Magnetic resonance imaging targeted biopsy in biopsy-naïve patients and the risk of overtreatment in prostate cancer: a grading issue

OBJECTIVE

To evaluate the impact of applying the 2014 and 2019 International Society of Urological Pathology (ISUP) recommendations on grade group distribution and concordance with radical prostatectomy (RP).

MATERIALS AND METHODS

Overall, 655 biopsy-naïve patients diagnosed by magnetic resonance imaging (MRI) targeted and systematic biopsies for Prostate Imaging Reporting and Data System score ≥3 lesions were identified from a prospectively maintained database from 2016 and 2022. Clinically significant prostate cancer was detected in 249 patients, of whom 69 underwent RP. Wilcoxon signed rank and McNemar's tests were used to compare the ISUP grade group distribution and concordance with RP after applying the 2014 (i.e., highest grade) and 2019 (i.e., global grade) ISUP recommendations, respectively.

RESULTS

Compared to the 2014 ISUP recommendations, the 2019 ISUP recommendations were associated with a significant decrease in ISUP Grade Group 4 (range of difference from -13% to -5%) and an increase in ISUP Grade Group 2 (range of difference from +6% to +11%) in MRI targeted biopsy only, MRI targeted with perilesional biopsies, and MRI targeted with systematic biopsies (all P < 0.01). In patients who underwent RP, a significant decrease in downgrading was observed with all biopsy strategies (range of difference from -19% to -12%; P ≤ 0.008), along with an increase in concordance with RP specimen (range of difference from +12% to +13%; P ≤ 0.02). The use of the 2019 ISUP recommendation was associated with RP specimen a lower treatment burden.

CONCLUSIONS

The use of the 2019 ISUP recommendations mitigates the grade migration induced by MRI targeted biopsy and improves the concordance with the final RP specimen.

A Two-Step Diagnostic Approach for NTRK Gene Fusion Detection in Biliary Tract and Pancreatic Adenocarcinomas

BACKGROUND

It is of interest to determine the incidence and molecular characteristics of NTRK gene fusions in patients with bilio-pancreatic cancers, because of possible treatment with TRK inhibitors for advanced tumors. The aim of the present study was to apply the guidelines for NTRK testing algorithm to a series of patients with bilio-pancreatic cancers.

METHODS

Immunohistochemistry screening was applied on formalin-fixed paraffin-embedded archival blocks from surgical resections, biopsies, or cytological samples of biliary tract and pancreatic adenocarcinomas. The presence of at least a weak staining in rare tumor cells led to testing by 2 RNA-based NGS panels.

RESULTS

For biliary tract tumors, 153 samples have been selected. A total of 140 samples were suitable to perform IHC, and 17 samples were IHC positive. RNA NGS testing of the 17 IHC-positive samples revealed a single NTRK3 gene fusion (ETV6(4)-NTRK3(14)) that was detected by both NGS panels. In this perihilar cholangiocarcinoma, IHC performed on a biopsy showed a weak focal cytoplasmic and nuclear staining. No other NTRK fusion was detected on the 16 other samples with both panels. Overall in the patients screened by IHC and confirmed by NGS, the percentage of NTRK fusions was 0.7%. For pancreatic cancers, 319 samples have been selected and 297 were suitable to perform IHC. Nineteen samples were IHC positive. No fusion was detected by NGS.

CONCLUSION

NTRK gene fusions are rare in bilio-pancreatic cancers but testing is of high interest due to possible treatment with specific TRK inhibitors.

Implementation of fetal clinical exome sequencing: Comparing prospective and retrospective cohorts

PURPOSE

We compared the diagnostic yield of fetal clinical exome sequencing (fCES) in prospective and retrospective cohorts of pregnancies presenting with anomalies detected using ultrasound. We evaluated factors that led to a higher diagnostic efficiency, such as phenotypic category, clinical characterization, and variant analysis strategy.

METHODS

fCES was performed for 303 fetuses (183 ongoing and 120 ended pregnancies, in which chromosomal abnormalities had been excluded) using a trio/duo-based approach and a multistep variant analysis strategy.

RESULTS

fCES identified the underlying genetic cause in 13% (24/183) of prospective and 29% (35/120) of retrospective cases. In both cohorts, recessive heterozygous compound genotypes were not rare, and trio and simplex variant analysis strategies were complementary to achieve the highest possible diagnostic rate. Limited prenatal phenotypic information led to interpretation challenges. In 2 prospective cases, in-depth analysis allowed expansion of the spectrum of prenatal presentations for genetic syndromes associated with the SLC17A5 and CHAMP1 genes.

