Clinical impacts of resection margin status and clinicopathologic parameters on pancreatic ductal adenocarcinoma

Prognostic relevance of the most predominant and least differentiated grades of gastric adenocarcinoma after curative gastrectomy

BACKGROUND

Prognostic relevance of differentiation grade has remained controversial in gastric adenocarcinoma (GAC) after curative resection.

METHODS

GAC patients who underwent curative gastrectomy were analyzed. Differentiation grade was evaluated according to either the most predominant or least differentiated component. Impacts of clinicopathologic parameters on postoperative recurrence and nodal metastasis were analyzed by the multivariate Cox regression analysis in pT1/2/3/4a and pT1b/2/3 GAC and by the logistic regression analysis in pT1b GAC, respectively.

RESULTS

154 patients with GAC, consisting of 34 pT1a (recurrence rate 0%), 45 pT1b (4.4%), 18 pT2 (22.2%), 40 pT3 (35.0%), and 17 pT4a (76.5%), were included. In pT1/2/3/4a GAC, recurrence was significantly associated with only depth of invasion (pT) and grade of venous invasion (VI), although either mode of differentiation grade was significantly associated with pT by the Spearman's rank correlation test. Next, given no recurrence in pT1a and high-grade histopathology in nearly all pT4a, pT1b/2/3 GAC was analyzed, revealing that recurrence was significantly associated with only VI grade and nodal metastasis. Finally, nodal metastasis was not found in any pT1a GAC, of which 44.1% was predominantly high-grade. In pT1b GAC, nodal metastasis was irrelevant to either mode of differentiation grade, tumor size, and ulceration status but was only associated with lymphatic invasion, suggesting that endoscopic resection of pT1 GAC with negative margin can be curative even with high-grade histopathology.

CONCLUSION

Either mode of differentiation grade revealed limited prognostic relevance after curative gastrectomy. Our results may warrant a controversy over current curability evaluation of endoscopic GAC resection.

The impact of vascular margin invasion on local recurrence after pancreatoduodenectomy in pancreatic adenocarcinoma

PURPOSE

Pancreatic ductal adenocarcinoma (PADC) still has nowadays a very impaired long-term survival. Most studies are focused on overall survival; however, local recurrence occurs about up to 50% of cases and seems to be highly related with margin resection status. We aim to analyze the impact of vascular resection margins on local recurrence (LR) and to assess its impact on overall and disease-free survival.

METHODS

Eighty out of 191 patients who underwent pancreatoduodenectomy in a university hospital between 2006 and 2021 with PDAC diagnosis were analyzed and vascular margin status specifically addressed. Univariate and multivariate were performed. Time to LR was compared by using the Kaplan-Meier method and prognostic factors assessed using Cox regression hazards model.

RESULTS

LR appeared in 10 (50%) of the overall R1 resections in the venous margin and 9 (60%) in the arterial one. Time to LR was significantly shorter when any margin was overall affected (23.2 vs 44.7 months, p = 0.01) and specifically in the arterial margin involvement (13.7 vs 32.1 months, p = 0.009). Overall R1 resections (HR 2.61, p = 0.013) and a positive arterial margin (HR 2.84, p = 0.012) were associated with local recurrence on univariate analysis, whereas arterial positive margin remained significant on multivariate analysis (HR 2.70, p = 0.031).

CONCLUSIONS

Arterial margin invasion is correlated in our cohort with local recurrence. Given the limited ability to modify this margin intraoperatively, preoperative therapies should be considered to improve local margin clearance.

FSCN1 and epithelial mesenchymal transformation transcription factor expression in human pancreatic intraepithelial neoplasia and ductal adenocarcinoma

BACKGROUND

The actin regulatory protein fascin (FSCN1) and epithelial mesenchymal transition (EMT) transcription factor (TF) SLUG/SNAI2 have been shown to be expressed in PDAC and its precursor lesions (pancreatic intraepithelial neoplasia (PanIN), graded 1-3) in in vitro and murine in vivo studies. Our aim was to investigate the expression of FSCN1 and EMT-TFs and their association with survival in human PanIN and PDAC.

METHODS

Expression was investigated in silico using TCGA PanCancer Atlas data (177 PDAC samples with mRNA data) and immunohistochemical staining of a tissue microarray (TMA) (59 PDAC patients).

RESULTS

High FSCN1 expression was associated with poorer overall survival (p = 0.02) in the TCGA data. EMT-TF expression was not associated with survival, however FSCN1 expression correlated with that of the EMT-TFs SLUG/SNAI2 (rho = 0.49, p < 0.001) and TWIST1 (rho = 0.52, p < 0.001). TMA IHC showed low expression of SNAI2 and TWIST1 in normal ductal epithelium, while FSCN1 was not expressed. SNAI2 increased slightly in PanIN1-2, then decreased in higher grade lesions. TWIST1 increased in PanIN2-3 and was retained in PDAC. FSCN1 was increasingly expressed from PanIN2 onwards. SNAI2 and TWIST1 expression positively correlated in all grades of PanIN and PDAC (rho = 0.52, p < 0.001). FSCN1 correlated positively with SNAI2 in PanIN1 (rho = 0.56, p < 0.01).

