Pathologic Examination of Pancreatic Specimens Resected for Treated Pancreatic Ductal Adenocarcinoma: Recommendations From the Pancreatobiliary Pathology Society

Histopathologic Grading of Residual Tumor Predicts Survival of Intrahepatic Cholangiocarcinoma Patients Treated With Neoadjuvant Therapy: Major Pathologic Response and Its Clinical Significance

Neoadjuvant therapy (NAT) is increasingly used to treat patients with initially unresectable intrahepatic cholangiocarcinoma (iCCA). A histopathologic grading system for residual tumors that can predict patient survival is lacking in the literature. This retrospective study enrolled 151 iCCA patients who received NAT. The percentage of residual viable tumor (%RVT) extent was calculated by RVT surface area/total tumor bed area ×100 and scored in 5% increments. Kaplan-Meier and Cox regression analyses were used to investigate its correlations with recurrence-free survival (RFS) and overall survival (OS). Tumor regression grading by the College of American Pathologists (CAP) and MD Anderson (MDA) methodologies were also validated. A 10% RVT-based tumor regression score (TRS) showed a significant correlation with both OS and RFS. TRS and major pathologic response (mPR) were therefore defined as follows: TRS 1/mPR, tumor with 0 to 10% RVT; TRS 2, more than 10% RVT. Patients graded as TRS 1/mPR had superior OS ( P =0.006) and RFS ( P <0.001) compared with those with TRS 2 in univariate analysis. In a multivariate analysis including ypTNM stages, lymphovascular invasion, and perineural invasion, TRS 1/mPR was also found to be an independent prognostic factor for both OS (hazard ratio [HR]: 0.226; 95% CI: 0.053-0.966, P =0.045) and RFS (HR: 0.474; 95% CI: 0.231-0.974, P =0.042). As for the CAP and MDA grading methodologies, they were found to correlate with RFS (CAP: P =0.002; MDA: P =0.001), but not with OS (CAP: P =0.181; MDA: P =0.09). Our study revealed that a TRS of ≤10% RVT significantly correlates with longer OS and RFS and can be suggested as an mPR in iCCA. This indicator is easily applicable, prognostically relevant, and could be further validated in future prospective clinical trials.

Diagnostic Pearls and Pitfalls in the Evaluation of Biopsies of the Pancreas

CONTEXT.—

The examination of small pancreatic biopsies is a difficult task for pathologists. This is due to the scant and fragmented material often obtained from diagnostic procedures as well as the significant overlap between different neoplastic and nonneoplastic entities. In the upcoming neoadjuvant era, biopsies could become even more important, representing the only possibility to look at the real histomorphology of tumors before chemotherapy-induced modifications.

OBJECTIVES.—

To summarize and discuss the state-of-the-art diagnostic workflow for small pancreatic biopsies, including the most important morphologic and immunohistochemical features and molecular alterations. The main diagnostic pearls and pitfalls of this challenging scenario are also discussed. The most important topics of this review are represented by: (1) pancreatic ductal adenocarcinoma, along with its main differential diagnoses, including autoimmune pancreatitis; (2) solid hypercellular neoplasms, including neuroendocrine neoplasms, acinar cell carcinoma, pancreatoblastoma, and solid pseudopapillary neoplasms; and (3) cystic lesions. Real-world considerations will also be presented and discussed.

DATA SOURCES.—

Sources included a literature review of published studies and the author's own work.

CONCLUSIONS.—

The correct diagnosis of pancreatic lesions is a crucial step in the therapeutic journey of patients. It should be based on robust, standardized, and reliable hallmarks. As presented and discussed here, the integration of morphology with immunohistochemistry, and, in selected cases, with molecular analysis, represents a decisive step in this complex scenario.

Frozen section analysis of pancreatic resection margins during pancreaticoduodenectomy for pancreatic adenocarcinoma is not affected by neoadjuvant therapy

BACKGROUND/OBJECTIVES

The aim of our study was to evaluate if the histopathological changes occurring in the pancreas post neoadjuvant-therapy (PNAT) for pancreatic ductal adenocarcinoma (PDAC) may negatively affect the assessment of intra-operative frozen section (FS) analysis of pancreatic resection margins (PRMs).

METHODS

The clinicopathological data of patients who underwent pancreatoduodenectomy for PDAC between 2015 and 2022 were analyzed. Comparison of the accuracy of the FS analysis in treatment naïve (TN) and PNAT patients for all pancreatic margins was performed.

RESULTS

We identified 81 patients with PDAC (40 female, 41 male) of which 47 (58.0 %) were TN and 34 (42.0 %) PNAT. Including FSs performed for re-excisions of initially positive PRMs, we identified 2/103 discrepancies for the pancreatic neck margin, one in a TN patient and one in a PNAT patient; one discrepancy for the common bile duct margin (1/47) in a TN patient; and 2/14 discrepancies for the uncinate margin, both in TN patients. In summary, accuracy of FS analysis was similar in the PNAT and TN groups (98.8 % vs. 96.7 %).

