Is it time to stop checking frozen section neck margins during pancreaticoduodenectomy?

Contemporary report of surgical outcomes after single-stage total pancreatectomy: A 10-year experience

BACKGROUND

Surgeons rarely perform elective total pancreatectomy (TP). Our study seeks to report surgical outcomes in a contemporary series of single-stage (SS) TP patients.

METHODS

Between the years 2013 to 2023 we conducted a retrospective review of 60 consecutive patients who underwent SSTP. Demographics, pathology, treatment-related variables, and survival were recorded and analyzed.

RESULTS

SSTP consisted of 3% (60/1859) of elective pancreas resections conducted. Patient median age was 68 years. Ninety percent of these patients (n = 54) underwent SSTP for pancreatic ductal adenocarcinoma (PDAC). Conversion from a planned partial pancreatectomy to TP occurred intraoperatively in 31 (52%) patients. Fifty-nine patients (98%) underwent an R0 resection. Median length of hospital stay was 6 days. The majority of morbidities were minor, with 27% patients (n = 16) developing severe complications (Clavien-Dindo ≥3). Thirty and ninety-day mortality rates were 1.67% (one patient) and 5% (three patients), respectively. Median survival for the entire cohort was 24.4 months; 22.7 months for PDAC patients, with 1-, 3-, and 5-year survival of 68%, 43%, and 16%, respectively. No mortality occurred in non-PDAC patients (n = 6).

CONCLUSION

Elective single-stage total pancreatectomy can be a safe and appropriate treatment option. SSTP should be in the armamentarium of surgeons performing pancreatic resection.

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 and diagnostic accuracy of intraoperative frozen sections in hepato-pancreato-biliary surgical pathology

BACKGROUND AND PURPOSE

Hepato-pancreato-biliary (HPB) surgeries are one of the most challenging and complex procedures. Intraoperative frozen section (IFS) diagnosis plays a pivotal role in management decisions. Comprehensive large cohort studies evaluating utility of IFS in HPB malignancies are lacking. This study aimed to evaluate the accuracy of frozen section analysis and to analyse discrepancies and impact of IFS on the surgical decisions.

PATIENTS AND METHODS

This was a retrospective study of IFS received for the HPB specimens between years 2009 and 2021. The results were compared to the permanent sections to evaluate diagnostic accuracy, sensitivity and specificity. Indications, disagreements and impact on the surgical management were analysed.

RESULTS

A total of 1008 specimens were evaluated: bile duct margin (279; 27.7%), gallbladder (203; 20.1%), liver lesions (125 cases; 12.4%), lymph nodes (147; 14.6%), pancreatic margin (120; 11.9%) and deposits (134; 13.3%). IFS were diagnosed as negative for malignancy (805; 79.9%), positive for dysplasia (8; 0.8%), suspicious for malignancy (6; 0.6%) and positive for malignancy (189; 18.8%). The overall diagnostic accuracy was 98.4%, and the discordant rate was 1.6%. The sensitivity, specificity, positive predictive value and negative predictive value were 94.7%, 99.4%, 97.5% and 98.6% respectively. The most important reason of discordant results was technical, followed by interpretational and sampling errors.

CONCLUSION

The study demonstrates high diagnostic accuracy (98.4%) of IFS in a large dataset of HPB specimens. This comprehensive analysis apprises of the indications, errors and the impact of IFS diagnosis on subsequent HPB surgical management.

Predicting Surgical Margins in Patients With Borderline Resectable and Locally Advanced Pancreatic Cancer Undergoing Resection

BACKGROUND

Many patients with borderline resectable/locally advanced pancreatic ductal adenocarcinoma (borderline resectable [BR]/locally advanced [LA] pancreatic ductal adenocarcinoma [PDAC]) undergoing resection will have positive resection margins (R1), which is associated with poor prognosis. It might be useful to preoperatively predict the margin (R) status.

