Pancreatectomy with Para-Aortic Lymph Node Dissection for Pancreatic Head Adenocarcinoma: Pattern of Nodal Metastasis Spread and Analysis of Prognostic Factors

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.

Intraoperative paraaortic lymph node sampling during resection for pancreatic cancer: evolving role in the modern chemotherapy era

BACKGROUND

The role of paraaortic lymph node (PALN) sampling for pancreatic cancer (PC) remains controversial. This study aimed to assess the yield of PALN sampling and its impact on long-term outcomes.

METHODS

Patients treated from 2005 to 2018 were included. Since 2015, patients with borderline resectable or unresectable (BR/UR) tumours received standardized neoadjuvant therapy (NAT), whereas patients with resectable tumours underwent upfront resection.

RESULTS

Among 771 patients with PALN excision, metastasis was confirmed in 76 patients (10%) and 59 proceeded to planned resection. PALN metastasis was associated with early recurrence and shorter survival after upfront resection (1-year recurrence-free rate: 23% vs 57% for resectable tumours, P < 0.001, 9% vs 52% for BR/UR tumours, P = 0.006; median overall survival (OS): 19 vs 31 months for resectable tumours, P < 0.001, 17 vs 23 months for BR/UR tumours, P = 0.057). In contrast, they were both similar between patients with/without PALN metastasis following NAT for BR tumours (1-year recurrence-free rate, 50% vs 58%, P = 0.88; median OS, 28 vs 35 months, P = 0.45, respectively).

CONCLUSIONS

Occult metastasis to PALNs is not uncommon in patients with potentially resectable PC. Its prognostic impact depends on the treatment strategy, and the intraoperative decision for resection should be individualized.

Importance of Nodal Metastases Location in Pancreatoduodenectomy for Pancreatic Ductal Adenocarcinoma: Results from a Prospective, Lymphadenectomy Protocol

BACKGROUND

Implementing a prospective lymphadenectomy protocol, we investigated the nodal yields and metastases per anatomical stations and nodal echelon following upfront pancreatoduodenectomy (PD) for cancer. Next, the relationship between the extension of nodal dissection, the number of examined and positive nodes (ELN/PLN), disease staging and prognosis was assessed.

METHODS

Lymphadenectomy included stations 5, 6, 8a-p, 12a-b-p, 13, 14a-b, 17, and jejunal mesentery nodes. Data were stratified by N-status, anatomical stations, and nodal echelons. First echelon was defined as stations embedded in the main specimen and second echelon as stations sampled as separate specimens. Recurrence and survival analyses were performed by using standard statistics.

RESULTS

Overall, 424 patients were enrolled from June 2013 through December 2018. The median number of ELN and PLN was 42 (interquartile range [IQR] 34-50) and 4 (IQR 2-8). Node-positive patients were 88.2%. The commonest metastatic sites were stations 13 (77.8%) and 14 (57.5%). The median number of ELN and PLN in the first echelon was 28 (IQR 23-34) and 4 (IQR 1-7). While first-echelon dissection provided enough ELN for optimal nodal staging, the aggregate rate of second-echelon metastases approached 30%. Nodal-related factors associated with recurrence and survival were N-status, multiple metastatic stations, metastases to station 14, and jejunal mesentery nodes.

CONCLUSIONS

First-echelon dissection provides adequate number of ELN for optimal staging. Nodal metastases occur mostly at stations 13/14, although second-echelon involvement is frequent. Only station 14 and jejunal mesentery nodes involvement was prognostically relevant. This latter station should be included in the standard nodal map and analyzed pathologically.

Neoadjuvant Treatment Strategies in Resectable Pancreatic Cancer

Simple Summary

Only 10–20% of patients with newly diagnosed resectable pancreatic adenocarcinoma have potentially resectable disease. Upfront surgery is the gold standard, but it is rarely curative. After surgical extirpation of tumors, up to 80% of patients will develop cancer recurrence, and the initial relapse is metastatic in 50–70% of these patients. Adjuvant chemotherapy offers the best strategy to date to improve overall survival but faces real challenges; some patients will experience rapid disease progression within 3 months of surgery and patients who do not receive all planned cycles of chemotherapy have unfavourable oncological outcomes. The neoadjuvant approach is therefore logical but requires further investigation. This approach shows favourable trends regarding disease-free survival and overall survival but, in the absence of rigorous published phase III trials, is not validated to date. Here, we intend to provide a comprehensive analysis of the literature to provide direction for future studies.

