Cine magnetic resonance imaging predicts thrombus adhesion in metastatic renal cell carcinoma with an inferior vena cava tumor thrombus: A case of pathological complete response with pembrolizumab plus lenvatinib.

Introduction: Renal cell carcinoma with an inferior vena cava tumor thrombus is a challenging disease that requires a multimodal treatment approach. Pembrolizumab plus lenvatinib has displayed promising efficacy in metastatic renal cell carcinoma. Case presentation: A 61-year-old man was diagnosed with metastatic renal cell carcinoma and a tumor thrombus adhering to the inferior vena cava wall by cine magnetic resonance imaging. After 6 months of pembrolizumab and lenvatinib therapy, tumor shrinkage was detected, excluding the advanced portion of the inferior vena cava thrombus, and nephrectomy and thrombectomy were performed. Adhesion of the tumor thrombus to the inferior vena cava wall was observed during surgery. Resection produced a remarkable pathological complete response with no viable cells in the resected specimens, including the thrombus site. Conclusion: This case highlights the potential of pembrolizumab plus lenvatinib for treating advanced renal cell carcinoma with an inferior vena cava thrombus and the utility of cine magnetic resonance imaging for evaluating thrombus adhesion to the inferior vena cava.

CDX2-induced intestinal metaplasia in human gastric organoids derived from induced pluripotent stem cells.

Intestinal metaplasia is related to gastric carcinogenesis. Previous studies have suggested the important role of CDX2 in intestinal metaplasia, and several reports have shown that the overexpression of CDX2 in mouse gastric mucosa caused intestinal metaplasia. However, no study has examined the induction of intestinal metaplasia using human gastric mucosa. In the present study, to produce an intestinal metaplasia model in human gastric mucosa in vitro, we differentiated human-induced pluripotent stem cells (hiPSC) to gastric organoids, followed by the overexpression of CDX2 using a tet-on system. The overexpression of CDX2 induced, although not completely, intestinal phenotypes and the enhanced expression of many, but not all, intestinal genes and previously reported intestinal metaplasia-related genes in the gastric organoids. This model can help clarify the mechanisms underlying intestinal metaplasia and carcinogenesis in human gastric mucosa and develop therapies to restitute precursor conditions of gastric cancer to normal mucosa.

Increased expression of SPRR1A is associated with a poor prognosis in pancreatic ductal adenocarcinoma.

OBJECTIVES: Small proline-rich protein 1A (SPRR1A) is recognized as a squamous differentiation marker but is also upregulated in some non-squamous cancers. However, its expression in pancreatic ductal adenocarcinoma (PDAC) has not been investigated. This study elucidated the expression of SPRR1A in PDAC and its effect on the prognosis and malignant behavior of PDAC. METHODS: We examined the SPRR1A expression by immunohistochemistry in 86 surgical PDAC cases and revealed the relationship between its expression and the prognosis of the PDAC patients. Furthermore, we overexpressed SPRR1A in pancreatic cancer cell lines (PK-1 and Panc-1) and assessed the phenotype and gene expression changes in vitro. RESULTS: Among the 84 cases, excluding 2 with squamous differentiation, 31 (36.9%) had a high SPRR1A expression. The overall survival (median 22.1 months vs. 33.6 months, p = 0.0357) and recurrence-free survival (median 10.7 months vs. 15.5 months, p = 0.0298) were significantly lower in the high-SPRR1A-expression group than in the low-SPRR1A-expression group. A multivariate analysis indicated that a high SPRR1A expression (HR 1.706, 95% CI 1.018 to 2.862, p = 0.0427) and residual tumor status (HR 2.687, 95% CI 1.487 to 4.855, p = 0.00106) were independent prognostic factors. The analysis of TCGA transcriptome data demonstrated that the high-SPRR1A-expression group had a significantly worse prognosis than the low-SPRR1A-expression group, which supported our data. SPRR1A overexpression in PK-1 and Panc-1 did not result in remarkable changes to in vitro phenotypes, such as the cell proliferation, chemo-resistance, EMT, migration or global gene expression. CONCLUSION: Increased expression of SPRR1A is associated with a poor prognosis in PDAC and may serve as a novel prognostic marker. However, our in vitro study suggests that the SPRR1A expression may be a consequence, not a cause, of the aggressive behavior of PDAC.