METHODS

Data from patients with BR/LA PDAC who underwent a pancreatectomy between 2008 and 2018 at Brigham and Women's Hospital were retrospectively reviewed. Logistic regression analysis was used to evaluate the association between R status and relevant preoperative factors. Significant predictors of R1 resection on univariate analysis (P < .1) were entered into a stepwise selection using the Akaike information criterion to define the final model.

RESULTS

A total of 142 patients with BR/LA PDAC were included in the analysis, 60(42.3%) had R1 resections. In stepwise selection, the following factors were identified as positive predictors of an R1 resection: evidence of lymphadenopathy at diagnosis (OR = 2.06, 95% CI: 0.99-4.36, P = .056), the need for pancreaticoduodenectomy (OR = 3.81, 96% CI: 1.15-15.70, P = .040), extent of portal vein/superior mesenteric vein involvement at restaging (<180°, OR = 3.57, 95% CI: 1.00-17.00, P = .069, ≥180°, OR = 7,32, 95% CI: 1.75-39.87, P = .010), stable CA 19-9 serum levels (less than 50% decrease from diagnosis to restaging, OR = 2.27, 95% CI: 0.84-6.36 P = .107), and no preoperative FOLFIRINOX (OR = 2.17, 95% CI: 0.86-5.64, P = .103). The prognostic nomogram based on this model yielded a probability of achieving an R1 resection ranging from <5% (0 factors) to >70% (all 5 factors).

CONCLUSIONS

Relevant preoperative clinicopathological characteristics accurately predict positive resection margins in patients with BR/LA PDAC before resection. With further development, this model might be used to preoperatively guide surgical decision-making in patients with BR/LA PDAC.

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.

Intraoperative Pancreatic Neck Margin Assessment During Pancreaticoduodenectomy for Pancreatic Adenocarcinoma in the Era of Neoadjuvant Therapy: A Multi-institutional Analysis from the Central Pancreatic Consortium

BACKGROUND

Data regarding the survival impact of converting frozen-section (FS):R1 pancreatic neck margins to permanent section (PS):R0 by additional resection (i.e., converted-R0) during upfront pancreaticoduodenectomy for pancreatic ductal adenocarcinoma (PDAC) are conflicting. The impact of neoadjuvant therapy on this practice and its relationship with overall survival (OS) is incompletely understood.

METHODS

We reviewed PDAC patients (80% borderline resectable/locally advanced [BR/LA]) undergoing pancreaticoduodenectomy after neoadjuvant therapy at seven, academic, high-volume centers (2010-2018). Multivariable models examined the association of PS:R0, PS:R1, and converted-R0 margins with OS.

RESULTS

Of 272 patients receiving at least 2 (median 4) cycles of neoadjuvant chemotherapy (71% mFOLFIRINOX or gemcitabine/nab-paclitaxel) and undergoing pancreaticoduodenectomy with intraoperative frozen-section assessment of the transected pancreatic neck margin, PS:R0 (n = 220, 80.9%) was observed in a majority of patients; 18 patients (6.6%) had converted-R0 margins following additional resection, whereas 34 patients (12.5%) had persistently positive PS:R1 margins. At a median follow-up of 42 months, PS:R0 resection was associated with improved OS compared with either converted-R0 or PS:R1 resection (median 25 vs. 14 vs. 16 months, respectively; p = 0.023), with no survival difference between the converted-R0 and PS:R1 groups (p = 0.9). On Cox regression, SMA margin positivity (hazard ratio 2.2, p = 0.012), but not neck margin positivity (hazard ratio 1.2, p = 0.65), was associated with worse OS.

CONCLUSIONS

In this multi-institutional cohort of predominantly BR/LA PDAC patients undergoing pancreaticoduodenectomy following modern neoadjuvant therapy, pursuing a negative neck margin intraoperatively if the initial margin is positive does not appear to be associated with improved survival.

[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.

