Reappraisal of Nodal Staging and Study of Lymph Node Station Involvement in Pancreaticoduodenectomy with the Standard International Study Group of Pancreatic Surgery Definition of Lymphadenectomy for Cancer

SEER-based evaluation of lymph node yield as a prognostic indicator of cancer-specific survival in nonmetastatic pancreatic ductal adenocarcinoma

BACKGROUND/OBJECTIVES

Although the American Joint Committee on Cancer (AJCC) 8th edition recommends harvesting at least 12 lymph nodes for optimal staging in pancreatic ductal adenocarcinoma (PDAC), the precise lymph node yield (LNY) needed for accurate prognostication in different treatment settings remains unclear. This study aimed to identify subgroup-specific LNY cutoffs and evaluate their prognostic significance in nonmetastatic PDAC.

METHODS

We analyzed 5609 patients with nonmetastatic PDAC from the Surveillance, Epidemiology, and End Results (SEER) database undergoing pancreatectomy. Patients were categorized by nodal status (N0 vs. N+) and receipt of neoadjuvant therapy (NAT) or upfront surgery (UPS). We used maximum selected rank statistics and a conditional inference tree approach to determine optimal LNY cutoffs for each subgroup. Kaplan-Meier curves and Cox proportional hazards models were employed to assess cancer-specific survival (CSS) and identify independent prognostic factors.

RESULTS

Distinct LNY thresholds were identified for N0 (>13) and N+ (>10) cohorts, with the highest cutoffs in N0-NAT subgroups (>27). Across all analyses, patients exceeding these LNY cutoffs demonstrated significantly prolonged CSS. The N0-NAT group with LNY >27 achieved the longest median survival (60 months), whereas N+ patients undergoing UPS with LNY ≤10 had the poorest outcomes (16 months). Multivariate Cox regressions consistently showed that higher LNY was an independent predictor of improved survival.

CONCLUSIONS

Higher LNY thresholds than the current AJCC standard of 12 appear beneficial for more accurate staging and improved survival in resected PDAC. Tailoring LNY goals based on nodal status and treatment modality may further refine prognostic stratification and guide more effective therapeutic strategies.

Evaluation of prognostic significance of histopathological characteristics and tumor-infiltrating lymphocytes for pancreatic cancer survival

With a 5-year survival of ˂ 10%, pancreatic cancer is one of the leading causes of cancer-related deaths. Given the role of the distribution of tumor-infiltrating lymphocyte (TILs) subtypes in the tumor and its microenvironment in predicting prognosis, the development of new targeted therapies based on T-cell adaptive response has gained considerable attention. This study aimed to examine the peritumoral spread of TILs and its relationship with other prognostic parameters and survival. This study included 60 patients with pancreatic cancer who had undergone surgery with follow-up between 2011 and 2021. Demographic characteristics, tumor histopathological features, peritumoral TILs counts, and intratumoral programmed cell death protein-1 (PD-1) and programmed death ligand - 1 (PD-L1) positivity were evaluated. Furthermore, overall survival and their efficacy in predicting survival according to TNM stage were analyzed. The number of cluster differentiation-3 positive (CD3 P) TILs increased with advancing pathological T stage. CD3 P and CD8 P TIL counts were higher in patients with peripancreatic fatty tissue invasion. Patients with PD-L1 positivity and higher TIL counts had better survival rates. PD-L1-negative patients with a low CD8 positive/total lymph node count (P/T) ratio had a longer survival. Moreover, patients with poorly differentiated tumors with low CD3 P/T and CD8 P/T ratios had a longer survival. The CD3 P/T and CD8 P/T ratios were compatible with the automatic and manual measurements. Age, tumor differentiation, N stage, and peritumoral TIL count and subtype, when evaluated together with the presence of PD-L1 in the tumor tissue, may have prognostic significance for survival in patients with pancreatic cancer.

Lymph node examination and survival in resected pancreatic ductal adenocarcinoma: retrospective study

BACKGROUND

The minimum number of examined lymph nodes (ELN) required for adequate staging and best prediction of survival has not been established in pancreatic ductal adenocarcinoma (PDAC). The aim of the study was to investigate the influence of ELN on staging and survival in PDAC.

METHODS

Patients undergoing partial or total pancreatectomy for PDAC at two European university hospitals between 2007 and 2018 were retrospectively reviewed. Multivariate Cox regression model and survival analyses were performed to verify adequate staging.

RESULTS

Overall 341 (73 per cent) patients showed lymph node metastasis (N1/N2), whereas 125 (27 per cent) patients had no lymph node involvement (N0). With increasing number of ELN, the proportion of positive lymph nodes increased. The minimum number of ELN needed to detect lymph node involvement was 21. In multivariate analysis, examination of <21 lymph nodes was a significant negative predictor for survival. Examination of ≥21 ELN reversed this effect and ruled out possible misclassification.

CONCLUSION

The number of ELN affects survival in PDAC. Possible misclassification was identified when <21 lymph nodes were examined. Therefore, at least 21 lymph nodes must be examined to avoid false lymph node classification in all types of resection.

Prognostic effect of CD73 in pancreatic ductal adenocarcinoma for disease-free survival after radical surgery

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with a high potency of metastasis or recurrence after radical resection. Effective predictors for metastasis and recurrence postoperatively were dominant for the development of systemic adjuvant treatment regimens. The ATP hydrolase correlated gene CD73 was described as a promoter in tumor growth and immune escape of PDAC. However, there lacked research focused on the role of CD73 in PDAC metastasis. This study aimed to investigate the expression of CD73 in PDAC patients with different outcomes as well as the prognostic effect of CD73 for disease-free survival (DFS).

METHODS

The expression level of CD73 in cancerous samples from 301 PDAC patients was evaluated by immunohistochemistry (IHC) and translated into a histochemistry score (H-score) by the HALO analysis system. Then, the CD73 H-score was involved in multivariate Cox regression along with other clinicopathological characteristics to find independent prognostic factors for DFS. Finally, a nomogram was constructed based on those independent prognostic factors for DFS prediction.

RESULTS

Higher CD73 expression was found in PDAC patients with tumor metastasis postoperatively. Meanwhile, higher CD73 expressions were also investigated in PDAC patients diagnosed with advanced N stage and T stage. Furthermore, CD73 H-score along with tumor margin status, CA19-9, 8th N stage, and adjuvant chemotherapy was indicated as independent prognostic factors for DFS in PDAC patients. The nomogram based on these factors predicted DFS in a good manner.

CONCLUSION

CD73 was associated with PDAC metastasis and served as an effective prognostic factor for DFS in PDAC patients after radical surgery.

Pathological staging in postneoadjuvant pancreatectomy for pancreatic cancer: implications for adjuvant therapy

BACKGROUND

It is unclear whether pathological staging is significant prognostically and can inform the delivery of adjuvant therapy after pancreatectomy preceded by neoadjuvant therapy.

METHODS

This multicentre retrospective study included patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma after neoadjuvant treatment at two Italian centres between 2013 and 2017. T and N status were assigned in accordance with the seventh and eighth editions of the AJCC staging system, as well as according to a modified system with T status definition combining extrapancreatic invasion and tumour size. Patients were then stratified by receipt of adjuvant therapy. Survival analysis and multivariable interaction analysis of adjuvant therapy with pathological parameters were performed. The results were validated in an external cohort from the USA.

RESULTS

The developmental set consisted of 389 patients, with a median survival of 34.6 months. The modified staging system displayed the best prognostic stratification and the highest discrimination (C-index 0.763; 1-, 2- and 3-year time-dependent area under the curve (AUC) 0.746, 0.722, and 0.705; Uno's AUC 0.710). Overall, 67.0 per cent of patients received adjuvant therapy. There was no survival difference by receipt of adjuvant therapy (35.0 versus 36.0 months; P = 0.772). After multivariable adjustment, interaction analysis suggested a benefit of adjuvant therapy for patients with nodal metastases or with tumours larger than 2 cm with extrapancreatic extension, regardless of nodal status. These results were confirmed in the external cohort of 216 patients.

CONCLUSION

Modified staging with a T status definition combining extrapancreatic invasion and tumour size is associated with better prognostic segregation after postneoadjuvant pancreatectomy. This system allows identification of patients who might benefit from adjuvant therapy.

Prognostic Factors in Resected Pancreatic Ductal Adenocarcinoma: Is Neutrophil-Lymphocyte Ratio a Useful Marker?

BACKGROUND

The aim of this study is to analyze the role of neutrophil-lymphocyte ratio (NLR) and its variation pre- and postoperatively (delta NLR) in the overall survival after pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) at a single center and to identify factors associated with overall survival.

