A case of acinar cell carcinoma originating from the accessory papilla of the duodenum

CASE PRESENTATION

A 61-year-old female was referred to our hospital with a neoplastic lesion in the duodenum. Computed tomography with contrast enhancement revealed a 10-mm tumor in the duodenum. Upper gastrointestinal endoscopy revealed a submucosal tumor-like lesion in the descending part of the duodenum. Endoscopic ultrasound revealed a well-defined hypoechoic tumor. Biopsy and immunohistochemical findings including negative Synaptophysin and Chromogranin A staining and positive Trypsin and BCL10 staining suggested a carcinoma with acinar cell differentiation. Pancreatoduodenectomy was performed, and the resected specimen had a 15-mm solid nodule in the submucosal layer of the duodenum. Pancreatogram of the resected specimen revealed a tumor localized in the accessory papilla region. In histopathological examination, the tumor was found in the submucosa of the duodenum with pancreatic tissue present nearby, and these were separated from the pancreatic parenchyma by the duodenal muscle layer. These findings led to a diagnosis of acinar cell carcinoma originating from the accessory papilla of the duodenum.

CONCLUSION

Acinar cell carcinoma originating from the accessory papilla of the duodenum is exceptionally rare, with no reported cases to date. The origin was considered to be pancreatic tissue located in the accessory papilla region.

Japanese Society of Medical Oncology clinical guidelines: Molecular testing for colorectal cancer treatment, 5th edition

Molecular testing to determine optimal therapies is essential for managing patients with colorectal cancer (CRC). In October 2022, the Japanese Society of Medical Oncology published the 5th edition of the Molecular Testing Guideline for Colorectal Cancer Treatment. In this guideline, in patients with unresectable CRC, RAS/BRAF V600E mutational and mismatch repair tests are strongly recommended prior to first-line chemotherapy to select optimal first- and second-line therapies. In addition, HER2 testing is strongly recommended because the pertuzumab plus trastuzumab combination is insured after fluoropyrimidine, oxaliplatin, and irinotecan in Japan. Circulating tumor DNA (ctDNA)-based RAS testing is also strongly recommended to assess the indications for the readministration of anti-EGFR antibodies. Both tissue- and ctDNA-based comprehensive genomic profiling tests are strongly recommended to assess the indications for targeted molecular drugs, although they are currently insured in patients with disease progression after receiving standard chemotherapy (or in whom disease progression is expected in the near future). Mutational and mismatch repair testing is strongly recommended for patients with resectable CRC, and RAS/BRAF V600E mutation testing is recommended to estimate the risk of recurrence. Mutational and mismatch repair and BRAF testing are also strongly recommended for screening for Lynch syndrome. Circulating tumor DNA-based minimal residual disease (MRD) testing is strongly recommended for estimating the risk of recurrence based on clinical evidence, although MRD testing was not approved in Japan at the time of the publication of this guideline.

EBV+ nodal T/NK-cell lymphoma associated with clonal hematopoiesis and structural variations of the viral genome

Epstein-Barr virus (EBV)+ nodal T- and NK-cell lymphoma (EBV+ nPTCL) is a peripheral T-cell lymphoma (PTCL) that presents as a primary nodal disease with T-cell phenotype and EBV harboring on tumor cells. To date, the genetic aspect of EBV+ nPTCL has not been fully investigated. In this study, whole-exome and/or genome sequencing was performed on 22 cases of EBV+ nPTCL. TET2 (68%) and DNMT3A (32%) were observed to be the most frequently mutated genes whose presence was associated with poor overall survival (p = 0.004). The RHOA p.Gly17Val mutation was identified in two patients who had TET2 and/or DNMT3A mutations. In four patients with TET2/DNMT3A alterations, blood cell-rich tissues (bone marrow [BM] or spleen) were available as paired normal samples. Three out of these four cases had at least one identical TET2/DNMT3A mutation in the BM or spleen. Additionally, the whole part of the EBV genome was sequenced and structural variations (SVs) were found frequent among the EBV genomes (63%). The most frequently identified type of SV was deletion. In one patient, four pieces of human chromosome 9, including PD-L1 were identified to be tandemly incorporated into the EBV genome. The 3'-untranslated region of PD-L1 was truncated, causing a high-level of PD-L1 protein expression. Overall, the frequent TET2 and DNMT3A mutations in EBV+ nPTCL seem to be closely associated with clonal hematopoiesis and, together with the EBV genome deletions, may contribute to the pathogenesis of this intractable lymphoma.

Brentuximab vedotin plus AVD followed by involved-node radiotherapy in a patient with classic Hodgkin lymphoma following gray zone lymphoma after autologous stem-cell transplantation failure

BACKGROUND

No consensus has been reached yet concerning treatment strategies for a sequential classic Hodgkin lymphoma (CHL) following gray zone lymphoma (GZL). Prognosis of GZL after a failed autologous hematopoietic stem-cell transplantation (auto-HCT) is poor and treatment strategy is very limited. As yet there are limited data showing clinical outcomes of brentuximab vedotin (BV) for GZL, especially for sequential CHL after GZL.

CASE PRESENTATION

We report a case of CHL following primary refractory GZL after a failed auto-HCT and showed favorable response to first-line CHL-directed chemoradiotherapy consisting of BV plus doxorubicin, vinblastine, and dacarbazin (AVD) followed by irradiation. The sequential cases with an early evolution, whose diagnosis of second lymphoma was made within a year, have been recently reported very poor survival shorter than a year. Whether a sequential CHL following GZL should be treated as a primary or relapsed disease has not been clearly elucidated. Our patient showed favorable response to first-line CHL-directed chemoradiotherapy without allogenic hematopoietic stem-cell transplantation and has in continuous remission for 2 years.

CONCLUSIONS

The management of our case could help for physicians to make better treatment decisions and provide insights for further exploration in future studies.

Diagnostic utility of DNA integrity number as an indicator of sufficient DNA quality in next-generation sequencing-based genomic profiling

OBJECTIVES

DNA integrity number (DIN) is a metric for assessing DNA degradation, calculated based on electrophoresis using the Agilent TapeStation System. The utility of DIN as a diagnostic indicator of sufficient DNA quality in clinical next-generation sequencing (NGS) has not been well described.

METHODS

We evaluated the DINs of 166 tumor formalin-fixed, paraffin-embedded (FFPE) tissue samples submitted for 124-gene panel sequencing. We also investigated a new metric on the electropherogram that could improve the predictive accuracy of the DIN.

RESULTS

A DIN cutoff of 2.5 discriminated samples with successful analysis (n = 143) from samples with failed analysis (n = 23), with a sensitivity of 0.84 and a specificity of 0.78 (area under the curve [AUC] = 0.88). The DIN was positively correlated with the mean coverage (r = 0.72, P < .0001) but could not discriminate success from failure when the DIN was below 2.5 (negative predictive value, 0.44). We introduced a new metric, the peak/base ratio, that distinguished success from failure with higher accuracy than the DIN (cutoff = 1.6; sensitivity = 0.98, specificity = 0.83, and AUC =0.96).

CONCLUSIONS

To predict successful NGS, the DNA quality of FFPE tissue can be easily and reliably assessed using the DIN and peak/base ratio.

Brain metastasis and intracranial leptomeningeal metastasis from malignant peripheral nerve sheath tumors: illustrative cases

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft-tissue tumors. Intracranial metastasis from MPNSTs is quite rare.

OBSERVATIONS

The authors report on a 73-year-old male whose MPNST metastasized to the brain and a 32-year-old male with leptomeningeal metastasis from MPNST and review 41 cases of MPNST that developed intracranial metastasis, as reported in the literature.

LESSONS

Brain metastasis and leptomeningeal metastasis of MPNSTs show different clinical courses and require pathology-specific treatment.

Clinical outcomes of patients diagnosed with cancer of unknown primary or malignancy of undefined primary origin who were referred to a regional cancer center

BACKGROUND

A regional cancer hospital has been identified to be crucial in the management of malignancies of undefined primary origin (MUO) and cancer of unknown primary (CUP). This hospital primarily consists of oncologists with expertise in CUP, pathologists, and interventional radiologists. Early consultation or referral of MUO and CUP to a cancer hospital is deemed important.

METHODS

This study retrospectively collected and analyzed the clinical, pathological, and outcome data of all patients (n = 407) referred to the Aichi Cancer Center Hospital (ACCH) in Japan over an 8-year period.