Epithelial-derived factors induce muscularis mucosa of human induced pluripotent stem cell-derived gastric organoids.

Human gastric development has not been well studied. The generation of human pluripotent stem cell-derived gastric organoids (hGOs) comprising gastric marker-expressing epithelium without an apparent smooth muscle (SM) structure has been reported. We modified previously reported protocols to generate hGOs with muscularis mucosa (MM) from hiPSCs. Time course analyses revealed that epithelium development occurred prior to MM formation. Sonic hedgehog (SHH) and TGF-ß1 were secreted by the epithelium. HH and TGF-ß signal inhibition prevented subepithelial MM formation. A mechanical property of the substrate promoted SM differentiation around hGOs in the presence of TGF-ß. TGF-ß signaling was shown to influence the HH signaling and mechanical properties. In addition, clinical specimen findings suggested the involvement of TGF-ß signaling in MM formation in recovering gastric ulcers. HH and TGF-ß signaling from the epithelium to the stroma and the mechanical properties of the subepithelial environment may influence the emergence of MM in human stomach tissue.

Differentiation of Human Induced Pluripotent Stem Cells Into Testosterone-Producing Leydig-like Cells.

Late-onset hypogonadism (LOH) syndrome, due to a partial lack of testosterone, decreases the quality of life of older men. Testosterone is mainly secreted by Leydig cells in the testes. Leydig cell transplantation is expected to be a promising alternative to conventional testosterone replacement therapy for LOH syndrome. We herein report a simple and robust protocol for directed differentiation of human induced pluripotent stem cells (hiPSCs) into Leydig-like cells by doxycycline-inducible overexpression of NR5A1 and treatment with a combination of 8-bromoadenosine-3',5'-cyclic monophosphate (8-Br-cAMP) and forskolin. The differentiated cells expressed the steroidogenic enzyme genes STAR, CYP11A1, CYP17A1, and HSD3B2 and the specific markers of adult Leydig cells HSD17B3, INSL3, and LHCGR. Furthermore, we confirmed the secretion of functional testosterone from the cells into the culture supernatant by a testosterone-sensitive cell proliferation assay. These findings showed that the hiPSCs were able to be differentiated into Leydig-like cells, supporting the expectation that hiPSC-derived Leydig-like cells can be novel tools for treating LOH syndrome.

Correction to: Retinoic acid receptor γ activation promotes differentiation of human induced pluripotent stem cells into esophageal epithelium.

In the original publication of the article, the following errors were noted and corrected in this correction.

Retinoic acid receptor γ activation promotes differentiation of human induced pluripotent stem cells into esophageal epithelium.

BACKGROUND: The esophagus is known to be derived from the foregut. However, the mechanisms regulating this process remain unclear. In particular, the details of the human esophagus itself have been poorly researched. In this decade, studies using human induced pluripotent stem cells (hiPSCs) have proven powerful tools for clarifying the developmental biology of various human organs. Several studies using hiPSCs have demonstrated that retinoic acid (RA) signaling promotes the differentiation of foregut into tissues such as lung and pancreas. However, the effect of RA signaling on the differentiation of foregut into esophagus remains unclear. METHODS: We established a novel stepwise protocol with transwell culture and an air-liquid interface system for esophageal epithelial cell (EEC) differentiation from hiPSCs. We then evaluated the effect of all-trans retinoic acid (ATRA), which is a retinoic acid receptor (RAR)α, RARß and RARγ agonist, on the differentiation from the hiPSC-derived foregut. Finally, to identify which RAR subtype was involved in the differentiation, we used synthetic agonists and antagonists of RARα and RARγ, which are known to be expressed in esophagus. RESULTS: We successfully generated stratified layers of cells expressing EEC marker genes that were positive for lugol staining. The enhancing effect of ATRA on EEC differentiation was clearly demonstrated with quantitative reverse transcription polymerase chain reaction, immunohistology, lugol-staining and RNA sequencing analyses. RARγ agonist and antagonist enhanced and suppressed EEC differentiation, respectively. RARα agonist had no effect on the differentiation. CONCLUSION: We revealed that RARγ activation promotes the differentiation of hiPSCs-derived foregut into EECs.

