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

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.

The impact of cirrhosis on short and long postoperative outcomes after distal pancreatectomy

BACKGROUND

The impact of cirrhosis on the postoperative outcomes of distal pancreatectomy is yet to be reported. We aimed to evaluate the outcomes of distal pancreatectomy in patients with cirrhosis.

METHODS

We conducted a retrospective, multicentric study patients with cirrhosis who underwent planned distal pancreatectomy between 2008 and 2020 in French high volume centers. Patients with cirrhosis were matched 1:4 for demographic, surgical, and histologic criteria with patients without cirrhosis. The primary endpoint was severe morbidity (Clavien-Dindo grade ≥III). The secondary endpoints were postoperative complications, specifically related to cirrhosis and pancreatic surgery, and survival for patients with pancreatic adenocarcinoma.

RESULTS

Overall, 32 patients with cirrhosis were matched with 128 patients without cirrhosis. Most patients (93.5%) had Child-Pugh A cirrhosis. The severe morbidity rate after distal pancreatectomy was higher in patients with cirrhosis than in those without cirrhosis (28.13% vs 25.75%, P = .11. The operative time was significantly longer in the cirrhotic group compared with controls (P = .01). However, patients with and without cirrhosis had comparable blood loss and conversion rates. Postoperatively, the two groups had similar rates of pancreatic fistula, hemorrhage, reoperation, postoperative mortality, and survival rates at 1, 3, and 5 years.

CONCLUSION

The current study suggests that distal pancreatectomy in high-volume centers is feasible for patients with compensated cirrhosis.

Clamp-crushing Pancreatic Transection in Minimally Invasive Distal Pancreatectomy

BACKGROUND

Minimally invasive distal pancreatectomy has become a widely accepted procedure for tumors located in the pancreatic body or tail. However, pancreatic transection by linear stapler is generally avoided for pancreatic body tumors located above the portal vein because the surgical margin width is narrowed after taking into account the cutting allowance for insertion of the stapling device. Herein, we report a parenchymal clamp-crushing procedure that provides a sufficient surgical margin in pancreatic transection.

METHODS

Two patients with suspected early pancreatic cancer underwent pancreatic transection using the clamp-crushing procedure. The planned pancreatic transection line was set just to the left of the gastroduodenal artery in both cases. Robotic and laparoscopic distal pancreatectomy were performed in 1 patient each. Patients were positioned supine with split legs. Parenchymal transection was performed with crushing by VIO 3 (ERBE Elektromedizin) operated in softCOAG Bipolar mode with Effect 2/modulation 50. After crushing, remnant tissue was cut in autoCUT Bipolar mode operated by VIO 3 with Effect 2/modulation 50, or cut after secured by clipping.

RESULTS

The surgical duration was 253 and 212 minutes, and estimated blood loss was 0 and 50 mL in the 2 patients, and both were discharged with uneventful courses. Pathologic examination confirmed a negative surgical margin in both patients.

CONCLUSION

Clamp-crushing pancreatic transection for distal pancreatectomy might be a suitable treatment option for achieving sufficient surgical margin in pancreatic body tumors located close to the portal vein.

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.

Machine Learning of Histopathological Images Predicts Recurrences of Resected Pancreatic Ductal Adenocarcinoma With Adjuvant Treatment

OBJECTIVES

Pancreatic ductal adenocarcinoma is an intractable disease with frequent recurrence after resection and adjuvant therapy. The present study aimed to clarify whether artificial intelligence-assisted analysis of histopathological images can predict recurrence in patients with pancreatic ductal adenocarcinoma who underwent resection and adjuvant chemotherapy with tegafur/5-chloro-2,4-dihydroxypyridine/potassium oxonate.

MATERIALS AND METHODS

Eighty-nine patients were enrolled in the study. Machine-learning algorithms were applied to 10-billion-scale pixel data of whole-slide histopathological images to generate key features using multiple deep autoencoders. Areas under the curve were calculated from receiver operating characteristic curves using a support vector machine with key features alone and by combining with clinical data (age and carbohydrate antigen 19-9 and carcinoembryonic antigen levels) for predicting recurrence. Supervised learning with pathological annotations was conducted to determine the significant features for predicting recurrence.

RESULTS

Areas under the curves obtained were 0.73 (95% confidence interval, 0.59-0.87) by the histopathological data analysis and 0.84 (95% confidence interval, 0.73-0.94) by the combinatorial analysis of histopathological data and clinical data. Supervised learning model demonstrated that poor tumor differentiation was significantly associated with recurrence.