RESULTS

In total, 30% of patients were referred for a second opinion. Among 285 patients, 13% had non-neoplastic disease or confirmed primary site and 76% had confirmed CUP (cCUP), with 29% of cCUP being identified as favorable risk. In 155 patients with unfavorable-risk CUP, 73% had primary sites predicted by immunohistochemistry (IHC) and distribution of metastatic sites, whereas 66% of them received site-specific therapies based on the predicted primary sites. The median overall survival (OS) was found to be poor in patients with MUO (1 month) and provisional CUP (6 months). In addition, the median OS of 206 patients with cCUP treated at the ACCH was 16 months (favorable risk, 27 months; unfavorable risk, 12 months). No significant difference was noted in OS between patients with non-predictable and predictable primary-sites (13 vs 12 months, p = 0.411).

CONCLUSION

The outcome of patients with unfavorable-risk CUP remains to be poor. Site-specific therapy based on IHC is not recommended for all patients with unfavorable-risk CUP.

Abstract 3599: Molecular characterization of mouse colorectal cancer cell lines with high potential of peritoneal metastasis

Background: Peritoneal metastasis occurs in approximately 7% of colorectal cancer (CRC) patients and is associated with worse prognosis compared to non-peritoneal metastasis. In CRC patients with peritoneal metastasis, administration of systemic chemotherapy only slightly improves overall survival. Therefore, a better understanding of the biology of peritoneal metastasis and the development of new molecular therapeutics for CRC patients with peritoneal metastasis are urgently needed.

Materials and Methods: CT26 mouse CRC cell lines with low metastatic potentials (CT26-N5) and high metastatic potentials to peritoneum (CT26-P6) were established after several rounds of in vivo selection by orthotopic transplantation of CT26 cells into the syngeneic BALB/c mice. Transcriptomic and proteomic analyses were conducted on CT26-N5 and CT26-P6 cells.

Results: Orthotopic transplantation of CT26-P6 cells exhibited significantly increased peritoneal metastasis compared to CT26-N5 cells, while growth of primary tumors was not different between these CT26 sublines. In addition, CT26-P6 cells had higher cell migration and invasion potential in vitro than CT26-N5 cells. Integrated analyses of transcriptome and proteome resulted in identification of molecular signatures associated with peritoneal metastasis. An actin-binding protein Advillin, encoded by the Avil gene, was markedly increased at both mRNA and protein levels in CT26-P6 cells compared to CT26-N5 cells. Knockdown of Avil using siRNA or shRNA in CT26-P6 cells significantly reduced cell migration and invasion in vitro and occurrence of peritoneal metastasis in vivo. Gene Set Enrichment Analysis on transcriptome datasets from CT26-P6 cells and CT26-N5 cells identified interferon gamma response as the most significantly enriched pathway in CT26-cells. In addition, Immunoprecipitation coupled with LC-MS/MS identified potential interaction between Avil and a molecule X that regulates epithelial-mesenchymal transition in CRC. Consistent with the findings in mouse CT26 cells, AVIL knockdown in CRC patient-derived cells (PDCs) suppressed cell migration and invasion in vitro. While AVIL expression was induced by interferon gamma in CRC PDCs, JAK inhibitors, Momelotinib and Ruxolitinib, significantly reduced interferon gamma-induced AVIL expression, suggesting regulation of AVIL by interferon gamma.

Conclusion: Molecular characterization of mouse colorectal cancer cell lines with different metastatic potential identified AVIL as a potential therapeutic target in CRC patients with peritoneal metastasis. Regulation of AVIL expression by interferon gamma may suggest functional relevance of tumor immune microenvironment in the development of peritoneal metastasis in CRC.

Citation Format: Haruki Mori, Hisanori Isomura, Shuang Zhou, Taisuke Kajino, Yuichi Abe, Takashi Kinoshita, Seiji Natsume, Yusuke Sato, Akira Ouchi, Toru Miyake, Waki Hosoda, Koji Komori, Yasuhiro Shimizu, Masaji Tani, Ayumu Taguchi. Molecular characterization of mouse colorectal cancer cell lines with high potential of peritoneal metastasis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3599.

CD83 expression characterizes precursor exhausted T cell population

T cell exhaustion is a main obstacle against effective cancer immunotherapy. Exhausted T cells include a subpopulation that maintains proliferative capacity, referred to as precursor exhausted T cells (T_PEX). While functionally distinct and important for antitumor immunity, T_PEX possess some overlapping phenotypic features with the other T-cell subsets within the heterogeneous tumor-infiltrating T-lymphocytes (TIL). Here we explore surface marker profiles unique to T_PEX using the tumor models treated by chimeric antigen receptor (CAR)-engineered T cells. We find that CD83 is predominantly expressed in the CCR7⁺PD1⁺ intratumoral CAR-T cells compared with the CCR7^-PD1⁺ (terminally differentiated) and CAR-negative (bystander) T cells. The CD83⁺CCR7⁺ CAR-T cells exhibit superior antigen-induced proliferation and IL-2 production compared with the CD83^- T cells. Moreover, we confirm selective expression of CD83 in the CCR7⁺PD1⁺ T-cell population in primary TIL samples. Our findings identify CD83 as a marker to discriminate T_PEX from terminally exhausted and bystander TIL.

The Absence of Cancer in the Location of a Breast Tissue Marker After Neoadjuvant Chemotherapy may Predict Pathological Complete Response with High Accuracy: Results from a Phase II Trial

BACKGROUND

It is difficult to determine pathological complete response (pCR) before surgery in clinical complete response (cCR) cases by imaging alone. We designed a prospective study to evaluate whether a breast tissue marker placed in a tumor before neoadjuvant chemotherapy (NAC) can predict a pCR, possibly removing the need for surgery.

METHODS

We recruited patients with primary invasive breast cancer assigned to undergo curative surgery and possible NAC. A breast marker (UltraClip^®) was placed in the primary tumor before standard NAC. We evaluated the probability of no cancer in the marker but cancer in removed specimens from a cCR group.

RESULTS

A total of 102 patients were enrolled. Patients were categorized by cancer stage and subtypes. Seventy-two patients (70.6%) received standard NAC; 23 (34.3%) attained cCR, of whom pCR was obtained in 12 (52.2%). The probability of no cancer in the marker's location but cancer in the removed specimens was 4.3% (95% confidence interval, 0.1-21.9). The false-negative rate was 9.1% (1/11), and the negative predictive value was 92.3% (12/13). In only one case, no cancer was found in the marker's location, but cancer cells were present in the removed specimen.

CONCLUSIONS

The absence of cancer in the location of a breast tissue marker after NAC predicted pCR with high accuracy. Therefore, the rebiopsy of a marker's location might mean surgery is unnecessary.

The impact of combined PD-L1 positive score on clinical response to nivolumab in patients with advanced esophageal squamous cell carcinoma

BACKGROUND

Nivolumab is recommended for patients with advanced esophageal squamous cell carcinoma (aESCC) refractory or intolerant to fluoropyrimidine- and platinum-based chemotherapy regardless of the tumor proportion score (TPS). However, the role of combined positive score (CPS) in predicting nivolumab efficacy remains unclear. We aimed to study whether TPS or CPS is a more suitable biomarker for predicting nivolumab efficacy in these patients.

METHODS

We retrospectively collected data from patients with aESCC treated with fluoropyrimidines and platinum and subsequently received nivolumab monotherapy between January 1, 2014 and September 15, 2020. Next, we evaluated the efficiencies of TPS and CPS in predicting the clinical response to nivolumab using PD-L1 IHC 22C3 pharmDx assay.

RESULTS

This study included 50 patients (CPS groups: ≥ 10/1-10/ < 1, n = 24/18/8, respectively; TPS groups, ≥ 10%/1%-10%/ < 1%, n = 17/8/25, respectively). The median progression-free survival was 3.2, 2.5, and 1.5 months in the ≥ 10, 1-10 [hazard ratio (HR) vs. CPS of ≥ 10 group, 1.01; p = 0.98; adjusted HR, 1.33; p = 0.56], and < 1 CPS groups (HR vs. CPS of ≥ 10 group, 3.44; p = 0.006; adjusted HR, 1.67; p = 0.41), respectively. For the patients with CPS of ≥ 10/1-10/ < 1 and TPS of ≥ 10%/1%-10%/ < 1%, the objective response rate was 30%/25%/0% and 36%/0%/19% and the disease control rate was 60%/50%/12% (p = 0.06) and 65%/40%/38% (p = 0.30), respectively.

CONCLUSIONS

This study suggests that a CPS of < 1 is not a strong predictor of efficacy but can predict the absence of response to nivolumab in patients with aESCC.