CONCLUSIONS

The histopathological changes occurring in the pancreas PNAT for PDAC do not affect the histopathological interpretation of FS analysis of PRMs, and the accuracy of FS analysis is similar in the PNAT and TN patients.

Neoadjuvant Treatment with Changes in Chemotherapy Regimens According to Carbohydrate Antigen 19-9 Level for Resectable/Borderline Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND

The response of carbohydrate antigen (CA) 19-9 to neoadjuvant therapy (NAT) for pancreatic ductal adenocarcinoma (PDAC) may contribute to outcomes. This study aimed to investigate the effect of changes in NAT regimens based on CA19-9 level.

METHODS

This single-center retrospective study included patients with resectable/borderline resectable (R/BR)-PDAC undergoing NAT from 2008 to 2022. A CA19-9 level lower than 150 IU/mL after NAT was the criterion for resection. If the level did not decrease, the chemotherapy regimen was changed to satisfy the criterion. The patient cohort was divided into group A (satisfied criterion without changing chemotherapy), group B (did not receive chemotherapy change, could not satisfy the criterion), group C (received chemotherapy change, satisfied the criterion), and group D (received chemotherapy change, could not satisfy the criterion).

RESULTS

The study cohort included 283 patients. After first-line chemotherapy, 112 (39.6%) patients did not satisfy the criterion (groups B [n = 64], C [n = 32], and D [n = 16]). Of the 283 patients, 48 (17%) received a chemotherapy change (groups C and D). The patients in groups C and D showed significantly better overall survival (OS, 35.9 months) than the group B patients (25.7 months) (P = 0.035). The OS of the group C patients (63.8 months) was similar to the OS of the group A patients (n = 171: 56.3 months; P = 0.430). Multivariate analysis of the patients in groups B, C, and D identified chemotherapy change as an independent prognostic factor for OS and progression-free survival.

CONCLUSION

Changing the chemotherapy targeting the CA19-9 level can improve the outcome of R/BR-PDAC patients with poor biologic response to first-line NAT.

The Association between Sampling and Survival in Patients with Pancreatic Ductal Adenocarcinoma Who Received Neoadjuvant Therapy and Pancreaticoduodenectomy

Adequate sampling is essential to an accurate pathologic evaluation of pancreatectomy specimens resected for pancreatic ductal adenocarcinoma (PDAC) after neoadjuvant therapy (NAT). However, limited data are available for the association between the sampling and survival in these patients. We examined the association of the entire submission of the tumor (ESOT) and the entire submission of the pancreas (ESOP) with disease-free survival (DFS) and overall survival (OS), as well as their correlations with clinicopathologic features, for 627 patients with PDAC who received NAT and pancreaticoduodenectomy. We demonstrated that both ESOT and ESOP were associated with lower ypT, less frequent perineural invasion, and better tumor response (p < 0.05). ESOP was also associated with a smaller tumor size (p < 0.001), more lymph nodes (p < 0.001), a lower ypN stage (p < 0.001), better differentiation (p = 0.02), and less frequent lymphovascular invasion (p = 0.009). However, since ESOP and ESOT were primarily conducted for cases with no grossly identifiable tumor or minimal residual carcinoma in initial sections, potential bias cannot be excluded. Both ESOT and ESOP were associated with less frequent recurrence/metastasis and better DFS and OS (p < 0.05) in the overall study population. ESOP was associated with better DFS and better OS in patients with ypT0/ypT1 or ypN0 tumors and better OS in patients with complete or near-complete response (p < 0.05). ESOT was associated with better OS in patients with ypT0/ypT1 or ypN0 tumors (p < 0.05). Both ESOT and ESOP were independent prognostic factors for OS according to multivariate survival analyses. Therefore, accurate pathologic evaluation using ESOP and ESOT is associated with the prognosis in PDAC patients with complete or near-complete pathologic response and ypT0/ypT1 tumor after NAT.

Pathologic assessment of hepatocellular carcinoma in the era of immunotherapy: a narrative review

Background and Objective

Immune checkpoint inhibitor (ICI)-based therapy has achieved impressive success in various cancer types. Several ICIs have been unprecedentedly approved as the treatment regimens for advanced hepatocellular carcinoma (HCC) in recent decade. Meanwhile, numerous clinical trials are being performed to exploit more ICIs into initially unresectable HCC and postoperative HCC to expectantly induce adequate tumor downstaging for further resection or implement adjuvant treatment for relapse-free survival, respectively. In this review, we aim to summarize some pragmatic histomorphologic, immunohistochemical, and molecular pathologic parameters which promisingly indicate the response of neoadjuvant/conversion ICI-related therapy and predict the efficacy of adjuvant/therapeutic ICI-related therapy for HCC.