CONCLUSIONS

Results indicate that machine learning with the integration of artificial intelligence-driven evaluation of histopathological images and conventional clinical data provides relevant prognostic information for patients with pancreatic ductal adenocarcinoma.

Impact of resection margins and para-aortic lymph node metastases on recurrence patterns and prognosis in resectable pancreatic cancer - a long-term population-based cohort study

BACKGROUND

Pancreatic cancer remains a leading cause of cancer-related death. To individualise management and improve survival, more accurate prognostic models are needed.

METHODS

All patients resected for pancreatic ductal adenocarcinoma in a tertiary Swedish centre during 2009-2019 were thoroughly analysed with regards to pathological and clinical parameters including tumour grade, resection margin status, para-aortic lymph node engagement (node station 16), and systemic treatment.

RESULTS

The study cohort included 275 patients. Overall median survival was 21.2 months (95% CI 17.5-24.8). Year of resection, margin status (R1 subdivided into R11mm/R1ink), perineural invasion, differentiation grade, TNM stage, and adjuvant therapy were independent factors with significant impact on survival. Margin status also significantly affected recurrence-free survival and relapse patterns, with local and peritoneal relapses being associated with R1-status (p < 0.001 and p = 0.007). Presence of para-aortic lymph node metastases was associated with shorter recurrence-free survival as compared to N1 status only.

CONCLUSION

Survival in resected pancreatic cancer is improving over time. Resection margin status is a key factor affecting recurrence patterns and prognosis. Given the poor recurrence-free survival in node station 16 metastasised patients, the rational for resection remains in doubt, and improved treatment strategies for this patient group is necessary.

Minimally invasive versus open distal pancreatectomy for resectable pancreatic cancer (DIPLOMA): an international randomised non-inferiority trial

Background

The oncological safety of minimally invasive surgery has been questioned for several abdominal cancers. Concerns also exist regarding the use of minimally invasive distal pancreatectomy (MIDP) in patients with resectable pancreatic cancer as randomised trials are lacking.

Methods

In this international randomised non-inferiority trial, we recruited adults with resectable pancreatic cancer from 35 centres in 12 countries. Patients were randomly assigned to either MIDP (laparoscopic or robotic) or open distal pancreatectomy (ODP). Both patients and pathologists were blinded to the assigned approach. Primary endpoint was radical resection (R0, ≥1 mm free margin) in patients who had ultimately undergone resection. Analyses for the primary endpoint were by modified intention-to-treat, excluding patients with missing data on primary endpoint. The pre-defined non-inferiority margin of -7% was compared with the lower limit of the two-sided 90% confidence interval (CI) of absolute difference in the primary endpoint. This trial is registered with the ISRCTN registry (ISRCTN44897265).

Findings

Between May 8, 2018 and May 7, 2021, 258 patients were randomly assigned to MIDP (131 patients) or ODP (127 patients). Modified intention-to-treat analysis included 114 patients in the MIDP group and 110 patients in the ODP group. An R0 resection occurred in 83 (73%) patients in the MIDP group and in 76 (69%) patients in the ODP group (difference 3.7%, 90% CI -6.2 to 13.6%; p_{non-inferiority} = 0.039). Median lymph node yield was comparable (22.0 [16.0-30.0] vs 23.0 [14.0-32.0] nodes, p = 0.86), as was the rate of intraperitoneal recurrence (41% vs 38%, p = 0.45). Median follow-up was 23.5 (interquartile range 17.0-30.0) months. Other postoperative outcomes were comparable, including median time to functional recovery (5 [95% CI 4.5-5.5] vs 5 [95% CI 4.7-5.3] days; p = 0.22) and overall survival (HR 0.99, 95% CI 0.67-1.46, p = 0.94). Serious adverse events were reported in 23 (18%) of 131 patients in the MIDP group vs 28 (22%) of 127 patients in the ODP group.

Interpretation

This trial provides evidence on the non-inferiority of MIDP compared to ODP regarding radical resection rates in patients with resectable pancreatic cancer. The present findings support the applicability of minimally invasive surgery in patients with resectable left-sided pancreatic cancer.

Funding

Medtronic Covidien AG, Johnson & Johnson Medical Limited, Dutch Gastroenterology Society.

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

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