACKGROUND

Resection margin status is an important prognostic factor in pancreatic cancer; however, the impact of positive resection margins in those who received neoadjuvant therapy remains unclear. The current study investigates the prognostic impact of resection margin status after neoadjuvant therapy and pancreaticoduodenectomy for patients with pancreatic adenocarcinoma.

METHODS

Patients who underwent pancreaticoduodenectomy for pancreatic adenocarcinoma between 2006 and 2013 were identified from the National Cancer Database. Multivariable logistic regression analysis was utilized to examine the predictive value of neoadjuvant therapy for resection margin status. Long-term outcomes were compared using a Cox proportional hazards model.

RESULTS

7917 patients were identified in total: 1077 (13.6%) and 6840 (86.4%) patients received neoadjuvant therapy and upfront surgery, respectively. Upfront surgery was independently predictive of a positive margin (25.7% vs. 17.7%; OR, 1.54) compared to neoadjuvant therapy. After receipt of neoadjuvant therapy, positive margins (median overall survival, 18.5 vs. 25.9 months; HR, 1.58) remained significantly associated with poor survival on multivariable analysis.

DISCUSSION

While neoadjuvant therapy is associated with decreased R1/R2-resection rates after pancreaticoduodenectomy, the poor prognostic impact of positive margins is not abrogated by neoadjuvant therapy, stressing the need for complete tumor clearance and postoperative treatment even after neoadjuvant therapy.

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.

Does revision of resection margins based on frozen section improve overall survival following pancreatoduodenectomy for pancreatic ductal adenocarcinoma? A meta-analysis

BACKGROUND

Margin status is the main surgical determinant of long-term outcome in pancreatic cancer. Intraoperative frozen section (IOFS) detects microscopic positive margins at a stage when margin revision is possible. The aim of this study was to determine if IOFS driven-revision of pancreatic resection margin(s) improves overall survival (OS) in pancreatic cancer.

METHODS

A systematic review of major reference databases was undertaken. Patients were divided into 3 groups based on initial FS (FSR0 for negative margin and FSR1 for positive microscopic margin) and final Permanent Section report (PSR0 for negative margin and PSR1 for positive microscopic margin): Group 1 (FSR0 → PSR0), Group 2 (FSR1 → PSR0), and Group 3 (FSR1 → PSR1). Patients in Groups 2 and 3 had surgical revision of the FSR1 margin. Data was meta-analysed.

RESULTS

4 studies included in the final analysis. No difference in OS and incidence of lymph node metastases between Groups 2 and 3 (P = 0.590 and P = 0.410).

CONCLUSIONS

IOFS-based revision of R1 pancreatic resection margin does not improve OS, even when it results in an R0 margin. This suggests that any benefit of margin revision based on FS is over-ridden by markers of more advanced or aggressive disease.

The Impact of New Technologic and Molecular Advances in the Daily Practice of Gastrointestinal and Hepatobiliary Pathology

The practice of anatomic pathology, and of gastrointestinal pathology in particular, has been dramatically transformed in the past decade. In addition to the multitude of diseases, syndromes, and clinical entities encountered in daily clinical practice, the increasing integration of new technologic and molecular advances into the field of gastroenterology is occurring at a fast pace. Application of these advances has challenged pathologists to correlate newer methodologies with existing morphologic criteria, which in many instances still provide the gold standard for diagnosis. This review describes the impact of new technologic and molecular advances on the daily practice of gastrointestinal and hepatobiliary pathology. We discuss new drugs that can affect the gastrointestinal tract and liver, new endoluminal techniques, new molecular tests that are often performed reflexively, new imaging techniques for evaluating hepatocellular carcinoma, and modified approaches to the gross and histologic assessment of tissues that have been exposed to neoadjuvant therapies.

[Total pancreatectomy for pancreatic cancer]

AIM

to determine the indications and to evaluate early and long-term outcomes of total pancreatectomy for pancreatic cancer.

MATERIAL AND METHODS

Treatment of 29 patients who underwent one- and two-stage pancreatectomy for different malignancies was analyzed.

RESULTS

Median of surgery duration and intraoperative blood loss was 280 min and 2200 ml respectively. Postoperative complications were observed in 9 (31%) patients. There were 2 (6.9%) deaths. 1- and 3-year overall actual survival was 61% and 16% respectively in case of ductal adenocarcinoma. Median was 18 months. Patients after surgery for primary multiple lesion (cancer of pancreatic body-tail and major duodenal papilla), pancreatic metastases of renal cancer, mucinous cystadenoma and neuroendocrine cancer are still alive. Follow-up periods are 4, 49, 49 and 65 months respectively.