Methods

We searched PubMed using the terms hepatocellular carcinoma, immunotherapy, immune checkpoint inhibitor, immune checkpoint blockade, conversion therapy, neoadjuvant therapy, adjuvant therapy, biomarker, pathologic evaluation, pathologic assessment till February 2023.

Key Content and Findings

Although there is no consensus regarding the pathologic evaluation of relevant HCC specimens, it is encouraging that a few of studies have concentrated on this field, and moreover, the methods and parameters noted on other cancer types are also worthy of reference. For the pathologic assessment of HCC specimens underwent immunotherapy, a suitable sampling scheme, identifying immunotherapy-related pathologic response, and quantification of pathologic response rate should be emphasized. For the patients of HCC who are scheduled to receive immunotherapy, tumor-infiltrating lymphocyte, intratumoral tertiary lymphoid structure, programmed cell death ligand 1, Wnt/β-catenin, microsatellite instability and mismatch repair, tumor mutational burden and tumor neoantigen, as well as some other signaling pathways are the potential predictive biomarkers of treatment response of ICI.

Conclusions

The management of HCC in the era of immunotherapy arises a brand-new pathological challenge that is to provide an immunotherapy-related diagnostic report. Albeit many related researches are preclinical or insufficient, they may tremendously alter the immunotherapy strategy of HCC in future.

Microscopic tumor mapping of post-neoadjuvant therapy pancreatic cancer specimens to predict post-surgical recurrence: A prospective cohort study

BACKGROUND

Although various pathological grading systems are available for evaluating the response of pancreatic ductal adenocarcinoma (PDAC) to neoadjuvant therapy (NAT), their prognostic value has not been thoroughly validated. This study examined whether microscopic tumor mapping of post-NAT specimens could predict tumor recurrence.

METHODS

This prospective study enrolled 52 patients who underwent pancreaticoduodenectomy after NAT for PDAC between 2019 and 2021. Microscopic mapping was performed to identify residual tumor loci within the tumor bed using 4 mm2 pixels. Patients were divided into small extent (SE; n = 26) and large extent (LE; n = 26) groups using a cutoff value of 226 mm2. The diagnostic performance for predicting tumor recurrence was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

Carbohydrate antigen 19-9 levels were normalised after NAT in more patients in the SE group (SE 21 [80.8%] vs. LE 13 [50.0%]; P = 0.041). Tumor size (P < 0.001), T stage (P < 0.001), positive lymph node yield (P = 0.024), and perineural invasion rate (P = 0.018) were significantly greater in the LE group. The 3-year disease-free survival rate was significantly lower in the LE group (SE 83.3% vs. LE 50.0%, P = 0.004). The area under the ROC curve for mapping extent was 0.743, which was greater than that of the other tumor response scoring systems.

CONCLUSIONS

Microscopic tumor mapping of the residual tumor in post-NAT specimens is a significant predictor of post-surgical recurrence, and offers better prognostic performance than the current grading systems.

Long-term outcomes of neoadjuvant gemcitabine, nab-paclitaxel, and S1 (GAS) in borderline resectable pancreatic cancer with arterial contact: Results from a phase II trial

BACKGROUND/PURPOSE

This study reports the long-term results of a phase II trial evaluating the clinical efficacy of neoadjuvant gemcitabine, nab-paclitaxel, and S1 (GAS) in borderline resectable pancreatic cancer with arterial contact (BRPC-A).

METHODS

A multicenter, single-arm, phase II trial was conducted. Patients received six cycles of GAS and patients without progressive disease were intended for R0 resection.

RESULTS

Of the 47 patients, 45 (96%) underwent pancreatectomy. At the time of this analysis, all patients were updated with no loss to follow-up. A total of 30 patients died, while the remaining 17 patients were followed for a median of 68.1 months. The updated median overall survival (OS) was 41.0 months, with 2- and 5-year OS rates of 68.0% and 44.6%, respectively. Multivariate analysis in the preoperative model showed that a tumor diameter reduction rate ≥10% and a CA19-9 reduction rate ≥95% after neoadjuvant chemotherapy remained independently associated with favorable survival. In the postoperative multivariate model, no lymph node metastasis, no major surgical complications, and completion of adjuvant chemotherapy were independently associated with improved OS.

CONCLUSIONS

This long-term evaluation of the neoadjuvant GAS trial demonstrated the high efficacy of the regimen, suggesting that it is a promising treatment option for patients with BRPC-A.

Essentials of macroscopic evaluation of specimens from gastrointestinal tract

An astute macroscopic examination, coupled with correlating the gross findings with clinical indication and operative notes along with judicious, yet all pertinent sectioning for pathological examination is crucial for an accurate histopathological diagnosis, eventually leading to optimal patient care. This succinct review highlights the general concepts that lay the foundation of evaluating and grossing specimens from the luminal gastrointestinal (GI) tract. We also discuss the gross evaluation and sectioning of small therapeutic resections, along with a systematic approach and rationale when grossing and submitting histological sections from larger oncological resections from the luminal GI tract. Selected site-specific considerations, for example, grossing treated rectal and oesophageal cancers or taking sections from mucinous tumours of the appendix, among others, are also discussed.

