N0/N1, PNL, or LNR? The effect of lymph node number on accurate survival prediction in pancreatic ductal adenocarcinoma

The relationship between DNA mismatch repair gene and other prognostic parameters in pancreatic adenocarcinoma

The aim of the study was to determine DNA mismatch repair (MMR) proteins by immunohistochemically using MLH1, MSH2, MSH6, and PMS2 antibodies in patients diagnosed as pancreatic ductal adenocarcinoma and to assess its relationship with histopathological and clinical prognostic parameters. Fifty cases with a diagnosis of pancreatic ductal adenocarcinoma who underwent surgical resection, were included in the study. Demographic and histopathological features of the patients were collected from the medical records. The relationships between microsatellite status and prognostic parameters were determined. The mean age of the patients was 66.5 ± 9.5 years (range: 47-87) and male/female ratio was 1.63 (31/19). No errors were detected in DNA MMR proteins in any of the cases, and were classified as microsatellite stable. The mean tumor diameter was 4.01 ± 1.77 cm and 74% of the tumors were localized in the pancreatic head. All of the cases had lymphatic invasion, whereas vascular invasion was detected in only 78% and perineural invasion in 98% of the patients. When the relationship between prognostic parameters and survival was evaluated, statistically significant correlation was observed in patient age and histopathological parameters such as tumor diameter, status of surgical margins, and vascular invasion (p < 0.05). Age, tumor size, presence of tumor at surgical margins, vascular invasion, and adjuvant treatment were correlated with survival. Although microsatellite instability was not detected in our cases, it is important to determine the microsatellite status by immunohistochemistry for predicting the chemotherapy response and determining the immunotherapy option in pancreatic adenocarcinomas.

Impact of Adherence to Operative Standards and Stage-Specific Guideline-Recommended Therapy in Nonmetastatic Pancreatic Adenocarcinoma

BACKGROUND

Achieving optimal surgical outcomes in pancreatic adenocarcinoma requires a combination of both curative-intent resection to oncologic standards and stage-specific neoadjuvant or adjuvant therapy. This investigation sought to examine factors associated with receipt of standard-adherent surgery (SAS) and guideline-recommended therapy (GRT) and determine the impact of compliance on patient survival.

PATIENTS AND METHODS

From the 2006-2016 National Cancer Database, 21,304 patients underwent resection for nonmetastatic pancreatic adenocarcinoma. SAS was defined as pancreatic resection with negative margins and ≥ 15 lymph nodes examined. Stage-specific GRT was defined by current National Comprehensive Cancer Network guidelines. Multivariable models were used to determine predictors of adherence to SAS and GRT and prognostic impact on overall survival.

RESULTS

Overall, SAS was achieved in 39% and GRT in 65% of patients, but only 30% received both SAS and GRT. Increasing age, minority race, uninsured status, and greater comorbidities were associated with a decreased odds of receiving both SAS and GRT (all p < 0.05). SAS (HR 0.79; CI 0.76-0.81; p < 0.001) and GRT (HR 0.67; CI 0.65-0.69; p < 0.001) were each independently associated with a survival advantage. Receipt of both SAS and GRT was associated with significant improvement in median OS compared with receiving neither (2.2 years vs 1.1 years; p < 0.001) which was independently associated with a 78% increased risk of death (HR 1.78; CI 1.70-1.86; p < 0.001).

CONCLUSIONS

Despite survival benefits associated with adherence to operative standards and receipt of guideline-recommended therapy, compliance remains poor. Future efforts must be directed toward improved education and implementation efforts around both operative standards and therapy guidelines.

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.

Higher Numbers of Examined Lymph Nodes Are Associated with Increased Survival in Resected, Treatment-Naïve, Node-Positive Esophageal, Gastric, Pancreatic, and Colon Cancers

BACKGROUND OR PURPOSE

The role of extended lymphadenectomy as part of resection for lymph node (LN)-positive gastrointestinal (GI) malignancies remains controversial with no clear clinical guidance. The purpose of this retrospective study is to determine whether the number of LNs examined as part of GI malignancy resections affects overall survival (OS) among patients with node-positive esophageal, gastric, pancreatic, and colon cancers.

METHODS

Participants with LN-positive GI cancers who were diagnosed between 2004 and 2015 and underwent oncologic resections were selected from National Cancer Database (NCDB). The primary predictor was the number of examined LNs categorized in tertiles. The effect on OS was measured by hazard ratio (HR) derived from multivariate Cox regression analyses.

RESULTS

From 2004 to 2015, 1877, 10,086, 18,193, and 102,500 patients with LN-positive esophageal, gastric, pancreatic, and colon adenocarcinomas who did not receive neoadjuvant treatment and underwent oncologic tumor resection were registered in the NCDB. Using multivariate Cox proportional hazard modeling, greater LNs examined in surgically resected LN-positive GI cancers were found to be associated with increased OS for all histologies. This association was the strongest (as compared to the lowest tertile) for gastric cancer (middle tertile: HR = 0.91, 95% CI, 0.86-0.96, p = 0.001; highest tertile: HR = 0.73, 95% CI, 0.69-0.78, p < 0.001), followed by colon (highest tertile: HR = 0.86, 95% CI, 0.84-0.88, p < 0.001), esophageal (highest tertile: HR = 0.83, 95% CI, 0.72-0.95, p = 0.01), and pancreatic (highest tertile: HR = 0.93, 95% CI, 0.89-0.98, p = 0.002) cancers.

DISCUSSION AND CONCLUSION

In patients with surgically resected node-positive GI malignancies who did not receive neoadjuvant systemic therapy, a higher number of examined LNs is associated with increased OS. This association is the strongest for gastric cancer, followed by colon, esophageal, and pancreatic cancers respectively.

A population-based study of synchronous distant metastases and prognosis in patients with PDAC at initial diagnosis

Objective

Cancer of the pancreas is a life-threatening condition and has a high distant metastasis (DM) rate of over 50% at diagnosis. Therefore, this study aimed to determine whether patterns of distant metastases correlated with prognosis in pancreatic ductal adenocarcinoma (PDAC) with metastatic spread, and build a novel nomogram capable of predicting the 6, 12, 18-month survival rate with high accuracy.

Methods

We analyzed data from the Surveillance, Epidemiology, and End Results (SEER) database for cases of PDAC with DM. Kaplan-Meier analysis, log-rank tests and Cox-regression proportional hazards model were used to assess the impact of site and number of DM on the cancer-specific survival (CSS) and over survival (OS). A total of 2709 patients with DM were randomly assigned to the training group and validation group in a 7:3 ratio. A nomogram was constructed by the dependent risk factors which were determined by multivariate Cox-regression analysis. An assessment of the discrimination and ability of the prediction model was made by measuring AUC, C-index, calibration curve and decision curve analysis (DCA). In addition, we collected 98 patients with distant metastases at the time of initial diagnosis from Ningbo University Affiliated LiHuili Hospital to verify the efficacy of the prediction model.

Results

There was a highest incidence of liver metastases from pancreatic cancer (2387,74.36%), followed by lung (625,19.47%), bone (190,5.92%), and brain (8,0.25%). The prognosis of liver metastases differed from that of lung metastases, and the presence of multiple organ metastases was associated with poorer prognosis. According to univariate and multivariate Cox-regression analyses, seven factors (i.e., diagnosis age, tumor location, grade of tumor differentiation, T-stage, receipt of surgery, receipt of chemotherapy status, presence of multiple organ metastases) were included in our nomogram model. In internal and external validation, the ROC curves, C-index, calibration curves and DCA were calculated, which confirmed that this nomogram can precisely predict prognosis of PDAC with DM.

Conclusion

Metastatic PDAC patients with liver metastases tended to have a worse prognosis than those with lung metastases. The number of DM had significant effect on the overall survival rate of metastatic PDAC. This study had a high prediction accuracy, which was helpful clinicians to analyze the prognosis of PDAC with DM and implement individualized diagnosis and treatment.

