Adjuvant radiotherapy and lymph node status for pancreatic cancer: results of a study from the Surveillance, Epidemiology, and End Results (SEER) Registry Data

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.

Survival Benefits and Disparities in Adjuvant Radiation Therapy for Patients with Pancreatic Cancer

BACKGROUND

The effects of adjuvant radiation therapy on pancreatic cancer outcomes after resection are not well defined in the literature.

METHODS

We abstracted data from the Surveillance, Epidemiology, and End Result (SEER) database to explore the impact of adjuvant radiation on cancer-specific survival in pancreatic cancer patients who received surgical resection.

RESULTS

A total of 10,224 patients met our inclusion criteria with 6768 (66.2%) patients treated with surgery only and 3456 (33.8%) treated with surgery plus adjuvant radiation. Surgery followed by adjuvant radiation was associated with significantly improved survival (HR: 0.753, CI: 0.718-0.789, p<0.001). Additionally, female gender and married status were both independently associated with better survival (p<0.05), while advanced age, Caucasian race, higher TNM stage, and higher grade had worse survival outcomes (p<0.05) Asian and Spanish-Hispanic-Latino patients were less likely to receive adjuvant radiotherapy (p<0.05).

CONCLUSION

Adjuvant radiation was associated with significantly improved survival after resection for pancreatic cancer. There are significant differences in the patient populations who receive adjuvant radiation.

The benefit of adjuvant radiotherapy on overall survival in resected stage I to II pancreatic cancer: A propensity-adjusted analysis

BACKGROUND

The survival time of patients with early pancreatic cancer (PC) is still disappointing, even after surgical resection. PC has an extremely poor prognosis. Herein, we aimed to investigate the survival effect of postoperative radiotherapy (PORT) on resected stage I to II PC.

MATERIAL AND METHODS

A large eligible sample of patients was identified from 2010 to 2015 from the Surveillance, Epidemiology, and End Results (SEER) registry. Survival analysis was conducted to evaluate the efficiency of PORT. Propensity score matching (PSM) analysis was used to reduce selection bias and to make the groups comparable.

RESULTS

A total of 3219 patients with resected stage I to II PC was included after rigid screening. The median overall survival (OS) was 26 months with PORT (n = 1055) versus 21 months with non-PORT (n = 2164) before matching (p<0.001). By multivariable analysis, PORT remained a favorable prognostic predictor for OS. In PSM analysis, receiving PORT was associated with improved OS (median, 26 months vs. 23 months; at 2 years, 51.7% vs. 46.7%; at 5 years, 23.3% vs. 17.4% (P = 0.006). After further meticulous exploration, only the stage IIB subgroup benefited from PORT (p<0.001). This result was due to the positive lymph node state (N+), whose mortality risk was cut by 23.4% (p<0.001) by PORT.

CONCLUSION

Addition of PORT to the treatment of patients with resected stage I to II PC conveys a survival benefit, particularly among those with N-positive or stage IIB disease.

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.

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.

Large database utilization in health outcomes research in pancreatic cancer: an update

We sought to review published aggregate dataset studies on pancreatic cancer in the national and international settings, discuss the advantages and disadvantages these datasets possess, and possible future directions. A combination of Google Scholar, PubMed, and MEDLINE were used with search terms "pancreatic cancer" + "resectable" + "national cancer database", "pancreatic cancer" + "unresectable" + "national cancer database" and more broadly "borderline resectable pancreatic cancer", "locally advanced pancreatic cancer", "unresectable pancreatic cancer", and "resectable pancreatic cancer". Original articles and abstracts from this search were included, including data from the Surveillance, Epidemiology, and End Results (SEER) database, National Cancer Database (NCDB), and SEER-Medicare within the United States (US), as well as international database studies. Multiple database studies have been published regarding the role for radiotherapy in resected pancreatic cancer (n=6), the timing of additional therapy in resectable pancreatic cancer (n=4), and the role for radiotherapy and resection in locally advanced pancreatic cancer (LAPC) (n=4). Studies from both SEER and NCDB found a survival benefit to post-operative radiotherapy. In resectable pancreatic cancer, neoadjuvant treatment was found to be superior to adjuvant (NCDB). Chemoradiotherapy was found to be more beneficial than chemotherapy alone in LAPC, and patients who received highly-conformal or stereotactic body radiotherapy (SBRT) had improved survival compared to either conformal radiotherapy or chemotherapy alone. These studies also found that up to 10% of patients underwent resection, with a 90% margin-negative rate, and either one-half to one-third the risk of death of non-surgical patients. Criticism of large datasets includes lack of granularity of performance status, diagnosis, treatment, and outcomes-related data compared to properly administered prospective trials, as well as cross-over between treatment arms that cannot be accounted for, and concerns over quality of data represented. The US has witnessed a growing number of comparative effectiveness studies in pancreatic cancer. When taken together, certain themes emerge that are consistent with both single-institution data and clinical trials. These studies have also provided insight into questions not readily answerable by clinical trials. However, they require caution in interpretation.