Landmark Series: Importance of Pancreatic Resection Margins

An important goal of cancer surgery is to achieve negative surgical margins and remove all disease completely. For pancreatic neoplasms, microscopic margins may remain positive despite gross removal of the palpable mass, and surgeons must then consider extending resection, even to the point of completion pancreatectomy, an option that renders the patient with significant adverse effects related to exocrine and endocrine insufficiency. Counterintuitively, extending resection to ensure clear margins may not improve patient outcome. Furthermore, the goal of improving survival by extending the resection may not be achieved, as an initial positive margin may indicate more aggressive underlying tumor biology. There is a growing body of literature on this topic, and this landmark series review will examine the key publications that guide our management for resection of pancreatic ductal adenocarcinoma, intraductal papillary mucinous neoplasms, and pancreatic neuroendocrine tumors.

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.

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.

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.

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.

[Surgery of pancreatic cancer: techniques to avoid local recurrence]

BACKGROUND

In addition to the prognostically important systemic recurrence, a high rate of local recurrence is a relevant problem of pancreatic cancer surgery. Improvement of local control is a requirement for surgical resection as a prerequisite for a potentially curative treatment.

OBJECTIVES

Summary of the current evidence on frequency, relevance, and risk factors of local recurrence. Presentation of strategies for reduction of local recurrence with a special focus on surgical resection techniques.

MATERIAL AND METHODS

Analysis and appraisal of currently available scientific literature on the topic.

RESULTS AND CONCLUSION

Local recurrences occur as the first manifestation of tumor recurrence in 20-50% of patients after resection of pancreatic cancer. The considerable variations of reported local recurrence rates depend on the quality of surgery, regimens of (neo)adjuvant therapy as well as the design of surveillance and duration of follow-up. An R1 status is an important risk factor for local recurrence highlighting the relevance of a local radical resection. The majority of local recurrences consist of perivascular and lymph node recurrences. Therefore, lymphadenectomy, radical dissection directly at the celiac and mesenteric vessels including resection of the periarterial nerve plexus and vascular resection are starting points for improving surgical resection techniques. The safety and efficacy of radical resection techniques in the context of multimodal treatment of pancreatic cancer have to be further evaluated in prospective studies.

Malignant epithelial/exocrine tumors of the pancreas

Pancreatic malignant exocrine tumors represent the most important cause of cancer-related death for pancreatic neoplasms. The most common tumor type in this category is represented by pancreatic ductal adenocarcinoma (PDAC), an ill defined, stroma-rich, scirrhous neoplasm with glandular differentiation. Here we present the relevant characteristics of the most important PDAC variants, namely adenosquamous carcinoma, colloid carcinoma, undifferentiated carcinoma, undifferentiated carcinoma with osteoclast-like giant cells, signet ring carcinoma, medullary carcinoma and hepatoid carcinoma. The other categories of malignant exocrine tumors, characterized by fleshy, stroma-poor, circumscribed neoplasms, include acinar cell carcinoma (pure and mixed), pancreatoblastoma, and solid pseudopapillary neoplasms. The most important macroscopic, histologic, immunohistochemical and molecular hallmarks of all these tumors, highlighting their key diagnostic/pathological features are presented. Lastly, standardized indications regarding gross sampling and how to compile a formal pathology report for pancreatic malignant exocrine tumors will be provided.

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.

Conversion to open laparotomy during laparoscopic distal pancreatectomy: lessons from a single-center experience in 70 consecutive patients

PURPOSE

The purpose of this study was to determine the factors influencing conversion from laparoscopic distal pancreatectomy (LDP) to open surgery, and the effect of such conversion on the outcome.

METHODS

This retrospective single-center study included 70 consecutive patients undergoing LDP. The primary endpoint was the rate of conversion to open surgery during LDP. The secondary endpoints were determining the reasons for conversion to open surgery, with detailed analyses of these cases and a comparison of the surgical outcome with and without conversion.