METHODS

A retrospective study of consecutive patients undergoing pancreatectomy due to PDAC or undifferentiated carcinoma from January 2010 to January 2020 was performed. Association between the evaluated factors and overall survival was analyzed using a log-rank test and Cox proportional hazard regression model.

RESULTS

Overall, 242 patients underwent pancreatectomy for PDAC or undifferentiated carcinoma. OS was 22.8 months (95% confidence interval (CI): 19.5-29), and survival rates at 1, 3, and 5 years were 72%, 32.5%, and 20.8%, respectively. NLR and delta NLR were not significantly associated with survival (hazard ratio (HR) = 1.14, 95%CI: 0.77-1.68, p = 0.5). Lymph node ratio was significantly associated (HR = 1.66, 95%CI: 1.21-2.26, p = 0.001) in the bivariate analysis. In multivariable analysis, the only factors that were significantly associated with survival were perineural invasion (HR = 1.94, 95%CI: 1.21-3.14, p = 0.006), surgical margin (HR = 1.83, 95%CI: 1.10-3.02, p = 0.019), tumor size (HR = 1.01, 95%CI: 1.003-1.027, p = 0.16), postoperative CA 19-9 level (HR = 1.001, p < 0.001), and completion of adjuvant treatment (HR = 0.53, 95%CI: 0.35-0.8, p = 0.002).

CONCLUSION

Neutrophil-lymphocyte ratio and delta NLR were not associated with the overall survival in this cohort. Risk factors such as perineural invasion, surgical margins, CA19-9 level, and tumor size showed worse survival in this study, whereas completing adjuvant treatment was a protective factor.

Prognostic Impact of Gastroduodenal Artery Involvement in Cancer of the Pancreatic Head

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) contacting major arteries such as the celiac, common hepatic, and superior mesenteric artery is linked to poor prognosis and classified as borderline resectable. Although PDAC involving the gastroduodenal artery (GDA) is considered resectable, the prognostic impact of GDA involvement remains unclear. Here we investigated the prognostic impact of GDA involvement in PDAC after resection.

METHODS

This study included 105 patients with resectable PDAC or borderline resectable with portal vein involvement. Patients were divided into two groups: those with tumor-GDA contact ≤ 180° and those with GDA contact > 180°. We evaluated the prognostic impact of GDA involvement between these groups.

RESULTS

Both recurrence-free and overall survival after the surgery were significantly poorer with GDA contact > 180° than ≤ 180°. The poorer prognosis with GDA contact > 180° was verified by multivariate analysis and propensity score matching analysis to match patient backgrounds between the groups. The frequency of postoperative distant metastasis was also significantly higher in patients with GDA contact > 180°.

CONCLUSIONS

GDA involvement is an independent factor significantly associated with postoperative survival in PDAC, and the poorer prognosis with GDA involvement may be linked to the development of postoperative distant metastasis.

Reevaluation of regional lymph nodes in patients with pancreatic ductal adenocarcinoma in the pancreatic body and tail

Introduction

In patients with pancreatic ductal adenocarcinoma (PDAC) in the pancreatic body (Pb) and tail (Pt), the appropriate area for lymphadenectomy is controversial. This study aimed to reevaluate the extent of lymph node (LN) metastasis in Pb- and Pt-PDAC, and to define the optimal area of LN dissection.

Patients and methods

This single-center retrospective study evaluated patients with Pb- and Pt-PDAC who underwent distal pancreatectomy with extended lymphadenectomy between 2006 and 2020. LN metastasis in >3.0% of patients were defined as new regional LN.

Results

The study cohort included 135 patients with Pb-PDAC and 42 patients with Pt-PDAC. In patients with Pb-PDAC, LNs around the splenic artery (SPA) had the highest metastasis-positive rate (54.1%). LNs along the left gastric artery, common hepatic artery, celiac axis (CA), superior mesenteric artery (SMA), and splenic hilus were defined as new regional LNs. In patients with Pt-PDAC, LNs at the splenic hilum had the highest metastasis-positive rate (38.1%). The station and LN around the SPA were defined as new regional LNs in those with Pt-PDAC. Metastasis beyond the newly defined regional LNs was not associated with survival. The incidence of LN metastasis was lower in patients who received preoperative chemotherapy than in those who underwent upfront surgery in both Pb- and Pt-PDAC.

Conclusion

Although it needs to be verified in future multicenter studies, LN of both the CA and SMA systems should be dissected in patients with Pb-PDAC. However, only those around the SPA and splenic hilus should be dissected routinely in those with Pt-PDAC.

Pancreatoduodenectomy at the Verona Pancreas Institute: the Evolution of Indications, Surgical Techniques, and Outcomes: A Retrospective Analysis of 3000 Consecutive Cases

OBJECTIVE

The aim of the present study was to critically reappraise the experience at our high-volume institution to obtain new insights for future directions.

SUMMARY BACKGROUND DATA

The indications, surgical techniques, and perioperative management of pancreatoduodenectomy (PD) have profoundly evolved over the last 20 years.

METHODS

All consecutive PDs performed during the last 20 years at the Verona Pancreas Institute were divided into four 5-year timeframes and retrospectively analyzed in terms of indications, intraoperative features, and surgical outcomes. Significant milestones were provided to understand practice changes using a before-after analysis method.

RESULTS

The study population consisted of 3000 patients. The median age, ASA ≥ 3 and number of nonbenchmark cases significantly increased over time ( P < 0.005). Pancreatic cancer was the leading indication, representing 60% of patients/year in the last timeframe, 40% of whom received neoadjuvant treatment. Conversely, after the development of International Guidelines, the proportion of resected cystic neoplasms progressively and thoroughly decreased. Given the increased complexity of surgery for pancreatic cancer, the evolution of technologies, surgical techniques, and postoperative management allowed the maintenance of favorable surgical outcomes over time, with a stable 20.0% of patients with a Clavien-Dindo grade ≥ 3, an 11.7% failure to rescue and a 2.3% in-hospital mortality rate. The incidence of postoperative pancreatic fistula, hemorrhage, and delayed gastric emptying was 22.4%, 13.4%, and 12.4%, respectively.

CONCLUSIONS

PD significantly evolved in Verona over the past 2 decades. Surgeries of greater complexity are currently performed on increasingly frailer patients, mostly for pancreatic cancer and often after neoadjuvant chemotherapy. However, the progression of all fields of pancreatic surgery, including the expanding use of postoperative pancreatic fistula mitigation strategies, has allowed satisfactory outcomes to be maintained.

Reassessment of the Optimal Number of Examined Lymph Nodes in Pancreatoduodenectomy for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of this study was to reappraise the optimal number of examined lymph nodes (ELNs) in pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

SUMMARY BACKGROUND DATA

The well-established threshold of 15 ELNs in PD for PDAC is optimized for detecting 1 positive node (PLN) per the previous 7th edition of the American Joint Committee on Cancer (AJCC) staging manual. In the framework of the 8th edition, where at least 4 PLN are needed for an N2 diagnosis, this threshold may be inadequate for accurate staging.

METHODS

Patients who underwent upfront PD at 2 academic institutions between 2000 and 2016 were analyzed. The optimal ELN threshold was defined as the cut-point associated with a 95% probability of identifying at least 4 PLNs in N2 patients. The results were validated addressing the N-status distribution and stage migration.

RESULTS

Overall, 1218 patients were included. The median number of ELN was 26 (IQR 17-37). ELN was independently associated with N2-status (OR 1.27, P < 0.001). The estimated optimal threshold of ELN was 28. This cut-point enabled improved detection of N2 patients and stage III disease (58% vs 37%, P = 0.001). The median survival was 28.6 months. There was an improved survival in N0/N1 patients when ELN exceeded 28, suggesting a stage migration effect (47 vs 29 months, adjusted HR 0.649, P < 0.001). In N2 patients, this threshold was not associated with survival on multivariable analysis.

CONCLUSION

Examining at least 28 LN in PD for PDAC ensures optimal staging through improved detection of N2/stage III disease. This may have relevant implications for benchmarking processes and quality implementation.

Evaluation of the 8th Edition AJCC Staging System for the Clinical Staging of Pancreatic Cancer

The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic cancer (PC) has been validated for pathological staging; however, its significance for clinical staging remains uncertain. We validated the prognostic performance and suitability of the current staging system for the clinical staging of PC. We identified 1043 patients from our PC registry who were staged by imaging according to the 8th edition staging system and conducted analysis, including overall survival (OS) comparison. Gradual prognostic stratification according to stage hierarchy yielded significant OS differences between stage groups, except between stage I and II (p = 0.193). A substage comparison revealed no survival differences between IB (T2N0) and IIA (T3N0), which were divided by the T3 criterion only (p = 0.278). A higher N stage had significantly shorter OS than a lower N stage (all pairwise p < 0.05). However, among the 150 patients who received upfront surgery, the pathological stage was more advanced than the clinical stage in 86 (57.3%), mostly due to a false-negative cN0 (70.9%). Our results suggest that the new definition of T3 and the number-based N criteria in the 8th edition AJCC staging system may be not adequate for clinical staging. Establishing separate criteria more suitable for clinical staging should be considered.

