Implicaciones pronósticas del estudio estandarizado de los márgenes de resección en el cáncer de páncreas

Non-arbitrary minimum threshold of yearly performed pancreatoduodenectomies: National multicentric study

BACKGROUND

Annual hospital volume of pancreatoduodenectomies could influence postoperative outcomes. The aim of this study is to establish with a non-arbitrary method the minimum threshold of yearly performed pancreatoduodenectomies in order to improve several postoperative quality outcomes.

METHOD

Prospective follow-up of patients submitted to pancreatoduodenectomy in participating hospitals during 1 year. The influence of hospital volume on quality outcomes was analyzed by univariable and multivariable models. The minimum threshold of yearly performed pancreatoduodenectomies to improve outcomes was established by Akaike's information criteria.

RESULTS

Data from 877 patients operated in 74 hospitals were analyzed. Of 12 quality outcomes, 9 were influenced by hospital pancreatoduodenectomy volume on multivariable analysis. To decrease the risk of complications and the risk of retrieving an insufficient number of lymph nodes at least 31 pancreatoduodenectomies per year should be performed. To decrease the risk of prolonged length of stay, postoperative death, and affected surgical margins, at least 37, 6, and 14 pancreatoduodenectomies per year should be performed, respectively.

CONCLUSION

Several postoperative quality outcomes are influenced by the number of yearly performed pancreatoduodenectomies and could be improved by establishing a minimum threshold of procedures. Number of procedures needed to improve quality outcomes has been established by a non-arbitrary method.

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.

Pancreatoduodenectomy with artery-first approach

"Artery-first approach" encompasses different aspects for the surgical treatment of pancreatic cancer. It is a surgical technique or set of techniques which share in common the dissection of the main arterial vasculature involved in pancreatic cancer, before any irreversible surgical step is performed. On the other hand it represents the need for a meticulous dissection of the arterial planes and clearing of the retropancreatic tissue between the superior mesenteric artery, the common hepatic artery and portal vein in an attempt to achieve R0 resections. The recent expansion of this approach is based mainly on three factors: venous involvement should not be considered a contraindication for resection, most of the pancreatic resections performed with a standard procedure may be in fact non-oncological (R1) resections and the postero-medial or vascular margin is the most frequently invaded by the tumor. This review aimed to summarize and update the artery-first approach in pancreaticoduodenectomy.

Multicolour versus monocolour inking specimens after pancreaticoduodenectomy for periampullary cancer: A single centre prospective randomised clinical trial

BACKGROUND

R status represents an important prognostic factors in periampullary cancers. Thus, it is useful to verify if it can be influenced by different techniques of margination.

METHODS

Single-centre, randomised clinical trial of patients affected by periampullary cancer who underwent pancreaticoduodenectomies which included two different types of margination: arm A (multicolour inking) and arm B (monocolour inking). The primary endpoint was the overall R1 resection rate and its difference between the two arms. The secondary endpoints were the R1 resection rate in each margin and its difference between the two arms, and the impact of margin status on survival.

RESULTS

Fifty patients were randomised, 41 analysed: 22 in arm A, 19 arm B. The overall R1 status was 61%, without significant differences between the two arms. The margin most commonly involved was the superior mesenteric artery (SMA) (36.6%). A trend in favour of arm B was shown for the superior mesenteric artery margin (arm A = 22.7% versus arm B = 52.6%; P = 0.060). The anterior surface (P = 0.015), SMA (P = 0.047) and pancreatic remnant (P = 0.018) margins significantly influenced disease-free survival.

CONCLUSIONS

The R status was not influenced by different techniques of margination using a standardised pathological protocol. The SMA margin seemed to be the most important margin for evaluating both R status and disease-free survival.

Vascular resection in pancreaticoduodenectomy for periampullary cancers. A 10 year retrospective cohort study

BACKGROUND

Pancreaticoduodenectomy (PD) is the only chance of cure for periampullary cancers. This study aims to evaluate survival and complication rates for PD with additional vascular resection performed for local vascular involvement and compare to standard PD.

MATERIALS AND METHODS

A retrospective cohort analysis of a departmental hepato-pancreatobiliary database from 2004 to 2014 was performed. All patients (n = 92) who underwent PD without vascular resection (n = 72), with venous resection (n = 16), with both arterial and venous resection (n = 4) were included in the study. Patients who received palliative double bypass (n = 6) were also included for survival analysis. Survival and post-operative complications were assessed.

RESULTS

Median survival for standard PD and PD with venous resection was 21 months and 18 months respectively (P = 0.588). Patients who received PD with venous and arterial resection had a median survival of 7 months, significantly less than standard PD (P = 0.044). Median survival in the palliative bypass group was 4 months, comparable to PD with venous and arterial resection (P = 0.191). There was a significant survival advantage in patients who received an R0 resection (median survival 24 months) compared to those who received an R1 resection (median survival 18 months) (P < 0.02). Patients with a lymph node ratio <0.2 had a median survival of 25 months, which was significantly higher than that of patients who had a lymph node ratio ≥0.2 (9 months) (P < 0.005).

CONCLUSION

PD with venous resection has similar survival to standard PD with no increased risk of procedure specific post-operative complications. On the other hand, PD with venous resection and additional arterial resection has no survival benefit and may be a step too far in our experience.

Redefining the R1 resection in patients with pancreatic ductal adenocarcinoma

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

Superior Mesenteric Artery Margin of Posttherapy Pancreaticoduodenectomy and Prognosis in Patients With Pancreatic Ductal Adenocarcinoma

Negative-margin resection is crucial to favorable prognosis in patients with pancreatic ductal adenocarcinoma. However, the definition of a negative superior mesenteric artery margin (SMAM) varies. The College of American Pathologists defines positive SMAM as the presence of tumor cells at the margin, whereas the European protocol is based on a 1 mm clearance. In this study, we examined the prognostic significance of the SMAM distance in 411 consecutive pancreatic ductal adenocarcinoma patients who completed neoadjuvant therapy and pancreaticoduodenectomy. Per College of American Pathologists criteria, 32 (7.8%) had positive margins, and 379 (92.2%) had negative margins. Among margin-negative group, SMAM was ≤ 1, 1.0 to 5.0, and >5.0 mm in 66, 145, and 168 patients, respectively. There was no difference in either disease-free survival (DFS) or overall survival (OS) between the positive-margin group and SMAM ≤ 1 mm (P > 0.05). However, patients with SMAM 1.0 to 5.0 mm had better OS than those with positive margins or SMAM ≤ 1 mm (P = 0.02). Patients with SMAM > 5.0 mm had better DFS and OS than those with SMAM 1.0 to 5.0 mm and those with positive margins or SMAM ≤ 1 mm (P < 0.01). By multivariate analysis, the SMAM distance, tumor differentiation, lymph node metastasis, and histopathologic tumor response grade were independent prognostic factors for both DFS and OS. SMAM distance correlated with lower ypT and AJCC stages, smaller tumor size, better histopathologic tumor response grade, fewer lymph node metastases, and recurrences (P < 0.05). Thus our results strongly support use of SMAM > 1 mm for R0 resection in posttherapy pancreaticoduodenectomy specimens.