EUS fine-needle pancreatic core biopsy can determine eligibility for tumor-agnostic immunotherapy

Comments on and Illustrations of the EFSUMB CEUS Guidelines: Transabdominal and Endoscopic Ultrasound Features of Intrapancreatic Metastases and the Role of Multiparametric Imaging and EUS-Guided Sampling in Rare Pancreatic Tumors

A definite pathologic diagnosis of intrapancreatic metastasis is crucial for the management decision, i.e., curative or palliative surgery versus chemotherapy or conservative/palliative therapy. This review focuses on the appearance of intrapancreatic metastases on native and contrast-enhanced transabdominal ultrasound and endoscopic ultrasound. Differences and similarities in relation to the primary tumor, and the differential diagnosis from pancreatic carcinoma and neuroendocrine neoplasms are described. The frequency of intrapancreatic metastases in autopsy studies and surgical resection studies will be discussed. Further emphasis is placed on endoscopic ultrasound-guided sampling to confirm the diagnosis.

A special subtype: Revealing the potential intervention and great value of KRAS wildtype pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the predominant form of pancreatic cancer and has devastating consequences on affected families and society. Its dismal prognosis is attributed to poor specificity of symptoms during early stages. It is widely believed that PDAC patients with the wildtype (WT) KRAS gene benefit more from currently available treatments than those with KRAS mutations. The oncogenic genetic changes alternations generally found in KRAS wildtype PDAC are related to either the KRAS pathway or microsatellite instability/mismatch repair deficiency (MSI/dMMR), which enable the application of tailored treatments based on each patient's genetic characteristics. This review focuses on targeted therapies against alternative tumour mechanisms in KRAS WT PDAC.

Evaluation of MMR Status and PD-L1 Expression Using Specimens Obtained by EUS-FNB in Patients with Pancreatic Ductal Adenocarcinoma (PDAC)

Deficient DNA mismatch repair status (dMMR)/high microsatellite instability have been shown to be predictive biomarkers for immune checkpoint inhibitor drugs which block the programmed death protein-1/programmed death ligand-1 (PD-1/PD-L1) interaction between tumor cells and activated T cells. The aim of this study was to determine the prevalence of MMR status and quantification of PD-L1 expression in pancreatic endoscopic ultrasound-guided fine-needle biopsy (EUS FNB) specimens. Immunochemistry (IHC) was performed on consecutive archived treatment-naïve formalin-fixed paraffin-embedded EUS-FNB samples. The specimens were considered to have PD-L1 expression if PD-L1 was expressed in ≥1% of tumor cells and a high level of expression if ≥50%. Tumors with absent nuclear staining of DNA mismatch repair proteins (MLH1, MSH2, MSH6, or PMS2) were classified as dMMR. A total of 28 treatment-naïve patients who underwent EUS-FNB and had a final diagnosis of pancreatic ductal adenocarcinoma (PDAC) were included in the study. All the EUS-FNB samples were adequate for the evaluation of MMR and PD-L1 expression. None of the patients with PDAC included in the study had a dMMR tumor. PD-L1 expression was identified in 39% of the cohort (n = 11). Expression thresholds of ≥1%, ≥10%, and ≥50% in tumor cells were identified in 11 (39%), 4 (14%), and 1 (4%) patients, respectively. The evaluation of MMR status and PD-L1 can be successfully performed on EUS-FNB pancreatic specimens. Furthermore, MMR expression failed to show utility in recognizing immunotherapy vulnerability in pancreatic cancer; the only recommendation for testing remains for patients with heritable cancers. Meanwhile high PD-L1 expression was correlated with poor prognosis. This association may identify a subgroup of patients where immune checkpoints inhibitors could provide therapeutic benefits, spotlighting the role of EUS-FNB in the field of immune-oncology.

Comparison of Endoscopic Ultrasound-Guided Tissue Acquisition Using a 20-Gauge Menghini Needle with a Lateral Forward Bevel and a 22-Gauge Franseen Needle: A Single-Center Large Cohort Study

Background/Aims

Several fine-needle biopsy (FNB) needles are available for endoscopic ultrasound (EUS)-guided tissue acquisition. However, there is disagreement on which type of needle has the best diagnostic yield. The aim of this study was to compare the performance and safety of two commonly used EUS-FNB needles.

Methods

We retrospectively analyzed consecutive patients who underwent EUS-FNB between June 2016 and March 2020 in our hospital. Two types of needles were evaluated: a 20-gauge Menghini needle with a lateral forward bevel and a 22-gauge Franseen needle. Rapid on-site evaluation was performed in all the cases. A multivariate analysis was performed to clarify the negative predictive factors for obtaining a histological diagnosis. Propensity score matching was performed to compare the diagnostic yields of these two needles.

Results

We analyzed 666 patients and 690 lesions. The overall diagnostic rate of histology alone was 88.8%, and the overall adverse event rate was 1.5%. Transduodenal access and small lesions (≤2 cm) were identified as negative predictive factors for obtaining a histological diagnosis. After propensity score matching, 482 lesions were analyzed. The diagnostic accuracy rates of histology in the M and F needle groups were 89.2% and 88.8%, respectively (p=1.00).

Conclusions

Both the needles showed high diagnostic yield, and no significant difference in performance was observed between the two.

Fine Needle Aspiration versus Fine Needle Biopsy of Biliopancreatic Lesions: Are They Really Opposing Techniques or Can They Be Complementary? Our Experience in a Large Cohort of Cases from a Single Institution

INTRODUCTION

Nowadays, endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA), and fine needle biopsy (FNB) are considered the best procedures for the diagnosis of biliopancreatic lesions. These methods represent a milestone since they proved to be both safe for the patient and useful to achieve diagnostic material useful to plan the best treatment strategy.