CONCLUSION

Total pancreatectomy is difficult intervention followed by severe metabolic disorders. However it can improve long-term survival with acceptable incidence of postoperative complications and quality of life if clear indications for surgery are present.

Frozen section analysis of the pancreatic margin during pancreaticoduodenectomy for cancer: Does extending the resection to obtain a secondary R0 provide a survival benefit? Results of a systematic review

BACKGROUND

During pancreaticoduodenectomy, frozen section pancreatic margin analysis permits to extend the resection in case of a positive margin, to achieve R0 margin. We aim to assess if patients having an R0 margin following the extension of the pancreatectomy after a positive frozen section (secondary R0) have different survival compared to those with R1 resection or primary R0 resection.

METHODS

A systematic search was performed to identify all studies published up to March 2016 analyzing the survival of patients undergoing pancreaticoduodenectomy according to the results of frozen section pancreatic margin examination. Clinical effectiveness was synthetized through a narrative review with full tabulation of results.

RESULTS

Four studies published between 2010 and 2014 were retrieved, including 2580 patients. A primary R0 resection was obtained in a percentage of patients ranging from 36.2% to 85.5%, whereas secondary R0 in 9.4%-57.8% of cases and R1 in 5.1%-9.2%. Median survival ranged from 19 to 29 months in R0 patients, from 11.9 to 18 months in secondary R0, and from 12 to 23 months in R1 patients. None of the study demonstrated a survival benefit of extending the resection to obtain a secondary R0 pancreatic margin.

CONCLUSIONS

All the studies were concordant, and failed to demonstrate the survival benefit of additional pancreatic resection to obtain a secondary R0. However, inadequate surgery should not be advocated. This review suggests that re-resection of the pancreatic margin may have limited impact on patients' survival.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.

Frozen Section Interpretation of Pancreatic Margins: Subspecialized Gastrointestinal Pathologists Versus General Pathologists

Intraoperative assessment of pancreatic parenchymal margin during pancreatectomies is challenging and misinterpretation by the pathologist is a cause of incorrect frozen section (FS) diagnosis. Although the current literature supports that pancreatic margin FS diagnosis and its accuracy has no impact on the patient outcome for pancreatic ductal adenocarcinoma (PDAC) patients and reexcision in an attempt to achieve a negative intraoperative pancreatic margin after positive FS is not associated with increased overall survival; still it remains a routine practice in many institutions. To this end, we sought to assess the interobserver variation and accuracy of FS diagnosis between subspecialized gastrointestinal/pancreatobiliary (GI) and general pathologists. Seventy seven consecutive pancreatic parenchymal margin FSs performed on pancreatectomies for PDAC from 2010 to 2013 were retrieved at our institution. These were retrospectively evaluated by 2 GI and 2 general pathologists independently without knowledge of the original FS diagnosis or the final diagnosis. The specificity, sensitivity, positive predictive value, negative predictive value, and accuracy of GI versus general pathologist was 97.8% versus 87.5%, 61.1% versus 66.7%, 78.6% versus 41.4%, 95% versus 95.2%, and 93.5% versus 85.1%, respectively. The interobserver agreement between GI and general pathologists was fair (κ = .337, P < .001). The interobserver agreement between 2 GI pathologists was fair (κ = .373, P = .0005) and between 2 general pathologists was slight (κ = .195, P = .042). Although overall accuracy of subspecialized GI pathologists was higher than that of general pathologists, none had an accuracy of 100%. Our study reaffirms the challenging nature of these FSs.

Meta-analysis of radical resection rates and margin assessment in pancreatic cancer

BACKGROUND

R0 resection rates (complete tumour removal with negative resection margins) in pancreatic cancer are 70-80 per cent when a 0-mm margin is used, declining to 15-24 per cent with a 1-mm margin. This review evaluated the R0 resection rates according to different margin definitions and techniques.

METHODS

Three databases (MEDLINE from 1946, PubMed from 1946 and Embase from 1949) were searched to mid-October 2014. The search terms included 'pancreatectomy OR pancreaticoduodenectomy' and 'margin'. A meta-analysis was performed with studies in three groups: group 1, axial slicing technique (minimum 1-mm margin); group 2, other slicing techniques (minimum 1-mm margin); and group 3, studies with minimum 0-mm margin.