Clinical Evaluation of the Pancreatic Cancer Microenvironment: Opportunities and Challenges

Advances in our understanding of pancreatic ductal adenocarcinoma (PDAC) and its tumor microenvironment (TME) have the potential to transform treatment for the hundreds of thousands of patients who are diagnosed each year. Whereas the clinical assessment of cancer cell genetics has grown increasingly sophisticated and personalized, current protocols to evaluate the TME have lagged, despite evidence that the TME can be heterogeneous within and between patients. Here, we outline current protocols for PDAC diagnosis and management, review novel biomarkers, and highlight potential opportunities and challenges when evaluating the PDAC TME as we prepare to translate emerging TME-directed therapies to the clinic.

[Histopathologic diagnosis of solid and cystic pancreatic lesions with a focus on ductal adenocarcinoma : A vademecum for daily practice]

Pancreas pathology is constantly evolving and can present various challenges for pathologists. This paper is focused on providing helpful hints for daily routine diagnostics. During histopathological analysis of pancreas biopsies, pancreatic ductal adenocarcinoma must be distinguished not only from other solid neoplasms, but especially from its mimicker, autoimmune pancreatitis. This can be achieved by a systematic workup following clear diagnostic criteria. When analyzing samples from cystic pancreatic lesions, mucin-producing neoplasms must be detected due to their role as pancreatic cancer precursors; molecular analyses can help considerably with their detection and distinction. During frozen section examination, evaluation of the pancreatic neck margin and analysis of unclear lesions of the liver are two important tasks, which are explained further in this article. A special challenge is the evaluation of neoadjuvant treated pancreatic cancer, which requires a detailed macroscopic and microscopic workup. Finally, current advances in precision oncology and emerging approaches for pancreatic cancer within this field are discussed. With the advancement of technical possibilities and their increasingly broad implementation, the classification systems in pancreatic pathology will continue to gain in complexity, but also in accuracy.

Pancreatic Ductal Adenocarcinoma: Update of CT-Based Radiomics Applications in the Pre-Surgical Prediction of the Risk of Post-Operative Fistula, Resectability Status and Prognosis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is the seventh leading cause of cancer-related deaths worldwide. Surgical resection is the main driver to improving survival in resectable tumors, while neoadjuvant treatment based on chemotherapy (and radiotherapy) is the best option-treatment for a non-primally resectable disease. CT-based imaging has a central role in detecting, staging, and managing PDAC. As several authors have proposed radiomics for risk stratification in patients undergoing surgery for PADC, in this narrative review, we have explored the actual fields of interest of radiomics tools in PDAC built on pre-surgical imaging and clinical variables, to obtain more objective and reliable predictors.

METHODS

The PubMed database was searched for papers published in the English language no earlier than January 2018.

RESULTS

We found 301 studies, and 11 satisfied our research criteria. Of those included, four were on resectability status prediction, three on preoperative pancreatic fistula (POPF) prediction, and four on survival prediction. Most of the studies were retrospective.

CONCLUSIONS

It is possible to conclude that many performing models have been developed to get predictive information in pre-surgical evaluation. However, all the studies were retrospective, lacking further external validation in prospective and multicentric cohorts. Furthermore, the radiomics models and the expression of results should be standardized and automatized to be applicable in clinical practice.

Preoperative treatment with mFOLFIRINOX or Gemcitabine/Nab-paclitaxel +/- isotoxic high-dose stereotactic body Radiation Therapy (iHD-SBRT) for borderline resectable pancreatic adenocarcinoma (the STEREOPAC trial): study protocol for a randomised comparative multicenter phase II trial

BACKGROUND

For patients with pancreatic ductal adenocarcinoma (PDAC), surgical resection remains the only potentially curative treatment. Surgery is generally followed by postoperative chemotherapy associated with improved survival, yet neoadjuvant therapy is a rapidly emerging concept requiring to be explored and validated in terms of treatment options and oncological outcomes. In this context, stereotactic body radiation (SBRT) appears feasible and can be safely integrated into a neoadjuvant chemotherapy regimen of modified FOLFIRINOX (mFFX) with promising benefits in terms of R0 resection, local control and survival. However, the optimal therapeutic sequence is still not known, especially for borderline resectable PDAC, and the role of adding SBRT to chemotherapy in the neoadjuvant setting needs to be evaluated in randomised controlled trials. The aim of the STEREOPAC trial is to assess the impact and efficacy of adding isotoxic high-dose SBRT (iHD-SBRT) to neoadjuvant mFFX or Gemcitabine/Nab-Paclitaxel (Gem/Nab-P) in patients with borderline resectable PDAC.

