Identification of an N staging system that predicts oncologic outcome in resected left-sided pancreatic cancer

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prognostic Factors of Long-term Survival Following Radical Resection for Ampullary Carcinoma

BACKGROUND

The incidence of adenocarcinoma of the ampulla of Vater has been increasing over the past years. Nevertheless, it is still a rare disease and the prognostic factors predicting long-term survival are not sufficiently clarified. This study aims to evaluate the association between histopathological characteristics and long-term survival of patients with ampullary cancer after curative resection, as well as the efficiency of immunohistochemical expression of CK7, CK20, and CDX2 to distinguish the histopathological (intestinal or pancreaticobiliary) patterns.

METHODS

Demographic, histopathological data, pTNM stage, and immunohistochemical expression patterns were collected from 65 patients with adenocarcinoma of the ampulla of Vater. Five and 10-year overall and disease-free survival rates after curative resection were determined.

RESULTS

Of the 65 patients with ampullary carcinoma, 47 (72%) underwent radical resection. The 5- and 10-year overall survival rate was 46% and 37%, respectively. Our results demonstrate that the main prognostic factors were the presence and number of lymph node metastases, lymph node ratio (LNR), differentiation grade, and lymphovascular invasion. After multivariate analysis, only lymph node ratio ≥ 20% remained an independent prognostic factor of survival (HR: 2.63 95% CI: 1.05-6.61; p = 0.039).

CONCLUSION

Here, we demonstrated more evidence that the lymph node metastases are associated with poor prognosis in ampullary carcinoma. Particularly, the relation between the number of metastatic lymph nodes and the number of harvested lymph node (LNR) should be considered a major prognostic factor.

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.

Contrast-enhanced CT radiomics for predicting lymph node metastasis in pancreatic ductal adenocarcinoma: a pilot study

BACKGROUND

We developed a computational model integrating clinical data and imaging features extracted from contrast-enhanced computed tomography (CECT) images, to predict lymph node (LN) metastasis in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

This retrospective study included 159 patients with PDAC (118 in the primary cohort and 41 in the validation cohort) who underwent preoperative contrast-enhanced computed tomography examination between 2012 and 2015. All patients underwent surgery and lymph node status was determined. A total of 2041 radiomics features were extracted from venous phase images in the primary cohort, and optimal features were extracted to construct a radiomics signature. A combined prediction model was built by incorporating the radiomics signature and clinical characteristics selected by using multivariable logistic regression. Clinical prediction models were generated and used to evaluate both cohorts.

RESULTS

Fifteen features were selected for constructing the radiomics signature based on the primary cohort. The combined prediction model for identifying preoperative lymph node metastasis reached a better discrimination power than the clinical prediction model, with an area under the curve of 0.944 vs. 0.666 in the primary cohort, and 0.912 vs. 0.713 in the validation cohort.

CONCLUSIONS

This pilot study demonstrated that a noninvasive radiomics signature extracted from contrast-enhanced computed tomography imaging can be conveniently used for preoperative prediction of lymph node metastasis in patients with PDAC.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Yonsei criteria: a clinical reflection of stage I left-sided pancreatic cancer

In this study, we examined associations between pancreatic cancer that met the Yonsei criteria (YC) and classifications from the 8th edition of the American Joint Committee on Cancer (AJCC) staging system. Clinicopathological and survival data were collected from132 patients who underwent distal pancreatectomy for left-sided pancreatic ductal adenocarcinoma between January 2000 and December 2015, and the utility of the YC for selecting treatment and predicting survival was evaluated using the 8th AJCC staging manual. Of the 102 patients who ultimately qualified for the study, 45 patients were reclassified as stage I based on the 8th AJCC cancer staging system. Disease-free survival and disease-specific survival periods were longer in stage I patients who met the YC than in those who did not. Clinicopathological characteristics did not differ between stage I patients who did and did not meet the YC. These results suggest that meeting the YC criteria may be a clinical indicator that left-sided pancreatic cancer patients who are candidates for resection have early-stage disease according to the 8th edition of the AJCC staging manual.

The Role of Fibroblasts in Pancreatic Cancer: Extracellular Matrix Versus Paracrine Factors

BACKGROUND AND AIM: Desmoplasia is a characteristic feature and a suspected mechanism of tumor progression in pancreatic ductal adenocarcinoma (PDAC). Main constituents of the stroma involve cancer-associated fibroblasts (CAFs) and extracellular matrix (ECM). The aim of this study was to dissect the interaction of CAFs, ECM, and PDAC cells in both an in vitro setting and a large-scale clinical cohort study. METHODS AND MATERIAL: Patients operated for PDAC were identified from our prospectively maintained clinical database. A standard pathology protocol was applied for pancreatoduodenectomy specimens also assessing CAF activation as either CAF grade 0 or CAF grade +. Interaction between a spectrum of pancreatic cancer cell lines (PCCs) and mouse embryonic fibroblasts (NIH 3T3) was assessed in a conditioned medium experimental setup. RESULTS: One hundred eleven patients operated for PDAC from 2001 to 2011 were identified. Univariate analysis disclosed CAF grade + (P = .030), positive M status (P < .001), and lymph node ratio (LNR) > 0.1 (P = .045) to impair overall survival. Independent prognostic factors were CAF grade (P = .050) and positive M status (P = .002). CAF grade correlated with N status (CC = 0.206, P = .030), LNR (CC = 0.187, P = .049), tumor size (CC = −0.275, P = .003), and M status (CC = 0.190, P = .045). In the in vitro setting, paracrine effects of pancreatic cancer cell resulted in morphological activation of fibroblasts and tumor cell differentiation–dependent increase of fibroblast growth. Paracrine effects of poorly differentiated PCCs led to an upregulation of Vimentin in NIH 3T3 fibroblasts. Paracrine effects of fibroblasts on their part promoted cancer cell motility in all PCCs. As the second stromal component, fibroblast-derived ECM resulted in significantly decreased proliferation depending on density and led to upregulation of ZEB1 in poorly differentiated PCCs. CONCLUSION: In PDAC patients, positive CAF grading was identified as a negative prognostic parameter correlating with positive N status, high LNR, positive M status, and smaller tumor size. Whereas bilateral interaction of PCCs and CAFs promotes tumor progression, ECM poses PCC growth restrictions. In summary, our study discloses differential effects of stromal components and may help to interpret heterogeneous results of former studies.