Subgroup analysis reveals molecular heterogeneity and provides potential precise treatment for pancreatic cancers

Background

The relationship between molecular heterogeneity and clinical features of pancreatic cancer remains unclear. In this study, pancreatic cancer was divided into different subgroups to explore its specific molecular characteristics and potential therapeutic targets.

Patients and methods

Expression profiling data were downloaded from The Cancer Genome Atlas database and standardized. Bioinformatics techniques such as unsupervised hierarchical clustering was used to explore the optimal molecular subgroups in pancreatic cancer. Clinical pathological features and pathways in each subgroup were also analyzed to find out the potential clinical applications and initial promotive mechanisms of pancreatic cancer.

Results

Pancreatic cancer was divided into three subgroups based on different gene expression features. Patients included in each subgroup had specific biological features and responded significantly different to chemotherapy.

Conclusion

Three distinct subgroups of pancreatic cancer were identified, which means that patients in each subgroup might benefit from targeted individual management.

Postoperative serum CA19-9, CEA and CA125 predicts the response to adjuvant chemoradiotherapy following radical resection in pancreatic adenocarcinoma

OBJECTIVE

To evaluate the prediction of benefits from adjuvant chemoradiotherapy by postoperative serum CA19-9, CA125 and CEA.

METHODS

The relations between benefits from adjuvant chemoradiotherapy and levels of postoperative serum CA19-9, CA125 and CEA were investigated in 804 pancreatic adenocarcinoma patients who received radical resection.

RESULTS

Adjuvant chemoradiotherapy was an independent factor for late recurrence [12.2 vs. 8.5 months, P = 0.001 for recurrence free survival (RFS)] and long survival [23.7 vs. 17.0 months, P < 0.001 for overall survival (OS)] in resected pancreatic adenocarcinoma. Postoperative serum CA19-9, CA125 and CEA were independent risk predictors for poor surgical outcome in pancreatic adenocarcinoma (P < 0.001 for all). Adjuvant chemradiotherapy (hazard ratio: 0.359, 95% confidence interval: 0.253-0.510, P < 0.001 for OS; hazard ratio: 0.522, 95% confidence interval: 0.387-0.705, P < 0.001 for RFS) were confirmed to improve the surgical outcome in patients with abnormal levels of any one of the three postoperative markers, but not in patients with normal levels of the three postoperative markers. In the subgroup of patients with negative lymph node, its improvement of surgical outcome was also significant in patients with abnormal levels of any one of postoperative serum CA19-9, CA125 and CEA (hazard ratio: 0.412, 95% confidence interval: 0.244-0.698, P = 0.001 for OS; hazard ratio: 0.546, 95% confidence interval: 0.352-0.847, P = 0.007 for RFS).

CONCLUSION

Postoperative serum CA19-9, CA125 and CEA could serve as predictors of response for adjuvant chemoradiotherapy even if the status of lymph nodes is negative.

Prognostic Role of Metastatic Lymph Node Ratio in Papillary Thyroid Carcinoma

Background

The aim of this study is to elucidate the clinicopathological significances, including the prognostic role, of metastatic lymph node ratio (mLNR) and tumor deposit diameter in papillary thyroid carcinoma (PTC) through a retrospective review and meta-analysis.

Methods

We categorized the cases into high (≥ 0.44) and low mLNR (< 0.44) and investigated the correlations with clinicopathological parameters in 64 PTCs with neck level VI lymph node (LN) metastasis. In addition, meta-analysis of seven eligible studies was used to investigate the correlation between mLNR and survival.