Directed differentiation of human induced pluripotent stem cells into mature stratified bladder urothelium.

For augmentation or reconstruction of urinary bladder after cystectomy, bladder urothelium derived from human induced pluripotent stem cells (hiPSCs) has recently received focus. However, previous studies have only shown the emergence of cells expressing some urothelial markers among derivatives of hiPSCs, and no report has demonstrated the stratified structure, which is a particularly important attribute of the barrier function of mature bladder urothelium. In present study, we developed a method for the directed differentiation of hiPSCs into mature stratified bladder urothelium. The caudal hindgut, from which the bladder urothelium develops, was predominantly induced via the high-dose administration of CHIR99021 during definitive endoderm induction, and this treatment subsequently increased the expressions of uroplakins. Terminal differentiation, characterized by the increased expression of uroplakins, CK13, and CK20, was induced with the combination of Troglitazone + PD153035. FGF10 enhanced the expression of uroplakins and the stratification of the epithelium, and the transwell culture system further enhanced such stratification. Furthermore, the barrier function of our urothelium was demonstrated by a permeability assay using FITC-dextran. According to an immunohistological analysis, the stratified uroplakin II-positive epithelium was observed in the transwells. This method might be useful in the field of regenerative medicine of the bladder.

[A Case of Systemic Polyarteritis Nodosa Presenting with Scrotal Pain].

A 76-year-old man with a history of hypertension was admitted with high fever and left scrotal pain. Laboratory findings revealed high serum C-reactive protein levels. The left epididymis appeared to be swollen on computed tomography. The patient was diagnosed with bacterial epididymitis and treatment with antibiotics was initiated. Despite treatment, his left scrotal pain and fever did not improve. Additionally, he developed right scrotal and posterior neck pain. For histopathological diagnosis, a left high orchiectomy was performed and the findings revealed thickened arteriolar walls with infiltration of inflammatory cells around the testis, leading to a final diagnosis of systemic polyarteritis nodosa. Treatment with steroids led to complete resolution of the patient's systemic pain and inflammation.

Clinicopathological analysis of clinically occult extrapulmonary lymphangioleiomyomatosis in intra-pelvic and para-aortic lymph nodes associated with pelvic malignant tumors: A study of nine patients.

The clinicopathological and immunohistochemical characteristics of clinically occult extrapulmonary lymphangioleiomyomatosis in lymph nodes (LN-LAM) being dissected during surgical staging of pelvic malignancy have not been well investigated. We assessed samples from nine female patients (median age, 61). None had past or familial history of tuberous sclerosis and had LAM lesions other than LN such as lung. The primary malignancies included four endometrial endometrioid carcinomas, one endometrial carcinosarcoma, three ovarian serous carcinomas and one urothelial carcinoma. Median follow-up was 43 months. The number of affected LNs ranged from 1 to 15 (median, 2) with sizes ranging from 1 to 13 mm (median, 3.0). Six cases had clinically occult LN-LAM only within the pelvic LNs, two only within para-aortic LNs, and one within both pelvic and para-aortic lymph nodes. Immunohistochemically, LAM cells exhibited a strong diffuse positivity for ß-catenin and E-cadherin in all nine cases. Clinically occult LN-LAM mainly affects peri- or post-menopausal women. On rare occasions, occult LN-LAM may manifest as systemic LAM, including in the lung. ß-catenin and E-cadherin carry potential utility as additional diagnostic markers.

ROS1-rearranged high-PD-L1-expressing lung adenocarcinoma manifesting as mediastinal tumor: A case report.