Impact of pancreatic fat infiltration on postoperative pancreatic fistula occurrence in patients undergoing invagination pancreaticojejunostomy

BACKGROUND

No studies to date have determined the impact of pancreatic fat infiltration on postoperative pancreatic fistula (POPF) occurrence in patients undergoing invagination pancreaticojejunostomy (IV-PJ).

METHODS

The medical records of patients with a soft pancreas who underwent pancreatoduodenectomy followed by IV-PJ were reviewed . The pancreatic fat ratio on computed tomography (CT) images (I-PFR) was determined using preoperative CT and verified by histologic examination. The relationship between the I-PFR and POPF occurrence was determined. Patients were classified into 2 groups based on I-PFR value (fatty and non-fatty pancreas). Postoperative outcomes were compared between the two groups, and specifically among patients who developed POPF.

RESULTS

Of 221 patients, POPF occurred in 67 (30.3%). I-PFR was positively correlated with histologic-calculated fat ratio (ρ = 0.517, p < 0.001). This index was shown to be an independent predictor of POPF. Based on an I-PFR cut-off value of 3.2%, 92 patients were classified in the fatty pancreas group. Subgroup analysis of the patients who developed POPF showed that incidence of abscess formation and hemorrhage tended to be higher in patients with fatty pancreas than in those with non-fatty pancreas.

CONCLUSIONS

Pancreatic fat infiltration is highly associated with POPF and possibly causes subsequent serious complications in patients undergoing IV-PJ.

The cAMP/PKA/CREB and TGFβ/SMAD4 Pathways Regulate Stemness and Metastatic Potential in Colorectal Cancer Cells

SIGNIFICANCE

This study identifies signaling pathways essential for maintaining the stemness and metastatic potential of colorectal cancer cells and proposes CREB as a therapeutic target in metastatic colorectal cancer.

Prognostic Significance of Intraoperative Peritoneal Lavage Cytology in Patients with Pancreatic Ductal Adenocarcinoma: A Single-Center Experience and Systematic Review of the Literature

BACKGROUND

The prognostic significance of peritoneal lavage cytology (PLC) in patients with pancreatic ductal adenocarcinoma (PDAC) remains controversial. The purpose of this study was to evaluate the prognostic impact of PLC status in PDAC patients.

METHODS

Patients intending to undergo resection for PDAC between 2007 and 2020 were included. Survival was compared among patients who underwent resection with negative or positive PLC status and those who did not undergo resection. Univariable and multivariable analyses were conducted to evaluate the prognostic impact of positive PLC status. A systematic literature review was performed to evaluate the correlation between prognosis and the positive PLC rate.

RESULTS

A total of 480 patients formed the study cohort and were divided as follows: 438 in the negative PLC group, 18 in the positive PLC group, and 24 in the no resection group. Although the median survival time significantly differed between the negative and positive PLC groups (35.7 vs. 13.6 months, P < 0.001), it did not significantly differ between the positive PLC and no resection groups (13.6 vs. 12.2 months, P = 0.605). Multivariable analyses demonstrated that positive PLC status (hazard ratio = 3.54, 95% confidence interval = 1.97-6.38, P < 0.001) was the strongest poor prognostic factor. Based on statistical analyses for the systematic review, the prognostic impact of positive PLC status weakened significantly as the institutional positive PLC rate increased (P = 0.044).

CONCLUSIONS

Resection did not improve the prognosis of patients with positive PLC status in our cohort. The institutional positive PLC rate may be a good reference for surgical indication in these patients.

Successful IMRT and concurrent chemotherapy for a patient with intrathoracic extensive-stage small cell lung cancer

Treatment of extensive-stage (ES) small cell lung cancer (SCLC) is a challenge with poor local control and dismal overall survival. Although single extrathoracic metastasis was defined as M1b according to the eighth edition of the tumour-node-metastasis (TNM) classification of lung cancer, M1b includes involvement of a single intrathoracic nonregional lymph node (LN) such as pericardial, internal mammary or paravertebral LNs. Here, we report a successful treated case of a 50-year-old female with ES-SCLC with right pericardial LN involvement, cT1cN3M1b (LYM). She initially received two cycles of induction chemotherapy consisting of cis-Diamminedichloroplatinum/cisplatin (CDDP) and etoposide and achieved a very good partial response. She then received curative chemoradiotherapy with intensity-modulated techniques (45 Gy in 30 fractions BID), followed by an additional cycle of chemotherapy. She is free of recurrence for more than 2.5 years.

PCR-based quantitative detection of intraperitoneal free cancer cells for predicting locoregional recurrence after rectal cancer resection

INTRODUCTION

Locoregional recurrence after curative resection remains an important issue in the treatment of colorectal cancer (CRC). The aim of the present study was to investigate the clinical significance of quantitative detection of intraperitoneal free cancer cells by a PCR-based method for predicting locoregional recurrence after CRC resection.

METHOD

A total of 114 patients with CRC were enrolled between March 2017 and December 2018, and 95 patients with Stage I-III CRC were analyzed. Peritoneal lavage fluid was collected before and after tumour resection and subjected to cytology and quantitative reverse transcription-PCR (qRT-PCR) with carcinoembryonic antigen (CEA) as a genetic marker.

RESULTS

2.1% of patients had positive cytology after resection, whereas 9.5% had positive CEA qRT-PCR (PCR+) after resection. Eight of nine PCR+ patients after resection had tumours in the rectum. Fifteen (15.8%) patients developed recurrence during the follow-up period, including three with locoregional recurrence. One of 86 (1.2%) PCR- patients and 2 of 9 (22.2%) PCR+ patients after resection developed locoregional recurrence. Overall and in rectal cancer patients, the 3-year cumulative risk of locoregional recurrence was 25.0% and 28.6% for PCR+ patients, which is significantly higher than PCR- patients (1.3% and 0%, P < 0.001 and P = 0.001, respectively).

CONCLUSION

Intraperitoneal free cancer cells can serve as a sensitive predictor of locoregional recurrence after rectal cancer resection. qRT-PCR for CEA can be a suitable method for detecting intraperitoneal free cancer cells in peritoneal lavage fluid.

Robot-assisted enucleation of a giant submucosal tumor in the upper esophagus

Few reports have demonstrated robotic surgery for large tumors in the upper esophagus. We report a case of a 52-year-old woman with a giant submucosal tumor in the upper esophagus successfully enucleated using robotic surgery. She presented with odynophagia and dysphagia, with subsequent evaluation revealing a submucosal mass measuring approximately 10 cm in diameter in the upper esophagus. The mass was compressing the trachea and enlarged over 3 years. Endoscopic ultrasound fine needle aspiration of the tumor was non-diagnostic. Robot-assisted esophageal submucosal tumor enucleation was performed for diagnosis and treatment. Flexible forceps control allowed for a multi-directional approach to dissect the tumor and stable forceps handling was critical in this delicate procedure. Subsequent pathological review revealed a well-differentiated esophageal liposarcoma. While surgical margins were not entirely negative, the local recurrence rate of the tumor is low. At the patient's request, we decided to observe the patient without additional resection.

A Schizophyllum commune fungus ball in a lung cancer cavity: a case report

Background

Schizophyllum commune is a basidiomycete that lives in the environment and can cause infections, mainly those of the respiratory system. Although S. commune is increasingly reported as a cause of allergic bronchopulmonary mycosis and sinusitis, cases of fungal ball formation are extremely uncommon. Identification of S. commune is difficult using routine mycological diagnostic methods, and in clinically suspicious cases, internal transcribed spacer sequencing should be used for diagnosis. Here, we report a first case of lung cancer with a fungal ball formation of S. commune, confirmed by analyzing the internal transcribed spacer.

Case presentation

A 76-year-old man with diabetes and hypertension was admitted to the hospital with a chief complaint of hemosputum, which he had for about 19 months. A computed tomography image of the patient’s chest showed a cavity and internal nodule in the left upper lobe of his lung. A left upper lobectomy was performed, and histopathological examination revealed squamous cell carcinoma of the lung and a fungal ball. The isolate from the surgical specimen was identified as S. commune by analyzing the internal transcribed spacer. The patient had no recurrence of the infection during 5 months of follow-up.

Conclusions

Only three cases of lung fungal balls caused by S. commune have been previously reported, and this is the first case of lung cancer cavity with a fungal ball formation. In cases of fungal ball formation in the lung, S. commune should be considered a possible causative microorganism.