Results

Among 64 PTCs with neck level VI LN metastasis, high mLNR was found in 34 PTCs (53.1%). High mLNR was significantly correlated with macrometastasis (tumor deposit diameter ≥ 0.2 cm), extracapsular spread, and number of metastatic LNs. Based on linear regression test, mLNR was significantly increased by the largest LN size but not the largest metastatic LN (mLN) size. High mLNR was not correlated with nuclear factor κB or cyclin D1 immunohistochemical expression, Ki-67 labeling index, or other pathological parameters of primary tumor. Based on meta-analysis, high mLNR significantly correlated with worse disease-free survival at the 5-year and 10-year follow-up (hazard ratio [HR], 4.866; 95% confidence interval [CI], 3.527 to 6.714 and HR, 5.769; 95% CI, 2.951 to 11.275, respectively).

Conclusions

Our data showed that high mLNR significantly correlated with worse survival, macrometastasis, and extracapsular spread of mLNs. Further cumulative studies for more detailed criteria of mLNR are needed before application in daily practice.

Adjuvant radiotherapy and chemotherapy improve survival in patients with pancreatic adenocarcinoma receiving surgery: adjuvant chemotherapy alone is insufficient in the era of intensity modulation radiation therapy

In the era of intensity modulation radiation therapy (IMRT), no prospective randomized trial has evaluated the efficacy of adjuvant therapies such as adjuvant concurrent chemoradiotherapy (CCRT), adjuvant sequential chemotherapy and radiotherapy (CT-RT), and adjuvant CT alone in resectable pancreatic adenocarcinoma (PA). Through propensity score matching, we designed a nationwide, population-based, head-to-head cohort study to determine the effects of dissimilar adjuvant treatments on resectable PA. We minimized the confounding of various adjuvant treatment outcomes among the following resectable PA groups of patients from the Taiwan Cancer Registry database: group 1, adjuvant CCRT; group 2, adjuvant sequential CT-RT; and group 3, adjuvant CT alone. All the studied techniques are IMRTs. The matching process yielded a final cohort of 588 patients (196, 196, and 196 patients in groups 1, 2, and 3, respectively). In both univariate and multivariate Cox regression analyses, adjusted hazard ratios (aHRs; 95% confidence interval [CI]) of death derived for the adjuvant CCRT and adjuvant sequential CT-RT cohorts compared with the adjuvant CT alone cohort were 0.398 (0.314-0.504) and 0.307 (0.235-0.402), respectively. A combination of adjuvant IMRT and CT for resectable PA treatment improves survival to a greater extent than does adjuvant CT alone.

Evaluation of the 8th AJCC staging system for pathologically versus clinically staged pancreatic adenocarcinoma: A time to revisit a dogma?

BACKGROUND

The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic exocrine adenocarcinoma has been released. The current study seeks to assess the 7th and 8th editions among patients registered within the surveillance, epidemiology and end results (SEER) database.

METHODS

SEER database (2010-2013) has been accessed through SEER*Stat program and AJCC 8th edition stages were reconstructed utilizing the collaborative stage descriptions. Kaplan-Meier analysis of overall survival and pancreatic cancer-specific survival analyses (according to both 7th and 8th editions and according to whether pathological or clinical staging were conducted) has been performed. Multivariate analysis of factors affecting pancreatic cancer-specific survival was also conducted through a Cox proportional hazard model.

RESULTS

A total of 18  948 patients with pancreatic adenocarcinoma were identified in the period from 2010-2013. Pancreatic cancer-specific survival among pathologically staged patients and according to the 8th edition showed significant differences for all pair wise comparisons among different stages (P < 0.0001) except for the comparison between stage IA and stage IB (P = 0.307) and the comparison between stage IB and stage IIA (P = 0.116). Moreover, P value for stage IA vs IIA was 0.014; while pancreatic cancer-specific survival according to the 7th edition among pathologically staged patients showed significant differences for all pair wise comparisons among different stages (P < 0.0001) except for the comparison between IA and IB (P = 0.072), the comparison between stage IIA and stage IIB (P = 0.065), the comparison between stage IIA and stage III (P = 0.059) and the comparison between IIB and III (P = 0.595). Among clinically staged patients (i.e. those who did not undergo initial radical surgery), the prognostic performance of both 7th and 8th stages for both overall survival and pancreatic cancer-specific survival was limited.

CONCLUSION

There is clearly a need to have two staging systems for pancreatic adenocarcinoma: pathological and clinical staging systems.