CONCLUSIONS

Increased expression of EMT-TFs in low-grade PanIN followed by FSCN1 in PanIN3 and PDAC suggests EMT-TFs may trigger FSCN1 expression and are potential early diagnostic markers. FSCN1 expression correlated with overall survival in PDAC and may have value as a prognostic marker.

The Impact of Involved Resection Margin on Recurrence and Survival After Pancreaticoduodenectomy for Periampullary Carcinoma, with Emphasis on Pancreatic Head Carcinoma

BACKGROUND

The supposed adverse effect of involved resection margin during pancreaticoduodenectomy (PD) for periampullary carcinoma or pancreatic head carcinoma (CaP) on long-term oncological outcomes is still inconclusive.

METHODS

This is a retrospective study on periampullary carcinoma undergoing PD. Patients with R0 (margin clear) resection were compared to patients with R1 (microscopically directly involved margin) resection. Patients with gross involved margin (R2 resection) were excluded. Long-term oncological outcomes measured included incidence and site of recurrent disease, overall survival (OS) and disease-free survival (DFS). A subgroup analysis was made on patients with CaP.

RESULTS

Between January 2003 and December 2019, 203 PD were identified for present study. The incidence of R1 resection was common (12% in periampullary carcinoma and 20% in CaP). In periampullary carcinoma, R1 resection had greater proportion of CaP, lesser proportion of carcinoma of ampulla (CaA), more perineural invasion, more lymph node (LN) metastasis. R1 group had a shorter OS and DFS, but no difference in the incidence and site of recurrent disease. In the subgroup of CaP (91 patients), R1 group did not differ from R0 group except for more LN metastasis. There was no difference in incidence and site of recurrent disease, OS and DFS. On multivariable analysis, R1 resection was not an independent factor for OS and DFS for periampullary carcinoma or for CaP only.

CONCLUSION

Involved resection margin was not uncommon. It was not associated with higher incidence of recurrent disease including local recurrence, and was not an independent prognosticator for OS and DFS.

A Novel Validated Recurrence Stratification System Based on 18F-FDG PET/CT Radiomics to Guide Surveillance After Resection of Pancreatic Cancer

objective

Despite the heterogeneous biology of pancreatic cancer, similar surveillance schemas have been used. Identifying the high recurrence risk population and conducting prompt intervention may improve prognosis and prolong overall survival.

Methods

One hundred fifty-six resectable pancreatic cancer patients who had undergone ¹⁸F-FDG PET/CT from January 2013 to December 2018 were retrospectively reviewed. The patients were categorized into a training cohort (n = 109) and a validation cohort (n = 47). LIFEx software was used to extract radiomic features from PET/CT. The risk stratification system was based on predictive factors for recurrence, and the index of prediction accuracy was used to reflect both the discrimination and calibration.

Results

Overall, seven risk factors comprising the rad-score and clinical variables that were significantly correlated with relapse were incorporated into the final risk stratification system. The 1-year recurrence-free survival differed significantly among the low-, intermediate-, and high-risk groups (85.5, 24.0, and 9.1%, respectively; p < 0.0001). The C-index of the risk stratification system in the development cohort was 0.890 (95% CI, 0.835-0.945).

Conclusion

The ¹⁸F-FDG PET/CT-based radiomic features and clinicopathological factors demonstrated good performance in predicting recurrence after pancreatectomy in pancreatic cancer patients, providing a strong recommendation for an adequate adjuvant therapy course in all patients. The high-risk recurrence population should proceed with closer follow-up in a clinical setting.

Effect and limitation of neoadjuvant chemotherapy for pancreatic ductal adenocarcinoma: consideration from a new perspective

BACKGROUND

Effect of neoadjuvant chemotherapy (NAC) for pancreatic ductal adenocarcinoma (PDAC) has remained under investigation. We investigated its effect from a unique perspective and discussed its application.

PATIENTS AND METHODS

We retrospecively analyzed consecutive 131 PDAC patients who underwent pancreatoduodenectomy and distal pancreatectomy. Clinicopathologic data at surgery and postoperative prognosis were compared between patients who underwent upfront surgery (UFS) (n = 64) and those who received NAC (n = 67), of which 62 (92.5%) received gemcitabine plus S-1 (GS). The GS regimen resulted in about 15% of partial response and 85% of stable disease in a previous study which analyzed a subset of this study subjects.

RESULTS

Tumor size was marginally smaller, degree of nodal metastasis and rate of distant metastasis were significantly lower, and pathologic stage was significantly lower in the NAC group than in the UFS group. In contrast, significant differences were not observed in histopathologic features such as vessel and perineural invasions and differentiation grade. Notably, disease-free and overall survivals were similar between the two groups adjusted for the pathologic stage, suggesting that effects of NAC, including macroscopically undetectable ones such as control of micro-metastasis and devitalizing tumor cells, may not be remarkable in the majority of PDAC, at least with respect to the GS regimen.

CONCLUSIONS

NAC may be useful in downstaging and improving prognosis in a small subset of tumors. However, postoperative prognosis may be determined at the pathologic stage of resected specimen with or without NAC. Therefore, NAC may be applicable to borderline resectable and locally advanced PDAC for enabling surgical resection, but UFS would be desirable for primary resectable PDAC.