SRGN-Triggered Aggressive and Immunosuppressive Phenotype in a Subset of TTF-1-Negative Lung Adenocarcinomas

BACKGROUND

About 20% of lung adenocarcinoma (LUAD) is negative for the lineage-specific oncogene Thyroid transcription factor 1 (TTF-1) and exhibits worse clinical outcome with a low frequency of actionable genomic alterations. To identify molecular features associated with TTF-1-negative LUAD, we compared the transcriptomic and proteomic profiles of LUAD cell lines. SRGN, a chondroitin sulfate proteoglycan Serglycin, was identified as a markedly overexpressed gene in TTF-1-negative LUAD. We therefore investigated the roles and regulation of SRGN in TTF-1-negative LUAD.

METHODS

Proteomic and metabolomic analyses of 41 LUAD cell lines were done using mass spectrometry. The function of SRGN was investigated in 3 TTF-1-negative and 4 TTF-1-positive LUAD cell lines and in a syngeneic mouse model (n = 5 to 8 mice per group). Expression of SRGN in was evaluated in 94 and 105 surgically resected LUAD tumor specimens using immunohistochemistry. All statistical tests were two-sided.

RESULTS

SRGN was markedly overexpressed at mRNA and protein levels in TTF-1-negative LUAD cell lines (P < .001 for both mRNA and protein levels). Expression of SRGN in LUAD tumor tissue was associated with poor outcome (hazard ratio = 4.22, 95% confidential interval = 1.12 to 15.86; likelihood ratio test, P = .03), and with higher expression of Programmed cell death 1 ligand 1 (PD-L1) in tumor cells and higher infiltration of Programmed cell death protein 1 (PD-1)-positive lymphocytes. SRGN regulated expression of PD-L1, as well as proinflammatory cytokines including Interleukin-6 (IL-6), Interleukin-8 (IL-8), and C-X-C motif chemokine 1 (CXCL1) in LUAD cell lines, and increased migratory and invasive properties of LUAD cells and fibroblasts, and enhanced angiogenesis. SRGN was induced by DNA de-methylation resulting from Nicotinamide N-methyltransferase (NNMT)-mediated impairment of methionine metabolism.

CONCLUSION

Our findings suggest that SRGN plays a pivotal role in tumor-stromal interaction and reprogramming into an aggressive and immunosuppressive tumor microenvironment in TTF-1-negative LUAD.

MYB mediates downregulation of the colorectal cancer metastasis suppressor heterogeneous nuclear ribonucleoprotein L-like during epithelial-mesenchymal transition

Heterogeneous nuclear ribonucleoprotein L-like (HNRNPLL), a suppressor of colorectal cancer (CRC) metastasis, is transcriptionally downregulated when CRC cells undergo epithelial-mesenchymal transition (EMT). Here we show that decrease of MYB mediates the downregulation of HNRNPLL during EMT. The promoter activity was attributed to a region from -273 to -10 base pairs upstream of the transcription start site identified by 5'-RACE analysis, and the region contained potential binding sites for MYB and SP1. Luciferase reporter gene assays and knockdown or knockout experiments for genes encoding the MYB family proteins, MYB, MYBL1, and MYBL2, revealed that MYB was responsible for approximately half of the promoter activity. On the other hand, treatment with mithramycin A, an inhibitor for SP1 and SP3, suppressed the promoter activity and their additive contribution was confirmed by knockout experiments. The expression level of MYB was reduced on EMT while that of SP1 and SP3 was unchanged, suggesting that the downregulation of HNRNPLL during EMT was mediated by the decrease of MYB expression while SP1 and SP3 determine the basal transcription level of HNRNPLL. Histopathological analysis confirmed the accumulation of MYB-downregulated cancer cells at the invasion front of clinical CRC tissues. These results provide an insight into the molecular mechanism underlying CRC progression.

Impact of PD-L1 combined positive score (CPS) on clinical response to nivolumab in patients with advanced esophageal squamous cell carcinoma

e16045

Background: The ATTRACTION-3 trial showed that nivolumab (Nivo) significantly improved overall survival (OS) of patients (pts) with previously treated advanced esophageal squamous cell carcinoma (ESCC) regardless of tumor programmed cell death ligand-1 (PD-L1) expression assessed with tumor proportion score (TPS). On the other hand, pembrolizumab prolonged OS in advanced esophageal carcinoma pts with combined positive score (CPS) of ≥ 10 in the KEYNOTE-181 trial. Whether CPS can predict clinical outcome of Nivo in advanced ESCC pts remains unclear. Methods: We retrospectively evaluated advanced ESCC pts who received Nivo at a single institution between January 2014 and September 2020. The main eligibility criteria were as follows: refractory or intolerant to fluoropyrimidines and platinum, no prior anti-PD-1/PD-L1 antibody treatment, no comorbid malignancies, and available tissue specimens obtained before initiation of Nivo. PD-L1 immunostaining was performed using PD-L1 IHC 22C3 pharmDx assay, and the tumors were classified into three groups depending on CPS (≥ 10, 1–10, < 1). The adjusted hazard ratios (aHRs) for progression-free survival (PFS) and OS were calculated using a multivariate Cox model that contained variables with p values < 0.05 in the univariate analysis. Results: Among 69 pts, 50 were eligible (CPS ≥ 10/CPS 1–10/CPS < 1, 23/18/9). Patient characteristics were as follows (CPS ≥ 10/CPS 1–10/CPS < 1): age, ≥ 65, 70/67/67%; male, 83/67/78%; PS ≥ 1, 61/72/44%; second-line treatment, 65/61/56%; disease status, recurrent, 61/33/78%; prior esophagectomy, 65/33/44%; prior radiotherapy, 57/56/56%; prior taxane, 52/28/44%; the number of metastatic sites, ≥ 2, 48/61/89%; lymph node metastasis, 78/83/89%, lung metastasis, 26/22/56%; liver metastasis, 17/17/44%. Among 42 pts (84%) with disease progression after Nivo treatment, 24 pts received salvage-line chemotherapy. The adjustment factor for PFS was liver metastasis, while that for OS was not detected. The median PFS was 4.1 months (mo) in CPS ≥ 10 and 2.5 mo in CPS 1–10 (HR vs. CPS ≥ 10, 1.06; 95% CI, 0.51–2.17; p = 0.864; aHR, 1.15; 95% CI, 0.54–2.36; p = 0.713), and 1.4 mo in CPS < 1 (HR vs. CPS ≥ 10, 3,78; 95% CI, 1.53–8.92; p = 0.005; aHR, 1.91; 95% CI, 0.67–5.39; p = 0.223). The median OS was 12.3 mo in CPS ≥ 10, 10.2 mo in CPS 1–10 (HR vs. CPS ≥ 10, 1.72; 95% CI, 0.75–4.00; p = 0.201), and 9.0 mo in CPS < 1 (HR vs. CPS ≥ 10, 2.31; 95% CI, 0.92–5.69; p = 0.075). Objective response rate (CPS ≥ 10/CPS 1–10/CPS < 1) in 40 pts who had measurable lesions were 32/25/0%, respectively. Conclusions: The pts with CPS of < 1 did not respond to Nivo. Our study suggests that CPS is useful for predicting response to Nivo in pts with advanced ESCC.[Table: see text]

Multiregion whole-exome sequencing of intraductal papillary mucinous neoplasms reveals frequent somatic KLF4 mutations predominantly in low-grade regions

OBJECTIVE

Intraductal papillary mucinous neoplasms (IPMNs) are non-invasive precursor lesions that can progress to invasive pancreatic cancer and are classified as low-grade or high-grade based on the morphology of the neoplastic epithelium. We aimed to compare genetic alterations in low-grade and high-grade regions of the same IPMN in order to identify molecular alterations underlying neoplastic progression.

DESIGN

We performed multiregion whole exome sequencing on tissue samples from 17 IPMNs with both low-grade and high-grade dysplasia (76 IPMN regions, including 49 from low-grade dysplasia and 27 from high-grade dysplasia). We reconstructed the phylogeny for each case, and we assessed mutations in a novel driver gene in an independent cohort of 63 IPMN cyst fluid samples.

RESULTS

Our multiregion whole exome sequencing identified KLF4, a previously unreported genetic driver of IPMN tumorigenesis, with hotspot mutations in one of two codons identified in >50% of the analyzed IPMNs. Mutations in KLF4 were significantly more prevalent in low-grade regions in our sequenced cases. Phylogenetic analyses of whole exome sequencing data demonstrated diverse patterns of IPMN initiation and progression. Hotspot mutations in KLF4 were also identified in an independent cohort of IPMN cyst fluid samples, again with a significantly higher prevalence in low-grade IPMNs.

CONCLUSION

Hotspot mutations in KLF4 occur at high prevalence in IPMNs. Unique among pancreatic driver genes, KLF4 mutations are enriched in low-grade IPMNs. These data highlight distinct molecular features of low-grade and high-grade dysplasia and suggest diverse pathways to high-grade dysplasia via the IPMN pathway.