Developing and validating a prognostic nomogram for ovarian clear cell carcinoma patients: A retrospective comparison of lymph node staging schemes with competing risk analysis

Purpose

Lymph node (LN) involvement is a key factor in ovarian clear cell carcinoma (OCCC) although, there several indicators can be used to define prognosis. This study examines the prognostic performances of each indicator for OCCC patients by comparing the number of lymph nodes examined (TNLE), the number of positive lymph nodes (PLN), lymph node ratio (LNR), and log odds of metastatic lymph nodes (LODDS).

Methods

1,300 OCCC patients who underwent lymphadenectomy between 2004 and 2015 were extracted from the Surveillance Epidemiology and End Results (SEER) database. Primary outcomes were Overall Survival (OS) and the cumulative incidence of Cancer-Specific Survival (CSS). Kaplan–Meier’s and Fine-Gray’s tests were implemented to assess OS and CSS rates. After conducting multivariate analysis, nomograms using OS and CSS were constructed based upon an improved LN system. Each nomograms’ performance was assessed using Receiver Operating Characteristics (ROC) curves, calibration curves, and the C-index which were compared to traditional cancer staging systems.

Results

Multivariate Cox’s regression analysis was used to assess prognostic factors for OS, including age, T stage, M stage, SEER stage, and LODDS. To account for the CSS endpoint, a proportional subdistribution hazard model was implemented which suggested that the T stage, M stage, SEER stage, and LNR are all significant. This enabled us to develop a LODDS-based nomogram for OS and a LNR-based nomogram for CSS. C-indexes for both the OS and CSS nomograms were higher than the traditional American Joint Committee on Cancer (AJCC), 8th edition, staging system. Area Under the Curve (AUC) values for predicting 3- and 5-year OS and CSS between nomograms also highlighted an improvement upon the AJCC staging system. Calibration curves also performed with consistency, which was verified using a validation cohort.

Conclusions

LODDS and LNR may be better predictors than N stage, TNLE, and PLNs. For OCCC patients, both the LODDS-based and LNR-based nomograms performed better than the AJCC staging system at predicting OS and CSS. However, further large sample, real-world studies are necessary to validate the assertion.

CHRNB2 represses pancreatic cancer migration and invasion via inhibiting β-catenin pathway

Background

Pancreatic cancer is one of the most lethal disease with highly fatal and aggressive properties. Lymph node ratio (LNR), the ratio of the number of metastatic lymph nodes to the total number of examined lymph nodes, is an important index to assess lymphatic metastasis and predict prognosis, but the molecular mechanism underlying high LNR was unclear.

Methods

Gene expression and clinical information data of pancreatic cancer were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Patients in TCGA were averagely divided into low and high LNR groups. Then, Weighted Gene Co-expression Network Analysis (WGCNA) was utilized to build co-expression network to explore LNR-related modules and hub genes. GO and KEGG analysis was performed to find key pathways related to lymph node metastasis. Next, GSE101448 and the overall survival data in TCGA was employed to further select significant genes from hub genes. Considering the key role of CHRNB2 in LNR and survival, gene set enrichment analysis (GSEA) was applied to find pathways related to CHRNB2 expression in pancreatic cancer. The contribution of CHRNB2 to migrative and invasive ability of pancreatic cancer cells was confirmed by Transwell assays. We finally explored the role of CHRNB2 in EMT and β-catenin pathway via Western Blot.

Results

High LNR was significantly related to high T stages and poor prognosis. In WGCNA, 14 hub genes (COL5A1, FN1, THBS2, etc.) were positively related to high LNR, 104 hub genes (FFAR1, SCG5, TMEM63C, etc.) were negatively related to high LNR. After taking the intersection with GSE101448, 13 genes (CDK5R2, SYT7, CACNA2D2, etc.) which might prevent lymph node metastasis were further selected. Among them, CHRNB2 showed the strongest relationship with long survival. Moreover, CHRNB2 also negatively related to the T stages and LNR. Next, knockdown of CHRNB2 expression could acetylcholine (ACh)-independently increase the migration and invasion of pancreatic cancer cells, while CHRNB2 overexpression ACh-independently decrease the migration and invasion of pancreatic cancer cells. For exploring the underlying mechanism, CHRNB2 downregulated β-catenin pathway might through controlling its upstream regulators such as SOX6, SRY, SOX17, and TCF7L2.

Conclusions

CHRNB2 negatively relates to lymph node metastasis in pancreatic cancer patients. CHRNB2 could inhibit β-catenin pathway, EMT, migration and invasion of pancreatic cancer cells via ACh-independent mechanism.

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.

Artificial intelligence in pancreatic cancer

Pancreatic cancer is the deadliest disease, with a five-year overall survival rate of just 11%. The pancreatic cancer patients diagnosed with early screening have a median overall survival of nearly ten years, compared with 1.5 years for those not diagnosed with early screening. Therefore, early diagnosis and early treatment of pancreatic cancer are particularly critical. However, as a rare disease, the general screening cost of pancreatic cancer is high, the accuracy of existing tumor markers is not enough, and the efficacy of treatment methods is not exact. In terms of early diagnosis, artificial intelligence technology can quickly locate high-risk groups through medical images, pathological examination, biomarkers, and other aspects, then screening pancreatic cancer lesions early. At the same time, the artificial intelligence algorithm can also be used to predict the survival time, recurrence risk, metastasis, and therapy response which could affect the prognosis. In addition, artificial intelligence is widely used in pancreatic cancer health records, estimating medical imaging parameters, developing computer-aided diagnosis systems, etc. Advances in AI applications for pancreatic cancer will require a concerted effort among clinicians, basic scientists, statisticians, and engineers. Although it has some limitations, it will play an essential role in overcoming pancreatic cancer in the foreseeable future due to its mighty computing power.

Total Neoadjuvant Treatment for Pancreatic Ductal Adenocarcinoma Is Associated With Limited Lymph Node Yield but Improved Ratio

INTRODUCTION

The lymph node yield (LNY) and lymph node ratio (LNR) of nodal metastases following pancreatoduodenectomy (PD) have been reported as prognostic parameters in patients with pancreatic ductal adenocarcinoma (PDAC). However, they have not been compared in the setting of various neoadjuvant therapy modalities.

METHODS

A single institutional retrospective study identified 134 patients diagnosed with resectable, BLR- and LA-PDAC who underwent PD at Fox Chase Cancer Center between 2010 and 2019. Patients were categorized based on first-line treatment as follows: surgery first (SF), total neoadjuvant therapy (TNT), and single modality neoadjuvant therapy (SMNT). The histopathological reports of the surgical specimens were examined to obtain LNY and determine the counts of lymph nodes with metastases. Subsequently, LNR was calculated as the number of positive lymph nodes divided by the number of lymph nodes examined.

RESULTS

Overall, 49, 38, 27, 12, and 8 patients underwent SF approach, SMNT, incomplete TNT, induction TNT, and consolidation TNT, respectively. There was no difference in R0 resection and vascular resection between the groups (P = 0.096 and 0.794, respectively). The median counts of LNY were 22, 15, 21, 11.5, and 10, respectively (P < 0.001). The average LNR was 0.16, 0.07, 0.03, 0.02, and 0.02, respectively (P < 0.001). There were statistically significant differences in overall survival in the TNT groups (log-rank test P = 0.030).

CONCLUSIONS

PDAC patients who undergo the TNT modality exhibit lower LNY and improved LNR compared with the SF approach and SMNT neoadjuvant therapy groups. This is likely explained by the increased treatment response and lymph node obliteration associated with the TNT approach. Our results question the minimal requirement of 11-18 harvested lymph nodes for PD following TNT.