CONCLUSION

fCES is diagnostically efficient in fetuses presenting with cerebral, skeletal, urinary, or multiple anomalies. The comparison between the 2 cohorts highlights the importance of providing detailed phenotypic information for better interpretation and prenatal reporting of genetic variants.

Painful ophthalmoplegia in a patient with a history of marginal zone lymphoma

A 73-year-old man with a history of marginal zone lymphoma was admitted to the emergency room for diplopia and ipsilateral headache. The Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) demonstrated intense and symmetrical hypermetabolism of the cavernous sinuses, and hypermetabolic lesions diffusely in the lymph nodes and bones. The diagnosis of high-grade relapse of lymphomatous disease was made. In this context, the homogenous and symmetric lesion of the cavernous sinuses, without any other encephalic or meningeal lesions, raised the hypothesis of a paraneoplastic origin. A plausible paraneoplastic link between the neuro-ophthalmological lesion and the malignant disorder is IgG4-related disease, a condition that may be associated with lymphoma. As in our case, this diagnosis is often presumptive because histopathological confirmation is difficult to obtain.

Magnets and a self-retractable wire for endoscopic septotomies: from concept to first-in-human use

BACKGROUND

A medical device that allows simple and safe performance of an endoscopic septotomy could have several applications in the gastrointestinal (GI) tract. We have developed such a device by combining two magnets and a self-retractable wire to perform a progressive septotomy by compression of the tissues. We describe here the concept, preclinical studies, and first clinical use of the device for the treatment of symptomatic epiphrenic esophageal diverticulum (EED).

METHODS

The MAGUS (MAgnetic Gastrointestinal Universal Septotome) device was designed based on previous knowledge of compression anastomosis and currently unmet needs. After initial design, the feasibility of the technique was tested on artificial septa in pigs. A clinical trial was then initiated to assess the feasibility and safety of the technique.

RESULTS

Animal studies showed that the MAGUS can perform a complete septotomy at various levels of the GI tract. In two patients with a symptomatic EED, uneventful complete septotomy was observed within 28 and 39 days after the endoscopic procedure.

CONCLUSIONS

This new system provides a way of performing endoluminal septotomy in a single procedure. It appears to be effective and safe for managing symptomatic EED. Further clinical applications where this type of remodeling of the GI tract could be beneficial are under investigation.

NTRK gene fusions in bilio-pancreatic cancers

e16664

Background: Gene fusions involving one of the 3 neurotrophic tyrosine receptor kinases ( NTRK) have been identified in approximately 1% of solid tumors and inhibitors of TRK have been shown to have anti-tumor activity regardless of tumor type. NTRK gene fusions have been previously reported in bilio-pancreatic tumors. It is of interest therefore to determine incidence and molecular characteristics of NTRK gene fusions in these patients. Methods: Formalin-fixed paraffin-embedded archival blocks from surgical resections, biopsies or cytological samples of biliary tract tumors (BTC) including intra-hepatic (IH), extra-hepatic (EH), perihilar cholangiocarcinoma (PH) and gallbladder tumors (G), and pancreatic adenocarcinoma (PA) were retrieved from the tumor bank of CUB Hôpital Erasme between JAN 2010 and OCT 2019. A two-step diagnostic method incorporating immunohistochemistry (IHC) screening followed by NGS analysis was used. Pan–TRK IHC (monoclonal antibody clone EPR17341 [AbCam, Cambridge, MA]) was used for the screening method. Staining intensity (negative, weak, moderate or strong) pattern (diffuse, focal or rare positive cells), and localization (cytoplasmic or nuclear) were evaluated. The presence of at least weak staining tumor cells led to testing by a RNA-based NGS panel (Oncomine Focus Assay ThermoFisher Scientific). Results: For BTC, 162 archival tumors samples have been selected. 149 samples were suitable to perform IHC.17 samples were IHC positive including 9 IH, 3 PH, 2 EH and 3 G tumor samples. Intensity of staining was weak in 16 samples and moderate in one. Staining location was cytoplasmic (14/17), nuclear (2/17), and nuclear+cytoplasmic (1/17). Pattern of staining was rare positive cells (2/17), focal (4/17) and diffuse (11/17). NGS testing of the 17 IHC positive samples revealed a single NTRK3 gene fusion ( ETV6(4)- NTRK3(14)). In this PH tumor, IHC had a weak focal cytoplasmic and nuclear staining. Overall in the patients screened by IHC and confirmed by NGS, percentage of NTRK fusions was 0.67 %. For PA, 319 archival tumor samples have been selected and 297 were suitable for IHC. 19 samples were IHC positive. Intensity of staining was weak in 18 samples and moderate in one. Staining location was cytoplasmic (18/19) and nuclear (1/19). Pattern of staining was focal in 2 cases and diffuse in 17 cases. No fusion was detected by NGS. Conclusions: NTRK gene fusions are rare in bilio-pancreatic cancers but testing is of high interest due to the emergence of possible treatment with specific TRK inhibitors. These results support the use of NGS to confirm positive IHC results during diagnostic screening.