Abstract

Complete surgical resection is the cornerstone of curative therapy for resectable pancreatic adenocarcinoma. Upfront surgery is the gold standard, but it is rarely curative. Neoadjuvant treatment is a logical option, as it may overcome some of the limitations of adjuvant therapy and has already shown some encouraging results. The main concern regarding neoadjuvant therapy is the risk of disease progression during chemotherapy, meaning the opportunity to undergo the intended curative surgery is missed. We reviewed all recent literature in the following areas: major surveys, retrospective studies, meta-analyses, and randomized trials. We then selected the ongoing trials that we believe are of interest in this field and report here the results of a comprehensive review of the literature. Meta-analyses and randomized trials suggest that neoadjuvant treatment has a positive effect. However, no study to date can be considered practice changing. We considered design, endpoints, inclusion criteria and results of available randomized trials. Neoadjuvant treatment appears to be at least a feasible strategy for patients with resectable pancreatic cancer.

Impact of Lymph Node Metastases Around the Superior Mesenteric Artery on Postoperative Outcomes of Pancreatic Head Cancer

BACKGROUND

The neural plexus and lymph nodes around the superior mesenteric artery (LN#14), are the most frequent sites involved by pancreatic head cancer. However the influence of metastases to LN#14 on patients' prognosis has rarely been evaluated.

METHODS

The patients who underwent pancreatectomy for pancreatic head cancer between January 2010 and December 2018 were selected. The patients with nodal metastases were classified into an LN#14 + or LN#14-group according to LN#14 metastasis. Clinical and pathological characteristics and prognosis were compared between the two groups.

RESULTS

In total, 99 patients underwent pancreatectomy. Ninety-four patients were positive for lymph node metastases and 14 and 80 were classified as LN#14 + and LN#14 - , respectively. Postoperative median overall survival (OS) of the LN#14 + and LN#14 - groups was 10.2 and 31.1 months, respectively (P < 0.001). Median OS of the LN#14 + group was worse than that of patients with ≥ 4 metastatic nodes in the LN#14 - group (n = 35, 24.7 months, P = 0.002). In multivariate analysis, LN#14 + (hazard ratio [HR] = 3.89, 95% confidence interval [CI], 1.64-8.86) was one of the independent predictors of worse OS.

CONCLUSION

It might be feasible to recognize LN#14 metastases as an important prognostic factor independently from other regional lymph node metastases.

Para-aortic lymph node metastasis detected intraoperatively by systematic frozen section examination in pancreatic head adenocarcinoma: is resection improving the prognosis?

BACKGROUND

This study aimed to evaluate the controversial benefit of a pancreaticoduodenectomy (PD) in patients with PALN metastasis intraoperatively detected by systematic frozen section examination in pancreatic adenocarcinoma.

METHODS

PALN intraoperative examination by frozen section was systematically performed from January 2006 to February 2018 prior to performing PD for pancreatic adenocarcinoma. Until June 2012, PALN + patients still underwent PD (PALN+/PD group) in the framework of a prospective study. Since July 2012, PALN+ was considered as contraindicating the planned PD (PALN+/No-PD group). Post-operative morbidity and survival were compared between these two groups.

RESULTS

Of the 32 PALN + patients intraoperatively detected, the first 13 underwent a PD, while the last 19 did not undergo resection. Seven patients (54%) among 13 PALN+/PD patients developed a post-operative complication against 3 (16%) among 19 PALN+/No-PD patients (p = 0.049). The median length of stay was 5 days longer for PALN+/PD patients (p = 0.001). The median survival did not differ between PALN+/No-PD and PALN+/PD groups (respectively 13.4 months (95%CI:7.6-19.3) and 11.5 months (95%CI:5.9-17.1), p = 0.471). No patient was alive 4 years after surgery in both the PALN+/No-PD or PALN+/PD groups.

CONCLUSION

In case of PALN detected intraoperatively in pancreatic adenocarcinoma, PD does not improve survival compared to current palliative treatment.