Successful bronchial arterial infusion chemotherapy combined with radiotherapy for an endobronchial metastasis after resection of small cell lung cancer

Bronchial arterial infusion (BAI) chemotherapy has been reported to be an effective treatment option for centrally located early-stage squamous cell lung cancer (SCC) and has a favourable response rates for patients with stage III or IV or recurrent non-small cell lung cancer (NSCLC) without distant metastases who cannot tolerate standard chemotherapy. Here, we report a case of an 83-year-old male with a solitary polypoid endobronchial metastatic tumour in the left main bronchus one year and 10 months after video-assisted thoracoscopic surgery (VATS) combined segmentectomy (left S6 + S8a) for small cell lung cancer (SCLC), pT1bN0. He was treated with BAI of 100 mg of cis-Diamminedichloroplatinum/cisplatin (CDDP), followed by thoracic radiotherapy (56 Gy in 28 fractions). There was no recurrence for 2.5 years. BAI chemotherapy combined with radiotherapy seemed to be an effective salvage option for the treatment of solitary endobronchial metastases of SCLC in patients unfit for standard chemoradiotherapy.

Marked improvement of oral intake with nivolumab monotherapy in a patient with microsatellite instability-high gastric cancer with insufficient oral intake

Although immune checkpoint inhibitors are commonly less effective for patients with a poor general condition, they can be effective and should be considered for poor general conditions in the case of MSI-H tumor.

Dramatic Response in a Patient with Metastatic Gastric Cancer Using Trifluridine/Tipiracil after Rapid Disease Progression while on Nivolumab

The introduction of immune checkpoint inhibitors has redefined the treatment strategy and changed the way tumor assessments are made because of its response pattern. Studies have suggested that initiating chemotherapy after checkpoint inhibitors may have high anti-tumor activity in some cancer types. This response pattern has not been reported in patients with gastric cancer, and particularly for the combination of trifluridine/tipiracil. A 69-year-old man presented at follow-up for metastatic gastric cancer being treated with nivolumab, an anti-PD-1 antibody. Computed tomography of the liver showed a rapid 4-fold growth of the metastasis compared with baseline measurements taken while receiving paclitaxel and ramucirumab. It met the definition of a phenomenon called hyperprogressive disease. Nivolumab was discontinued, and he was switched to trifluridine/tipiracil. The liver metastasis was shrunk markedly after 2 months with improvement in his performance status and laboratory data. Sequential therapy starting with immune checkpoint inhibitors followed by cytotoxic agents such as trifluridine/tipiracil may have an apparent efficacy in gastric cancer even though prior immunotherapy demonstrates hyperprogressive disease.

Ursodeoxycholic acid and bezafibrate were useful for steroid-refractory, immune-related hepatitis: a case report

Background

Immune checkpoint inhibitors have shown clinically significant antitumor efficacy and have been approved for the treatment of various kinds of advanced malignancies. On the other hand, these immunotherapies show unique adverse events, termed “immune-related adverse events,” which are distinctly associated with conventional cytotoxic chemotherapy. Hepatotoxicity is recognized as an immune-related adverse event; prompt treatment with corticosteroids is recommended. However, some cases are refractory to steroids. Here, we report the first case (to our knowledge) of steroid-refractory immune-related hepatitis that was successfully treated with ursodeoxycholic acid and bezafibrate.

Case presentation

A 68-year-old Asian man, came to our hospital for the treatment of malignant melanoma involving the gingiva and presenting with multiple lymph node and bone metastases was administered nivolumab as a first-line treatment. Two months into treatment, the patient developed diarrhea as a result of immune-related colitis; the colitis was treated successfully with prednisolone 60 mg/ day, resulting in improvement in the patient’s symptoms. However, when steroids were being tapered, acute elevation of liver enzymes was observed. Autoimmune hepatitis was suspected as an immune-related adverse event, and treatment with intravenous prednisolone 60 mg/ day was reinitiated. However, restoration of the steroid treatment failed to improve the patient’s liver enzymes. On the basis of histological findings from liver biopsy and exclusion of other etiologies such as viral infection and other drug-induced hepatitis, steroid-refractory hepatic immune-related adverse event was deemed the most likely cause of the patient’s acute hepatitis. In general, mycophenolate mofetil or tacrolimus is known to provide benefits in cases of steroid-refractory hepatitis. We therefore decided to add oral ursodeoxycholic acid and bezafibrate in consideration of the patient’s background of repeated aspiration pneumonia. Administration of this regimen resulted in an improvement in liver function, which remained normal even after tapering of prednisolone.

Conclusions

Ursodeoxycholic acid and bezafibrate may be useful for treatment of steroid-refractory immune-related adverse event hepatitis.

Comparison of Surgical Outcomes Between Invasive Mucinous and Non-Mucinous Lung Adenocarcinoma

BACKGROUND

Invasive mucinous adenocarcinoma (IMA) is a rare subtype of invasive lung adenocarcinoma. However, the clinical course and prognostic outcomes following IMA resection, particularly postoperative recurrence, remain unclear.

METHODS

We pathologically reevaluated 1362 lung adenocarcinoma resections performed at our institution, categorizing cases into the IMA group (72 cases) and non-IMA group (1290 cases). The IMA group was further classified into pneumonia and nodular types based on preoperative computed tomography.

RESULTS

Overall, the IMA group had lower carcinoembryonic antigen levels (3 vs 8 ng/mL; P < .01), fewer lymph node metastasis (4% vs 24%; P < .01), and more KRAS mutations (56% vs 7%; P < .01) than the non-IMA group. Although postoperative recurrence rates did not differ between both groups (32% vs 27%; P = 0.35), lung recurrence occurred more frequently in the IMA group (83% vs 17%; P < .01). Propensity score-matched pair analysis showed that the IMA group had fewer lymph node metastasis (3% vs 35%; P < .01), more KRAS mutations (56% vs 9%; P < .01), and higher intrapulmonary recurrence rate (84% vs 31%; P < .01) than the non-IMA group. The 5-year overall survival rates did not differ between both groups (74% vs 81%; P = 0.26). However, among patients with intrapulmonary recurrence, those in the IMA group had significantly worse prognosis than those in the non-IMA group (35% vs 77%; P < .01).

CONCLUSIONS

Intrapulmonary recurrence, which induced significantly worse prognosis, was more likely to occur in the IMA than non-IMA group.

Novel Resistance Mechanisms Including L1196Q, P1094H, and R1248_D1249 Insertion in Three Patients With NSCLC After ALK Tyrosine Kinase Inhibitor Treatment

OBJECTIVES

The purposes of this study are to clarify the details of the ALK tyrosine kinase inhibitor (TKI) resistance mechanism in rebiopsy cases and to predict novel resistance gene alterations using molecular dynamics simulation.

METHODS

A total of 21 patients with ALK-positive NSCLC who underwent a rebiopsy after ALK TKI failure were included in this analysis. ALK fluorescence in situ hybridization and reverse transcription polymerase chain reaction were performed with paired initial and rebiopsy tumor specimens.

RESULTS

Nine patients had no known ALK resistance mechanisms. Four had ALK amplification. L1196M, I1171N, and G1269A, mutations that are known to indicate resistance to ALK TKIs, were detected in one patient each. Small cell carcinoma and sarcomatoid transition were found in one case each. L1196Q, P1094H, and exon 24 76-base pair insertion were detected after the second-generation ALK TKIs.

CONCLUSIONS

The combination of a genetic analysis and a computational simulation model may make a prediction of resistance mechanisms for overcoming ALK TKI resistance, and the construction of a genomic and simulation fused database is important for the development of personalized medicine in this field.

Pancreatic neuroendocrine carcinoma G3 may be heterogeneous and could be classified into two distinct groups

BACKGROUND/OBJECTIVES

Pancreatic neuroendocrine carcinoma (PanNEC)-G3 often presents along with genetic abnormalities such as KRAS, RB1, and TP53 mutations. However, the association between these genetic findings and response to chemotherapy and prognosis has not been clarified. This study aimed to clarify the clinicopathological features of PanNEC-G3.

METHODS

We performed a subgroup analysis of the Japanese PanNEN-G3 study (multicenter, retrospective study), which revealed that Rb loss and KRAS mutation were predictors of the response to platinum-based regimen in PanNEN-G3. We re-classified WHO grades of PanNENs using the 2017 WHO classification and then analyzed the clinicopathological features and prognostic factors in 49 patients with PanNEC-G3.