Lymph node ratio is a superior predictor in surgically treated early-onset pancreatic cancer

Background

The prognostic performance of four lymph node classifications, the 8th American Joint Committee on Cancer (AJCC) Tumor Node Metastasis (TNM) N stage, lymph node ratio (LNR), log odds of positive lymph nodes (LODDS), and examined lymph nodes (ELN) in early-onset pancreatic cancer (EOPC) remains unclear.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was searched for patients with EOPC from 2004 to 2016. 1048 patients were randomly divided into training (n = 733) and validation sets (n = 315). The predictive abilities of the four lymph node staging systems were compared using the Akaike information criteria (AIC), receiver operating characteristic area under the curve (AUC), and C-index. Multivariate Cox analysis was performed to identify independent risk factors. A nomogram based on lymph node classification with the strongest predictive ability was established. The nomogram’s precision was verified by the C-index, calibration curves, and AUC. Kaplan–Meier analysis and log-rank tests were used to compare differences in survival at each stage of the nomogram.

Results

Compared with the 8th N stage, LODDS, and ELN, LNR had the highest C-index and AUC and the lowest AIC. Multivariate analysis showed that N stage, LODDS, LNR were independent risk factors associated with cancer specific survival (CSS), but not ELN. In the training set, the AUC values for the 1-, 3-, and 5-year CSS of the nomogram were 0.663, 0.728, and 0.760, respectively and similar results were observed in the validation set. In addition, Kaplan–Meier survival analysis showed that the nomogram was also an important factor in the risk stratification of EOPC.

Conclusion

We analyzed the predictive power of the four lymph node staging systems and found that LNR had the strongest predictive ability. Furthermore, the novel nomogram prognostic staging mode based on LNR was also an important factor in the risk stratification of EOPC.

Comparison of laparoscopic versus open radical antegrade modular pancreatosplenectomy for pancreatic cancer: A systematic review and meta-analysis

BACKGROUND

Laparoscopic radical antegrade modular pancreatosplenectomy (l-RAMPS) provides a new surgical approach for patients with pancreatic cancers of the body and tail. However, whether it can achieve comparable outcomes to the open RAMPS (o-RAMPS) remains an issue.

METHODS

To evaluate the safety and effectiveness of l-RAMPS, the studies in the databases of Medline, Embase, and the Cochrane Library published before September 13, 2021 were searched and a meta-analysis was performed using the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. The perioperative and oncological outcomes were analyzed.

RESULTS

Five retrospective cohorts involving 189 patients were included for final pooled analysis. There were no significant differences in the patients' operation time, intra-abdominal bleeding rate, intra-abdominal infection rate, mild morbidity (Clavien-Dindo classification = 1), moderate to severe morbidity (Clavien-Dindo classification ≥2), overall morbidity, wound infection rate, pancreatic fistula rate, delayed gastric emptying rate, reoperation rate, length of hospital stay, postoperative mortality, R0 resection rate, and 2-year overall survival between the 2 approaches. Besides, l-RAMPS was associated with less blood loss (mean difference (MD) = -232.69, 95% confidence interval (CI) = -316.93 to -148.46, P < 0.00001) and shorter days until oral feeding (MD = -0.79, 95% CI = -1.35 to -0.22, P = 0.006). However, the pooled analysis also indicated a significantly fewer lymph nodes dissected (MD = -3.01, 95% CI = -5.59 to -0.43, P = 0.02) in l-RAMPS approach.

CONCLUSIONS

Although l-RAMPS provides similar outcomes associated with benefits of minimal invasiveness compared to o-RAMPS, it harvested significantly fewer lymph nodes which might have potentially negative influence on the patients' long-term survival. L-RAMPS is still in the infancy stage and further investigation is needed to verify its feasibility.

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.

Toward an Optimized Staging System for Pancreatic Ductal Adenocarcinoma: A Clinically Interpretable, Artificial Intelligence-Based Model

PURPOSE

The American Joint Committee on Cancer (AJCC) eighth edition schema for pancreatic ductal adenocarcinoma treats T and N stage as independent factors and uses positive lymph nodes (PLNs) to define N stage, despite data favoring lymph node ratio (LNR). We used artificial intelligence-based techniques to compare PLN with LNR and investigate interactions between tumor size and nodal status.

METHODS

Patients who underwent pancreatic ductal adenocarcinoma resection between 2000 and 2017 at six institutions were identified. LNR and PLN were compared through shapley additive explanations (SHAP) analysis, with the best predictor used to define nodal status. We trained optimal classification trees (OCTs) to predict 1-year and 3-year risk of death, incorporating only tumor size and nodal status as variables. The OCTs were compared with the AJCC schema and similarly trained XGBoost models. Variable interactions were explored via SHAP.

RESULTS

Two thousand eight hundred seventy-four patients comprised the derivation and 1,231 the validation cohort. SHAP identified LNR as a superior predictor. The OCTs outperformed the AJCC schema in the derivation and validation cohorts (1-year area under the curve: 0.681 v 0.603; 0.638 v 0.586, 3-year area under the curve: 0.682 v 0.639; 0.675 v 0.647, respectively) and performed comparably with the XGBoost models. We identified interactions between LNR and tumor size, suggesting that a negative prognostic factor partially overrides the effect of a concurrent favorable factor.

CONCLUSION

Our findings highlight the superiority of LNR and the importance of interactions between tumor size and nodal status. These results and the potential of the OCT methodology to combine them into a powerful, visually interpretable model can help inform future staging systems.

Surgery for pancreatic cancer: current controversies and challenges

Two areas that remain the focus of improvement in pancreatic cancer include high post-operative morbidity and inability to uniformly translate surgical success into long-term survival. This narrative review addresses specific aspects of pancreatic cancer surgery, including neoadjuvant therapy, vascular resections, extended pancreatectomy, extent of lymphadenectomy and current status of minimally invasive surgery. R0 resection confers longer disease-free survival and overall survival. Vascular and adjacent organ resections should be undertaken after neoadjuvant therapy, only if R0 resection can be ensured based on high-quality preoperative imaging, and that too, with acceptable post-operative morbidity. Extended lymphadenectomy does not offer any advantage over standard lymphadenectomy. Although minimally invasive distal pancreatectomies offers some short-term benefits over open distal pancreatectomy, safety remains a concern with minimally invasive pancreatoduodenectomy. Strict adherence to principles and judicious utilization of surgery within a multimodality framework is the way forward.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Resected pancreatic adenocarcinoma: An Asian institution's experience

BACKGROUND

Pancreatic adenocarcinoma (PDAC) is highly lethal. Surgery offers the only chance of cure, but 5-year overall survival (OS) after surgical resection and adjuvant therapy remains dismal. Adjuvant trials were mostly conducted in the West enrolling fit patients. Applicability to a general population, especially Asia has not been described adequately.

AIM

We aimed to evaluate the clinical outcomes, prognostic factors of survival, pattern, and timing of recurrence after curative resection in an Asian institution.

METHODS AND RESULTS

The clinicopathologic and survival outcomes of 165 PDAC patients who underwent curative resection between 1998 and 2013 were reviewed retrospectively. Median age at surgery was 62.0 years. 55.2% were male, and 73.3% had tumors involving the head of pancreas. The median OS of the entire cohort was 19.7 months. Median OS of patients who received adjuvant chemotherapy was 23.8 months. Negative predictors of survival include lymph node ratio (LNR) of >0.3 (HR = 3.36, P = .001), tumor site involving the body or tail of pancreas (HR = 1.59, P = .046), presence of perineural invasion (PNI) (HR = 2.36, P = .018) and poorly differentiated/undifferentiated tumor grade (HR = 1.86, P = .058). The median time to recurrence was 8.87 months, with 66.1% and 81.2% of patients developing recurrence at 12 months and 24 months respectively. The most common site of recurrence was the liver.