METHODS

This is a randomised comparative multicentre phase II trial, planning to enrol patients (n = 256) diagnosed with a borderline resectable biopsy-confirmed PDAC. Patients will receive 4 cycles of mFFX (or 6 doses of Gem/Nab-P). After full disease restaging, non-progressive patients will be randomised for receiving either 4 additional mFFX cycles (or 6 doses of Gem/Nab-P) (Arm A), or 2 mFFX cycles (or 3 doses of Gem/Nab-P) + iHD-SBRT (35 to 55 Gy in 5 fractions) + 2 mFFX cycles (or 3 doses of Gem/Nab-P) (Arm B). Then curative surgery will be performed followed by adjuvant chemotherapy according to patient's condition. The co-primary endpoints are R0 resection and disease-free survival after the complete sequence strategy. The secondary endpoints include resection rate, overall survival, locoregional failure / distant metastasis free interval, pathologic complete response, toxicity, postoperative complications and quality of life assessment.

DISCUSSION

This trial will help define the best neoadjuvant treatment sequence for borderline resectable PDAC and aims to evaluate if a total neoadjuvant treatment integrating iHD-SBRT improves the patients' oncological outcomes.

TRIAL REGISTRATION

The study was registered at ClinicalTrails.gov (NCT05083247) on October 19th, 2021, and in the Clinical Trials Information System (CTIS) EU CT database (2022-501181-22-01) on July 2022.

Comparative Analyses of the Clinicopathologic Features of Short-Term and Long-Term Survivors of Patients with Pancreatic Ductal Adenocarcinoma Who Received Neoadjuvant Therapy and Pancreatoduodenectomy

Neoadjuvant therapy (NAT) is increasingly used to treat patients with pancreatic ductal adenocarcinoma (PDAC). Patients with PDAC often show heterogenous responses to NAT with variable clinical outcomes, and the clinicopathologic parameters associated with these variable outcomes remain unclear. In this study, we systematically examined the clinicopathologic characteristics of 60 short-term survivors (overall survival < 15 months) and 149 long-term survivors (overall survival > 60 months) and compared them to 352 intermediate-term survivors (overall survival: 15-60 months) of PDAC who received NAT and pancreatoduodenectomy. We found that the short-term survivor group was associated with male gender (p = 0.03), tumor resectability prior to NAT (p = 0.04), poorly differentiated tumor histology (p = 0.006), more positive lymph nodes (p = 0.04), higher ypN stage (p = 0.002), and higher positive lymph node ratio (p = 0.03). The long-term survivor group had smaller tumor size (p = 0.001), lower ypT stage (p = 0.001), fewer positive lymph nodes (p < 0.001), lower ypN stage (p < 0.001), lower positive lymph node ratio (p < 0.001), lower rate of lymphovascular invasion (p = 0.001) and perineural invasion (p < 0.001), better tumor response grading (p < 0.001), and less frequent recurrence/metastasis (p < 0.001). The ypN stage is an independent predictor of both short-term and long-term survivors by multivariate logistic regression analyses. In addition, tumor differentiation was also an independent predictor for short-term survivors, and tumor response grading and perineural invasion were independent predictors for long-term survivors. Our results may help to plan and select post-operative adjuvant therapy for patients with PDAC who received NAT and pancreatoduodenectomy based on the pathologic data.

Prognosticators for Patients with Pancreatic Ductal Adenocarcinoma Who Received Neoadjuvant FOLFIRINOX or Gemcitabine/Nab-Paclitaxel Therapy and Pancreatectomy

Neoadjuvant FOLFIRINOX and gemcitabine/nab-paclitaxel (GemNP) therapies are increasingly used to treat patients with pancreatic ductal adenocarcinoma (PDAC). However, limited data are available on their clinicopathologic prognosticators. We examined the clinicopathologic factors and survival of 213 PDAC patients who received FOLFIRINOX with 71 patients who received GemNP. The FOLFIRINOX group was younger (p < 0.01) and had a higher rate of radiation (p = 0.049), higher rate of borderline resectable and locally advanced disease (p < 0.001), higher rate of Group 1 response (p = 0.045) and lower ypN stage (p = 0.03) than the GemNP group. Within FOLFIRINOX group, radiation was associated with decreased lymph node metastasis (p = 0.01) and lower ypN stage (p = 0.01). The tumor response group, ypT, ypN, LVI and PNI, correlated significantly with both DFS and OS (p < 0.05). Patients with the ypT0/T1a/T1b tumor had better DFS (p = 0.04) and OS (p = 0.03) than those with ypT1c tumor. In multivariate analysis, the tumor response group and ypN were independently prognostic factors for DFS and OS (p < 0.05). Our study demonstrated that the FOLFIRINOX group was younger and had a better pathologic response than the GemNP group and that the tumor response group, ypN, ypT, LVI and PNI, are significant prognostic factors for survival in these patients. Our results also suggest that the tumor size of 1.0 cm is a better cut off for ypT2. Our study highlights the importance of systemic pathologic examination and the reporting of post-treatment pancreatectomies.