RESULTS

The rates of Rb loss and KRAS mutation in PanNEC-G3 were 54.5% and 48.7%, respectively. Patients with Rb loss and/or KRAS mutation showed a higher response rate to first-line platinum-based regimen than those without Rb loss or KRAS mutation (object response rate 70.0% vs 33.3%, odds ratio 9.22; 95% CI 1.26-67.3, P = 0.029), but tended to have shorter overall survival rates than those without Rb loss or KRAS mutation (median 239 vs 473 days, hazard ratio 2.11; 95% CI 0.92-4.86, P = 0.077).

CONCLUSIONS

Patients with PanNEC-G3 have varied clinical outcomes for platinum-based regimen. When grouped based on Rb loss and KRAS mutation, there seemed to be two groups with distinct prognoses and responses to the platinum-based regimen. PanNEC-G3 could, therefore, be classified into two distinct groups based on immunohistochemical and genetic findings.

Japanese Society of Medical Oncology Clinical Guidelines: Molecular Testing for Colorectal Cancer Treatment, 4th edition

Molecular testing to select the appropriate targeted and standard of care therapies is essential for managing patients with colorectal cancer (CRC). The Japanese Society of Medical Oncology previously published clinical guidelines for molecular testing in CRC. In the third edition published in 2018, RAS and BRAF V600E mutations should be tested prior to first‐line chemotherapy to assess the benefit of anti–epidermal growth factor receptor (EGFR) antibody therapy in patients with unresectable CRC. Microsatellite instability (MSI) testing was recommended in patients with curatively resected stage II CRC because deficient mismatch repair is associated with low risk of recurrence. MSI testing was also recommended in patients with CRC suspected to be Lynch syndrome. The main aim of this fourth edition is to reflect recent advances in comprehensive genomic profiling (CGP) tests and liquid biopsy. Here, CGP tests performed on tumor tissues are strongly recommended to assess the benefit of molecular targeted drugs in patients with CRC. Circulating tumor DNA (ctDNA)‐based CGP tests are also proposed. ctDNA testing is recommended to determine the optimal treatment based on the risk of recurrence for curatively resected CRC and evaluate the suitability and monitor the therapeutic effects of anti–EGFR antibodies in patients with unresectable CRC. While both MSI testing and immunohistochemistry are strongly recommended to determine the indication of immune checkpoint inhibitors in patients with unresectable CRC, next‐generation sequencing‐based tests are weakly recommended because these tests have not been validated in clinical trials.

Genomic characterization of malignant progression in neoplastic pancreatic cysts

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are non-invasive neoplasms that are often observed in association with invasive pancreatic cancers, but their origins and evolutionary relationships are poorly understood. In this study, we analyze 148 samples from IPMNs, MCNs, and small associated invasive carcinomas from 18 patients using whole exome or targeted sequencing. Using evolutionary analyses, we establish that both IPMNs and MCNs are direct precursors to pancreatic cancer. Mutations in SMAD4 and TGFBR2 are frequently restricted to invasive carcinoma, while RNF43 alterations are largely in non-invasive lesions. Genomic analyses suggest an average window of over three years between the development of high-grade dysplasia and pancreatic cancer. Taken together, these data establish non-invasive IPMNs and MCNs as origins of invasive pancreatic cancer, identifying potential drivers of invasion, highlighting the complex clonal dynamics prior to malignant transformation, and providing opportunities for early detection and intervention.

Long-Term Recurrence of Completely Resected NSCLC

Introduction

The aim of this study is to evaluate the clinical backgrounds, including driver mutations, of those patients with early stage NSCLC who experienced recurrence beyond 5 years after complete resection.

Methods

We used a cohort of 512 consecutive cases of surgically resected NSCLC without other malignances from 2006 to 2011 in Aichi Cancer Center Hospital. The inclusion criteria for this cohort were patients with primary NSCLC who underwent a surgically curable operation.

Results

A total of 172 patients (32.8%) had recurrence after the surgery. Among the recurrent cases, 17 patients (3.3%) had a relapse more than 5 years after the surgery, and all except one (16 of 17, 94.1%) had driver mutations, including gene rearrangements.

Conclusions

Even in early stage NSCLC after complete resection, it was found that some cases had a relapse more than 5 years after the surgery. Most of these cases had some kind of driver mutations; so more than 5 years of postoperative surveillance may be beneficial, especially in those with driver gene mutants.

Salivary Secretory Carcinoma Harboring a Novel ALK Fusion: Expanding the Molecular Characterization of Carcinomas Beyond the ETV6 Gene

Secretory carcinoma (SC) of the salivary glands is a low-grade carcinoma characterized by a well-defined morphology and immunohistochemical features. ETV6-NTRK3 fusions are detected in the great majority of SCs. Recently, other partners fused to ETV6 have been documented in a small portion of SCs, suggesting the presence of alternative genetic fusion. In this study, we examined the genetic fusion of 9 SCs using fluorescence in situ hybridization, reverse transcription-polymerase chain reaction, and next-generation sequencing (ArcherDx). Classic ETV6 exon 5-NTRK3 exon 15 fusion was detected in 8 of 9 SCs. The remaining tumor was negative for the ETV6-NTRK3 fusion but harbored a novel fusion, CTNNA1 exon 11-ALK in exon 20. Immunohistochemically, pan-TRK was positive in 8 tumors with ETV6-NTRK3 fusion but negative in an ALK-rearranged SC, while ALK was positive only in the ALK-rearranged tumor. Histologically, the ALK-rearranged tumor showed dominant macrocystic architecture. In conclusion, we found a case of SC with CTNNA1-ALK fusion. Because ALK fusion after exon 20 on the ALK side (upstream of the tyrosine kinase domain) has been reported to activate a carcinogenic kinase in various ALK-rearranged tumors, ALK inhibitors may be a possible therapeutic option for ALK-rearranged SC. In addition, ALK immunohistochemistry can be a screening tool for ALK-rearranged SC. This study also expands the molecular spectrum of this tumor beyond the ETV6 gene.

Targeted RNA sequencing with touch imprint cytology samples for non-small cell lung cancer patients

Background

RNA‐based sequencing is considered ideal for detecting pathogenic fusion‐genes compared to DNA‐based assays and provides valuable information about the relative expression of driver genes. However, RNA from formalin‐fixed paraffin‐embedded tissue has issues with both quantity and quality, making RNA‐based sequencing difficult in clinical practice. Analyzing stamp‐derived RNA with next‐generation sequencing (NGS) can address the above‐mentioned obstacles. In this study, we validated the analytical specifications and clinical performance of our custom panel for RNA‐based assays on the Ion Torrent platform.

Methods

To evaluate our custom RNA lung panel, we first examined the gene sequences of RNA derived from 35 NSCLC tissues with diverse backgrounds by conventional methods and NGS. Next, we moved to the clinical phase, where clinical samples (all stamp‐derived RNA) were used to examine variants. In the clinical phase we conducted an NGS analysis while simultaneously applying conventional approaches to assess the feasibility and validity of the panel in clinical practice.

Results

In the prerun phase, all of the variants confirmed with conventional methods were detected by NGS. In the clinical phase, a total of 80 patients were enrolled and 80 tumor specimens were sequenced from February 2018 to December 2018. There were 66 cases in which the RNA concentration was too low to be measured, but sequencing was successful in the vast majority of cases. The concordance between NGS and conventional methods was 95.0%.

Conclusions

RNA extraction using stamp specimens and panel sequencing by NGS were considered applicable in clinical settings.

Key points

Significant findings of the study

Next‐generation sequencing using RNA from stamp specimens was able to detect driver gene changes in non‐small cell lung cancer including fusion genes with the same accuracy as conventional methods.

What this study adds

Using RNA from stamp specimens obtained from biopsy increases the number of candidate cases for RNA sequencing in clinical settings.

Clinicopathological Features, Surgical Outcomes, Oncogenic Status and PD-L1 Expression of Pulmonary Pleomorphic Carcinoma

BACKGROUND/AIM

Pulmonary pleomorphic carcinoma (PPC) is rare, and few studies have reported its features. We assessed the clinicopathological features, surgical outcomes, oncogenic status and programmed death-ligand 1 (PD-L1) expression of PPC.

PATIENTS AND METHODS

We retrospectively reviewed data from 22 consecutive patients who underwent resection of PPC between 2007 and 2017.

RESULTS

The predominant tissue type of the epithelial component was adenocarcinoma in 15 patients (68%) and the others in 7 patients (32%), and the 3-year disease-free survival rate tended to be better in patients with an adenocarcinoma component compared to patients with another component (40.0% vs. 17.1%, p=0.059). PD-L1 expression was observed in all eight tumors whose PD-L1 status could be examined and high PD-L1 expression (≥50%) was frequent (5/8, 63%).