Prognosis of pancreatic head cancer with different patterns of lymph node metastasis

BACKGROUND

The nodal stage of pancreatic ductal adenocarcinoma (PDAC) is revised in the AJCC 8th edition. Studies on the prognosis of PDAC according to lymph node metastasis (LNM) are still ongoing. We attempted to find the patterns of nodal involvement and to reveal its clinical significance to overall survival (OS).

METHODS

We analyzed 585 patients who received pancreatic head cancer surgery diagnosed as PDAC from January 2007 to December 2016. Patients were classified into three groups: Group 1 (G1, patients without LNM), Group 2 (G2, those with LNM only in the peripancreatic area), and Group 3 (G3 those with LNM in the other area and/or peripancreatic LNM). Risk factors were analyzed by Cox-regression test and overall survival was compared by Kaplan-Meier analysis.

RESULTS

LNM in peripancreatic area was the most common (88.7%). In the multivariate analysis, T stage, nuclear differentiation, adjuvant treatment, and the G2 and G3 were independent risk factors for OS (G2 over G1, HR 1.384, 95% CI 1.046-1.802; P = .036 and G3 over G1, HR 2.383, 95% CI 1.378-4.103; P = .001). G3 showed worse OS than G2 (P = .006). In the N1 status, LNM to the pericholedochal (PC) and superior mesenteric artery (SMA) areas resulted in worse OS than the G2 (P = .011 and P = .019).

CONCLUSIONS

We found that LNM beyond the peripancreatic area significantly affects OS in pancreatic head cancer patients. Depending on the station of the LNM, different risk-stratification and treatment strategies will need to be considered.

Current status and future perspectives of clinical research in pancreatic cancer: Establishment of evidence by science

Pancreatic cancer is one of the most aggressive diseases in the world due to a lack of early detection, leading to an overall 5-year survival of only 10%. In recent years, clinical trials targeted pancreatic cancer in efforts to improve survival. These studies introduce new technologies, concepts, and evidence which have instilled new optimism for improving prognosis. This review summarizes the current status of the recent (5-year) clinical trials and describes contemporary research on pancreatic cancer, including surgical technology, diagnostic skills, traditional chemoradiotherapy, neoadjuvant chemotherapy, immunotherapy, targeted therapy, and precision medicine. Then, the future trend and direction of clinical trials on pancreatic cancer are discussed.

Clinical implications of lymphadenectomy for invasive ductal carcinoma of the body or tail of the pancreas

Aim

The appropriate extent of lymphadenectomy for pancreatic cancer of the body/tail has not been standardized worldwide. The present study evaluated the optimal extent of harvesting lymph nodes.

Methods

Patients who underwent distal pancreatectomy for invasive ductal carcinoma of the pancreas between 2007 and 2018 were retrospectively reviewed. Patients were subclassified into three groups depending on the tumor location: pancreatic body (Pb), proximal pancreatic tail (Ptp), and distal pancreatic tail (Ptd). The pancreatic tail was further divided into even sections of Ptp and Ptd. Patterns of lymph node metastasis and the impact of lymph node metastasis on the prognosis were examined.

Results

A total of 120 patients were evaluated. Fifty-eight patients had a tumor in the Pb, 38 in the Ptp, and 24 in the Ptd. No patients with a Ptd tumor had metastasis beyond the peripancreatic and splenic hilar lymph nodes (LN-PSH). All patients with metastasis to the lymph nodes along the common hepatic artery (LN-CHA) or along the left lateral superior mesenteric artery (LN-SMA) also had metastasis to the LN-PSH. Recurrence after surgery occurred significantly earlier in this population. In a multivariate analysis, metastasis to the LN-CHA or LN-SMA (hazard ratio [HR] 3.3; P = .04) was an independent risk factor for overall survival. Furthermore, high levels of preoperative serum CA19-9 (HR 10.9; P = .013) were a predictive factor for metastasis to the LN-CHA or LN-SMA.

Conclusions

Metastasis to the LN-CHA or LN-SMA was rare but a significant prognostic factor in patients with pancreatic body/tail cancer.

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.

Para-aortic lymph node involvement should not be a contraindication to resection of pancreatic ductal adenocarcinoma

BACKGROUND

Para-aortic lymph nodes (PALN) are found in the aortocaval groove and they are staged as metastatic disease if involved by pancreatic ductal adenocarcinoma (PDAC). The data in the literature is conflicting with some studies having associated PALN involvement with poor prognosis, while others not sharing the same results. PALN resection is not included in the standard lymphadenectomy during pancreatic resections as per the International Study Group for Pancreatic Surgery and there is no consensus on the management of these cases.

AIM

To investigate the prognostic significance of PALN metastases on the oncological outcomes after resection for PDAC.

METHODS

This is a retrospective cohort study of data retrieved from a prospectively maintained database on consecutive patients undergoing pancreatectomies for PDAC where PALN was sampled between 2011 and 2020. Statistical comparison of the data between PALN+ and PALN- subgroups, survival analysis with the Kaplan-Meier method and risk analysis with univariable and multivariable time to event Cox regression analysis were performed, specifically assessing oncological outcomes such as median overall survival (OS) and disease-free survival (DFS).

RESULTS

81 cases had PALN sampling and 17 (21%) were positive. Pathological N stage was significantly different between PALN+ and PALN- patients (P = 0.005), while no difference was observed in any of the other characteristics. Preoperative imaging diagnosed PALN positivity in one case. OS and DFS were comparable between PALN+ and PALN- patients with lymph node positive disease (OS: 13.2 mo vs 18.8 mo, P = 0.161; DFS: 13 mo vs 16.4 mo, P = 0.179). No difference in OS or DFS was identified between PALN positive and negative patients when they received chemotherapy either in the neoadjuvant or in the adjuvant setting (OS: 23.4 mo vs 20.6 mo, P = 0.192; DFS: 23.9 mo vs 20.5 mo, P = 0.718). On the contrary, when patients did not receive chemotherapy, PALN disease had substantially shorter OS (5.5 mo vs 14.2 mo; P = 0.015) and DFS (4.4 mo vs 9.8 mo; P < 0.001). PALN involvement was not identified as an independent predictor for OS after multivariable analysis, while it was for DFS doubling the risk of recurrence.

CONCLUSION

PALN involvement does not affect OS when patients complete the indicated treatment pathway for PDAC, surgery and chemotherapy, and should not be considered as a contraindication to resection.

Prognostic impact of para-aortic lymph node status in resected pancreatic ductal adenocarcinoma and invasive intraductal papillary mucinous neoplasm - Time to consider a reclassification?

BACKGROUND

Para-aortic lymph node (PALN) metastases in pancreatic ductal adenocarcinoma (PDAC) correlates with poor prognosis. The role of PALN in invasive intraductal papillary mucinous neoplasms (inv-IPMN) has not been well explored. The present study investigated the rate of metastatic PALN, lymph node ratio (LNR) and the overall nodal (N) status as prognostic factors in PDAC and inv-IPMN.

METHODS

This consecutive single-center series included patients with PDAC or inv-IPMN in the pancreatic head who underwent pancreatoduodenectomy or total pancreatectomy, including PALN resection between 2009 and 2018. Median overall survival (mOS) and impact of clinicopathological factors, including PALN status on survival, were evaluated.

RESULTS

403 patients were included, 314 had PDAC and 89 inv-IPMN. PALN were metastatic in 16% of PDAC and 17% of inv-IPMN. N0 status was present in 6% of the patients with PDAC and 16% of inv-IPMN patients (p = 0.007). LNR >15% was more common in PDAC (52%) than in inv-IPMN (34%) (p = 0.004). mOS was 12.7 months in the presence of PALN metastases and 22.7 months without (p < 0.0001). Age >70 years, CA19-9 >200 U/mL, PDAC and N2 status were significantly associated with worse survival in a multivariable analysis. PALN status and LNR were not independent prognostic factors. In N2 status mOS was similar regardless the presence of PALN metastases.

CONCLUSION

The frequency of PALN metastases was similar in PDAC and inv-IPMN. Although PALN positive status entailed a shorter mOS, it was not an independent risk factor for death, and did not influence survival in N2-staged disease. The M1-status for PALN positivity may need reconsideration.