RESULTS

Seven patients (10%) required conversion to open surgery during LDP. Pancreatic ductal adenocarcinoma (PDAC) was identified as a risk factor for conversion (p = 0.010). The reasons for conversion included technical difficulty (two bleeding, one severe adhesion) and pancreatic stump-related issues (two margin-positive, two stapling failures). Although the overall morbidity rate (29 vs. 11%, p = 0.48) and the rate of clinically relevant postoperative pancreatic fistula (14 vs. 5%, p = 0.82) were no different for the patients with or without open conversion, the postoperative hospital stay was significantly longer in the former (median 15 vs. 10 days, p = 0.03).

CONCLUSIONS

Careful preoperative assessment is required when planning LDP for PDAC. Although conversion to open surgery does not result in failure of LDP, efforts to reduce the duration of postoperative hospital stay and the occurrence of complications are desirable to improve the outcome of LDP.

Impact of resection margins on long-term survival after pancreaticoduodenectomy for pancreatic head carcinoma

BACKGROUND

The impact of resection margin status on long-term survival after pancreaticoduodenectomy (PD) for patients with pancreatic head carcinoma remains controversial and depends on the method used in the histopathological study of the resected specimens. This study aimed to examine the impact of resection margin status on the long-term overall survival of patients with pancreatic head carcinoma after PD using the tumor node metastasis standard.

METHODS

Consecutive patients with pancreatic head carcinoma who underwent PD at the Chinese People's Liberation Army General Hospital between May 2010 and May 2016 were included. The impact of resection margin status on long-term survival was retrospectively analyzed.

RESULTS

Among the 124 patients, R0 resection was achieved in 85 patients (68.5%), R1 resection in 38 patients (30.7%) and R2 resection in 1 patient (0.8%). The 1- and 3-year overall survival (OS) rates were significantly higher for the patients who underwent R0 resection than the rates for those who underwent R1 resection (1-year OS rates: 69.4% vs 53.0%; 3-year OS rates: 26.9% vs 11.7%). Multivariate analysis showed that resection margin status and venous invasion were significant risk factors for OS.

CONCLUSION

Resection margin was an independent risk factor for OS for patients with pancreatic head carcinoma after PD. R0 resection was associated with significantly better OS after surgery.

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.

Histopathological assessment of prognostic factors in pancreatic resection specimens using a standardised protocol

BACKGROUND

Adenocarcinoma involving the pancreas shows differences in prognostic parameters including resection margin status depending on subtype.

AIM

To assess the reported incidence of each type and the rate of R1 resection using detailed histopathological examination protocol.

METHODS

All pancreaticoduodenectomies between June 2011 and June 2013 at our institute were analysed. These were classified according to the site of origin, R1 status, size, stage at resection, lymph node status and the rate of lymphovascular and perineural invasion.

RESULTS

58 adenocarcinomas included 23 ductal, 16 intraductal papillary mucinous neoplasm (IPMN) related, 8 duodenal, 7 ampullary and 4 distal common bile duct (CBD) tumours. The CBD, pancreatic ductal and IPMN-related adenocarcinomas had the highest rates of R1 resection, at 75%, 69.5 and 62.5%, with the posterior and SMV margins most frequently involved. Ampullary adenocarcinoma had lower rates of R1 resection (14%) as well as perineural invasion (0%).

CONCLUSION

Ampullary adenocarcinomas had a lower rate of R1 resection and perineural invasion, both of which are parameters associated with a poorer outcome. This correlates with literature indicating ampullary tumours have a better prognosis. Our study also highlights the high rate of detection of microscopic margin involvement when a detailed histopathological examination protocol is employed.

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.