A Single-Institution Validation Study of Lymph Node Staging By the AJCC 8th Edition for Patients with Pancreatic Head Cancer: A Proposal to Subdivide the N2 Category

BACKGROUND

According to the revised staging of the American Joint Committee on Cancer, 8th edition (AJCC8), the N category in pancreatic ductal adenocarcinoma is classified as N0 (0), N1 (1-3), and N2 (≥ 4) based on the number of metastatic lymph nodes (LNs). This study aimed to validate this classification and analyze cutoff values of metastatic LN numbers.

METHODS

Patients with pancreatic head ductal adenocarcinoma who underwent pancreaticoduodenectomy at our institution between 2005 and 2016 without preoperative therapy were retrospectively analyzed. The patients were staged by AJCC8, and prognostic analyses were performed. The best cutoff value for the metastatic LN number was determined by the minimum P value approach.

RESULTS

In 228 of 309 patients, LN metastases were found (median number of examined LNs, 41). The median survival time (MST) was 56 months in the N0 group, 34 months in the N1 group, and 20 months in the N2 group (N0 vs N1: P = 0.023; N1 vs N2: P < 0.001). The best cutoff number of metastatic LNs was 4 for patients with LN metastases and 7 for patients with N2 disease. The MST for patients with four to six positive nodes (N2a) was significantly longer than for those with seven or more positive nodes (N2b) (24.0 vs 19.1 months: P = 0.012). For N2b patients, conventional adjuvant chemotherapy did not show survival benefits (P = 0.133), and overall survival did not differ significantly from that for patients with para-aortic LN metastasis (P = 0.562).

CONCLUSION

The N staging of AJCC8 was valid. Clinicians should regard N2b as similar to distant LN metastasis, and more intensive adjuvant therapy may be indicated for this group.

Should a standard lymphadenectomy include the No. 9 lymph nodes for body and tail pancreatic ductal adenocarcinoma?

OBJECTIVES

This study aimed to use a retrospective data base to investigate whether a standard lymphadenectomy during distal pancreatectomy should include the No. 9 lymph nodes (LNs) for resectable pancreatic ductal adenocarcinoma (PDAC) located in the body and tail of the pancreas.

METHODS

Data from 169 patients undergoing curative distal pancreatectomy for PDAC between Jan 1, 2013 and Dec 31, 2016 were collected. According to the tumor location, patients were divided into three groups: pancreatic neck tumor, pancreatic body and tail tumor with margin-to-bifurcation-distance (MTBD) ≤ 2.5 cm and pancreatic body and tail tumor with MTBD > 2.5 cm. The metastatic rate of the No. 9 LNs was compared among the 3 groups. The survival outcomes were analyzed.

RESULTS

The involvement rate for No. 9 LNs was 20.7% (6/29) for pancreatic neck tumors, 17.6% (15/85) for body and tail tumors with MTBD ≤ 2.5 cm and 1.8% (1/55) for MTBD > 2.5 cm. The No. 9 LNs were significantly more frequently involved in neck or body and tail tumors with MTBD ≤2.5 cm than with the cases with MTBD >2.5 cm (OR 0.082, P = 0.016). No. 9 LN involvement was not associated with worse survival compared with survival associated with involvement of other LNs (P = 0.780).

CONCLUSIONS

For PDAC located in the neck or in the body and tail of the pancreas with MTBD ≤ 2.5 cm, the involvement rate for No. 9 LNs is high. Standard lymphadenectomy should include the No. 9 LNs.

Risk factors related to metastasis of para-aortic lymph nodes in pancreatic ductal adenocarcinoma: A retrospective observational study

This study was designed to explore the risk factors related to metastasis of para-aortic lymph node (PALN).Clinicopathologic data of 241 patients with resectable or borderline resectable pancreatic cancer who underwent pancreaticoduodenectomy with extended lymphadenectomy between January 2008 and December 2015 were collected, potential factors related to metastasis of PALN were analyzed.Positive rate of PALN was 19.5% (47/241). Univariate analysis showed that back pain (P = .028), preoperative CA19-9 level (P < .001), tumor size (P < .001), portal vein (PV)/superior mesenteric vein (SMV) invasion (P < .001), superior mesenteric artery (SMA) invasion (P < .001), and diameter > 1.0 cm were in correlation with PALN involvement, multivariate analysis revealed that preoperative CA19-9 level, PV/SMV invasion, SMA invasion and diameter > 1.0 cm were independent risk factors to metastasis of PALN. Patients with LN8+ had a higher positive rate of PALN than with LN8- (38.1% vs 15.6%, P = .001), similar results could be found when LN12+ (35.8% vs 13.2%, P < .001) and LN14+ (41.2% vs 11.0%, P < .001), multivariate analysis showed that LN8+ and LN14+ were closely in correlation with PALN metastasis.Several factors were related to the status of PALN, preoperative CA19-9 level, PV/SMV invasion, SMA invasion and diameter > 1.0 cm were 4 independent risk factors to PALN metastasis. LN8+ and LN14+ were 2 strong predictors of PALN metastasis. A comprehensive analysis covering all possible risk factors related to metastasis of PALN should be given before design of treatment plan whenever involvement of PALN was suspected.

