Can standardized pathology examination increase the lymph node yield following laparoscopic distal pancreatectomy for ductal adenocarcinoma?

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Robot-Assisted Versus Laparoscopic Distal Pancreatectomy in Patients with Resectable Pancreatic Cancer: An International, Retrospective, Cohort Study

BACKGROUND

Robot-assisted distal pancreatectomy (RDP) is increasingly used as an alternative to laparoscopic distal pancreatectomy (LDP) in patients with resectable pancreatic cancer but comparative multicenter studies confirming the safety and efficacy of RDP are lacking.

METHODS

An international, multicenter, retrospective, cohort study, including consecutive patients undergoing RDP and LDP for resectable pancreatic cancer in 33 experienced centers from 11 countries (2010-2019). The primary outcome was R0-resection. Secondary outcomes included lymph node yield, major complications, conversion rate, and overall survival.

RESULTS

In total, 542 patients after minimally invasive distal pancreatectomy were included: 103 RDP (19%) and 439 LDP (81%). The R0-resection rate was comparable (75.7% RDP vs. 69.3% LDP, p = 0.404). RDP was associated with longer operative time (290 vs. 240 min, p < 0.001), more vascular resections (7.6% vs. 2.7%, p = 0.030), lower conversion rate (4.9% vs. 17.3%, p = 0.001), more major complications (26.2% vs. 16.3%, p = 0.019), improved lymph node yield (18 vs. 16, p = 0.021), and longer hospital stay (10 vs. 8 days, p = 0.001). The 90-day mortality (1.9% vs. 0.7%, p = 0.268) and overall survival (median 28 vs. 31 months, p = 0.599) did not differ significantly between RDP and LDP, respectively.

CONCLUSIONS

In selected patients with resectable pancreatic cancer, RDP and LDP provide a comparable R0-resection rate and overall survival in experienced centers. Although the lymph node yield and conversion rate appeared favorable after RDP, LDP was associated with shorter operating time, less major complications, and shorter hospital stay. The specific benefits associated with each approach should be confirmed by multicenter, randomized trials.

A Novel Criterion for Lymph Nodes Dissection in Distal Pancreatectomy for Ductal Adenocarcinoma: A Population Study of the US SEER Database

OBJECTIVE

The aim of this study was to clarify the minimum number of examined lymph nodes (MNELNs) required to ensure the quality of lymph node detection and its impact on long-term survival in distal pancreatectomy for pancreatic ductal adenocarcinoma.

METHODS

Clinicopathological characteristics and survival data of patients with resectable pancreatic cancer who underwent distal pancreatectomy between 2004 and 2017 were collected from the Surveillance, Epidemiology, and End Results database. The associations between the number of examined lymph nodes (ELNs) and number of positive lymph nodes (PLNs), stage migration, and overall survival were investigated through adjusted multivariate models with locally weighted scatterplot smoothing smoothing fitting curves and estimation of the structural breakpoints. Kaplan-Meier survival analysis and X-tile software were used to identify the ideal cut-off value for ELNs.

RESULTS

In total, 2610 consecutive patients who underwent distal pancreatectomy between 2004 and 2017 were included in this study. The optimal ELN count according to the associations between the number of ELNs and number of PLNs, odds ratio for stage migration, or hazard ratio for overall survival were 19, 17, and 19, respectively. Furthermore, the optimal division of ELN count for maximum overall survival was divided into three populations (ELN ≤ 8, ELN 9-18, ELN ≥ 19) based on X-tile software.

CONCLUSION

A minimal count of 19 lymph nodes was demanded to guarantee the quality of lymph node examination in patients with distal pancreatectomy. Long-term survival could be delimited by MNELNs. A sufficient number of ELNs could improve the accuracy of cancer staging and reflect a better overall survival.

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

Background

Resection margin status is considered one of the few surgeon-controlled parameters affecting prognosis in pancreatic ductal adenocarcinoma (PDAC). While studies mostly focus on resection margins in pancreatoduodenectomy, little is known about their role in distal pancreatectomy (DP). This study aimed to investigate resection margins in DP for PDAC.

Methods

Patients who underwent DP for PDAC between October 2004 and February 2020 were included (n = 124). Resection margins and associated parameters were studied in two consecutive time periods during which different pathology examination protocols were used: non-standardized (period 1: 2004–2014) and standardized (period 2: 2015–2020). Microscopic margin involvement (R1) was defined as ≤1 mm clearance.

Results

Laparoscopic and open resections were performed in 117 (94.4%) and 7 (5.6%) patients, respectively. The R1 rate for the entire cohort was 73.4%, increasing from 60.4% in period 1 to 83.1% in period 2 (p = 0.005). A significantly higher R1 rate was observed for the posterior margin (35.8 vs. 70.4%, p < 0.001) and anterior pancreatic surface (based on a 0 mm clearance; 18.9 vs. 35.4%, p = 0.045). Pathology examination period, poorly differentiated PDAC, and vascular invasion were associated with R1 in the multivariable model. Extended DP, positive anterior pancreatic surface, lymph node ratio, perineural invasion, and adjuvant chemotherapy, but not R1, were significant prognostic factors for overall survival in the entire cohort.

Conclusions

Pathology examination is a key determinant of resection margin status following DP for PDAC. A high R1 rate is to be expected when pathology examination is meticulous and standardized. Involvement of the anterior pancreatic surface affects prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10464-6.

Long term oncological outcome of laparoscopic techniques in pancreatic cancer

The laparoscopic technique in distal pancreatic resection (LDP) has been widely accepted, and outcome data support the hypothesis that survival is improved, partly due to improved postoperative safety and recovery, thus optimizing treatment with adjuvant chemotherapy. But laparoscopic pancreaticoduodenectomy (LPD or Whipple-procedures) has spread more slowly, due to the complexity of the procedure. Surgical safety has been a problem in hospitals with low patient volume, resulting in raised postoperative mortality, requiring careful monitoring of outcome during the surgical learning curve. Robotic assistance is expected to improve surgical safety, but data on long term oncological outcome of laparoscopic Whipple procedures with or without robotic assistance is scarce. Future research should still focus surgical safety, but most importantly long term outcome, recorded as recurrence at maximal follow up or - at best - overall long term survival (OS). Available data show median survival above 2.5 years, five year OS more than 30% after LDP even in series with suboptimal adjuvant chemotherapy. Also after LPD, long term survival is reported equal to or longer than open resection. However, surgical safety during the learning curve of LPD is a problem, which hopefully can be facilitated by robotic assistance. Patient reported outcome should also be an endpoint in future trials, including patients with pancreatic ductal adenocarcinoma.