CONCLUSION

The survival of Asian patients with resected PDAC who received adjuvant chemotherapy is comparable to reported randomized trials. Clinical characteristics seem similar to Western patients. Hence, geographical locations may not be a necessary stratification factor in RCTs. Conversely, lymph node ratio and status of PNI ought to be incorporated.

Predictive Performance of Current Nodal Staging Systems in Various Categories of Pancreatic Cancer

BACKGROUND

Nodal staging systems (NSS) for pancreatic ductal adenocarcinoma (PDAC) classify patients on the basis of number of metastatic lymph nodes (MLN), metastatic/retrieved lymph node ratio (LNR), and log odds of positive LN (LODDS). The relative prognostic performance of these NSS, however, remains unclear.

PATIENTS AND METHODS

We identified 2584 patients who underwent surgery for PDAC between 2010 and 2019. Subgroups of each staging system were classified using K-adaptive partitioning method and assessed by comparing time-dependent areas under the curve (AUC) 5 years after surgery.

RESULTS

Patients were subgrouped by MLN (0, 1-3, ≥ 4), LNR (0, 0-0.23, > 0.23), and LODDS (< - 3.5, - 3.5 to - 0.970, > - 0.97). All three NSS were independent prognostic factors for overall survival (OS) and recurrence-free survival (RFS). The AUCs for OS were comparable for the MLN (0.622), LNR (0.609), and LODDS (0.596) systems. Subgroup evaluation based on 12 retrieved lymph nodes (RLN), R1 resection, and extent of resection showed that the AUCs of the MLN and LNR NSS were comparable for OS and RFS regardless of the number of RLNs, R1 resection, and extent of resection. By contrast, the AUCs of the LODDS NSS were lower.

CONCLUSION

The NSS based on the number of MLN is the best prognostic indicator, with prognostic performance comparable to the other NSS and greater convenience for practical use. This NSS was applicable regardless of the numbers of RLN, R1 resection, and extent of resection.

Original study: The rescue staging for pancreatic ductal adenocarcinoma with inadequate examined lymph nodes

BACKGROUND

In previous studies, it's recommended that the lymph node involvement should be evaluated with enough examined lymph nodes (eLNs) in the 8th American Joint Committee on Cancer (AJCC) staging system for pancreatic cancer. This study aims to put forward a rescue staging system for pancreatic ductal adenocarcinoma (PDAC) patients with inadequate eLNs after pancreatoduodenectomy (PD).

METHOD

11,224 PDAC patients undergoing PD in The Surveillance, Epidemiology, and End Results (SEER) database were included. Another Ruijin Pancreatic Disease Center (RJPDC) database consisted of 821 patients was utilized for external validation.

RESULTS

The proportions of patients with eLNs≥15 were 44.7% and 32.8% in SEER and RJPDC database separately. The rescue staging system was put forward relying on LNR (HR = 1.83, 95% CI 1.74-1.92, P < 0.001) for N staging of eLNs<15 population and pLNs for the rest. The TNM modalities were also rearranged in the rescue system for better survival coordination. The C-index of rescue staging system was 0.638 while that of AJCC 8th staging system was 0.613 in SEER database. Similar phenomena were observed in RJPDC database. Kaplan-Meier analyses revealed reliable internal coherences (SEER: Ib: P = 0.26; IIa: P = 0.063; IIb: P = 0.53; IIIa: P = 0.11.

RJPDC

Ib: P = 0.32; IIa: P = 0.66; IIb: P = 0.76; IIIa: P = 0.66) and significant staging efficiency (SEER: P < 0.001; RJPDC: P = 0.002).

CONCLUSION

A rescue staging system was put forward regardless of the eLNs number. And the novel system manifested better predictive capacity than 8th AJCC staging system.

A proposal to modify the 8th edition of the UICC staging system for pancreatic adenocarcinoma

PURPOSE

The aim of this study was to validate and improve the 8th edition of the Union for International Cancer Control (UICC) staging system for pancreatic ductal adenocarcinoma (PDAC).

METHODS

Prognostic impact of the pathological tumor (pT) and lymph node (pN) stages between the 7th and 8th editions were compared using a single-center cohort of 311 patients who underwent curative pancreatic resection for PDAC.

RESULTS

Applying the 7th edition T staging system resulted in a clustering of pT3 cases (92.3%) and failed to show significant prognostic differences between the three pT stages. However, applying the 8th edition T staging system yielded a more even distribution and resulted in an excellent prognostic separation between the pT stages based on decreases in median survival (month [pT1: 69.4, pT2: 27.6, pT3: 16.7], p=0.001). In pN staging system, the 8th edition provided more precise prognostication in median survival (month [pN0: 41.7, pN1: 25.6, pN2: 14.4], p<0.001). Moreover, in the 8th edition pT2 category, patients with portal vein invasion (PVI) showed significantly worse survival than those without PVI (median survival months [without PVI: 38.2, with PVI: 17.1], p<0.001).

CONCLUSIONS

The 8th edition provides a more even distribution among stages and better stage discriminations compared to the 7th edition. The 8th edition pT2 category should be subdivided according to PVI status of the patient to allow for more precise patient prognostication.

Significance of Lymph Node Resection After Neoadjuvant Therapy in Pancreatic, Gastric, and Rectal Cancers

OBJECTIVE

Gastrointestinal cancers are increasingly being treated with NAT before surgical resection. Currently, quality metrics are linked to the number of LNs resected to determine subsequent treatment and prognosis. We hypothesize that NAT decreases LN metastasis, downstages patients, and decreases overall lymph node yields (LNY) compared to initial surgical resection. With increasing use of NAT, this brings into question the validity of quality metrics.

METHODS

Gastric (stage II/III), pancreatic (stage I/II/III), and rectal cancers (stage II/III) (2010-2015) treated with surgery with/without NAT were identified in National Cancer Database. We evaluated total LNY and LN metastasis with/without NAT and clinical and pathological stage to evaluate rates of downstaging.

RESULTS

A total of 7934 gastric, 15,908 pancreatic, and 21,354 rectal cancer patients were included of which 61.1%, 21.2%, and 85.7% received NAT, respectively. NAT patients were more likely to be downstaged (39.9% vs 11.1% gastric P< 0.001, 30.6% vs 3.2% pancreatic P< 0.001, 52.0% vs 16.3% rectal P< 0.001), have lower LNYs (18.8 vs 19.1 gastric P = 0.239, 18.4 vs 17.5 pancreatic P< 0.001, 15.7 vs 20.0 rectal P< 0.001) and have N0 pathologic disease (43.6% vs 26.7% gastric P< 0.001, 51.1% vs 30.9% pancreatic P< 0.001, 65.9% vs 49.4% rectal P< 0.001) when compared to initial surgical resection.

CONCLUSION

NAT for gastrointestinal cancers results in overall lower LN yields, lower LN metastases, and significant downstaging of tumors. As all patients undergoing NAT receive multimodality therapy, LN yield recommendations may not be true quality metric changing.

Role of Lymph Node Resection and Histopathological Evaluation in Accurate Staging of Nonfunctional Pancreatic Neuroendocrine Tumors: How Many Are Enough?

BACKGROUND

Nodal involvement has been identified as one of the strongest prognostic factors in patients with nonfunctional pancreatic neuroendocrine tumors (NF-PanNETs). Sufficient lymphadenectomy and evaluation is vital for accurate staging. The purpose of this study was to identify the optimal number of examined lymph nodes (ELN) required for accurate staging.

METHODS

The SEER database was used to identify patients with resected NF-PanNETs between 2004 and 2014. The distributions of positive lymph nodes (PLN) ratio and total lymph nodes were used to develop a mathematical model. The sensitivity of detecting nodal disease at each cutoff of ELN was estimated and used to identify the optimal cutoff for ELN.