Pancreatic Ductal Adenocarcinoma and Its Variants

Pancreatic cancer represents the seventh leading cause of cancer death in the world, responsible for more than 300,000 deaths per year. The most common tumor type among pancreatic cancers is pancreatic ductal adenocarcinoma, an infiltrating neoplasm with glandular differentiation that is derived from pancreatic ductal tree. Here we present and discuss the most important macroscopic, microscopic, and immunohistochemical characteristics of this tumor, highlighting its key diagnostic features. Furthermore, we present the classic features of the most common variants of pancreatic ductal adenocarcinoma. Last, we summarize the prognostic landscape of this highly malignant tumor and its variants.

Recent Advances in Pancreatic Cancer Surgery of Relevance to the Practicing Pathologist

Recent advances in pancreatic surgery have the potential to improve outcomes for patients with pancreatic cancer. We address 3 new, trending topics in pancreatic surgery that are of relevance to the pathologist. First, increasing awareness of the prognostic impact of intraoperatively detected extraregional and regional lymph node metastases and the international consensus definition on lymph node sampling and reporting. Second, neoadjuvant chemotherapy, which is capable of changing 10% to 20% of initially unresectable, to resectable disease. Third, in patients who remain unresectable following neoadjuvant chemotherapy, local ablative therapies may change indications for treatment and improve outcomes.

Analysis of prognostic factors for pancreatic head cancer according to para-aortic lymph node

This study was designed to investigate the relationship between prognosis of pancreatic head cancer and status of para-aortic lymph node (PALN). A total of 233 patients with pancreatic head cancer who underwent surgical resection between February 2008 and October 2015 were enrolled in this study. Univariate and multivariate analyses were used to reveal the prognostic factors. Prognostic factors for patients with and without metastasis of PALN were analyzed, respectively. The 5-year overall survival (OS) rate was 19.0% for all patients, and the positive rate of PALN metastasis was 18.9% (44/233). The 1-, 2-, 3-, and 5-year OS rates in patients without metastasis of PALN were 79.4%, 54.8%, 36.4%, and 22.9%, respectively, whereas the 1-, 2-, and 3-year survival rates were 54.0%, 14.8%, and 0%, respectively, in patients with metastasis of PALN. Preoperative CA19-9 level, tumor size, T status, N status, and adjuvant therapy were independent prognostic factors for all patients confirmed by multivariate analysis. For patients without PALN metastasis, back pain, tumor size, T status, N status, portal or superior mesenteric vein invasion, and adjuvant therapy were independent prognostic factors, while the only one influence factor for 2-year OS was adjuvant therapy for patients with metastasis of PALN. Metastasis of PALN was associated with poor prognosis for patients with pancreatic head cancer. Patients with and without metastasis of PALN had different prognostic factors, and adjuvant therapy was the only prognostic factor for patients with metastasis of PALN.

Positive para-aortic lymph nodes following pancreatectomy for pancreatic cancer. Systematic review and meta-analysis of impact on short term survival and association with clinicopathologic features

BACKGROUND

The relation between para-aortic lymph nodes (PALN) involvement and pancreatic ductal adenocarcinoma (PDAC) survival, along with the optimal handling of this particular lymph node station remain unclear. A systematic review and meta-analysis was performed to assess this.

METHODS

A search of Medline, Embase, Ovid and Cochrane databases was performed until July 2015 to identify studies reporting on the relation of PALN involvement and PDAC outcomes and a meta-analysis was performed following data extraction.