CONCLUSION

A predominant adenocarcinoma epithelial component in PPC might be associated with better survival outcomes and high PD-L1 expression might be frequent in PPC.

Intraductal Papillary Mucinous Neoplasms Arise From Multiple Independent Clones, Each With Distinct Mutations

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasms (IPMNs) are lesions that can progress to invasive pancreatic cancer and constitute an important system for studies of pancreatic tumorigenesis. We performed comprehensive genomic analyses of entire IPMNs to determine the diversity of somatic mutations in genes that promote tumorigenesis.

METHODS

We microdissected neoplastic tissues from 6-24 regions each of 20 resected IPMNs, resulting in 227 neoplastic samples that were analyzed by capture-based targeted sequencing. Somatic mutations in genes associated with pancreatic tumorigenesis were assessed across entire IPMN lesions, and the resulting data were supported by evolutionary modeling, whole-exome sequencing, and in situ detection of mutations.

RESULTS

We found a high prevalence of heterogeneity among mutations in IPMNs. Heterogeneity in mutations in KRAS and GNAS was significantly more prevalent in IPMNs with low-grade dysplasia than in IPMNs with high-grade dysplasia (P < .02). Whole-exome sequencing confirmed that IPMNs contained multiple independent clones, each with distinct mutations, as originally indicated by targeted sequencing and evolutionary modeling. We also found evidence for convergent evolution of mutations in RNF43 and TP53, which are acquired during later stages of tumorigenesis.

CONCLUSIONS

In an analysis of the heterogeneity of mutations throughout IPMNs, we found that early-stage IPMNs contain multiple independent clones, each with distinct mutations, indicating their polyclonal origin. These findings challenge the model in which pancreatic neoplasms arise from a single clone. Increasing our understanding of the mechanisms of IPMN polyclonality could lead to strategies to identify patients at increased risk for pancreatic cancer.

Chronic Mild Gut Inflammation Accelerates Brain Neuropathology and Motor Dysfunction in α-Synuclein Mutant Mice

Emerging findings suggest that Parkinson's disease (PD) pathology (α-synuclein accumulation) and neuronal dysfunction may occur first in peripheral neurons of the autonomic nervous system including the enteric branches of the vagus nerve. The risk of PD increases greatly in people over the age of 65, a period of life in which chronic inflammation is common in many organ systems including the gut. Here we report that chronic mild focal intestinal inflammation accelerates the age of disease onset in α-synuclein mutant PD mice. Wild-type and PD mice treated with 0.5% dextran sodium sulfate (DSS) in their drinking water for 12 weeks beginning at 3 months of age exhibited histological and biochemical features of mild gut inflammation. The age of onset of motor dysfunction, evaluated using a rotarod test, gait analysis, and grip strength measurements, was significantly earlier in DSS-treated PD mice compared to control PD mice. Levels of the dopaminergic neuron marker tyrosine hydroxylase in the striatum and numbers of dopaminergic neurons in the substantia nigra were reduced in PD mice with gut inflammation. Levels of total and phosphorylated α-synuclein were elevated in enteric and brain neurons in DSS-treated PD mice, suggesting that mild gut inflammation accelerates α-synuclein pathology. Markers of inflammation in the colon and brain, but not in the blood, were elevated in DSS-treated PD mice, consistent with retrograde transneuronal propagation of α-synuclein pathology and neuroinflammation from the gut to the brain. Our findings suggest that interventions that reduce gut inflammation may prove beneficial in the prevention and treatment of PD.

Abstract 3429: Genetic analysis of pancreatic neuroendocrine neoplasms grade 3

Pancreatic neuroendocrine neoplasms (PanNENs) are pancreatic tumors with neuroendocrine differentiation. PanNENs are classified into three grades according to the proliferating cell fraction as measured by Ki-67 or mitotic index. Among them, PanNEN grade 3 (PanNEN G3) shows the highest Ki-67 index &gt; 20%, which is morphologically divided into two categories, well-differentiated (PanNET G3) and poorly differentiated (PanNEC) tumors. Although sharing some overlapping histological features, both tumors also differ from each other with respect of clinical characteristics. To date, the molecular basis of these difference and similarity are poorly understood. To understand their molecular pathogenesis, we performed comprehensive genetic analysis on PanNEN G3.

In total, we enrolled 25 PanNEN G3 cases, including 13 PanNET G3, 10 PanNEC, and 2 PanNEN G3 NOS, which were analyzed for somatic mutations. All tumors showed neuroendocrine markers such as synaptophysin or chromogranin A. The median Ki67 index of PanNET G3 was 30.5% (15-78%), which was lower than that of PanNEC (median 70.9%, range 44-100 %). Genomic DNA was extracted from microdissected tumors and paired normal tissues from formalin-fixed paraffin-embedded PanNEN G3 specimens guided by H&E stained sections and subjected to whole-exome sequencing (WES). Copy number alterations were also analyzed on the basis of sequencing data. All tumor specimens were centrally reviewed by the two expert pathologists and assigned to PanNET G3, PanNEC, or PanNEN G3 not otherwise specified (PanNEN G3 NOS).

WES analysis detected a total of 1,688 somatic mutations with a median of 45 (range 21-450)/sample. There was no clear difference in mutational burden between PanNET G3 and PanNEC. Combined with copy number alterations, mutations most frequently affected TP53 (40%), followed by MEN1(28%), SMAD4 (28%), KRAS(24%), and CDKN2A (20%). Frequently mutated in PanNET G1/2, MEN1, DAXX, and ATRX mutations were associated with well-differentiated morphology (n=7/7), while tumors with KRAS or RB1 mutations exhibited poorly differentiated histology (n=5/5). MEN1, DAXX, and ATRX mutations frequently co-occurred with mutations in mTOR pathway genes, such as NF1, TSC2, or DEPDC5 (q&lt;0.001), suggesting that some PanNET G3 might evolve from PanNET G1/2 by acquiring mutations that activate the mTOR pathway. Whereas, in PanNEC, MEN1, DAXX, and ATRX had never been mutated and KRAS and RB1 are recurrently mutated. Therefore, PanNEC does not derive from PanNET and it occurs independently. In survival analysis of PanNEN G3, SMAD4 mutation as well as high grade pathology was significantly contributed to shorter overall survival.

Our results help understand a molecular basis of PanNEN G3, contributing to a better understanding and classification of PanNET G3 and PanNEC.

Citation Format: Nobuyuki Kakiuchi, Kenichi Yoshida, Yusuke Shiozawa, Akira Yokoyama, Keisuke Kataoka, Yoshikage Inoue, Yasuhide Takeuchi, Tomonori Hirano, Yoichi Fujii, Hiroo Ueno, Susumu Hijioka, Nobumasa Mizuno, Waki Hosoda, Yasushi Yatabe, Kenichi Chiba, Hiroko Tanaka, Yuichi Shiraishi, Satoru Miyano, Toshihiko Masui, Shinji Uemoto, Akihiko Yoshizawa, Hironori Haga, Norimitsu Uza, Hiroshi Seno, Yuzo Kodama, Seishi Ogawa. Genetic analysis of pancreatic neuroendocrine neoplasms grade 3 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3429.

Important cytological findings for distinction between follicular variant and conventional papillary thyroid carcinoma, including noninvasive follicular thyroid tumors with papillary-like nuclear features

We studied cytological specimens of conventional papillary thyroid carcinoma (PTC), follicular variant papillary thyroid carcinoma (FVPTC), and noninvasive follicular thyroid tumor with papillary-like nuclear features (NIFTP) (formerly noninvasive FVPTC) to identify useful cytological parameters for their differentiation. Cytological findings of invasive FVPTC and NIFTP were very similar to each other but differed from those of conventional PTC. Intranuclear cytoplasmic inclusions, true papillary cell clusters, monolayered cell sheets, ropy colloids, multinucleate giant cells, psammoma bodies, and cystic background were the observed characteristic features of conventional PTC. Microfollicular cell clusters and dense globules of colloids were characteristic features of invasive FVPTC and NIFTP. Scoring the eight parameters (intranuclear cytoplasmic inclusions, nuclear grooves, powdery chromatin, true papillary cell clusters, ropy colloids, multinucleate giant cells, psammoma bodies, and cystic background) readily distinguished NIFTP from conventional PTC, but could not distinguish NIFTP from invasive FVPTC. The average total score of NIFTP, invasive FVPTC, and conventional PTC were 2.60 ± 0.55, 2.63 ± 0.62, and 4.57 ± 0.99, respectively. The difference between conventional PTC and NIFTP or invasive FVPTC was statistically significant (p < 0.001, Student's t-test). Individuals with more than three of the identified parameters likely harbor conventional PTC, rather than NIFTP. In this way, 87.5% (112/128) of conventional PTCs could be differentiated from NIFTP, and definitively diagnosed as malignant by cytology.