Clinical Management: Resectable Disease

Despite the identification of more active systemic therapy combinations for pancreatic cancer, cures remain elusive and feasible only in patients with localized, operable disease. When examining outcome data from phase III adjuvant trials conducted during the past decade, the survival for patients with localized disease has improved, likely owing to a combination of factors including more active adjuvant therapy and improved surgical and perioperative care. Perhaps the greatest recent change in the care of patients with localized pancreatic cancer has been the extension of surgery to tumors previously thought to be inoperable because of involvement of major blood vessels. These so-called "borderline resectable pancreatic cancers" have now been objectively defined, and their management is being studied in randomized trials. This has been made feasible by the availability of more active systemic therapy combinations that are increasingly being used in the neoadjuvant setting. Given the increasing activity of systemic regimens, the challenges in delivering such therapy in the postoperative setting, and the numerous novel agents in late stages of clinical development, it is reasonable to hypothesize that the neoadjuvant setting may eventually become the standard of care for patients with resectable disease.

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.

Advances in Diagnostic and Intraoperative Molecular Imaging of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. To improve outcomes, there is a critical need for improved tools for detection, accurate staging, and resectability assessment. This could improve patient stratification for the most optimal primary treatment modality. Molecular imaging, used in combination with tumor-specific imaging agents, can improve established imaging methods for PDAC. These novel, tumor-specific imaging agents developed to target specific biomarkers have the potential to specifically differentiate between malignant and benign diseases, such as pancreatitis. When these agents are coupled to various types of labels, this type of molecular imaging can provide integrated diagnostic, noninvasive imaging of PDAC as well as image-guided pancreatic surgery. This review provides a detailed overview of the current clinical imaging applications, upcoming molecular imaging strategies for PDAC, and potential targets for imaging, with an emphasis on intraoperative imaging applications.

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.

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.

Adjuvant Therapy for a Microscopically Incomplete Resection Margin after an Esophagectomy for Esophageal Squamous Cell Carcinoma

Purpose: To investigate the prognosis of esophageal squamous cell carcinoma with a microscopically incomplete (R1) resection margin following an esophagectomy, as well as the impact of adjuvant treatment on survival. Methods: Data obtained from 124 patients with R1-resected ESCC were reviewed. The impact of clinicopathological factors and adjuvant treatment on the overall survival, locoregional recurrence, and distant recurrence were explored. Results: For a median follow-up time of 16.8 months, the median overall survival of 124 patients was 25.6 months. The 1, 3, and 5-year overall survival rates were 75.6%±4.0%, 35.9%±5.1%, and 23.2%±5.0%, respectively. Adjuvant therapy was administered in 78 patients. In the univariate analyses, patients with a pN0 stage (log rank, p=0.028) and adjuvant chemotherapy (log rank, p=0.032) exhibited more favorable overall survival. In the multivariate analyses, the pN stage (HR=2.192, p=0.004) and adjuvant chemotherapy (HR=0.032, p=0.004) were independent prognostic factors for overall survival. Locoregional recurrence was the main failure pattern after R1 resection. The pN stage (HR=2.567, p=0.009) and adjuvant radiotherapy (HR=0.278, p=0.000) were independent prognostic factors for locoregional recurrence. Conclusion: In R1-resected esophageal squamous cell carcinoma, adjuvant radiotherapy reduced locoregional recurrence; however, it did not improve overall survival. Adjuvant chemotherapy demonstrated benefits for overall survival. The pN stage was an independent prognostic factor for locoregional recurrence and overall survival.

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.

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.

The importance of surgical margins in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with a grim prognosis. Surgical resection offers the best chance for long-term survival, yet recurrence rates are high and outcomes are poor. The influence of margin status in PDAC is controversial, as conflicting data have been plagued by a lack of standardization in margin definitions, pathologic analysis, and reporting. Despite recent efforts, international consensus is still needed for this disease.

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.

Utility of the proximal margin frozen section for resection of gastric adenocarcinoma: a 7-Institution Study of the US Gastric Cancer Collaborative

BACKGROUND

The proximal gastric margin dictates the extent of resection for gastric adenocarcinoma (GAC). The value of achieving negative margins via additional gastric resection after a positive proximal margin frozen section (FS) is unknown.