RESULTS

Ten retrospective studies and two prospective non randomized studies (2467 patients) were included. Patients with positive PALN had worse one (p < 0.00001) and two year (p < 0.00001) survival when compared with patients with negative PALN. Even when comparing only patients with positive lymph nodes (N1), patients with PALN involvement presented with a significant lower one (p = 0.03) and two (p = 0.002) year survival. PALN involvement was associated with an increased possibility of positive margin (R1) resection (p < 0.00001), stations' 12, 14 and 17 malignant infiltration (p < 0.00001), but not with tumour stage (p = 0.78).

DISCUSSION

Involvement of PALN is associated with decreased survival in pancreatic cancer patients. However, existence of long term survivors among this subgroup of patients should be further evaluated, in order to identify factors associated with their favourable prognosis.

Prognostic value of lymph node metastases detected during surgical exploration for pancreatic or periampullary cancer: a systematic review and meta-analysis

BACKGROUND

Hepatic-artery and para-aortic lymph node metastases (LNM) may be detected during surgical exploration for pancreatic (PDAC) or periampullary cancer. Some surgeons will continue the resection while others abort the exploration.

METHODS

A systematic search was performed in PubMed, EMBASE and Cochrane Library for studies investigating survival in patients with intra-operatively detected hepatic-artery or para-aortic LNM. Survival was stratified for node positive (N1) disease.

RESULTS

After screening 3088 studies, 13 studies with 2045 patients undergoing pancreatoduodenectomy were included. No study reported survival data after detection of LNM and aborted surgical exploration. In 110 patients with hepatic-artery LNM, median survival ranged between 7 and 17 months. Estimated pooled mean survival in 84 patients with hepatic-artery LNM was 15 [95%CI 12-18] months (13 months in PDAC), compared to 19 [16-22] months in 270 patients with N1-disease without hepatic-artery LNM (p = 0.020). In 192 patients with para-aortic LNM, median survival ranged between 5 and 32 months. Estimated pooled mean survival in 169 patients with para-aortic LNM was 13 [8-17] months (11 months in PDAC), compared to 17 (6-27) months in 506 patients with N1-disease without para-aortic LNM (p < 0.001). Data on the impact of (neo)adjuvant therapy on survival were lacking.

CONCLUSION

Survival after pancreatoduodenectomy in patients with intra-operatively detected hepatic-artery and especially para-aortic LNM is inferior to patients undergoing pancreatoduodenectomy with other N1 disease. It remains unclear what the consequence of this should be since data on (neo-)adjuvant therapy and survival after aborted exploration are lacking.

The prognostic impact of para-aortic lymph node metastasis in pancreatic cancer: A systematic review and meta-analysis

PURPOSE

To evaluate by a meta-analytic approach the long-term prognostic impact of para-aortic lymph node (PALN) involvement in resected ductal adenocarcinoma of the pancreas.

METHODS

MEDLINE, Embase, PubMed and the Cochrane Library were searched from January 1990 to June 2015. Trials reporting Kaplan-Meier curves and comparing overall long-term survival of negative and metastatic PALN in patients who underwent resection for pancreatic cancer were included. Lymph nodes were classified according to the Japan Pancreatic Society rules and identified using hematoxylin and eosin staining. Hazard ratios (HRs) and 95%CI were estimated for each trial and pooled in a meta-analysis.

RESULTS

Thirteen eligible studies including 2141 patients (364 positive PALN; 1777 negative PALN) were identified. Most of the studies were retrospective. Heterogeneity among trials was high (I(2) = 98.7%; p < .001). PALN metastasis was associated with increased mortality when compared with patients with negative PALN regardless regional nodal status [HR 1.85, 95%CI 1.48-2.31; p < .001]. Median survival was significantly decreased in patients with positive PALN (WMD = -4.92 months 95%CI -6.40; -3.43; p < .001). Moreover, metastatic PALN affected mortality also when regional lymph nodes were positive [HR 1.67, 95%CI 1.34-2.08; p < .001]. No publication bias was detected.

CONCLUSIONS

PALN metastasis appears to correlate with poor prognosis in patients with pancreatic adenocarcinoma. The assessment of PALN status may be considered for a more accurate staging of the disease and appropriated subgroup survival reporting. However, the definitive avoidance of the resection in case of intraoperative metastatic PALN needs further investigation.