N, LNR or LODDS: Which Is the Most Appropriate Lymph Node Classification Scheme for Patients with Radically Resected Pancreatic Cancer?

Simple Summary

To date, no data are available regarding the most appropriate alternative LN classification system with respect to prognostic power and discriminative ability in cases with resectable pancreatic ductal adenocarcinoma (PDAC). We compared different lymph node classification systems with regard to accurate evaluation of overall survival in 319 patients with resected PDAC. One LNR and one LODDS classification scheme were found to out-perform the N category in distinct patient subgroups. Only the LODDS classification exhibited statistically significant, gradually increasing HRs of their subcategories and, at the same time, significantly better discriminative potential in the subgroups of patients with PDAC of the head or corpus and in patients with tumor-free resection margins or M0 status, respectively.

Abstract

Background: Even though numerous novel lymph node (LN) classification schemes exist, an extensive comparison of their performance in patients with resected pancreatic ductal adenocarcinoma (PDAC) has not yet been performed. Method: We investigated the prognostic performance and discriminative ability of 25 different LN ratio (LNR) and 27 log odds of metastatic LN (LODDS) classifications by means of Cox regression and C-statistic in 319 patients with resected PDAC. Regression models were adjusted for age, sex, T category, grading, localization, presence of metastatic disease, positivity of resection margins, and neoadjuvant therapy. Results: Both LNR or LODDS as continuous variables were associated with advanced tumor stage, distant metastasis, positive resection margins, and PDAC of the head or corpus. Two distinct LN classifications, one LODDS and one LNR, were found to be superior to the N category in the complete patient collective. However, only the LODDS classification exhibited statistically significant, gradually increasing HRs of their subcategories and at the same time significantly higher discriminative potential in the subgroups of patients with PDAC of the head or corpus and in patients with tumor free resection margins or M0 status, respectively. On this basis, we built a clinically helpful nomogram to estimate the prognosis of patients after radically resected PDAC. Conclusion: One LNR and one LODDS classification scheme were found to out-perform the N category in terms of both prognostic performance and discriminative ability, in distinct patient subgroups, with reference to OS in patients with resected PDAC.

Fluorescence Molecular Targeting of Colon Cancer to Visualize the Invisible

Colorectal cancer (CRC) is a common cause of cancer and cancer-related death. Surgery is the only curative modality. Fluorescence-enhanced visualization of CRC with targeted fluorescent probes that can delineate boundaries and target tumor-specific biomarkers can increase rates of curative resection. Approaches to enhancing visualization of the tumor-to-normal tissue interface are active areas of investigation. Nonspecific dyes are the most-used approach, but tumor-specific targeting agents are progressing in clinical trials. The present narrative review describes the principles of fluorescence targeting of CRC for diagnosis and fluorescence-guided surgery with molecular biomarkers for preclinical or clinical evaluation.

Accurate Nodal Staging in Pancreatic Cancer in the Era of Neoadjuvant Therapy

BACKGROUND

Nodal disease is prognostic in pancreatic ductal adenocarcinoma (PDAC); however, optimal number of examined lymph nodes (ELNs) required to accurately stage nodal disease in the current era of neoadjuvant therapy remains unknown. The aim of the study was to evaluate the optimal number of ELNs in patients with neoadjuvantly treated PDAC.

METHODS

A retrospective study was performed on patients with PDAC undergoing resection following neoadjuvant treatment between 2011 and 2018. Clinicopathological data were extracted and analyzed.

RESULTS

Of 546 patients included, 232 (42.5%) had lymph node metastases. The median recurrence free survival (RFS) was 10.6 months (95% confidence interval: 9.7-11.7) and nodal disease was independently associated with shorter RFS (9.1 vs 11.9 months; p < 0.001). A cutoff of 22 ELNs was identified that stratified patients by RFS. Patients with N1 and N2 disease had similar median RFS (9.1 vs 8.9 months; p = 0.410). On multivariable analysis, ELN of ≥ 22 was found to be significantly associated with longer RFS among patients with N0 disease (14.2 vs. 10.9 months, p = 0.046). However, ELN has no impact on RFS for patients with N1/N2 disease (9.5 vs. 8.4 months, p = 0.190). Adjuvant therapy was associated with RFS only in patients with residual nodal disease.

CONCLUSIONS

Lymph node metastases remain prognostic in PDAC patients after neoadjuvant treatment. Among N0 patients, a cutoff of 22 ELN was associated with improved RFS and resulted in optimal nodal staging.

Prognostic Performance of Alternative Lymph Node Classification Systems for Patients with Medullary Thyroid Cancer: A Single Center Cohort Study

BACKGROUND

Lymph node ratio (LNR) and the log odds of positive lymph nodes (LODDS) have been proposed as alternative lymph node (LN) classification schemes. Various cut-off values have been defined for each system, with the question of the most appropriate for patients with medullary thyroid cancer (MTC) still remaining open. We aimed to retrospectively compare the predictive impact of different LN classification systems and to define the most appropriate set of cut-off values regarding accurate evaluation of overall survival (OS) in patients with MTC.

METHODS

182 patients with MTC who were operated on between 1985 and 2018 were extracted from our medical database. Cox proportional hazards regression models and C-statistics were performed to assess the discriminative power of 28 LNR and 28 LODDS classifications and compare them with the N category according to the 8th edition of the AJCC/UICC TNM classification in terms of discriminative power. Regression models were adjusted for age, sex, T category, focality, and genetic predisposition.

RESULTS

High LNR and LODDS are associated with advanced T categories, distant metastasis, sporadic disease, and male gender. In addition, among 56 alternative LN classifications, only one LNR and one LODDS classification were independently associated with OS, regardless of the presence of metastatic disease. The C-statistic demonstrated comparable results for all classification systems showing no clear superiority over the N category.

CONCLUSION

Two distinct alternative LN classification systems demonstrated a better prognostic performance in MTC patients than the N category. However, larger scale studies are needed to further verify our findings.

Clinical significance and predictors of complete or near-complete histological response to preoperative chemoradiotherapy in patients with localized pancreatic ductal adenocarcinoma

BACKGROUND

The clinical value and predictors of a favorable histological response to preoperative chemoradiotherapy (CRT) in pancreatic ductal adenocarcinoma (PDAC) remains undefined.

OBJECTIVE

To assess the significance and predictors of a favorable histological response to preoperative CRT in patients with localized PDAC.

METHODS

The study included 203 patients with localized PDAC undergoing curative-intent resection after CRT. The rate of R0 resection and overall survival (OS) and recurrence-free survival (RFS) were correlated with the grading of histological response to determine optimal stratification. Clinical factors associated with a significant histological response were evaluated using multivariate regression analysis.

RESULTS

Among all patients, eight patients (3.9%) had a grade 4 (pCR); 40 (19.4%) had a grade 3 estimated rate of residual neoplastic cells <10% (near-pCR); and 155 (76.7%) had a grade 1/2 limited response. The 48 patients with pCR/near-pCR achieved significantly higher R0 resection rate (100%) than those with grade 1/2 (80.0%). The 5-year OS and RFS rates were significantly higher in the patients with pCR/near-pCR (45.3% and 36.5%) than in those with grade 1/2 (27.1% and 18.5%). Gemcitabine plus S-1 based CRT, serum CA19-9 level after CRT <83 U/mL, and interval from initial treatment to surgery ≥4.4 months were independent predictive factors for pCR/near-pCR.

CONCLUSIONS

pCR or near-pCR to preoperative CRT contributed to achieving a high rate of R0 resection and improving survival for localized PDAC. The use of gemcitabine plus S-1 as a radiosensitizer, lower serum CA19-9 level after CRT, and longer preoperative treatment duration were significantly associated with pCR or near-pCR.

Optimal extent of lymphadenectomy for radical surgery of pancreatic head adenocarcinoma: 2-year survival rate results of single-center, prospective, randomized controlled study

BACKGROUND

Radical pancreaticoduodenectomy is the only possible cure for pancreatic head adenocarcinoma, and although several RCT studies have suggested the extent of lymph node dissection, this issue remains controversial. This article wanted to evaluate the survival benefit of different lymph node dissection extent for radical surgical treatment of pancreatic head adenocarcinoma.

METHODS

A total of 240 patients were assessed for eligibility in the study, 212 of whom were randomly divided into standard lymphadenectomy group (SG) or extended lymphadenectomy group (EG), there were 97 patients in SG and 95 patients in EG receiving the radical pancreaticoduodenectomy.