ROS proto-oncogene 1 receptor tyrosine kinase (ROS1)-rearranged lung cancer is rare and comprises only 1% of lung adenocarcinoma cases. It has recently been reported to have good response to crizotinib, a tyrosine kinase inhibitor of anaplastic lymphoma kinase. Driver oncogene mutations with approved therapies seldom coexist with a high expression of Programmed death-ligand 1 (PD-L1). The present case report describes a rare case of ROS1 rearrangement with high-PD-L1-expressing occult lung adenocarcinoma. A 32-year-old woman presented with chest pain and a prolonged cough. Chest computed tomography (CT) revealed a 57×36-mm tumor in the mediastinum, with no tumors detected in other regions. Positron emission tomography (PET)-CT showed a strong fluorodeoxyglucose accumulation in the tumor (SUVmax 13.2). Mediastinal tumor resection was completely resected using a video-assisted thoracic surgery approach. Pathological examination showed the tumor cells were positive for thyroid transcription factor 1, Napsin-A, ROS1, and PD-L1 (tumor proportion score >99%). ROS1 rearrangement was confirmed by fluorescence in situ hybridization. The mediastinal tumor was diagnosed as mediastinal lymph node metastasis of ROS1-rearranged PD-L1 high-expression undifferentiated lung adenocarcinoma (pathological stage 3, TxN2M0). Two months after the operation, the CT scan showed multiple mediastinum lymph nodes metastases with rapid tumor growth. The patient achieved a complete response after three cycles of S-1 plus cisplatin with concurrent radiotherapy 60 Gy/30 Fr.

Successful Bridging Chemotherapy with Gemcitabine, Carboplatin, and Dexamethasone before Unrelated Stem Cell Transplantation for Hepatosplenic T-cell Lymphoma.

A 45-year-old woman was diagnosed with hepatosplenic T-cell lymphoma (HSTCL), a rare subtype of peripheral T-cell lymphoma. She received different types of chemotherapy, but disease progression was observed. To reduce the tumor burden before an unrelated bone marrow transplantation, combination chemotherapy consisting of the gemcitabine, carboplatin, and dexamethasone (GCD) was administered as bridging therapy, resulting in a reduction in the number of lymphoma cells. We were then able to perform bone marrow transplantation. Although she experienced some adverse events, she successfully achieved long-term remission. We herein report a successful case of HSTCL treated with unrelated stem cell transplantation following the GCD regimen as bridging chemotherapy.

Programmed Cell Death Ligand 1 Expression in Non-Small-cell Lung Cancer Patients With Interstitial Lung Disease: A Matched Case-control Study.

BACKGROUND: Programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) checkpoint inhibitors have demonstrated antitumor activity, and immunohistochemical analysis of PD-L1 expression has been used to identify the response in patients with non-small-cell lung cancer (NSCLC). Recently, considerable interest has ensued toward extending the benefit of these inhibitors to high-risk patients, such as those with NSCLC and interstitial lung disease (ILD). However, no studies have compared PD-L1 expression in NSCLC patients with and without ILD. Therefore, we conducted a case-control study to evaluate PD-L1 expression and stromal CD8+ lymphocyte density in these patients. MATERIALS AND METHODS: The data from patients with pathologic stage I or II NSCLC who had undergone surgery from January 2007 to January 2016 were analyzed. RESULTS: We identified 62 patients with pathologic stage I or II NSCLC and ILD. We compared these patients with 1:1-matched cohort. In both groups with and without ILD, approximately 60% were PD-L1+. Tumor cell PD-L1 expression was similar between the groups (median, 1%; interquartile range, 0%-5%; vs. median, 1%; interquartile range, 0%-5%; P = .49). The proportion of patients with positive (≥ 1%) and strongly positive (≥ 50%) PD-L1 expression was also similar between the 2 groups (P = .46 and P = 1.00, respectively). Additionally, the CD8+ lymphocyte density did not differ between patients with and without ILD. CONCLUSION: PD-L1 expression and stromal CD8+ lymphocyte density were comparable between the NSCLC patients with and without ILD. PD-1 axis inhibitors might be effective for NSCLC patients with ILD.

[A Case of Chromophobe Renal Cell Carcinoma Associated with Birt-Hogg-Dubé Syndrome].