Prognostic role of nodal ratio, LODDS, pN in patients with pancreatic cancer with venous involvement

BACKGROUND

The UICC/AJCC TNM staging system classifies lymph nodes as N0 and N1 in pancreatic cancer. Aim of the study is to determine whether the number of examine nodes, the nodal ratio (NR) and the logarithm odds of positive lymph nodes (LODDS) may better stratify the prognosis of patients undergoing pancreatectomy combined with venous resection for pancreatic cancer with venous involvement.

METHODS

A multicenter database of 303 patients undergoing pancreatectomy in 9 Italian referral centers was analyzed. The prognostic impact of number of retrieved and examined nodes, NR, LODDS was analyzed and compared with ROC curves analysis, Pearson test, univariate and multivariate analysis.

RESULTS

The number of metastatic nodes, pN, the NR and LODDS was significantly correlated with survival at multivariate analyses. The corresponding AUC for the number of metastatic nodes, pN, the NR and LODDS were 0.66, 0.69, 0.63 and 0.65, respectively. The Pearson test showed a significant correlation between the number of retrieved lymph nodes and number of metastatic nodes, pN and the NR. LODDS had the lower coefficient correlation. Concerning N1 patients, the NR, the LODDS and the number of metastatic nodes were able to significantly further stratify survival (p = 0.040; p = 0.046; p = 0.038, respectively).

CONCLUSIONS

The number of examined lymph nodes, the NR and LODDS are useful for further prognostic stratification of N1 patients in the setting of pancreatectomy combined with PV/SMV resection. No superiority of one over the others methods was detected.

The More the Better-Lower Rate of Stage Migration and Better Survival in Patients With Retrieval of 20 or More Regional Lymph Nodes in Pancreatic Cancer: A Population-Based Propensity Score Matched and Trend SEER Analysis

OBJECTIVE

The aim of this study was to assess the influence of regional lymph node (RLN) retrieval on stage migration and survival in pancreatic cancer.

METHODS

A total of 7685 stage I and II pancreatic cancer patients were identified in the Surveillance, Epidemiology, and End Results database in 2004-2011. The impact of RLN was assessed using Cox regression, propensity score methods, and joinpoint regression.

RESULTS

In 3079 patients, 1 to 10 RLNs were retrieved; in 2799 patients, 11 to 19 RLNs, and in 1807 patients, 20+ RLNs. The rate of node-positive pancreatic cancer increased with the number of retrieved RLN. This trend continued beyond 10 retrieved RLN (P < 0.001). In unadjusted analysis, retrieval of RLN did not influence survival (P = 0.178). When adjusting for significant bias in staging variables (P < 0.001), retrieval of 20+ RLNs compared to 11 to 19 RLNs was associated with an increased survival in node-negative (hazard ratio, 0.78; 95% confidence interval, 0.62-0.98; P = 0.033) and node-positive cancer (hazard ratio, 0.83; 95% confidence interval, 0.74-0.93; P = 0.002).

CONCLUSIONS

This population-based propensity score-adjusted investigation demonstrated that more retrieved RLNs in pancreatic cancer decreases the rate of stage migration and improves the oncological outcome in node-negative and positive cancer. Contradictory results may be explained by a bias in the cancer characteristics for a different extent of RLN retrieval.

Staging of pancreatic cancer based on the number of positive lymph nodes

BACKGROUND

The International Study Group on Pancreatic Surgery has stated that at least 12 lymph nodes should be evaluated for staging of pancreatic cancer. The aim of this population-based study was to evaluate whether the number of positive lymph nodes refines staging.

METHODS

Patients who underwent pancreatectomy for stage I-II pancreatic cancer between 2004 and 2012 were identified from the Surveillance, Epidemiology, and End Results database. The predictive value of the number of positive lymph nodes for survival was assessed by generalized receiver operating characteristic (ROC) curve analysis and propensity score-adjusted Cox regression analysis.

RESULTS

Some 5036 patients were included, with a median of 18 (i.q.r. 15-24) lymph nodes examined. Positive lymph nodes were found in 3555 patients (70·6 per cent). The median duration of follow-up was 15 (i.q.r. 8-28) months. ROC curve analysis revealed that two positive lymph nodes best discriminated overall survival. Patients with one or two positive lymph nodes (pN1a) and those with three or more positive lymph nodes (pN1b) had an increased risk of overall mortality compared with patients who were node-negative (pN0): hazard ratio (HR) 1·47 (95 per cent c.i. 1·33 to 1·64) and HR 2·01 (1·82 to 2·22) respectively. These findings were confirmed by propensity score-adjusted Cox regression analysis. The 5-year overall survival rates were 39·8 (95 per cent c.i. 36·5 to 43·3) per cent for patients with pN0, 21·0 (18·6 to 23·6) per cent for those with pN1a and 11·4 (9·9 to 13·3) per cent for patients with pN1b disease.