RESULT

The demography, histopathology and clinical characteristics were similar between the 2 groups. The 2-year overall survival rate in the SG was higher than the EG (39.5% vs 25.3%; P = .034). The 2-year overall survival rate in the SG who received postoperative adjuvant chemotherapy was higher than the EG (60.7% vs 37.1%; P = .021). There was no significant difference in the overall incidence of complications between the 2 groups (P = .502). The overall recurrence rate in the SG and EG (70.7% vs 77.5%; P = .349), and the patterns of recurrence between 2 groups were no significant differences.

CONCLUSION

In multimodality therapy system, the efficacy of chemotherapy should be based on the appropriate lymphadenectomy extent, and the standard extent of lymphadenectomy is optimal for resectable pancreatic head adenocarcinoma. The postoperative slowing of peripheral blood lymphocyte recovery might be 1 of the reasons why extended lymphadenectomy did not result in survival benefits.

CLINICAL TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov (NCT02928081) in October 7, 2016. https://clinicaltrials.gov/.

Validation and modification of the AJCC 8th TNM staging system for pancreatic ductal adenocarcinoma in a Chinese cohort: A nationwide pancreas data center analysis

Objective

To validate the 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC) in a Chinese cohort of radically resected patients and to develop a refined staging system for PDAC.

Methods

Data were collected from the China Pancreas Data Center (CPDC) for patients with resected PDAC in 2016 and 2017, and cancer-specific survival (CSS) was evaluated using the Kaplan-Meier method and log-rank test. Univariate and multivariate analyses based on Cox regression were performed to identify prognostic factors. The recursive partitioning analysis (RPA), Kaplan-Meier method, and log-rank test were performed on the training dataset to generate a proposed modification for the 8th TNM staging system utilizing the preoperative carbohydrate antigen (CA)19-9 level. Validation was performed for both staging systems in the validation cohort.

Results

A total of 1,676 PDAC patients were retrieved, and the median CSS was significantly different between the 8th TNM groupings, with no significant difference in survival between stage IB and IIA. The analysis of T and N stages demonstrated a better prognostic value in the N category. Multivariate analysis showed that the preoperative serum CA19-9 level was the strongest prognostic indicator among all the independent risk factors. All patients with CA19-9 >500 U/mL had similar survival, and we proposed a new staging system by combining IB and IIA and stratifying all patients with high CA19-9 into stage III. The modified staging system had a better performance for predicting CSS than the 8th AJCC staging scheme.

Conclusions

The 8th AJCC staging system for PDAC is suitable for a Chinese cohort of resected patients, and the N category has a better prognostic value than the T category. Our modified staging system has superior accuracy in predicting survival than the 8th AJCC TNM staging system.

Prognostic Discrimination of Alternative Lymph Node Classification Systems for Patients with Radically Resected Non-Metastatic Colorectal Cancer: A Cohort Study from a Single Tertiary Referral Center

BACKGROUND

Lymph node ratio (LNR) and the Log odds of positive lymph nodes (LODDS) have been proposed as a new prognostic indicator in surgical oncology. Various studies have shown a superior discriminating power of LODDS over LNR and lymph node category (N) in diverse cancer entities, when examined as a continuous variable. However, for each of the classification systems various cut-off values have been defined, with the question of the most appropriate for patients with CRC still remaining open. The present study aimed to compare the predictive impact of different lymph node classification systems and to define the best cut-off values regarding accurate evaluation of overall survival in patients with resectable, non-metastatic colorectal cancer (CRC).

METHODS

CRC patients who underwent surgical resection from 1996 to 2018 were extracted from our medical data base. Cox proportional hazards regression models and C-statistics were performed to assess the discriminative power of 25 LNR and 26 LODDS classifications. Regression models were adjusted for age, sex, extent of the tumor, differentiation, tumor size and localization.

RESULTS

Our study group consisted of 654 consecutive patients with non-metastatic CRC. C-statistic revealed 2 LNR and 5 LODDS classifications that demonstrated superior prognostic performance in patients with UICC III CRC, compared to the N category. No clear advantage of one classification over another could be demonstrated in any other patient subgroup.

CONCLUSIONS

Distinct LNR and LODDS classifications demonstrate a prognostic superiority over the N category only in patients with Stage III radically resected CRC.

Complete circumferential lymphadenectomy around the superior mesenteric artery with preservation of nerve plexus reduces locoregional recurrence after pancreatoduodenectomy for resectable pancreatic ductal adenocarcinoma

BACKGROUND

Evaluation of recurrence pattern and risk factors for recurrence are essential for good rates of survival after upfront pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

This retrospective study included 167 consecutive patients who underwent upfront PD for resectable PDAC between 2000 and 2018. Postoperative recurrences were classified into three patterns according to initial recurrence site: isolated locoregional, isolated distant, and simultaneous locoregional and distant recurrences.

RESULTS

This study found 114 patients who developed postoperative recurrence (68.3%), including 37 patients with isolated locoregional recurrence (32.5%), 67 patients with isolated distant recurrence (58.8%), and 10 patients with simultaneous locoregional and distant recurrences (6.0%). When locoregional recurrence was classified based on the location of recurrent lesions, locoregional recurrence most commonly occurred around the superior mesenteric artery (SMA) (70.2%), followed by around the hepatic artery (25.5%) and in the paraaortic region (14.9%). Multivariate analyses showed that complete circumferential lymphadenectomy around the SMA, including not only the right side, but also the left side, was an independent factor for reduction of locoregional recurrence (P = 0.019, odds ratio [OR]: 2.217). Lymph node metastasis was an independent risk factor for both locoregional (P < 0.001, OR: 3.686) and distant recurrences (P < 0.001, OR: 4.315). Non-completion of postoperative adjuvant therapy was a risk factor for distant recurrence (P < 0.001, OR: 3.748).

CONCLUSION

Based on our data, complete circumferential lymphadenectomy around the SMA might contribute to local control, and multidisciplinary treatment including neoadjuvant therapy might be needed for resectable PDAC with high risk for recurrence.

Prognostic value of the lymph node metastasis in patients with ampulla of Vater cancer after surgical resection

Backgrounds/Aims

Patients with Ampulla of Vater cancer have a better prognosis than those with other periampullary cancers. This study aimed to determine the prognostic impact of lymph node metastasis on survival in patients with ampulla of Vater cancer after surgical resection.

Methods

From 1991 to 2016, we retrospectively reviewed data on 104 patients with ampulla of Vater cancer who had received pancreaticoduodenectomy. Clinicopathologic factors such as lymph node ratio (LNR) and number of metastatic lymph nodes that influence survival were statistically analyzed.

Results

5-year survival rate after resection was 57.8%. Mean number of retrieved and metastatic lymph nodes was 13 and 0.95, respectively. In patients with lymph node metastasis, the median number of metastatic lymph nodes and was 1, and the mean LNR was 0.18. LNR >0.2 was a significant prognostic factor for overall survival. Patients with 0 or 1 metastatic lymph nodes had better survival than those with ≥2 metastatic lymph nodes. Univariate analysis revealed that histologic differentiation of tumor, lymph node metastasis, and T stage were significant prognostic factors for overall survival. Multivariate analysis revealed that tumor differentiation and number of metastatic lymph nodes were independent prognostic factors for survival.

Conclusions

Pancreaticoduodenectomy is an appropriate surgical procedure with acceptable long-term survival for ampulla of Vater cancer. Patients with LNR >0.2 and ≥2 positive lymph node metastasis had a poor survival. Tumor differentiation and ≥2 metastatic lymph nodes were independent significant prognostic factors for overall survival. Curative resection with lymph node dissection might control lymph node spread and enhance survival outcomes.

Does Site Matter? Impact of Tumor Location on Pathologic Characteristics, Recurrence, and Survival of Resected Pancreatic Ductal Adenocarcinoma

BACKGROUND

The authors hypothesized that in resected pancreatic adenocarcinoma (PDAC), pathologic characteristics, oncologic outcomes, prognostic factors, and the accuracy of the American Joint Committee on Cancer (AJCC) staging system might differ based on tumor location.

METHODS

Patients undergoing pancreatectomy for PDAC at two academic institutions from 2000 to 2015 were retrieved. A comparative analysis between head (H-PDAC) and body-tail (BT-PDAC) tumors was performed using uni- and multivariable models. The accuracy of the eighth AJCC staging system was analyzed using C-statistics.