METHODS

The US Gastric Cancer Collaborative includes all patients who underwent resection of GAC at seven institutions from 2000-2012. Intraoperative proximal margin FS data and final permanent section (PS) data were classified as R0 or R1, respectively; positive distal margins were excluded. The primary aim was to evaluate the impact on local recurrence of converting a positive proximal FS-R1 margin to a PS-R0 final margin by additional resection. Secondary endpoints were recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Of 860 patients, 520 had a proximal margin FS and 67 were positive. Of these, 48 were converted to R0 on PS by additional resection. R0 proximal margin was achieved in 447 patients (86 %), PS-R1 in 25 (5 %), and converted FS-R1-to-PS-R0 in 48 (9 %). The median follow-up was 44 months. Local recurrence was significantly decreased in the converted FS-R1-to-PS-R0 group compared to the PS-R1 group (10 vs. 32 %; p = 0.01). Median RFS was similar between the FS-R1-to-PS-R0 and PS-R1 cohorts (25 vs. 20 months; p = 0.49), compared to 37 months for the PS-R0 group. Median OS was similar between the FS-R1-to-PS-R0 conversion and PS-R1 groups (36 vs. 26 months; p = 0.14) compared to 50 months for the PS-R0 group. On multivariate analysis, increasing T-stage and N-stage were associated with worse OS; the FS-R1-to-PS-R0 proximal margin conversion was not significantly associated with improved RFS (p = 0.68) or OS (p = 0.44).

CONCLUSION

Conversion of a positive intraoperative proximal margin frozen section during gastric cancer resection may decrease local recurrence, but it is not associated with improved RFS or OS. This may guide decisions regarding the extent of resection.

Current and future intraoperative imaging strategies to increase radical resection rates in pancreatic cancer surgery

Prognosis of patients with pancreatic cancer is poor. Even the small minority that undergoes resection with curative intent has low 5-year survival rates. This may partly be explained by the high number of irradical resections, which results in local recurrence and impaired overall survival. Currently, ultrasonography is used during surgery for resectability assessment and frozen-section analysis is used for assessment of resection margins in order to decrease the number of irradical resections. The introduction of minimal invasive techniques in pancreatic surgery has deprived surgeons from direct tactile information. To improve intraoperative assessment of pancreatic tumor extension, enhanced or novel intraoperative imaging technologies accurately visualizing and delineating cancer cells are necessary. Emerging modalities are intraoperative near-infrared fluorescence imaging and freehand nuclear imaging using tumor-specific targeted contrast agents. In this review, we performed a meta-analysis of the literature on laparoscopic ultrasonography and we summarized and discussed current and future intraoperative imaging modalities and their potential for improved tumor demarcation during pancreatic surgery.

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

The use of frozen section to assess resection margins intraoperatively during pancreaticoduodenectomy facilitates further resection. However, it is unclear whether this actually improves patient survival.We reviewed the overall survival and resection margin status in consecutive pancreaticoduodenectomies performed for carcinoma. An R1 resection was defined as an incomplete excision (≤1 mm margin); R0(p) resection as complete excision without re-resection and R0(s) resection as an initially positive neck margin which was converted to R0 resection after re-resection. Between 2007 and 2012, 116 pancreatoduodenectomies were performed for adenocarcinoma; 101 (87%) underwent frozen section of the neck margin which was positive in 19 (19%). Sixteen of these patients had negative neck margins after re-excision but only seven patients had no other involved margins [true R0(s) resections]. Median survival for the R0(p), R0(s) and R1 groups were 29, 16, 23 months, respectively (p = 0.049; R0(p) versus R0(s) p = 0.040). Intra-operative frozen section increased the overall R0 rate by 7% but this did not improve survival. Our findings question the clinical benefit of intraoperative margin assessment, particularly if re-excision cannot be performed easily and safely.