RESULTS

A total of 1098 patients were included in the study of which 391 patients (35.6%) had nodal disease. The median ELN was 12 (interquartile range [IQR]: 7-19.5), and the median PLN was 2 (IQR: 1-4) for patients with nodal disease. With an increase in ELN, the sensitivity of detecting nodal disease increased from 12.0% (ELN: 1) to 92.2% (ELN: 20), plateauing at 20 ELN (< 1% increase in sensitivity with an additional ELN). This sensitivity increase pattern was similar in subgroup analyses with different T stages.

CONCLUSIONS

The sensitivity of detecting nodal disease in patients with NF-PanNETs increases with an increase in the number of ELN. Cutoffs for adequate nodal assessment were defined for all T stages. Utilization of these cutoffs in clinical settings will help with patient prognostication and management.

Role of Node Dissection in Pancreatic Tumor Resection

BACKGROUND

Pancreatic cancer is a lethal disease, and, even with modern therapies, the mortality has not decreased significantly in decades. The prognostic importance of lymph node status is well defined; however, the role of extended lymphadenectomy to improve local recurrence and overall survival remains debated. Six randomized controlled trials have evaluated the extent of lymph node dissection in pancreaticoduodenectomy for pancreatic cancer.

OBJECTIVE

We sought to review the current literature to evaluate the role of lymphadenectomy in pancreatic cancer. The impact of each trial and its contribution to the literature is discussed.

CONCLUSIONS

Multiple randomized trials have failed to note an improvement in overall survival with extended lymphadenectomy for pancreatic cancer. Rather, extended lymphadenectomy was associated with increased morbidity, operating room time, and length of stay.

P-glycoprotein associated with diabetes mellitus and survival of patients with pancreatic cancer: 8-year follow-up

Diabetes mellitus (DM) has a high prevalence in patients with pancreatic cancer (PaC), but the prognostic value of DM in PaC remains controversial. Alterations of P-glycoprotein (P-gp) and cytochrome P450 3A4 (CYP3A4) contribute to multidrug resistance and intestinal metabolism in a variety of cancer types, which may be implicated in DM development. This study aimed to explore the potential prognostic value of P-gp and CYP3A4 in PaC patients in the context of DM through long-term follow-up. We retrospectively reviewed the medical records of patients with PaC admitted at The First People's Hospital of Changzhou, Jiangsu, China, from January 2011 to November 2019 and identified two cohorts of adult patients with PaC, including 24 with DM and 24 without DM (non-DM). The baseline clinical characteristics and outcomes were compared. Immunohistochemistry showed that protein expression of P-gp, but not CYP3A, in duodenum tissues was significantly upregulated in PaC patients with DM compared with those without DM. Kaplan-Meier analysis and log-rank test showed that the survival of patients with PaC and DM/high expression of P-gp was not significantly reduced compared with that of patients without DM/low expression of P-gp. These findings suggested that P-gp expression levels were different in the DM and non-DM groups of patients with PaC, but DM and duodenal P-gp levels were not associated with the long-term survival of patients with PaC. It appears that the presence of DM or P-gp expression levels may not serve as effective prognostic markers for PaC.

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.

Impact of examined lymph node count on staging and long-term survival of patients with node-negative stage III gastric cancer: a retrospective study using a Chinese multi-institutional registry with Surveillance, Epidemiology, and End Results (SEER) data validation

Background

Accumulating evidence has confirmed the potential prognostic value of examined lymph nodes (ELNs) in patients with gastric cancer (GC). However, there is currently no consensus on the threshold ELN number for predicting both stage migration and long-term survival, especially in patients with stage III GC. This study aimed to validate the need to increase the ELN count to improve its prognostic accuracy in node-negative patients with stage III GC after curative gastrectomy.

Methods

This retrospective, population-based study analyzed the clinical data of 84 patients with node-negative stage III GC from three high-volume institutions in China and 196 cases from the Surveillance, Epidemiology and End Results (SEER) program registry. The optimal number of ELNs was determined by receiver operating characteristic (ROC) curve analysis. Clinicopathological characteristics significantly related to survival were evaluated using the Kaplan-Meier method and Cox proportional hazards analysis. Stratified analyses were adopted to assess the prognostic predictive ability of the identified optimal number of ELNs in different populations. Survival differences among subgroups were analyzed to assess the impact of ELN count on stage migration according to overall survival (OS) among GC patients.

Results

The optimal number of ELNs was >31 according to ROC analysis of patients with node-negative stage III GC who underwent gastrectomy. Multivariate analysis identified ELNs as an independent predictor of postoperative OS in patients with node-negative stage III GC in both the Chinese cohort [hazard ratio (HR) 0.235; P<0.001] and the SEER cohort (HR 0.421; P<0.010). Stratified analysis demonstrated that >31 ELNs was a prerequisite for accurate prognostic evaluation of patients with node-negative stage III GC, regardless of sex, tumor size, and other factors. Stage migration between pT4bN0M0 and pT4bN1M0 was detected in patients with >31 ELNs. A nomogram was created to predict OS among patients with node-negative stage III GC. These results were validated using data from the SEER cohort.

Conclusions

The number of ELNs was significantly associated with prognosis in patients with stage III GC after gastrectomy with systemic lymphadenectomy in both the Chinese and SEER cohorts. The results suggest that >31 ELNs are required for an accurate prognostic evaluation in patients with GC, especially those with node-negative stage III GC.

Timing But Not Patterns of Recurrence Is Different Between Node-negative and Node-positive Resected Pancreatic Cancer

OBJECTIVE

Our aim was to evaluate recurrence patterns of surgically resected PDAC patients with negative (pN0) or positive (pN1) lymph nodes.

SUMMARY BACKGROUND DATA

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer death by 2030. This is mostly due to early local and distant metastasis, even after surgical resection. Knowledge about patterns of recurrence in different patient populations could offer new therapeutic avenues.

METHODS

Clinicopathologic data were collected for 546 patients who underwent resection of their PDAC between 2005 and 2016 from 2 tertiary university centers. Patients were divided into an upfront resection group (n = 394) and a neoadjuvant group (n = 152).

RESULTS

Tumor recurrence was significantly less common in pN0 patients as compared with pN1 patients, (upfront surgery: 55% vs. 77%, P < 0.001 and 64% vs. 78%, P = 0.040 in the neoadjuvant group). In addition, time to recurrence was significantly longer in pN0 versus pN1 patients in the upfront resected patients (median 16 mo pN0 vs. 10 mo pN1 P < 0.001), and the neoadjuvant group (pN0 21 mo vs. 11 mo pN1, P < 0.001). Of the patients who recurred, 62% presented with distant metastases (63% of pN0 and 62% of pN1, P = 0.553), 24% with local disease (27% of pN0 and 23% of pN1, P = 0.672) and 14% with synchronous local and distant disease (10% of pN0 and 15% of pN1, P = 0.292). Similarly, there was no difference in recurrence patterns between pN0 and pN1 in the neoadjuvant group, in which 68% recurred with distant metastases (76% of pN0 and 64% of pN1, P = 0.326) and 18% recurred with local disease (pN0: 22% and pN1: 15%, P = 0.435).

CONCLUSION

Time to recurrence was significantly longer for pN0 patients. However, patterns of recurrence for pN0 vs. pN1 patients were identical. Lymph node status was predictive of time to recurrence, but not location of recurrence.

Predictors for Survival in an International Cohort of Patients Undergoing Distal Pancreatectomy for Pancreatic Ductal Adenocarcinoma

Background

Surgical factors, including resection of Gerota’s fascia, R0-resection, and lymph node yield, may be associated with survival after distal pancreatectomy (DP) for pancreatic ductal adenocarcinoma (PDAC), but evidence from large multicenter studies is lacking. This study aimed to identify predictors for overall survival after DP for PDAC, especially those related to surgical technique.