RESULTS

Among 1466 patients, 264 (18%) had BT-PDAC, which displayed greater tumor size but significantly lower rates of perineural invasion and G3/4 grading. Furthermore, BT-PDAC was associated with a lower frequency of nodal involvement and a greater representation of earlier stages. The recurrence-free survival and disease-specific survival times were longer for BT-PDAC (16 vs 14 months [p = 0.020] and 33 vs 26 months [p = 0.026], respectively), but tumor location was not an independent predictor of recurrence or survival in the multivariable analyses. The recurrence patterns did not differ. Certain prognostic factors (i.e., CA 19.9, grading, R-status, and adjuvant treatment) were common, whereas others were site-specific (i.e., preoperative pain, diabetes, and multivisceral resection). The performances of the AJCC staging system were similar (C-statistics of 0.573 for H-PDAC and 0.597 for BT-PDAC, respectively).

CONCLUSIONS

Despite differences in pathologic profile found to be in favor of BT-PDAC, tumor location was not an independent predictor of recurrence or survival after pancreatectomy. An array of site-specific prognostic factors was identified, but the AJCC staging system displayed similar prognostic power regardless of primary tumor location.

[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.

The eighth version of American Joint Committee on Cancer nodal classification for high grade pancreatic neuroendocrine tumor should be generalized for the whole population with this disease

Several indexes evaluating the lymph node metastasis of pancreatic neuroendocrine tumor (pNET) have been raised. We aimed to compare the prognostic value of the indexes via the analysis of Surveillance, Epidemiology, and End Results (SEER) database.We identified pNETs patients from SEER database (2004-2015). The prognostic value of N classification which adopted the 8th American Joint Committee on Cancer (AJCC) N classification for well differentiated pNET, revised N classification (rN) which adopted the AJCC 8th N classification for exocrine pancreatic cancer (EPC) and high grade pNET, lymph node ratio and log odds of positive nodes were analyzed.A total of 1791 eligible patients in the SEER cohort were included in this study. The indexes N, rN, lymph node ratio, and log odds of positive nodes were all significant independent prognostic factors for the overall survival. Specifically, the rN had the lowest akaike information criterion of 4050.19, the highest likelihood ratio test (χ) of 48.87, and the highest C-index of 0.6094. The rN was significantly associated with age, tumor location, tumor differentiation, T classification and M classification (P < .05 for all).The 8th version of AJCC N classification for high grade pNET could be generalized for the pNET population.

Role of lymphadenectomy in resectable pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) remains one of the most devastating malignant diseases, predicted to become the second leading cause of cancer-related death by 2030. Despite advances in surgical techniques and in systemic therapy, the 5-year relative survival remains a grim 9% for all stages combined. The extent of lymphadenectomy has been discussed intensively for decades, given that even in early stages of PC, lymph node (LN) metastasis can be detected in approximately 80%.

PURPOSE

The primary objective of this review was to provide an overview of the current literature evaluating the role of lymphadenectomy in resected PC. For this, we evaluated randomized controlled studies (RCTs) assessing the impact of extent of lymphadenectomy on OS and studies evaluating the prognostic impact of anatomical site of LN metastasis and the impact of the number of resected LNs on OS.

CONCLUSIONS

Lymphadenectomy plays an essential part in the multimodal treatment algorithm of PC and is an additional therapeutic tool to increase the chance for surgical radicality and to ensure correct staging for optimal oncological therapy. Based on the literature from the last decades, standard lymphadenectomy with resection of at least ≥ 15 LNs is associated with an acceptable postoperative complication risk and should be recommended to obtain local radicality and accurate staging of the disease. Although radical surgery including appropriate lymphadenectomy of regional LNs remains the only chance for long-term tumor control, future studies specifically assessing the impact of neoadjuvant therapy on extraregional LNs are warranted.

Reappraisal of nodal staging and study of lymph node station involvement in distal pancreatectomy for body-tail pancreatic ductal adenocarcinoma

BACKGROUND

The pattern of nodal spread in body-tail pancreatic ductal adenocarcinoma (PDAC) has been poorly investigated. This study analyzed the characteristics of lymph node (LN) involvement and the prognostic role of nodal metastases stratified by LN stations.

METHODS

All upfront distal pancreatectomies (DPs) for PDAC (2000-2017) with complete information on station 8,10,11, and 18 were included. Clinico-pathological correlates and survival were investigated using uni- and multivariable analyses.

RESULTS

Among 100 included patients, 28 were N0, 42 N1 and 30 N2. The median number of examined LN was 32 (IQR 26-44). Tumor size at preoperative imaging increased across N-classes. Preoperative size >27.5 mm was associated with N2 status. The frequency of nodal metastases at stations 8, 9, 10, 11, and 18 was 12.0%, 10.9%, 3.0%, 71.0%, and 19%, respectively. The pattern of LN spread was independent from primary tumor location (with tail tumors metastasizing to station 8/9 and body tumors to station 10), while it was highly associated with N-class. At multivariable analysis, tumor grading, adjuvant treatment, station 9 and 10 metastases were independent prognostic factors in node-positive patients.

CONCLUSIONS

In patients undergoing upfront DP for PDAC preoperative tumor size is associated with the degree of nodal spread. While station 11 was the most frequently involved, only station-9 and 10 metastases were independent prognostic factors. The site of nodal metastases was somewhat unpredictable based on tumor location. This data has potential implications for allocating patients to neoadjuvant treatment and supports the performance of routine splenectomy during DP for PDAC.

Reappraising the Concept of Conditional Survival After Pancreatectomy for Ductal Adenocarcinoma: A Bi-institutional Analysis

OBJECTIVE

To reappraise the concept of conditional survival (CS) following pancreatectomy for pancreatic ductal adenocarcinoma (PDAC), accounting for the patient's present disease status relative to recurrence.

BACKGROUND

CS, defined as the probability of surviving an additional time frame based on accrued lifespan, offers dynamic survival projections as compared with baseline overall survival.

METHODS

Patients undergoing pancreatectomy for PDAC at 2 institutions from 2000 to 2013 were retrospectively analyzed. The 12-month CS was estimated separately for patients who were disease-free or with recurrence at the given time points. Next, the conditional probability of reaching 60-months of survival was examined in each conditioning set across strata of prognostic covariates, including American Joint Committee on Cancer stage, tumor grade, R-status, and adjuvant treatment.

RESULTS

The study population consisted of 1005 patients. In disease-free patients, the 12-month CS increased as a function of time already survived, showing an opposite trend compared with overall survival. In patients who recurred, the 12-month CS was lower than the disease-free counterpart, especially within 24 months postoperatively. When stratifying by the levels of prognostic covariates, the 60-months CS estimates for disease-free patients tended to level off progressively, indicating that factors independently associated with survival at the time of pancreatectomy lost power over time. This concept did not apply to the conditioning set of patients with recurrence, where CS estimates across variables strata diverged with accrued lifespan.

CONCLUSION

This paper provides new information on how prognosis following pancreatectomy for PDAC evolves over time, adjusting for the time the patient already survived, and for the patient's present disease status relative to recurrence.

Response to Preoperative Therapy in Localized Pancreatic Cancer

Evaluation of response to preoperative therapy for patients with pancreatic adenocarcinoma has been historically difficult. Therefore, preoperative regimens have generally been selected on the basis of baseline data such as radiographic stage and serum CA 19-9 level and then typically administered for a pre-specified duration as long as 6 months or more. The decision to proceed with resection following preoperative therapy likewise has rested upon the absence of disease progression rather than evidence for tumor response. This article reviews the basis for the evaluation of therapeutic response after preoperative therapy for pancreatic cancer in the existing scientific literature, and providing updates and new perspectives.

Role of lymphadenectomy, adjuvant chemotherapy, and treatment at high-volume centers in patients with resected pancreatic cancer-a distinct view on lymph node yield

PURPOSE

While the importance of lymphadenectomy is well-established for patients with resectable pancreatic cancer, its direct impact on survival in relation to other predictive factors is still ill-defined.

METHODS

The National Cancer Data Base 2006-2015 was queried for patients with resected pancreatic adenocarcinoma (stage IA-IIB). Patients were dichotomized into the following two groups, those with 1-14 resected lymph nodes and those with ≥ 15. Optimal number of resected lymph nodes and the effect of lymphadenectomy on survival were assessed using various statistical modeling techniques. Mediation analysis was performed to differentiate the direct and indirect effect of lymph node resection on survival.