Surgery for Pancreatic Neuroendocrine Tumor G3 and Carcinoma G3 Should be Considered Separately

BACKGROUND

The role of surgery in pancreatic neuroendocrine neoplasm grade 3 (pNEN-G3) treatment remains unclear. We aimed to clarify the role of surgery for pNEN-G3, which has recently been reclassified as pancreatic neuroendocrine tumor-G3 (pNET-G3) and pancreatic neuroendocrine carcinoma-G3 (pNEC-G3), with and without metastases, respectively.

METHODS

We analyzed a subgroup of patients from the Japanese pancreatic NEC study, a Japanese multicenter case-series study of pNEN-G3. Pathologists subclassified 67 patients as having pNET-G3 or pNEC-G3 based on morphological features. We compared the overall survival (OS) rates among patients who were grouped according to whether they had undergone tumor-targeted surgery for tumors without (SwoM) or with (SwM) metastases, or non-surgical procedures (NS).

RESULTS

Data from 21 patients with pNET-G3 (SwoM, n = 6; SwM, n = 5; NS, n = 10) and 46 patients with pNEC-G3 (SwoM, n = 8; SwM, n = 5; NS, n = 33) were analyzed. OS of patients with pNET-G3 was significantly longer after SwoM and SwM than with NS (p = 0.018 and p = 0.022). In contrast, OS did not significantly differ between either SwoM or SwM and NS (p = 0.093 and p = 0.489) among patients with pNEC-G3.

CONCLUSION

The role of surgery should be considered separately for pNET-G3 and pNEC-G3. Although SwoM and SwM can be considered for pNET-G3, caution is advised before considering SwM and SwoM for pNEC-G3.

Single-cell sequencing defines genetic heterogeneity in pancreatic cancer precursor lesions

Intraductal papillary mucinous neoplasms (IPMNs) are precursors to pancreatic cancer; however, little is known about genetic heterogeneity in these lesions. The objective of this study was to characterize genetic heterogeneity in IPMNs at the single-cell level. We isolated single cells from fresh tissue from ten IPMNs, followed by whole genome amplification and targeted next-generation sequencing of pancreatic driver genes. We then determined single-cell genotypes using a novel multi-sample mutation calling algorithm. Our analyses revealed that different mutations in the same driver gene frequently occur in the same IPMN. Two IPMNs had multiple mutations in the initiating driver gene KRAS that occurred in unique tumor clones, suggesting the possibility of polyclonal origin or an unidentified initiating event preceding this critical mutation. Multiple mutations in later-occurring driver genes were also common and were frequently localized to unique tumor clones, raising the possibility of convergent evolution of these genetic events in pancreatic tumorigenesis. Single-cell sequencing of IPMNs demonstrated genetic heterogeneity with respect to early and late occurring driver gene mutations, suggesting a more complex pattern of tumor evolution than previously appreciated in these lesions. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

IPMNs with co-occurring invasive cancers: neighbours but not always relatives

OBJECTIVE

Intraductal papillary mucinous neoplasms (IPMNs) are precursor lesions that can give rise to invasive pancreatic carcinoma. Although approximately 8% of patients with resected pancreatic ductal adenocarcinoma have a co-occurring IPMN, the precise genetic relationship between these two lesions has not been systematically investigated.

DESIGN

We analysed all available patients with co-occurring IPMN and invasive intrapancreatic carcinoma over a 10-year period at a single institution. For each patient, we separately isolated DNA from the carcinoma, adjacent IPMN and distant IPMN and performed targeted next generation sequencing of a panel of pancreatic cancer driver genes. We then used the identified mutations to infer the relatedness of the IPMN and co-occurring invasive carcinoma in each patient.

RESULTS

We analysed co-occurring IPMN and invasive carcinoma from 61 patients with IPMN/ductal adenocarcinoma as well as 13 patients with IPMN/colloid carcinoma and 7 patients with IPMN/carcinoma of the ampullary region. Of the patients with co-occurring IPMN and ductal adenocarcinoma, 51% were likely related. Surprisingly, 18% of co-occurring IPMN and ductal adenocarcinomas were likely independent, suggesting that the carcinoma arose from an independent precursor. By contrast, all colloid carcinomas were likely related to their associated IPMNs. In addition, these analyses showed striking genetic heterogeneity in IPMNs, even with respect to well-characterised driver genes.

CONCLUSION

This study demonstrates a higher prevalence of likely independent co-occurring IPMN and ductal adenocarcinoma than previously appreciated. These findings have important implications for molecular risk stratification of patients with IPMN.

Rb Loss and KRAS Mutation Are Predictors of the Response to Platinum-Based Chemotherapy in Pancreatic Neuroendocrine Neoplasm with Grade 3: A Japanese Multicenter Pancreatic NEN-G3 Study

Purpose: Patients with pancreatic neuroendocrine neoplasm grade-3 (PanNEN-G3) show variable responses to platinum-based chemotherapy. Recent studies indicated that PanNEN-G3 includes well-differentiated neuroendocrine tumor with G3 (NET-G3). Here, we examined the clinicopathologic and molecular features of PanNEN-G3 and assessed the responsiveness to chemotherapy and survival.Experimental Design: A total of 100 patients with PanNEN-G3 were collected from 31 institutions, and after central review characteristics of each histologic subtype [NET-G3 vs. pancreatic neuroendocrine carcinoma (NEC-G3)] were analyzed, including clinical, radiological, and molecular features. Factors that correlate with response to chemotherapy and survival were assessed.Results: Seventy patients analyzed included 21 NETs-G3 (30%) and 49 NECs-G3 (70%). NET-G3 showed lower Ki67-labeling index (LI; median 28.5%), no abnormal Rb expression (0%), and no mutated KRAS (0%), whereas NEC-G3 showed higher Ki67-LI (median 80.0%), Rb loss (54.5%), and KRAS mutations (48.7%). Chemotherapy response rate (RR), platinum-based chemotherapy RR, and prognosis differed significantly between NET-G3 and NEC-G3. Chemotherapeutic outcomes were worse in NET-G3 (P < 0.001). When we stratified PanNEN-G3 with Rb and KRAS, PanNENs-G3 with Rb loss and those with mutated KRAS showed significantly higher RRs to platinum-based chemotherapy than those without (Rb loss, 80% vs. normal Rb, 24%, P = 0.006; mutated KRAS, 77% versus wild type, 23%, P = 0.023). Rb was a predictive marker of response to platinum-based chemotherapy even in NEC-G3 (P = 0.035).Conclusions: NET-G3 and NEC-G3 showed distinct clinicopathologic characteristics. Notably, NET-G3 does not respond to platinum-based chemotherapy. Rb and KRAS are promising predictors of response to platinum-based chemotherapy for PanNEN-G3, and Rb for NEC-G3. Clin Cancer Res; 23(16); 4625-32. ©2017 AACR.

Genetic analyses of isolated high-grade pancreatic intraepithelial neoplasia (HG-PanIN) reveal paucity of alterations in TP53 and SMAD4

High-grade pancreatic intraepithelial neoplasia (HG-PanIN) is the major precursor of pancreatic ductal adenocarcinoma (PDAC) and is an ideal target for early detection. To characterize pure HG-PanIN, we analysed 23 isolated HG-PanIN lesions occurring in the absence of PDAC. Whole-exome sequencing of five of these HG-PanIN lesions revealed a median of 33 somatic mutations per lesion, with a total of 318 mutated genes. Targeted next-generation sequencing of 17 HG-PanIN lesions identified KRAS mutations in 94% of the lesions. CDKN2A alterations occurred in six HG-PanIN lesions, and RNF43 alterations in five. Mutations in TP53, GNAS, ARID1A, PIK3CA, and TGFBR2 were limited to one or two HG-PanINs. No non-synonymous mutations in SMAD4 were detected. Immunohistochemistry for p53 and SMAD4 proteins in 18 HG-PanINs confirmed the paucity of alterations in these genes, with aberrant p53 labelling noted only in three lesions, two of which were found to be wild type in sequencing analyses. Sixteen adjacent LG-PanIN lesions from ten patients were also sequenced using targeted sequencing. LG-PanIN harboured KRAS mutations in 94% of the lesions; mutations in CDKN2A, TP53, and SMAD4 were not identified. These results suggest that inactivation of TP53 and SMAD4 are late genetic alterations, predominantly occurring in invasive PDAC. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.