Patients and Methods

Data from an international retrospective cohort including patients from 11 European countries and the USA who underwent DP for PDAC (2007–2015) were analyzed. Cox proportional hazard analyses were performed and included Gerota’s fascia resection, R0 resection, lymph node ratio, extended resection, and a minimally invasive approach.

Results

Overall, 1200 patients from 34 centers with median follow-up of 15 months [interquartile range (IQR) 5–31 months] and median survival period of 30 months [95% confidence interval (CI), 27–33 months] were included. Gerota’s fascia resection [hazard ratio (HR) 0.74; p = 0.019], R0 resection (HR 0.70; p = 0.006), and decreased lymph node ratio (HR 0.28; p < 0.001) were associated with improved overall survival, whereas extended resection (HR 1.75; p < 0.001) was associated with worse overall survival. A minimally invasive approach did not improve survival as compared with an open approach (HR 1.14; p = 0.350). Adjuvant chemotherapy (HR 0.67; p = 0.003) was also associated with improved overall survival.

Conclusions

This international cohort identified Gerota’s fascia resection, R0 resection, and decreased lymph node ratio as factors associated with improved overall survival during DP for PDAC. Surgeons should strive for R0 resection and adequate lymphadenectomy and could also consider Gerota’s fascia resection in their routine surgical approach.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08658-5) contains supplementary material, which is available to authorized users.

Understanding the Lymphatics: Review of the N Category in the Updated TNM Staging of Cancers of the Digestive System

OBJECTIVE. The N category has been significantly updated in the 8th edition of the American Joint Committee on Cancer's TNM classification. To ensure correct tumor staging, prognosis, and management, it is critical to be aware of these changes. This article reviews the updated N category, organ-specific regional lymph nodes, and lymphatic drainage pathways for cancers of the digestive system from the esophagus to the anal canal. CONCLUSION. Detection of lymph node involvement may be challenging, and knowledge of nodal characteristics, lymphatic drainage pathways, and imaging modalities is essential to optimize detection rate to ensure accurate staging, prognosis estimation, and streamlined management.

Score for the Overall Survival Probability of Patients With Pancreatic Adenocarcinoma of the Body and Tail After Surgery: A Novel Nomogram-Based Risk Assessment

Pancreatic adenocarcinoma of the body and tail often has a dismal prognosis and lacks a specific prognostic stage. The aim of this study was to construct a nomogram for predicting survival of patients with pancreatic adenocarcinoma of the body and tail after surgery. Data of patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database and from medical records of Sun Yat-sen University Cancer Center (SYSUCC). In a multivariate analysis for overall survival (OS), the following six variables were identified as independent predictors and incorporated into the nomogram: age, tumor differentiation, tumor size, lymph node ratio (LNR), and chemotherapy. A nomogram was built based on independent risk predictors. The concordance index (C-index) for nomogram, Tumor-Node-Metastasis (TNM) 7th and 8th stage system were 0.775 [95% confidence interval (CI), 0.731–0.819], 0.617 (95%CI, 0.575–0.659), and 0.632 (95%CI, 0.588–0.676), respectively. The calibrated nomogram predicted survival rates which closely corresponded to the actual survival rates. Furthermore, the values of the area under receiver operating characteristic (ROC) curves (AUC) of the nomograms were higher than those of the TNM 7th or 8th stage system in predicting 1-, 2-, and 3-year survival of patients in training and external validation cohorts. The well-calibrated nomogram could be used to predict prognosis for patients with pancreatic adenocarcinoma of the body and tail after surgery.

Development and validation of novel nomograms for predicting the survival of patients after surgical resection of pancreatic ductal adenocarcinoma

Background/Aims

Pancreatic ductal adenocarcinoma (PDAC) is associated with high mortality, even after surgical resection. The existing predictive models for survival have limitations. This study aimed to develop better nomograms for predicting overall survival (OS) and cancer‐specific survival (CSS) in PDAC patients after surgery.

Methods

A total of 6323 PDAC patients were retrospectively recruited from the Surveillance, Epidemiology, and End Results (SEER) database and randomly allocated into training, validation, and test cohorts. Multivariate Cox regression analysis was conducted to identify significant independent factors for OS and CSS, which were used for construction of nomograms. The performance was evaluated, validated, and compared with that of the 8th edition AJCC staging system.

Results

Ten independent factors were significantly correlated with OS and CSS. The 1‐, 3‐, and 5‐year OS rates were 40%, 20%, and 15%, and 1‐, 3‐, and 5‐year CSS rates were 45%, 24%, and 19%, respectively. The nomograms were calibrated well, with c‐indexes of 0.640 for OS and 0.643 for CSS, respectively. Notably, relative to the 8th edition AJCC staging system, the nomograms were able to stratify each AJCC stage into three prognostic subgroups for more robust risk stratification. Furthermore, the nomograms achieved significant clinical validity, exhibiting wide threshold probabilities and high net benefit. Performance assessment also showed high predictive accuracy and reliability.

Conclusions

The predictive ability and reliability of the established nomograms have been validated, and therefore, these nomograms hold potential as novel approaches to predicting survival and assessing survival risks for PDAC patients after surgery.

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.

Is the involvement of the hepatic artery lymph node a poor prognostic factor in pancreatic adenocarcinoma?

INTRODUCTION

The aim of this study is to analyze the impact of hepatic artery lymph node (HALN) involvement on the survival of patients undergoing pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PA).

METHODS

A single-center retrospective study analyzing patients who underwent PD for PA. Patients were included if, during PD, the HALN was submitted for pathologic evaluation. Patients were stratified by node status: PPLN- (peripancreatic lymph node)/HALN-, PPLN+/HALN- and PPLN+/HALN+. Survival analysis was estimated by the Kaplan-Meier method, and Cox regression was used for risk factors analyses.

RESULTS

Out of the 118 patients who underwent PD for PA, HALN status was analyzed in 64 patients. The median follow-up was 20months (r: 1-159months). HALN and PPLN were negative in 12patients (PPLN-/HALN-, 19%), PPLN was positive and HALN negative in 40patients (PPLN+/HALN-, 62%), PPLN and HALN were positive in 12 patients (PPLN+/HALN+, 19%) and PPLN was negative and HALN positive in 0 patients (PPLN-/HALN+, 0%). The overall 1, 3 and 5-year survival rates were statistically better in the PPLN-/HALN- group (82%, 72%, 54%) than in the PPLN+/HALN- group (68%, 29%, 21%) and the PPLN+/HALN+ group (72%, 9%, 9%, respectively) (P=.001 vs P=.007). The 1, 3 and 5-year probabilities of cumulative recurrence were also statistically better in the PPLN-/HALN- group (18%, 46%, 55%) than in the PPLN+/HALN- group (57%, 80%, 89%) and the PPLN+/HALN+ group (46%, 91%, 100%, respectively) (P=.006 vs P=.021). In the multivariate model, the main risk factor for overall survival and recurrence was lymphatic invasion, regardless of HALN status.

CONCLUSIONS

In pancreatic adenocarcinoma patients with lymph node disease, survival after PD is comparable regardless of HALN status.

Are ENT1/ENT1, NOTCH3, and miR-21 Reliable Prognostic Biomarkers in Patients with Resected Pancreatic Adenocarcinoma Treated with Adjuvant Gemcitabine Monotherapy?