RESULTS

A total of 21,912 patients were included; median age was 66 years (IQR 59-73), 48.9% were female. Median number of resected lymph nodes was 15 (IQR 10-22), 10,163 (46.4%) had 1-14 and 11,749 (53.6%) had ≥ 15 lymph nodes retrieved. Lymph node positivity increased by 4.1% per lymph node up to eight examined lymph nodes, and by 0.6% per lymph node above eight. Five-year overall survival was 17.9%. Overall survival was better in the ≥ 15 lymph node group (adjusted HR 0.91, CI 0.88-0.95, p < 0.001). On a continuous scale, survival improved with increasing LNs collected. Patients who underwent adjuvant chemotherapy and were treated at high-volume centers had improved overall survival compared with their counterparts (adjusted HR 0.59, CI 0.57-0.62, p < 0.001; adjusted HR 0.86, CI 0.83-0.89, p < 0.001, respectively). Mediation analysis revealed that lymphadenectomy had only 18% direct effect on improved overall survival, while 82% of its effect were mediated by other factors like treatment at high-volume hospitals and adjuvant chemotherapy.

DISCUSSION

While higher number of resected lymph nodes increases lymph node positivity and is associated with better overall survival, most of the observed survival benefit is mediated by chemotherapy and treatment at high-volume centers.

Prognostic impact of lymph node status in patients after total pancreatectomy for pancreatic ductal adenocarcinoma: A strobe-compliant study

The optimal number of examined lymph nodes (ELN) for staging and impact of nodal status on survival following total pancreatectomy (TP) for pancreatic ductal adenocarcinoma (PDAC) is unclear. The aim of this study was to evaluate the prognostic impact of different lymph node status after TP for PDAC.The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients who underwent TP for PDAC from 2004 to 2015. We calculated overall survival (OS) of these patients using Kaplan-Meier analysis and Cox proportional hazards model.Overall, 1291 patients were included in the study, with 869 node-positive patients (49.5%). A cut-off points analysis revealed that 19, 19, and 13 lymph nodes best discriminated OS for all patients, node-negative patients, and node-positive patients, respectively. Higher number of ELN than the corresponding cut-off points was an independent predictor for better prognosis [all patients: hazard ratios (HR) 0.786, P = .002; node-negative patients: HR 0.714, P = .043; node-positive patients: HR 0.678, P < .001]. For node-positive patients, 1 to 3 positive lymph nodes (PLN) correlated independently with better survival compared with those with 4 or more PLN (HR 1.433, P = .002). Moreover, when analyzed in node-positive patients with less than 13 ELN, neither the number of PLN nor lymph node ratio (LNR) was associated with survival. However, when limited node-positive patients with at least 13 ELN, univariate analyses showed that both the number of PLN and LNR were associated with survival, whereas multivariate analyses demonstrated that only number of PLN was consistently associated with survival (HR 1.556, P = .004).Evaluation at least 19 lymph nodes should be considered as quality metric of surgery in patients who underwent TP for PDAC. For node-negative patients, a minimal number of 19 lymph nodes is adequate to avoid stage migration. For node-positive patients, PLN is superior to LNR in predicting survival after TP, predominantly for those with high number of ELN.

Prognostic Significance of Lymph Node Metastasis and Micrometastasis Along the Left Side of Superior Mesenteric Artery in Pancreatic Head Cancer

BACKGROUNDS AND OBJECTIVES

Although metastasis in lymph nodes along the left side of superior mesenteric artery (SMA-LNs-lt) is sometimes found, survival benefit of SMA-LN-lt dissection for pancreatic head cancer is still unclear. The purpose of this study is to evaluate the prognostic significance of SMA-LN-lt metastasis and micrometastasis.

METHODS

A total of 166 patients with pancreatic head cancer who underwent pancreatectomy with lymphadenectomy including SMA-LNs-lt between 2002 and 2017 were reviewed retrospectively. Micrometastasis was evaluated by immunohistochemistry.

RESULTS

Twenty patients (12%) had SMA-LN-lt metastasis detected by hematoxylin and eosin (HE) staining, and eight patients (5%) had micrometastasis. Patients with SMA-LN-lt HE-positive or micrometastasis group experienced significantly shorter overall survival (OS) than those without (p = .015). In multivariate analysis, SMA-LN-lt HE-positive or micrometastasis (p = .034), portal vein resection (p = .002), histologic grade 2/3 (p = .046), LN metastasis (p = .002), and lack of adjuvant chemotherapy (p < .001) were independent risk factors. Within a subset of SMA-LN-lt HE-positive or micrometastasis group, lack of adjuvant chemotherapy (p = .003) was the independent poor prognostic factor.

CONCLUSIONS

In pancreatic head cancer, the rate of SMA-LN-lt HE-positive and micrometastasis was found in 12% and 5%, respectively. Adjuvant chemotherapy may contribute to improvement of prognosis in patients with LN metastasis including SMA-LN-lt metastasis and micrometastasis.

Local radicality and survival outcome of pancreatic cancer surgery

Pancreatic cancer remains a therapeutic challenge. Surgical resection in combination with systemic chemotherapy is the only option promising long-term survival and potential cure. However, only about 20% of patients are diagnosed with tumors that are still in a resectable stage. Even after potentially curative resection and modern regimens for adjuvant chemotherapy, the majority of patients develop local and systemic recurrence resulting in median overall survival times of 28-54 months. The predominance of systemic recurrence and its impact on survival may lead to the assumption that surgical radicality and local control play only minor roles in the treatment of pancreatic cancer. This review provides an overview of the recent literature on surgical radicality and survival outcome in pancreatic cancer. The current evidence on the extent of lymphadenectomy, the prognostic impact of the extent of lymph node involvement, and the impact of the resection margin status on postresection survival are reviewed. Data from recent studies performed in the context of modern surgery and adjuvant therapy provide good evidence of a considerable impact of local radicality on survival after pancreatic cancer surgery. Surgical techniques that have been developed to refine oncological resections and to increase local control as well as resectability are highlighted. These techniques include artery-first approaches, level-3 dissection with removal of the periarterial nerve plexus, the triangle operation, and extended resections. Local radicality and quality of surgical resection remain among the most important parameters that determine the chances for survival in patients with non-metastatic pancreatic cancer.

Does Neoadjuvant Chemotherapy Change the Role of Regional Lymphadenectomy in Pancreatic Cancer Survival?

OBJECTIVES

The objective of this study was to evaluate the role of lymph node (LN) dissection and staging in outcomes of patients with pancreatic adenocarcinoma (PDAC) who underwent neoadjuvant chemotherapy (NAC).

METHODS

National Cancer Database was queried for patients with stages I to III PDAC diagnosed between 2004 and 2014. Overall survival (OS) was derived from Kaplan-Meier methods, and Cox-regression model was used to evaluate associations between the number of LN examined, number of positive nodes, and LN ratio with OS.

RESULTS

A total 35,599 patients were included, 3395 (9%) underwent NAC, 19,865 (56%) received adjuvant chemotherapy (AC), and 12,299 (35%) underwent surgery alone. Cox-regression showed superior OS in NAC compared with AC and surgery alone (26 vs 23 vs 14 months, P < 0.001). Minimum number of LN examined affecting OS was 8 LNs in NAC (23.8 vs 26.6 months, P = 0.029), and 12 LNs in AC group (22 vs 23.1 months, P = 0.028). Lymph node ratio cutoff of greater than 0.2 was associated with decreased OS (19.4 vs 24.4 months, P < 0.001).

CONCLUSIONS

Neoadjuvant chemotherapy is associated with improved survival in PDAC. Lymph node yield remains a significant prognostic factor after NAC, whereas the minimum number of harvested LNs associated with sufficient staging and survival is decreased.

Microvascular invasion is a major prognostic factor after pancreatico-duodenectomy for adenocarcinoma

BACKGROUND

Microvascular invasion (MVI) has been proved to be poor prognostic factor in many cancers. To date, only one study published highlights the relationship between this factor and the natural history of pancreatic cancer. The aim of this study was to assess the impact of MVI, on disease-free survival (DFS) and overall survival (OS), after pancreatico-duodenectomy (PD) for pancreatic head adenocarcinoma. Secondarily, we aim to demonstrate that MVI is the most important factor to predict OS after surgery compared with resection margin (RM) and lymph node (LN) status.

MATERIALS AND METHODS

Between January 2015 and December 2017, 158 PD were performed in two hepato-bilio-pancreatic (HBP) centers. Among these, only 79 patients fulfilled the inclusion criteria of the study. Clinical-pathological data and outcomes were retrospectively analyzed from a prospectively maintained database.

RESULTS

Of the 79 patients in the cohort, MVI was identified in 35 (44.3%). In univariate analysis, MVI (P = .012 and P < .0001), RM (P = .023 and P = .021), and LN status (P < .0001 and P = .0001) were significantly associated with DFS and OS. A less than 1 mm margin clearance did not influence relapse (P = .72) or long-term survival (P = .48). LN ratio > 0.226 had a negative impact on OS (P = .044). In multivariate analysis, MVI and RM persisted as independent prognostic factors of DFS (P = .0075 and P = .0098, respectively) and OS (P < .0001 and P = .0194, respectively). Using the likelihood ratio test, MVI was identified as the best fit to predict OS after PD for ductal adenocarcinomas compared with the margin status model (R0 vs R1) (P = .0014).