A 61-year-old man with a left renal mass, which was detected by ultrasound during a routine health examination, was referred to our department. The patient had a surgical history of two pneumothorax operations, and the patient's brother also had a history of pneumothorax surgery. A case of Birt-Hogg-Dubé (BHD) syndrome was suspected based on patient history. The pathological diagnosis of the resected tumor, which used robot-assisted laparoscopic partial nephrectomy, was determined to be chromophobe renal cell carcinoma (grade 2, pT1a). BHD syndrome was confirmed by genetic testing, where a nonsense mutation of exon 9 in the FOLLICULIN (FLCN) gene was detected. The patient is currently alive 10 months after surgery.

Reduced Tumour Proportion Scores for Programmed Cell Death Ligand 1 in Stored Paraffin Tissue Sections.

BACKGROUND/AIM: We evaluated the effects of storage of formalin-fixed, paraffin-embedded (FFPE) sections on the tumour proportion score (TPS) for programmed cell death ligand 1 (PD-L1), as indicator in non-small cell lung cancer (NSCLC) tissues of treatment efficacy. MATERIALS AND METHODS: NSCLC postoperative specimens with PD-L1 TPS ≥50% were obtained and cut into five serial sections. One section was stained immediately, and four were stored at 4°C for 2, 4, 6, or 8 weeks. Slides were subjected to PD-L1 immunohistochemistry using the anti-PD-L1 clone 28-8. PD-L1 TPS were blindly evaluated by two independent pathologists. RESULTS: Twelve specimens (60 slides) were evaluated. After slide storage for 2, 4, 6, and 8 weeks, a TPS of <50% was obtained in five (41%), four (33%), seven (58%), and eight (67%) patients, respectively. CONCLUSION: TPS values for PD-L1 were reduced by long-term slide storage of FFPE specimens. Sectioned slides should be stained for PD-L1 without delay.

Predictive Performance of Four Programmed Cell Death Ligand 1 Assay Systems on Nivolumab Response in Previously Treated Patients with Non-Small Cell Lung Cancer.

INTRODUCTION: Nivolumab has demonstrated efficacy against metastatic NSCLC. Four programmed cell death ligand 1 (PD-L1) immunohistochemistry (IHC) assay systems are available for identification of responders among patients with NSCLC, and these assays show some differing characteristics. Accordingly, in this study, we evaluated the ability of these assays to identify responders to nivolumab therapy. METHODS: We retrospectively analyzed patients with previously treated advanced NSCLC, who received nivolumab between January 2016 and September 2016. Specimens were stained using four PD-L1 IHC assays (28-8, 22C3, SP142, and SP263). We classified patients as having test results that were strongly positive (tumor proportion score [TPS] ≥50%), weakly positive (TPS 1%-49%), or negative (TPS <1%). RESULTS: A total of 40 patients with NSCLC and their specimens were analyzed. Analytical comparisons demonstrated good concordance of PD-L1-stained tumor cells among the 28-8, 22C3, and SP263 assays (weighted κ coefficient 0.64-0.71), whereas the SP142 assay showed lower concordance with other assays (weighted κ coefficient 0.39-0.55). Progression-free survival in patients showing strongly positive PD-L1 staining classified by 28-8, 22C3, and SP263 assays was significantly longer than that in patients with a negative result for PD-L1 staining. Predictive performance of response to nivolumab, as assessed by receiver operating characteristic analysis, was also equivalent among the 28-8, 22C3, and SP263 assays (area under the curve 0.75-0.82), whereas the SP142 assay exhibited lower predictive performance (area under the curve 0.68). CONCLUSIONS: The 28-8, 22C3, and SP263 PD-L1 IHC assays showed equivalent predictive performance, whereas the SP142 assay showed lower predictive performance.

Alteration of PD-L1 expression and its prognostic impact after concurrent chemoradiation therapy in non-small cell lung cancer patients.