Evidence on equilibrative nucleoside transporter 1 (ENT1) and microRNA-21 (miR‑21) is not yet sufficiently convincing to consider them as prognostic biomarkers for patients with pancreatic ductal adenocarcinoma (PDAC). Here, we investigated the prognostic value of ENT1/ENT1, miR-21, and neurogenic locus homolog protein 3 gene (NOTCH3) in a well-defined cohort of resected patients treated with adjuvant gemcitabine chemotherapy (n = 69). Using a combination of gene expression quantification in microdissected tissue, immunohistochemistry, and univariate/multivariate statistical analyses we did not confirm association of ENT1/ENT1 and NOTCH3 with improved disease-specific survival (DSS). Low miR-21 was associated with longer DSS in patients with negative regional lymph nodes or primary tumor at stage 1 and 2. In addition, downregulation of ENT1 was observed in PDAC of patients with high ENT1 expression in normal pancreas, whereas NOTCH3 was upregulated in PDAC of patients with low NOTCH3 levels in normal pancreas. Tumor miR‑21 was upregulated irrespective of its expression in normal pancreas. Our data confirmed that patient stratification based on expression of ENT1/ENT1 or miR‑21 is not ready to be implemented into clinical decision-making processes. We also conclude that occurrence of ENT1 and NOTCH3 deregulation in PDAC is dependent on their expression in normal pancreas.

Lymph node ratio as valuable predictor in pancreatic cancer treated with R0 resection and adjuvant treatment

Background

Lymph-node (LN) metastasis is an important prognostic factor in resected pancreatic cancer. In this study, the prognostic value of American Joint Committee on Cancer (AJCC) 8th edition N stage, lymph-node ratio (LNR), and log odds of positive lymph nodes (LODDS) in resected pancreatic cancer was investigated.

Methods

Between January 2005 and December 2017, there were 351 patients with pancreatic cancer treated with R0 resection and adjuvant therapy at Seoul National University Hospital. Relationships between the three LN parameters and overall survival (OS) and recurrence-free survival (RFS) were evaluated using a log-rank test and Cox proportional hazard regression model. Each multivariate-adjusted LN parameter was internally validated by bootstrap-corrected Harrell’s C-index.

Results

The mean duration from surgery to adjuvant therapy was 47.6 ± 17.4 days. In total, the median OS and RFS was 31.7 (95% CI, 27.2-37.2) and 15.4 (95% CI, 13.5-17.7) months. The three LN classification systems were significantly correlated with OS and RFS in log-rank tests and multivariate-adjusted models (all p < 0.05). When internally validated, LNR showed the highest discrimination ability in predicting OS and RFS (each C–index = 0.65). LNR also showed the highest C-index in subgroup analysis, classified by adjuvant therapy modality. LNR and the AJCC 8th edition LN classification system were significantly associated with loco-regional recurrence (p = 0.026 and p = 0.027, respectively).

Conclusions

LNR, which showed the best prognostic performance and significant relationship with loco-regional recurrence, can help further stratify the patients and establish an active treatment plan.

Exploration of exact significance of lymph node ratio and construction of a novel stage in colon cancer with no distant metastasis

Aim

Lymph node ratio (LNR) seems to be more precise than classic N stage in classifying cancer stage. Thus, we aim to construct a modified classification system based on LNR for colon cancer without distant metastasis.

Methods

This study enrolled two independent cohorts of patients. The primary cohort enrolled 2,152 patients from 2008 to 2013 in Zhongshan Hospital, Fudan University. The validation cohort consisted of 77,406 patients from the Surveillance, Epidemiology, and End Results (SEER) registry from 2004 to 2014. The inclusion criteria were: pathologically confirmed colon cancer, and American Joint Committee on Cancer (AJCC) stage I/II/III. The exclusion criteria included: incomplete follow-up information, rectal cancer, and multiple primary sites. The prognostic value of LNR for overall survival was evaluated. The cutoff value of LNR was determined by the X-tile. Predictive performance of modified classification was determined by the concordance index.

Results

After analysis, 0.05 and 0.50 were determined as the best threshold values of LNR. A value of <0.05, 0.05–0.50 and >0.50 was reclassified as the mN0, mN1 and mN2 stage. A modified classification based on mN0, mN1, and mN2 was further constructed for stage I/II/III colon cancer. C-index of the modified classification was statistically more precise than AJCC classification (0.687 versus 0.605, P<0.001). The same results can also be determined in the validation cohort (0.715 versus 0.640, P<0.001). Furthermore, a prognostic nomogram including independent factors was constructed. The constructed nomogram showed good performance according to the calibration curve.

Conclusion

The clinical value of LNR level was preferable to classic N stage in colon cancer patients. Our proposed classification based on LNR and AJCC T category can effectively differentiate patients with varied survival outcomes.

Completion of Adjuvant Chemotherapy After Upfront Surgical Resection for Pancreatic Cancer Is Uncommon Yet Associated With Improved Survival

BACKGROUND

Multiple trials have demonstrated a survival benefit for adjuvant chemotherapy after resection of pancreatic adenocarcinoma. This study aimed to identify the rate for completion of adjuvant chemotherapy, factors associated with completion, and its impact on survival after surgical resection.

METHODS

The Surveillance Epidemiology and End Results Medicare-linked data was used to identify patients who underwent upfront resection for pancreatic adenocarcinoma from 2004 to 2013. Billing codes were used to quantify receipt and completion of chemotherapy. Factors associated with completion of chemotherapy were identified using multivariable regression. Kaplan-Meier and Cox proportional-hazards modeling were used to examine survival.

RESULTS

The inclusion criteria were met by 2440 patients. Of these patients, 65% received no adjuvant chemotherapy, 28% received incomplete therapy, and 7% completed chemotherapy. The factors associated with chemotherapy completion were nodal metastases and treatment at a National Cancer Institute-designated cancer center (p ≤ 0.05). Comorbidities decreased the odds of completion (p ≤ 0.05). The median overall survival (OS) was 14 months for the patients who received no adjuvant chemotherapy, 17 months for those who received incomplete adjuvant chemotherapy, and 22 months for those who completed adjuvant chemotherapy (p ≤ 0.05). More recent diagnosis, comorbidities, T stage, nodal metastases, and no adjuvant chemotherapy were associated with an increased hazard ratio for death (p ≤ 0.05). Evaluation of 15 or more nodes and completion of chemotherapy decreased the hazard ratio for death (p ≤ 0.05).

CONCLUSIONS

Only 7% of the Medicare patients who underwent upfront resection for pancreatic cancer completed adjuvant chemotherapy, yet completion of adjuvant chemotherapy was associated with improved OS. Completion of adjuvant chemotherapy should be the goal after upfront resection, but neoadjuvant chemotherapy may ensure that patients receive systemic chemotherapy.

Optimal Extent of Superior Mesenteric Artery Dissection during Pancreaticoduodenectomy for Pancreatic Cancer: Balancing Surgical and Oncological Safety

BACKGROUND

We describe the short- and long-term outcomes for PDAC patients after tailored mesopancreas dissection using supracolic artery-first approach followed by adjuvant therapy.

METHODS

This study analyzed 233 consecutive patients who underwent artery-first pancreaticoduodenectomy for PDAC. Dissection extent for the superior mesenteric artery (SMA) was categorized into three levels: level 2 (LV2) including regional lymph nodes, level 3 (LV3) with hemicircumferential nerve plexus dissection, and extended-level 3 (E-LV3) including borderline resectable cases for the SMA. All clinical, pathological, and survival outcomes were reviewed.

RESULTS

LV2/3/E-LV3 dissection was performed in 77/115/41 patients. The short-term outcomes were similar among groups without mortality. Although postoperative diarrhea requiring opioids was significantly more frequent in the E-LV3 group (76%) than other groups (vs. LV2 (21%), P < .0001; vs. LV3 (34%), P < .0001; LV2 vs. LV3, P = 0.20), most cases of diarrhea were well controlled. Adjuvant chemotherapy was introduced similarly among groups (LV2, 76%; LV3, 81%; E-LV3, 88%, P = 0.29). The 3- and 5-year overall survival rates in the LV2/3/E-LV3 groups were 42/33/42% and 27/22/26%, respectively, showing no significant difference among groups.