The daily practice reality of PD-L1 (CD274) evaluation in non-small cell lung cancer: A retrospective study

Treatment with pembrolizumab, an anti-programmed cell death-1 (PDCD-1) monoclonal antibody for the treatment of non-small cell lung cancers (NSCLCs) requires prior immunohistochemical (IHC) analysis of the expression of the programmed death-ligand 1 (PD-L1) (also known as CD274 molecule) which is a heterogeneous and complex marker. The present study aimed to investigate how pathological and technical factors (such as tumor location and sampling type, respectively) may affect the PD-L1 evaluation in patients with NSCLC in the daily practice of pathology laboratories. The current study was retrospective, and included 454 patients with NSCLC, for whom PD-L1 expression analysis by IHC was prospectively performed between November 2016 and January 2018. The association between PD-L1 expression and the clinicopathological characteristics of patients was statistically investigated using either the χ2 and Fisher exact tests or the Mann-Whitney and Kruskal-Wallis tests, depending on whether PD-L1 expression was assessed in three large categories (<1, 1-49, ≥50%) or in more precise percentages. Furthermore, the same statistical methodology was used to analyze the heterogeneity of PD-L1 expression according to its sampling type (cytology, biopsy or surgical specimen) and its location (primary tumor, lymph node or distant metastasis). Intra- and inter-observer discrepancies were also studied using double-blind evaluation and concordance analyses based on the weighted κ coefficient. The results demonstrated a significant association between PD-L1 expression and sample location (P=0.005), histological type (P=0.026), total number of mutations (P=0.004) and KRAS proto-oncogene, GTPase mutations (P=0.024). In addition, sampling type did not influence PD-L1 expression. The inter- and intra-observer discrepancies were 15% and between 16 and 17.5%, respectively. The present study confirmed that evaluation of PD-L1 expression by IHC can be performed on all types of samples. In addition, the results from the current study highlighted the heterogeneity of PD-L1 expression among the different types of sample location. In complex cases, a second evaluation of PD-L1 expression by IHC would be performed due to intra- and inter-observer discrepancies.

NTRK gene fusions in biliary tract cancers

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Background: Gene fusions involving one of the 3 neurotrophic tyrosine receptor kinases ( NTRK) have been identified in approximately 1% of solid tumors and inhibitors of TRK (e.g. larotrectinib) have been shown to have anti-tumor activity regardless of tumor type. NTRK gene fusions have been previously reported in bilio-pancreatic cancers. It is of interest therefore to determine the incidence and molecular characteristics of NTRK gene fusions in patients with bilio-pancreatic cancers. Methods: Formalin-fixed paraffin-embedded archival blocks from surgical resections, biopsies or cytological samples of biliary tract tumors including intra-hepatic cholangiocarcinoma (IH), extra-hepatic cholangiocarcinoma (EH), perihilar cholangiocarcinoma (PH) and gallbladder tumors (G) were selected/retrieved from the tumor bank of the CUB Hôpital Erasme between January 2010 and July 2019. A two-step diagnostic method incorporating immunohistochemistry (IHC) screening followed by NGS analysis was used. Pan–TRK IHC (monoclonal antibody clone EPR17341 [AbCam, Cambridge, MA]) was used for the screening method. Staining intensity (negative, weak, moderate or strong) and localization (cytoplasmic or nuclear) were evaluated. The presence of at least weak staining tumor cells led to testing by a RNA-based NGS panel (Oncomine Focus Assay, ThermoFisher scientific). Results: 145 archival tumors samples (81 surgical resections, 48 biopsies and 16 cytology) have been selected, including 61 IH, 32 PH, 26 EH and 26 G (67 female and 78 male). 134 samples were suitable to perform IHC. 17 samples were IHC positive. Intensity of staining was weak in 16 samples and moderate in one. Staining location was cytoplasmic (14/17), nuclear (2/17), and nuclear+cytoplasmic (1/17). NGS testing of the 17 IHC positive samples revealed a single NTRK3 gene fusion ( ETV6(4)- NTRK3(14)). In this case (female patient with a poorly differentiated PH, deceased), IHC had a weak focal cytoplasmic and nuclear staining. Overall in the patients screened by IHC and confirmed by NGS, the percentage of NTRK fusions was 0.75%. Conclusions: NTRK gene fusions are rare in biliary cancers but testing is of high interest due to the emergence of possible treatment with specific TRK inhibitors.