RESULTS

The R0 rates were 29 (95 per cent c.i. 26 to 32) per cent in group 1 (8 studies; 882 patients) and 49 (47 to 52) per cent in group 2 (6 studies; 1568 patients). The combined R0 rate (groups 1 and 2) was 41 (40 to 43) per cent. The R0 rate in group 3 (7 studies; 1926 patients) with a 0-mm margin was 72 (70 to 74) per cent The survival hazard ratios (R1 resection/R0 resection) revealed a reduction in the risk of death of at least 22 per cent in group 1, 12 per cent in group 2 and 23 per cent in group 3 with an R0 compared with an R1 resection. Local recurrence occurred more frequently with an R1 resection in most studies.

CONCLUSION

Margin clearance definitions affect R0 resection rates in pancreatic cancer surgery. This review collates individual studies providing an estimate of achievable R0 rates, creating a benchmark for future trials.

Distribution and pathological features of pancreatic, ampullary, biliary and duodenal cancers resected with pancreaticoduodenectomy

BACKGROUND

Pancreatic cancer (PC) has the worst survival of all periampullary cancers. This may relate to histopathological differences between pancreatic cancers and other periampullary cancers. Our aim was to examine the distribution and histopathologic features of pancreatic, ampullary, biliary and duodenal cancers resected with a pancreaticoduodenectomy (PD) and to examine local trends of periampullary cancers resected with a PD.

METHODS

A retrospective review of PD between January 2000 and December 2012 at a public metropolitan database was performed. The institutional ethics committee approved this study.

RESULTS

There were 142 PDs during the study period, of which 70 cases were pre-2010 and 72 post-2010, corresponding to a recent increase in the number of cases. Of the 142 cases, 116 were for periampullary cancers. There were also proportionately more PD for PC (26/60, 43% pre-2010 vs 39/56, 70% post-2010, P = 0.005). There were 65/116 (56%) pancreatic, 29/116 (25%), ampullary, 17/116 (15%) biliary and 5/116 (4%) duodenal cancers. Nodal involvement occurred more frequently in PC (78%) compared to ampullary (59%), biliary (47%) and duodenal cancers (20%), P = 0.002. Perineural invasion was also more frequent in PC (74%) compared to ampullary (34%), biliary (59%) and duodenal cancers (20%), P = 0.002. Microvascular invasion was seen in 57% pancreatic, 38% ampullary, 41% biliary and 20% duodenal cancers, P = 0.222. Overall, clear margins (R0) were achieved in fewer PC 41/65 (63%) compared to ampullary 27/29 (93%; P = 0.003) and biliary cancers 16/17 (94%; P = 0.014).

CONCLUSIONS

This study highlights that almost half of PD was performed for cancers other than PC, mainly ampullary and biliary cancers. The volume of PD has increased in recent years with an increased proportion being for PC. PC had higher rates of nodal and perineural invasion compared to ampullary, biliary and duodenal cancers.

Value of intraoperative neck margin analysis during Whipple for pancreatic adenocarcinoma: a multicenter analysis of 1399 patients

INTRODUCTION

During pancreaticoduodenectomy (PD) for ductal adenocarcinoma, a frozen section (FS) neck margin is typically assessed, and if positive, additional pancreas is removed to achieve an R0 margin. We analyzed the association of this practice with improved overall survival (OS).

METHODS

Patients who underwent PD for pancreatic ductal adenocarcinoma from January 2000 to August 2012 at 8 academic centers were classified by neck margin status as negative (R0) or microscopically positive (R1) on the basis of FS and permanent section (PS). Impact on OS of converting an FS-R1-neck margin to a PS-R0-neck margin by additional resection was assessed.

RESULTS

A total of 1399 patients had FS neck margins analyzed. Median OS was 19.7 months. On FS, 152 patients (10.9%) were R1, and an additional 51 patients (3.6%) had false-negative FS-R0 margins. PS-R0-neck was achieved in 1196 patients (85.5%), 131 patients (9.3%) remained PS-R1, and 72 patients (5.1%) were converted from FS-R1-to-PS-R0 by additional resection. Median OS for PS-R0-neck patients was 21.1 months versus 13.7 months for PS-R1-neck patients (P < 0.001) and 11.9 months for FS-R1-to-PS-R0 patients (P < 0.001). Both FS-R1-to-PS-R0 and PS-R1-neck patients had larger tumors (P = 0.001), more perineural invasion (P = 0.02), and more node positivity (P = 0.08) than PS-R0-neck patients. On multivariate analysis controlling for adverse pathologic factors, FS-R1-to-PS-R0 conversion remained associated with significantly worse OS compared with PS-R0-neck patients (hazard ratio: 1.55; P = 0.009).

CONCLUSIONS

For patients who undergo pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, additional resection to achieve a negative neck margin after positive frozen section is not associated with improved OS.