DISCUSSION

Our tailored dissection and preemptive use of opioid antidiarrheal effectively prevents intractable diarrhea, increasing the success of adjuvant chemotherapy.

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.

Prognostic Value of Metastatic Lymph Node Ratio in Pancreatic Cancer

Lymph node involvement in pancreatic adenocancer is one of the strongest predictors of prognosis. However, the extent of lymph node dissection is still a matter of debate and number of dissected nodes varies widely among patients. In order to homogenize this diverse group of patients and more accurately predict their prognosis, we aimed to analyze the effect of metastatic lymph node ratio as an independent prognostic factor. We retrospectively analyzed medical recordings of 326 patients with pancreatic cancer who were treated in a tertiary medical oncology center over a 10-year period. Both in univariate and multivariate analyses, metastatic lymph node ratio proved to be a strong predictor of prognosis which was unaffected from heterogeneity of our patient population and can be used to facilitate predict prognosis of patients who underwent lymph node dissection to various extents and with future studies it can emerge as a successful tool for creating prognostic subgroups of the disease.

Pancreatic Cancer Lymph Node Resection Revisited: A Novel Calculation of Number of Lymph Nodes Required

BACKGROUND

Pancreatic cancer is the third leading cause of cancer related deaths in the US. Although lymph node (LN) metastasis is a prognostic indicator, the extent of LN resection is still debated. Our goal was to use the distribution of the ratio of positive to negative LNs to derive a more adequate number of necessary examined LNs based on the target LN threshold (TLNT).

STUDY DESIGN

Using the National Cancer Database, we performed a retrospective study of surgically resected pancreatic adenocarcinoma (2010 to 2015). We evaluated the number of positive LNs and total LNs examined and the log of the ratio of positive LNs to negative LNs (LODDS). The distribution of LODDS was examined to determine a target LNs examined threshold sufficient to detect N1 disease. Using the LODDS distribution of N1 cases, target LNs examined threshold were calculated to encompass 90 of the N1 group distribution.

RESULTS

Of the total 24,038 resected patients included in this study, 26% underwent operation only, 18% received neoadjuvant therapy, and 56% underwent adjuvant therapy. In all, 8,144 (34%) patients had N0 disease and 15,894 (66%) had N1 disease. To capture 90% to 95% of the N1 group, the minimum number of LNs examined would be 18 (LODDS -2.74) to 24 (LODDS -3.04), respectively.

CONCLUSIONS

Although previous studies have suggested 11 to 17 LNs required for adequate LN sampling in pancreatic cancer, our findings suggest that to capture 90% of cases with N1 disease, 18 LNs is more appropriate.

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.

Accuracy of Nodal Positivity in Inadequate Lymphadenectomy in Pancreaticoduodenectomy for Pancreatic Ductal Adenocarcinoma: A Population Study Using the US SEER Database

Objectives: The optimal number of the examined lymph nodes (ELNs) in pancreaticoduodenectomy for pancreatic ductal adenocarcinoma has been widely studied. However, the accuracy of nodal positivity for the patients with inadequate lymphadenectomy is still unclear. The purpose of our study was to determine the accuracy of the number of positive nodes reported for patients with 1-3 positive nodes and the probability that 4 or more nodes could be positive along with tumor size and number of nodes examined. Methods: We obtained data on patients who underwent pancreaticoduodenectomy for resectable pancreatic ductal adenocarcinoma diagnosed during 2004-2013 from the US Surveillance, Epidemiology, and End Results registry. An mathematical model based on Hypergeometric Distribution and Bayes' Theorem was used to estimate the accuracy. Results: Among the 9,945 patients, 55.6% underwent inadequate lymphadenectomy. Of them, 1,842, 6,049, and 2,054 had T1, T2, and T3 stage disease, respectively. The accuracy of the number of observed positive nodes increased as the number of ELNs increased and the tumor size decreased. To rule out the possibility of N2 stage (4 and more positive nodes), there should be at least 13 ELNs for the patients with 1 observed positive lymph node and 14 for the patients with 2. Conclusion: Inadequate lymphadenectomy could result in underestimation of the N stage, and this would have adverse impact on recurrence, efficacy of postoperative treatment, and even overall survival. This model combined with the observed positive lymph nodes, the number of ELNs, and tumor size could provide a more accurate determination of nodal positivity of these patients.

Prognostic nomograms based on log odds of positive lymph nodes for patients with renal cell carcinoma: A retrospective cohort study

OBJECTIVES

The aim of the current study is to build prognostic nomograms for patients with renal cell carcinoma (RCC) and compare the predictive performance with the American Joint Committee on Cancer (AJCC) staging system.

METHODS

A total of 9453 patients were identified (2005-2015) from the Surveillance Epidemiology and End Results (SEER) database. Propensity-score matching (PSM) was conducted to reduce selective bias. The matched cohort was further divided equally into the development and the validation cohort. Nomograms based on log odds of positive lymph nodes (LODDS) were formulated to predict individualized cancer-specific survival (CSS) and overall survival (OS) for RCC. Then, the performance of nomograms was internally and externally validated via the concordance index (C-index) and calibration plots. Decision curve analysis (DCA) was used to compare the clinical practicable between nomograms and AJCC staging system.

RESULTS

LODDS was identified as an independent prognostic indicator for CSS and OS using univariate and multivariate Cox regression analyses. Two nomograms incorporating LODDS were formulated. The C-indices of the nomograms for predicting CSS and OS were 0.7561 (95% CI, 0.7356-0.7766) and 0.7140 (95% CI, 0.6936-0.7343) in the development cohort, which was higher than C-index of the AJCC staging system. The results were reproducible in the validation cohort. Moreover, internal and external calibration plots showed that the nomograms-predicted was consistent with the actual observation. Additionally, DCA demonstrated that the nomograms were superior to the AJCC staging system with obtaining more clinical net benefit.

CONCLUSIONS

LODDS could be considered as a reliable prognostic factor for patients with RCC. Two nomograms were able to more accurately and applicable than the AJCC staging system for predicting CSS and OS.

Clinical Implications of Extensive Lymph Node Metastases for Resected Pancreatic Cancer

BACKGROUND

Outcomes of patients with resected pancreatic ductal adenocarcinoma (PDA) and extensive lymph node metastases have not been fully characterized.

METHODS

A total of 637 patients underwent resection for pancreatic ductal adenocarcinoma (PDA) between 2002 and 2014 at the Thomas Jefferson University. Positive lymph node count (LNC) and positive lymph node ratio (LNR) were analyzed as predictors of cancer-specific outcomes, with a focus on outcomes of patients with extensive lymph node burden.

RESULTS

Resected patients with regional lymph node metastases had a median survival of 17.1 months (n = 425, 70%) compared with 25.5 months (n = 185, 30%) for patients without lymph node spread (N0) (hazard ratio [HR] = 1.9, p < 0.001). Overall survival decremented with increased lymph node spread, but plateaued for LNC ≥ 4 (HR 2.4 vs. N0, p < 0.001) and LNR ≥ 0.4 (HR 2.2, p < 0.001). Compared with historical cohorts with macroscopic metastatic disease, as opposed to microscopic, superior long-term survival was achieved in patients with extensive lymph node metastases (LNC ≥ 4); 24- and 36-month survivals were 25% (vs. 16%, p < 0.001) and 12% (vs. 6%, p < 0.001), respectively. Extensive lymph node burden was associated with increased baseline postoperative serum CA 19-9 (p = 0.044) and systemic recurrence (p < 0.001).

CONCLUSIONS

The prognostic impact of extensive lymph node spread after resection for PDA plateaus above a specific threshold (LNC ≥ 4 or LNR ≥ 0.4), supporting the new 8th edition AJCC criteria for N2 disease. Clinically, lymph node spread above this threshold seems to correlate with occult systemic disease (elevated postoperative CA 19-9 and systemic pattern of failure).