Integrated Pathologic Score Effectively Stratifies Patients With Pancreatic Ductal Adenocarcinoma Who Received Neoadjuvant Therapy and Pancreaticoduodenectomy

Neoadjuvant therapy is increasingly used to treat patients with pancreatic ductal adenocarcinoma (PDAC). Pathologic parameters of treated PDAC, including tumor (ypT) and lymph node (ypN) stage, and tumor response grading (TRG) are important prognostic factors in this group of patients. To our knowledge, a multifactorial prognostic score combining pathologic features including ypT, ypN, and TRG in treated PDAC patients has not been reported. Our cohort consisted of 398 PDAC patients who received neoadjuvant therapy and underwent pancreaticoduodenectomy at our institution. All pancreaticoduodenectomy specimens were grossly and microscopically evaluated using a standard protocol. The integrated pathologic score (IPS) was calculated as the sum of the scores for ypT, ypN, and TRG according to either the MD Anderson grading system (IPSMDA) or the College of American Pathologists (CAP) grading system (IPSCAP). The IPSMDA and IPSCAP were correlated with clinicopathologic parameters and patient survival. Using either IPSMDA or IPSCAP, PDAC patients were stratified into 3 distinct prognostic groups for both disease-free survival (DFS) ( P <0.001) and overall survival (OS) ( P <0.001). The IPSMDA and IPSCAP correlated with tumor differentiation, margin status, the American Joint Committee on Cancer (AJCC) stage, and tumor recurrence ( P <0.05). In multivariate analysis, IPSMDA, IPSCAP, margin status, and tumor differentiation were independent prognostic factors for both DFS ( P <0.05) and OS ( P <0.05). However, patients with AJCC stage IB, IIA, or IIB disease had no significant difference in either DFS or OS ( P >0.05). The IPS appears to provide improved prognostic information compared with AJCC staging for preoperatively treated patients with PDAC.

Multi-level integrative analysis of the roles of lncRNAs and differential mRNAs in the progression of chronic pancreatitis to pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors and approximately 5% of patients with chronic pancreatitis (CP) inevitably develop PDAC. This study aims explore the key gene regulation involved in the progression of CP to PDAC, with a particular emphasis on the function of lncRNAs.

RESULTS

A total of 103 pancreatic tissue samples collected from 11 to 92 patients with CP and PDAC, respectively, were included in this study. After normalizing and logarithmically converting the original data, differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEGs) in each dataset were selected. To determine the main functional pathways of differential mRNAs, we further annotated DEGs using gene ontology (GO) and analyzed the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. In addition, the interaction between lncRNA-miRNA-mRNA was clarified and the protein-protein interaction (PPI) network was constructed to screen for key modules and determine hub genes. Finally, quantitative real-time polymerase chain reaction (qPCR) was used to detect the changes in non-coding RNAs and key mRNAs in the pancreatic tissues of patients with CP and PDAC. In this study, 230 lncRNAs and 17,668 mRNAs were included. There were nine upregulated lncRNAs and 188 downregulated lncRNAs. Furthermore, 2334 upregulated differential mRNAs and 10,341 downregulated differential mRNAs were included in the enrichment analysis. From the KEGG enrichment analysis, cytokine-cytokine receptor interaction, calcium signaling pathway, cAMP signaling pathway, and nicotine addiction exhibited significant differences. Additionally, a total of 52 lncRNAs, 104 miRNAs, and 312 mRNAs were included in the construction of a potential lncRNA-miRNA-mRNA regulatory network. PPI network was established and two of the five central DEGs were created in this module, suggesting that lysophosphatidic acid receptor 1 (LPAR1) and regulator of calcineurin 2 (RCAN2) may play significant roles in the progression from CP to PDAC. Finally, the PCR results suggested that LINC01547/hsa-miR-4694-3p/LPAR1 and LINC00482/hsa-miR-6756-3p/RCAN2 play important roles in the carcinogenesis process of CP.

CONCLUSION

Two signaling axes critical in the progression of CP to PDAC were screened out. Our findings will be useful for novel insights into the molecular mechanism and potential diagnostic or therapeutic biomarkers for CP and PDAC.

Prognostic value of major pathological response following neoadjuvant therapy for non resectable pancreatic ductal adenocarcinoma

BACKGROUND

The aim of this study is to evaluate the impact of major pathological response on overall survival (OS) in borderline resectable and locally advanced pancreatic ductal adenocarcinoma following neoadjuvant treatment, and to identify predictors of major pathological response.