Concurrent chemoradiation therapy (CCRT) is the treatment of choice for locally advanced non-small cell lung cancer (LA-NSCLC). Several clinical trials that combine programmed cell death 1 (PD-1) axis inhibitors with radiotherapy are in development for patients with LA-NSCLC. However, the effect of CCRT on programmed cell death ligand-1 (PD-L1) expression on tumor cells is unknown. In this study, we analysed paired NSCLC specimens that had been obtained pre- and post-CCRT. PD-L1 expression on tumor cells was studied by immunohistochemistry. A total of 45 patients with LA-NSCLC were included, among which there were sufficient pre- and post-CCRT specimens in 35 patients. Overall, the percentage of tumor cells with PD-L1 expression significantly decreased between pre- and post-CCRT specimens (P = 0.024). Sixteen, 15, and 4 patients had decreased, unchanged, or increased PD-L1 expression after CCRT, respectively. Median OS of patients with decreased, unchanged, or increased PD-L1 expression was 85.1, 92.8, and 14.6 months, respectively (P < 0.001). In conclusion, the percentage of PD-L1-positive tumor cells significantly decreased after CCRT. Alteration of PD-L1 expression after neoadjuvant CCRT was associated with prognosis in patients with LA-NSCLC. These data should be considered when developing the optimal approach of integrating PD-1 axis inhibitors with CCRT.

Early Immune-Related Adverse Events and Association with Outcome in Advanced Non-Small Cell Lung Cancer Patients Treated with Nivolumab: A Prospective Cohort Study.

INTRODUCTION: Retrospective studies have shown immune-related adverse events (irAEs) to be associated with better prognosis. However, no prospective clinical trials have been conducted, and little is known regarding the association between irAEs and the outcome of patients with NSCLC after treatment with immunotherapy. METHODS: We conducted a prospective cohort study of patients with advanced NSCLC who were treated with nivolumab between January and December 2016. The association between clinical outcome and irAEs 2 to 6 weeks after commencement of nivolumab treatment was investigated. IrAEs were assessed by at least three independent medical professionals. RESULTS: A total of 43 patients were enrolled, including 19 patients with irAEs 2 weeks after commencement of nivolumab treatment. Common irAEs included rash, pyrexia, and diarrhea. Programmed cell death ligand 1-positive tumor cell expression was not significantly different between patients with and without irAEs. The objective response and disease control rates were higher in patients with irAEs than in those without irAEs (37% versus 17% and 74% versus 29% [p = 0.17 and p < 0.01], respectively]). Patients with irAEs were associated with a significantly longer median progression-free survival than those without (6.4 months [95% confidence interval: 2.5-not reached] versus 1.5 months [95% confidence interval: 1.2-2.3] [p = 0.01]). These findings were comparable to those for patients with and without irAEs 6 weeks after commencement of nivolumab treatment. CONCLUSIONS: Early irAEs are associated with a better outcome after treatment with immunotherapy. We predicted responses to nivolumab by using early irAEs. Further research is needed to elucidate the mechanisms of these associations.

Natural history and clinical characteristics of multiple pulmonary nodules with ground glass opacity.

BACKGROUND AND OBJECTIVE: Ground glass nodules (GGNs) are frequently encountered in the lungs. We report the natural history and characteristics of multiple GGNs, and propose a management plan for patients with multiple GGNs. METHODS: We retrospectively analysed patients with GGNs that met the following criteria: (i) GGN diameter of 3 cm or less, (ii) ground glass opacity proportion of 50% or more and (iii) observation without treatment for ≥6 months. We evaluated size changes in computed tomography images. Two end points, 'incidence of growth at 36 months' and 'time to growth' were analysed using logistic regression models and Cox proportional hazards model. RESULTS: Between April 2008 and December 2014, 187 patients fulfilled the inclusion criteria (78 (42%) had multiple lesions). Among the multiple-GGN patients, the median observation period was 45.5 months, 25 patients (32%) experienced GGN progression at 36 months and 4 patients (5.1%) after 36 months. Between the multiple and single GGNs, there were no significant differences in growth incidence at 36 months (P = 0.1), after 36 months (P = 0.6) or in time to growth (P = 0.3). Among patients with multiple GGNs who experienced one GGN growth, 41% of patients experienced residual GGN growth afterwards. CONCLUSION: Patients with multiple GGNs showed a tendency to growth within the first 36 months, and a significant proportion of patients experienced multiple GGN progression. We suggest that the optimal observation period for patients with multiple GGNs is 36 months, but careful observation is needed after a lesion begins to grow.