CONCLUSION

The number of positive lymph nodes in the resection specimen is a prognostic factor in patients with pancreatic cancer.

Multimodal treatment of resectable pancreatic ductal adenocarcinoma

After a timing preoperative staging, treatment of resectable pancreatic adenocarcinoma (PDAC) includes surgery and adjuvant therapies, the former representing the initial therapeutic option and the latter aiming to reduce the incidence of both distant metastases (chemotherapy) and locoregional failures (chemoradiotherapy). Herein, we provide a critical overview on the role of multimodal treatment in PDAC and on new opportunities related to current more active poli-chemotherapy regimens, targeted therapies, and the more recent immunotherapy approaches. Moreover, an analysis of pathological markers and clinical features able to help clinicians in the selection of the best therapeutic strategy will be discussed. Lastly, the role of neoadjuvant treatment of initially resectable disease will be considered mostly in patients whose malignancy shows morphological but not clinical or biological criteria of resectability. Depending on the results of these investigational studies, today a multidisciplinary approach can offer the best address therapy for these patients.

Predictors of adjuvant treatment for pancreatic adenocarcinoma at the population level

BACKGROUND

In the present study, we aimed to describe, at the population level, patterns of adjuvant treatment use after curative-intent resection for pancreatic adenocarcinoma (pcc) and to identify independent predictors of adjuvant treatment use.

METHODS

In this observational cohort study, patients undergoing pcc resection in the province of Ontario (population 13 million) during 2005-2010 were identified using the provincial cancer registry and were linked to administrative databases that include all treatments received and outcomes experienced in the province. Patients were defined as having received chemotherapy (ctx), chemoradiation (crt), or observation (obs). Clinicopathologic factors associated with the use of ctx, crt, or obs were identified by chi-square test. Logistic regression analyses were used to identify independent predictors of adjuvant treatment versus obs, and ctx versus crt.

RESULTS

Of the 397 patients included, 75.3% received adjuvant treatment (27.2% crt, 48.1% ctx) and 24.7% received obs. Within a single-payer health care system with universal coverage of costs for ctx and crt, substantial variation by geographic region was observed. Although the likelihood of receiving adjuvant treatment increased from 2005 to 2010 (p = 0.002), multivariate analysis revealed widespread variation between the treating hospitals (p = 0.001), and even between high-volume hepatopancreatobiliary hospitals (p = 0.0006). Younger age, positive lymph nodes, and positive surgical resection margins predicted an increased likelihood of receiving adjuvant treatment. Among patients receiving adjuvant treatment, positive margins and a low comorbidity burden were associated with crt compared with ctx.

CONCLUSIONS

Interinstitutional medical practice variation contributes significantly to differential patterns in the rate of adjuvant treatment for pcc. Whether such variation is warranted or unwarranted requires further investigation.

Pancreatic cancer metastatic to a limited number of lymph nodes has no impact on outcome

BACKGROUND

The purpose of this study was to determine the association of the extent of metastatic lymph node involvement with survival in pancreatic cancer.

METHODS

This is a retrospective review of a prospectively maintained database of patients who underwent resection for pancreatic adenocarcinoma, 1999-2011.

RESULTS

165 patients were identified and divided into 3 groups based on the number of positive lymph nodes - 0 (group A), 1-2 (B), >3 (C). Each group had 55 patients. Those in group C were more likely to have a higher T stage, poorly differentiated grade, lymphovascular invasion (LVI), higher mean intraoperative blood loss, positive margins, tumor location involving the uncinate process, and a higher likelihood of undergoing a pancreaticoduodenectomy. Median overall survival (OS) for group A, B and C was 25.5 months (mo), 21 mo and 12.3 mo, respectively (p < 0.001). No survival difference was noted for survival between groups A and B (p = 0.86). The ratio of involved lymph nodes <0.2 was predictive of improved survival (p < 0.001).