OBJECTIVE

Since in the literature, a debate between cytology and histology supporters is still ongoing and the trend is changing in favor of FNB, we would like to present our experience about the diagnostic yield of FNA and FNB. The aim of our study is to highlight FNA versus FNB diagnostic role of biliopancreatic lesions, highlight advantages, and drawbacks of these procedures, and our view on these 2 procedures and whether they should still be considered complementary or opposing techniques.

METHODS

We retrospectively reviewed our hospital series of 469 EUS diagnostics procedures of biliopancreatic lesions performed in 419 patients, between 2015 and 2019.

RESULTS

The overall adequacy rates of FNA and FNB were, respectively, 98.9 and 100%. Stratifying cases according to anatomic location of the mass (pancreas vs. biliary system), we detected 168 malignancies out of 349 pancreatic lesions (168/349; 48.1%), while biliary system cases positive for malignancy represented 33.8% (23/68 cases) (p value = 0.045, χ2 test). As for concomitant FNB, our series displayed a high rate of diagnostic concordance (88.8%).

CONCLUSIONS

Despite numerous data published, it is still unclear which is the most feasible method to use; therefore, we compared FNA, FNB, or their combination to understand the best applicable technique. Our experience confirmed that FNA is extremely efficient in the diagnosis of biliopancreatic lesions, especially in the hands of expert endoscopists and pathologists. Considering anatomic location, EUS-FNA is more accurate for mass-forming neoplasms in the pancreatic parenchyma rather than for lesions of the biliary system. Moreover, concomitant FNB usually confirmed the cytological diagnosis, allowing a deeper immunohistochemical characterization of the neoplasia. This proves that a "pure" cytology and "pure" histology approach should be looked differently since these are complementary techniques especially if we can obtain a cellblock from FNA.

Endoscopic ultrasound-guided tissue acquisition of solid mass lesions of the pancreas: A retrospective comparison study of fine-needle aspiration and fine-needle biopsy

BACKGROUND

Although endoscopic ultrasound guided fine-needle biopsy (EUS-FNB) has emerged as an alternative to fine-needle aspiration (FNA) for the sampling of solid pancreatic mass lesions, it remains unclear which method is more effective. We compared the diagnostic yields of FNA, FNB, and combined FNA/FNB at a tertiary care institution.

METHODS

Specimens from EUS-FNA (04/2014-08/2017) and EUS-FNB (10/2015-08/2017) with SharkCore needle of pancreatic solid mass lesions were retrieved. Clinical, radiologic, and pathologic data was recorded. Pathology results of malignancy/neoplasms with uncertain malignant potential were considered as true positive. The "negative" cases included were with ≥6 months of follow-up. Nondiagnostic cases showed unremarkable pancreatic tissue, nonpancreatic elements, atypia, or features suspicious for malignancy. Diagnostic yield was defined as percentage of lesions sampled in which a benign or malignant tissue diagnosis, as defined above, was obtained. Statistical comparisons were performed using Fisher's exact test and univariable and multivariable logistic regression analysis.

RESULTS

The study cohort included 76 FNA only cases, 88 FNB only cases, and 40 combined FNA/FNB cases. Diagnostic yields were 70% (FNA), 70% (FNB), and 83% (FNA/FNB), which were not statistically different. Increase in lesion size and presence of ROSE were significantly associated with a diagnostic outcome on both univariable and multivariable analysis, unlike the number of passes.

CONCLUSION

Our results demonstrate that for solid pancreatic lesions, the diagnostic yields of FNA, FNB, and combined FNA and FNB are comparable. Presence of ROSE and increasing lesion size increased the diagnostic yield while the number of passes had no significant impact.

The relationship between the PD-L1 expression of surgically resected and fine-needle aspiration specimens for patients with pancreatic cancer

BACKGROUND

Recently, therapeutic antibodies against programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) have shown promising clinical results for several solid tumors, including pancreatic cancer. In this study, we evaluated the relationship between the PD-L1 expression of surgical resected and fine-needle aspiration (FNA) specimens for patients with pancreatic cancer.

METHODS

Of 121 patients who underwent endoscopic ultrasound-guided (EUS)-FNA before surgery for pancreatic cancer in an academic center, the 94 (78%) with adequate FNA specimens for a histological evaluation were retrospectively analyzed. All the patients had undergone upfront surgery without any chemotherapy or radiotherapy. We performed immunohistochemistry (IHC) staining to investigate the PD-L1 expression in both resected and FNA specimens. The positive-stained cells were counted, and their percentage was used for the investigation.

RESULTS

Of the 94 patients, 16 (17%) and 11 (10%) were defined as positive on resected cancer specimens using cutoff points of 5% and 10% positively stained cancer cell counts, respectively. The concordance rates for the positive frequency of PD-L1 expression between resected and FNA specimens were 44% (7/16) and 55% (6/11) when the positivity was set to ≥ 5% and ≥ 10%, respectively. The concordance rates for the negative frequency of PD-L1 expression between two specimens were 97% (76/78) and 99% (82/83) when the positivity was set to ≥ 5% and ≥ 10%, respectively.

CONCLUSIONS

Approximately, half of the patients with PD-L1 expression positive and almost all the patients with PD-L1 expression negative could be diagnosed on FNA specimens.

Update on current pancreatic treatments: from molecular pathways to treatment

Pancreatic cancer is still diagnosed at a late stage although we have novel diagnostic tools. Pancreatic cancer chemotherapy treatment resistance is observed and therefore novel treatments are in need. Anti-cancer stem cell therapy, combination of chemotherapy and/or radiotherapy with immunotherapy, proteins/enzymes and gene therapy are currently under evaluation. Targeted treatment with tyrosine kinase inhibitors is also administered and novel inhibitors are also under evaluation. In the current review we present recent data from our search within the year 2018.