METHODS

Patients surgically resected following neoadjuvant treatment between 2010 and 2020 at the Pederzoli Hospital were retrospectively analyzed. Pathologic response was assessed using the College of American Pathologists (CAP) score, and major pathological response was defined as CAP 0-1. OS was estimated and compared using the Kaplan-Meier method and log-rank test. A logistic and Cox regression model were performed to identify predictors of major pathologic response and OS.

RESULTS

Overall, 200 patients were included in the study. A major and complete pathological response were observed in 52(26.0%) and 15(7.3%) patients respectively. The 1-, 3-, 5-year OS was 92.7, 67.2, and 41.7%, and 71.0, 37.4, and 20.8% in patients with or without major pathologic response respectively (log-rank test p < 0.001). Major pathologic response was confirmed as independent predictor of OS (OR 0.50 95%CI 0.29-0.88, p = 0.01). Post-treatment CA19-9 normalization (OR 4.20 95%CI 1.14-10.35, p = 0.02) and radiological post-treatment tumor residual size<25 mm (OR 2.71 95%CI 1.27-5.79, p = 0.01) were found to be independent predictors of major pathologic response.

CONCLUSION

Patients experienced a major pathological response after neoadjuvant treatment have an increased survival, and major pathologic response is an independent predictor of OS. A normal CA19-9 value and radiological tumor size at restaging are confirmed to be independent predictors of major pathologic response.

Neoadjuvant Chemotherapy Is Associated with Altered Immune Cell Infiltration and an Anti-Tumorigenic Microenvironment in Resected Pancreatic Cancer

PURPOSE

Neoadjuvant chemotherapy is increasingly administered to patients with resectable or borderline resectable pancreatic ductal adenocarcinoma (PDAC), yet its impact on the tumor immune microenvironment is incompletely understood.

EXPERIMENTAL

DESIGN

We employed quantitative, spatially resolved multiplex immunofluorescence and digital image analysis to identify T-cell subpopulations, macrophage polarization states, and myeloid cell subpopulations in a multi-institution cohort of up-front resected primary tumors (n = 299) and in a comparative set of resected tumors after FOLFIRINOX-based neoadjuvant therapy (n = 36) or up-front surgery (n = 30). Multivariable-adjusted Cox proportional hazards models were used to evaluate associations between the immune microenvironment and patient outcomes.

RESULTS

In the multi-institutional resection cohort, immune cells exhibited substantial heterogeneity across patient tumors and were located predominantly in stromal regions. Unsupervised clustering using immune cell densities identified four main patterns of immune cell infiltration. One pattern, seen in 20% of tumors and characterized by abundant T cells (T cell-rich) and a paucity of immunosuppressive granulocytes and macrophages, was associated with improved patient survival. Neoadjuvant chemotherapy was associated with a higher CD8:CD4 ratio, greater M1:M2-polarized macrophage ratio, and reduced CD15+ARG1+ immunosuppressive granulocyte density. Within neoadjuvant-treated tumors, 72% showed a T cell-rich pattern with low immunosuppressive granulocytes and macrophages. M1-polarized macrophages were located closer to tumor cells after neoadjuvant chemotherapy, and colocalization of M1-polarized macrophages and tumor cells was associated with greater tumor pathologic response and improved patient survival.

CONCLUSIONS

Neoadjuvant chemotherapy with FOLFIRINOX shifts the PDAC immune microenvironment toward an anti-tumorigenic state associated with improved patient survival.

Long-Term Outcomes of Venous Resections in Pancreatic Ductal Adenocarcinoma Patients: A Nationwide Cohort Study

To investigate whether pancreatic resections (PR) for pancreatic ductal adenocarcinoma (PDAC) is associated with worse survival when resection of the superior mesenteric vein/portal vein (SMV/PV) is required.

Background

PR for PDAC with resection of the superior mesenteric vein/portal vein (SMV/PV, PR+V resection) may be associated with inferior overall survival (OS) compared with PR without the need for SMV/PV resection (PR-V). We hypothesized that PR+V results in lower OS compared with PR-V.

Method

Retrospective study using data from the nationwide Danish Pancreatic Cancer Database from 2011 to 2020. Data on patients who underwent PR for PDAC were extracted. A group of PR patients found nonresectable on exploratory laparotomy (EXP) was also included. OS was assessed using Kaplan-Meier and Cox proportional hazards models adjusting for confounders (age, sex, R-resection level, chemotherapy, comorbidities, histology T and N classification, procedure subtype as well as tumor distance to the SMV/PV).

Results

Overall, 2403 patients were identified. Six hundred two underwent exploration only (EXP group), whereas 412 underwent pancreatic resection with (PR+V group) and 1389 (PR-V) without SMV/PV resection. Five-year OS for the PR+V group was lower (20% vs 30%) compared with PR-V, although multivariate Cox proportional hazards modeling could not associate PR+V status with OS (Hazard ratio 1.11, P = 0.408).