CONCLUSION

The MVI represents another major prognostic factor determining long-term outcomes.

Validation of the American Joint Committee on Cancer 8th edition staging system for the pancreatic ductal adenocarcinoma

BACKGROUND & AIMS

The American Joint Commission on Cancer (AJCC) 8th edition staging system for pancreatic ductal adenocarcinoma (PDA) contains several significant changes. This study aimed to validate the AJCC 8th edition staging system of PDA.

METHODS

We analyzed patients with resected PDA between 2001 and 2017 using the Korean Pancreatic Cancer (K-PaC) registry. Overall survival (OS) was estimated using the Kaplan-Meier survival curves and compared via the log-rank test.

RESULTS

In total, 701 resected PDA patients were identified. During a median follow-up of 24.5 months, the median OS was 21.7 months. Meanwhile, the median OS of each stage according to the AJCC 8th edition was 73.5 months (stage IA), 41.9 months (stage IB), 24.2 months (stage IIA), 18.3 months (stage IIB), and 16.8 months (stage III). However, the new N-category (pN1 vs. pN2) did not subdivide prognosis, although the lymph node ratio (i.e., the ratio of the number of LN involved to the number of examined LN) did. Although pT3 and pN2 belong under stage III, pN2 has a significantly longer median OS than pT3 (16.9 months vs 11.2 months; p < 0.01).

CONCLUSION

The AJCC 8th edition staging system appropriately stratifies the prognosis of PDA patients. However, the cutoff of the N-category is not statistically valid, and the new stage III includes a heterogeneous category (pN2 and pT4). Therefore, we propose that stage III be divided into stage IIIA (Tany N2 M0) and stage IIIB (T4 Nany M0).

Determining the optimal number of examined lymph nodes for accurate staging of pancreatic cancer: An analysis using the nodal staging score model

INTRODUCTION

The aim of this study was to determine the optimal number of examined lymph nodes (ELNs) for accurate staging of pancreatic cancer using the nodal staging score model.

MATERIALS AND METHODS

Clinicopathological data for patients with resected pancreatic cancer were collected from SEER database (development cohort [DC]) and Fudan University Shanghai Cancer Center database (validation cohort [VC]). Multivariable models were constructed to assess how the number of ELNs was associated with stage migration and overall survival (OS). Using the β-binomial distribution, we developed a nodal staging score model from the DC and tested it with the VC.

RESULTS

Both cohorts exhibited significant proportional increases from node-negative to node-positive disease (DC: odds ratio [OR], 1.047; P < 0.001; VC: OR, 1.035; P < 0.001) and improved OS (DC: hazard ratio [HR], 0.982; P < 0.001; VC: HR, 0.979; P < 0.001) as ELNs increased. Nodal staging scores escalated separately as ELNs increased for different tumor (T) stages, with plateaus at 16, 21, and 23 LNs (cut-offs) for T1, T2, and T3 tumors, respectively. Multivariable analysis indicated that examining more LNs than the corresponding cut-off value was a significant survival predictor (DC: HR, 0.813; P < 0.001; VC: HR, 0.696; P = 0.028).

CONCLUSION

The optimal number of ELNs for adequate staging of pancreatic cancer was related to T stage. We recommend examining at least 16, 21, and 23 LNs for T1, T2, and T3 tumors, respectively, as a nodal staging quality measure for both surgery and pathological analysis.

Comparison of 3 Ways of Dissecting the Pancreatoduodenectomy Specimen and Their Impact in the Lymph Node Count and the Lymph Node Metastatic Ratio

BACKGROUND

Lymph node metastasis (LNM) is a strong prognostic factor in the cancer of the pancreatobiliary tree, but it is influenced by the number of lymph nodes (LNs). The lymph node ratio (LNR) is considered a more reliable factor than the number of LNM. The aim was to examine the LN retrieval and the LNR of 3 pathologic work-up strategies.

METHODS

Pancreaticoduodenectomies (n = 165) were analyzed comparing 3 pathological dissection techniques, classified as "control," "Verbeke method," and "Adsay method" groups.

RESULTS

The mean of the dissected LNs and the number of cases with >20 LNs were superior in the Adsay method group, compared with the other groups ( P < .001). The LNR was different between the Adsay and Verbeke groups (0.144 vs 0.069, P = .032). The median of the 3 positive LNs was associated with decreased survival compared with an absence of LNM (3-year specific survival of 48% vs 22%, P = .011). In the multivariate analysis, LNM (hazard ratio = 6.148, 95% confidence interval = 2.02-8.1, P = .042) and the evaluation of >15 LNs (hazard ratio = 12.52, 95% confidence interval = 5.51-21.01, P = .001) were independent predictors of survival.

CONCLUSION

The Adsay technique for LN retrieval was associated with a better LN count, more cases with LNM, and an LNR >0.1.

Tumor size classification of the 8th edition of TNM staging system is superior to that of the 7th edition in predicting the survival outcome of pancreatic cancer patients after radical resection and adjuvant chemotherapy

The 8^th edition of TNM staging system has been released and it incorporates many changes to the T and N classifications for pancreatic cancer. Comparative study between the 7^th and 8^th edition of TNM staging system from Asian population has not been reported yet. This study aimed to compare the 7^th and 8^th edition of staging system for pancreatic cancer by using a cohort of pancreatic cancer patients from China after R0 pancreaticoduodenectomy and adjuvant chemotherapy. The results showed according to the pT classification of 7^th edition, pT3 was predominant (87.25%), however, the new edition led to a more equal distribution of pT classification. pT1, pT2 and pT3 was 27.45%, 56.86% and 15.69%, respectively. According to the new pN classification, 18.63% of the patients were pN2. The pT classification in the 8^th edition was significantly superior to that in the 7^th edition at stratifying patients by overall survival. The pN classification in the 8^th edition failed to show an advantage over the 7^th edition in stratifying patients by overall survival. Therefore, the new pT classification, but not the new pN classification, showed a significant advantage over the previous edition at predicting the overall survival of pancreatic cancer patients.

A Comprehensive Assessment of Accurate Lymph Node Staging and Preoperative Detection in Resected Pancreatic Cancer

BACKGROUND

The current (seventh edition) American Joint Commission on Cancer (AJCC) Staging System for pancreatic ductal adenocarcinoma (PDAC) dichotomizes pathologic lymph node (LN) involvement into absence (pN0) or presence (pN1) of disease. The recently announced eighth edition also includes stratification on the number of positive nodes. Furthermore, LNs detected on preoperative imaging (CT, MRI, or endoscopic ultrasound-EUS) are considered to be pathologically involved in other gastrointestinal cancers. However, this is less well defined for PDAC. Therefore, the three aims of this study were to determine (1) whether the new AJCC staging system led to more accurate staging, (2) the number of nodes needed to be examined to detect pathologic involvement, and (3) if pN disease could be reliably detected on preoperative imaging in PDAC.

METHODS

A retrospective review of all patients undergoing pancreatectomy at a single US academic center from January 1990 to September 2015. Pathology reports of resected specimens were reviewed to determine the total number of LNs examined and those positive for metastasis. CT, MRI, and/or EUS reports were used to determine the presence or absence of preoperatively detectable LN enlargement.

RESULTS

Of the 490 surgical resections for PDAC, pN1 disease was detected in 59.4% (n = 291) and was positively correlated with the number of LNs pathologically examined (P < 0.001). Patients with pN1 disease had a shorter overall survival (OS) than those without nodal involvement (25.1 vs. 44.0 months; P < 0.001); however, OS was not different when stratifying by the number of nodes as on the eighth AJCC system. Pathologic examination of > 20 LNs in treatment naïve patients was optimal to detect pN1 disease and predict longer OS for those without nodal involvement (median survival > 41.1 months, P = 0.03 when compared to < 15 or 15-19 LNs examined). LNs were detected by CT, MRI, or EUS in 30.7% (103/335) of patients. The positive predictive value (PPV) of preoperative LN detection for pathologic involvement was 77.3% for treatment naïve patients and 84.2% for those without biliary obstruction.

CONCLUSIONS

Although the LN scoring in the seventh PDAC AJCC Staging System was sufficient to predict OS of our patients, more LNs than previously considered (20 vs. 15) were optimal to detect pathologic involvement. Preoperative LN detection was an accurate predictor of pN1 disease for treatment naïve patients without biliary obstruction.