CONCLUSIONS

Resected pancreatic cancer patients with only 1-2 positive lymph nodes or less than 20% involvement have a similar prognosis to patients without nodal disease. Current staging should consider stratification based on the extent of nodal involvement.

How Does Outcomes Research Help Advance Our Knowledge of Patient Outcomes in Hepatopancreaticobiliary Surgery?

Randomized controlled trials have historically been regarded as the gold standard of modern clinical research tools, allowing us to elucidate the efficacy of novel therapeutics in an unparalleled manner. However, when attempting to generalize trial results to broader populations, it becomes apparent that the unexplained outcome variability exists among treatment recipients, suggesting that randomized controlled trials harbor inherent limitations. Herein, we explore the benefits of health services (outcomes) research utilization in addressing variation in patient outcomes following surgical intervention in the non-randomized setting, with a specific focus on hepatopancreaticobiliary surgery outcomes. To achieve this, we have constructed a framework that outlines the complex interactions existing between therapeutic, patient, and provider factors that subsequently lead to variation in outcomes. By exploring examples in the current literature, we have highlighted the areas where the knowledge is currently lacking and can be further strengthened through the application of outcomes research. Furthermore, we have attempted to demonstrate the utility of alternative study designs in the investigation of novel clinical questions currently unanswered in the field of hepatopancreaticobiliary surgery.

Lymph Node Evaluation for Pancreatic Adenocarcinoma and Its Value as a Quality Metric

BACKGROUND

Adequate lymph node evaluation (LNE) is recommended for surgically treated pancreatic adenocarcinoma because studies have shown an association between improved survival and adequate LNE. This study aimed to understand the mechanism of this association and determine whether LNE is a valuable quality metric.

METHODS

Using the linked Surveillance Epidemiology End Results Medicare database, we identified patients with surgically treated pancreatic adenocarcinoma from 2000 to 2010. Adequate LNE was defined as evaluation of ≥15 nodes. Survival was determined using Kaplan-Meier and Cox proportional hazards.

RESULTS

We identified 2629 patients who underwent resection for pancreatic adenocarcinoma. Overall, 33 % had adequate LNE. Adequate LNE was significantly associated with receipt of postoperative chemotherapy. A significant decrease in hazard of death was associated with adequate LNE (HR 0.86, p < 0.05). Receipt of postoperative chemotherapy was also significantly associated with decreased hazard of death (HR 0.77, p < 0.05). On unadjusted analysis, the survival benefit associated with adequate LNE was lost when stratified by receipt of postoperative chemotherapy.

CONCLUSION

The survival benefit associated with LNE is in part derived from the fact that patients who receive adequate LNE are also more likely to receive chemotherapy. Thus, the use of lymph node counts has limitations as a quality metric.

Impact of adjuvant treatment modalities on survival outcomes in curatively resected pancreatic and periampullary adenocarcinoma

BACKGROUND

We examined the impact of adjuvant modalities on resected pancreatic and periampullary adenocarcinoma (PAC).

METHODS

A total of 563 patients who were curatively resected for PAC were retrospectively analyzed between 2003 and 2013.

RESULTS

Of 563 patients, 472 received adjuvant chemotherapy (CT) alone, chemoradiotherapy (CRT) alone, and chemoradiotherapy plus chemotherapy (CRT-CT) were analyzed. Of the 472 patients, 231 were given CRT-CT, 26 were given CRT, and 215 were given CT. The median recurrence-free survival (RFS) and overall survival (OS) were 12 and 19 months, respectively. When CT and CRT-CT groups were compared, there was no significant difference with respect to both RFS and OS, and also there was no difference in RFS and OS among CRT-CT, CT and CRT groups. To further investigate the impact of radiation on subgroups, patients were stratified according to lymph node status and resection margins. In node-positive patients, both RFS and OS were significantly longer in CRT-CT than CT. In contrast, there was no significant difference between groups when patients with node-negative disease or patients with or without positive surgical margins were considered.

CONCLUSIONS

Addition of radiation to CT has a survival benefit in patients with node-positive disease following pancreatic resection.

Substaging of Lymph Node Status in Resected Pancreatic Ductal Adenocarcinoma Has Strong Prognostic Correlations: Proposal for a Revised N Classification for TNM Staging

BACKGROUND

The current tumor-node-metastasis staging system for the pancreas does not incorporate the number of lymph nodes (LNs) with metastasis.