Conclusion

When correcting for confounders, PR+V was not associated with lower OS compared with PR-V.

Critical issues in pathologic evaluation of pancreatic ductal adenocarcinoma resected after neoadjuvant treatment: a narrative review

BACKGROUND AND OBJECTIVE

Preoperative neoadjuvant therapy (NAT) is increasingly used in the treatment of patients with potentially resectable pancreatic ductal adenocarcinoma (PDAC). Because NAT often induces heterogeneous tumor response and extensive fibrosis both in tumor and adjacent pancreatic tissue, pathologic assessment of posttherapy pancreatectomy specimens is challenging. A limited number of studies examined the optimal grossing and sampling methods, tumor response grading (TRG), and the prognostic value of posttherapy tumor (ypT) and lymph node (ypN) stages of treated PDAC patients. In this review, we will provide an overview of the current status and critical issues in pathologic evaluation of PDAC resected after NAT.

METHODS

In PubMed, Google Scholar and Web of Science, we reviewed existing English literature (published up to December 2021) highlighting the most recent ones using electronic databases and authors' experience to outline the challenging aspects and new perspectives on pathologic assessment of the treated PDAC.

KEY CONTENT AND FINDINGS

The recent recommendations from the Pancreatobiliary Pathology Society (PBPS) provide the much-needed guidelines for systematic and standardized pathologic evaluation and reporting of treated PDAC for optimal patient care. For treated PDAC, tumor size measured by gross and radiology is not reliable. Histologic validation of tumor size on consecutive mapping sections is recommended for accurate ypT stage. A tumor size of 1.0 cm seems to be a better cutoff for ypT2 for treated PDACs. The published data suggested that the MD Anderson Cancer Center (MDA) TRG system is easy to use, has a better interobserver agreement and better correlation with patient prognosis compared to the College of American Pathologists (CAP) and Evans grading systems and may be used as an alternative TRG system for the CAP cancer protocol.

CONCLUSIONS

Systemic and standardized grossing and sampling are essential for accurate pathologic evaluation and reporting for optimal care of PDAC patients who received NAT. Future studies on optimal sampling and integration of histopathology with artificial intelligence (AI), molecular and immunohistochemical markers are needed for better and personalized care of treated PDAC patients.

High frequency of PDGFRA and MUC family gene mutations in diffuse hemispheric glioma, H3 G34-mutant: a glimmer of hope?

BACKGROUND

Diffuse hemispheric glioma H3 G34-mutant (G34-DHG) is a new type of pediatric-type diffuse high-grade glioma in the fifth edition of the WHO Classification of Tumors of the Central Nervous System. The current treatment for G34-DHG involves a combination of surgery and conventional radiotherapy or chemotherapy; however, the therapeutic efficacy of this approach is not satisfactory. In recent years, molecular targeted therapy and immunotherapy have achieved significant benefits in a variety of tumors. In-depth understanding of molecular changes and immune infiltration in G34-DHGs will help to establish personalized tumor treatment strategies. Here, we report the clinicopathological, molecular and immune infiltration characteristics of G34-DHG cases from our center along with cases from the HERBY Trial and the Chinese Glioma Genome Atlas database (CGGA).

METHODS

Hematoxylin-eosin (HE) and immunohistochemistry (IHC) staining were used to present the clinicopathological characteristics of 10 Chinese G34-DHG patients treated at our institution. To address the molecular characteristics of G34-DHG, we performed whole-exome sequencing (WES) and RNA sequencing (RNA-seq) analyses of 5 patients from our center and 3 Chinese patients from the Chinese Glioma Genome Atlas (CGGA) database. Additionally, 7 European G34-DHG patients from the HERBY Trail were also subjected to analyses, with 7 cases of WES data and 2 cases of RNA-seq data. Six G34-DHG patients from another organization were used as external validation.

RESULTS

WES showed a high frequency of PDGFRA mutation in G34-DHGs (12/15). We further identified frequent mutations in MUC family genes in G34-DHGs, including MUC16 (8/15) and MUC17 (8/15). Although no statistical difference was found, PDGFRA mutation tended to be an indicator for worse prognosis whereas MUC16/MUC17 mutation indicated a favorable prognosis in G34-DHGs. RNA sequencing results revealed that most G34-DHG are considered to be immune cold tumors. However, one patient in our cohort with MUC16 mutation showed significant immune infiltration, and the total overall survival of this patient reached 75 months.

CONCLUSIONS

Our results demonstrate that G34-DHG is a new high-grade glioma with high frequency of PDGFRA and MUC gene family mutations. PDGFRA may serve as an indicator of poor prognosis and an effective therapeutic target. Moreover, MUC16 tends to be a favorable prognostic factor and indicates high immune infiltration in certain patients, and these findings may provide a new direction for targeted therapy and immunotherapy of patients with G34-DHGs.