METHODS

Among 1649 pancreaticoduodenectomies, 227 stringently defined pancreatic ductal adenocarcinomas (PDACs) that had undergone a specific approach of LN harvesting were analyzed for the prognostic value of LN substaging protocols used for other gastrointestinal (GI) organs.

RESULTS

The median number of LNs harvested was 18, and the median number of LNs with metastasis was 3. Lymph node metastasis was detected in 175 cases (77 %). The number of LNs involved correlated significantly with clinical outcome. When cases were substaged with the protocol already in use for the upper GI organs (N0: no metastasis, N1: metastasis to 1-2 LNs; N2: metastasis to ≥3 LNs), the median overall survival times were 35, 21, and 18 months, and the respective 3-year survival rates were 46, 34, and 20 % (p = 0.004). Analysis of the Surveillance, Epidemiology and End Results (SEER) database also confirmed the survival differences between these substages (median overall survival times of 23, 15, and 14 months and respective 3-year survival rates of 37, 22, and 18 %; p < 0.0001). The substaging protocol for the lower GI organs (N0: no metastasis; N1: metastasis to 1-3 LNs; N2: metastasis to ≥4 LNs) also was significant, with median overall survival times of 35, 21, 18 months and respective 3-year survival rates of 46, 26, and 23 %; p = 0.009). The association between higher N stage and shorter survival persisted with multivariate modeling for both protocols, although the prognostic value of the upper GI protocol appeared to be slightly stronger according to the Akaike Information Criterion method.

CONCLUSION

In conclusion, with proper LN harvesting, the LN metastasis rate in PDACs is very high (77 %). Substaging of LN metastasis has significant prognostic value and needs to be considered in the N staging of PDACs. The protocol already in use for other upper GI tract organs, which currently also is proven significant for ampulla, would be preferable, although the lower GI tract protocol also is applicable.

Pancreatic adenocarcinoma: number of positive nodes allows to distinguish several N categories

OBJECTIVE

To determine the prognostic value of PLN and LNR based on a large series with standardized lymphadenectomy and pathological workup.

BACKGROUND

Lymph node (LN) involvement is a major prognostic factor in pancreatic adenocarcinoma. However, the distinction N0/N1 is not sufficient to accurately predict prognosis. To improve prognostic accuracy in N1 tumors, different LN parameters have been tested. Previous studies were based on series with variable numbers of examined lymph nodes (ELN) and came to inconsistent conclusions as to the value of the number of positive lymph nodes (PLN) and the lymph node ratio (LNR).

METHODS

811 patients who underwent pancreatoduodenectomy for pancreatic adenocarcinoma between October 2001 and June 2012 were identified from a prospective database. Clinicopathological parameters included LN status (N0/N1), ELN, PLN, and LNR. Univariate and multivariate survival analyses were performed.

RESULTS

The median number of ELN was 24 (interquartile range: 18-32). By univariate analysis, both PLN and LNR were significantly associated with survival in N1 tumors. However, by multivariate analysis, only the number of PLN was confirmed as independent predictor of survival. Median survival in patients with only 1 PLN was 31.1 months and comparable to the survival in N0 (33.2 months). With increasing numbers of PLN median survival significantly decreased (2-3 PLN: 26.1 months, 4-7 PLN: 21.9 months, ≥8 PLN: 18.3 months, P < 0.0001).

CONCLUSIONS

This study demonstrates that, based on high numbers of ELN, PLN is superior to LNR in predicting survival and allows to distinguish several N-categories that improve prognostic accuracy in LN-positive resectable pancreatic adenocarcinoma.

Adjuvant chemoradiation for pancreatic cancer: what does the evidence tell us?

The role of adjuvant chemoradiation (CRT) for pancreas cancer remains unclear. A handful of randomized trials conducted decades of ago ignited a debate that continues today about whether CRT improves survival after surgery. The many flaws in these trials are well described in the literature, which include the use of antiquated radiation delivery techniques and suboptimal doses. Recent prospective randomized data is lacking, and we eagerly await the results the ongoing Radiation Therapy Oncology Group (RTOG) 0848 trial that is evaluating the utility of high quality adjuvant CRT in resected pancreas cancer patients. Until the results of RTOG 0848 are available we should look to other studies from the modern era to guide adjuvant treatment recommendations. Here we review the current state of the art for adjuvant pancreas CRT with respect to patient selection, radiation techniques, radiation dose, and integration with novel systemic agents.