Michitaka Nakano

Bi-cytopenia possibly induced by anti-PD-1 antibody for primary malignant melanoma of the esophagus: A case report.

Background:Anti-programmed cell death 1 antibody nivolumab is a promising agent for various cancers. Immune-related adverse events are recognized; however, bi-cytopenia with nivolumab has not been reported. Case presentation:A 73-year-old man was diagnosed with advanced primary malignant melanoma of the esophagus with liver, lung, and lymph node metastases. Previous therapies including dacarbazine and radiation of 39 Gy to the esophageal region were performed, but the liver metastases deteriorated. The patient was then administered nivolumab (2 mg/kg, every 3 weeks). After 3 cycles, the esophageal tumor and lymph nodes showed marked reductions in size, the lung metastases disappeared, and the liver metastases shrank partially. The treatment continued with 7 cycles for 4 months. However, severe anemia and thrombocytopenia appeared in the 6th cycle, and intermittent blood transfusions were required. The patient received high-dose intravenous methylprednisolone therapy for bi-cytopenia, but it was ineffective. Seven months after the initiation of nivolumab, the patient died of tumor. Although the mechanisms of bi-cytopenia were unclear, it could have been induced by nivolumab. Conclusion:The present case shows a rare but serious life-threatening bi-cytopenia possibly associated with nivolumab and suggests the importance of awareness of hematological adverse events during nivolumab therapy.

Pancreatic acinar cell carcinoma presenting with panniculitis, successfully treated with FOLFIRINOX: A case report

Pancreatic acinar cell carcinoma (PACC) is a rare tumor of the exocrine pancreas, representing only 1% of all pancreatic malignancies. A 50-year-old man presented with edema of the thumb joints bilaterally, followed by an appearance of masses in the bilateral lower extremities and fever (38°C). The masses were diagnosed as panniculitis by skin biopsy, and multiple intraperitoneal masses were incidentally detected on pelvic magnetic resonance imaging performed to investigate the leg abnormalities. The patient was referred to the Kyushu University Hospital for further investigation, and fluorodeoxyglucose-positron emission tomography/computed tomography (CT) revealed high-uptake tumors in the pancreatic tail, in the periphery of the liver, and in the pelvis. Laboratory examinations revealed high serum concentrations of pancreatic exocrine enzymes, such as lipase, trypsin, elastase 1 and pancreatic phospholipase A2. Histological examination of a bioptic specimen obtained from a hepatic lesion revealed proliferation of atypical cells arranged in a tubular or glandular pattern. Immunohistochemical staining revealed that the atypical cells were positive for cytokeratin (CK)7, CK19 and lipase, but negative for CK20 and thyroid transcription factor-1, leading to a final diagnosis of acinar cell carcinoma of the pancreatic tail (T4bN0M1, stage IV according to the 7th edition of the TNM Classification of Malignant Tumors). Combined chemotherapy with oxaliplatin, irinotecan and fluorouracil (FOLFIRINOX) was administered and fever was soon alleviated. The serum levels of lipase also declined and panniculitis completely resolved. As of the start of the 8th course of chemotherapy, the levels of the pancreatic exocrine enzymes were within normal ranges and CT revealed partial response. Therefore, the severe lipase hypersecretion syndrome was well controlled by the FOLFIRINOX regimen and shrinkage of the mass was also achieved. Thus, the FOLFIRINOX regimen may represent an effective treatment option for advanced PACC.

Programmed death-ligand 1 expression is associated with fibrosarcomatous transformation of dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is a locally invading tumor, characterized by the presence of the collagen type I α 1 (COL1A1)-platelet-derived growth factor (PDGF) β fusion gene. We herein report the case of a 31-year-old man with a history of resection of an abdominal wall DFSP. The patient presented with chest pain and a computed tomography scan revealed a large mass in the posterior mediastinum and another mass in the right lung. The mediastinal mass was a sarcomatous lesion expressing the COL1A1-PDGFβ fusion gene, suggesting that it represented a metastasis of the DFSP following fibrosarcomatous (FS) transformation. Following resection of the mediastinal metastasis and subsequent radiotherapy, the mass in the right lung was also resected. Due to the emergence of pleural and pancreatic tail metastases, the patient was treated with a combination therapy of adriamycin and ifosfamide. After five courses, the disease progressed and the patient was subsequently treated with pazopanib for ~2 months until further progression. Three years after the diagnosis of the mediastinal metastasis of DFSP, the patient was referred to another hospital for palliative care. The expression of programmed cell death 1 ligand (PD-L1) in the primary and metastatic tumors was investigated: PD-L1 expression was detected in the metastasis but not in the primary tumor. Given that the metastatic tumor exhibited FS transformation (DFSP-FS), PD-L1 expression may be induced by FS transformation, contributing to the metastasis through escape from immune surveillance. Further investigation of the PD-L1 pathway in DFSP and DFSP-FS in primary as well as metastatic sites is required to evaluate the clinical efficacy of therapies targeting the PD-L1 signaling cascade.

Efficacy and safety of an increased-dose of dexamethasone in patients receiving fosaprepitant chemotherapy in Japan

BACKGROUND Antiemetic triplet therapy including dexamethasone (DEX) is widely used for patients receiving highly emetogenic chemotherapy (HEC). In Japan, the appropriate dose of DEX has not been established for this combination. MATERIALS AND METHODS To assess the efficacy and safety of increased-dose DEX, we retrospectively examined patients receiving HEC with antiemetic triplet therapy. RESULTS Twenty-four patients (fosaprepitant group) were given an increased-dose of DEX (average total dose: 45.8mg), fosaprepitant, and 5-HT3 antagonist. A lower-dose of DEX (33.6mg), oral aprepitant, and 5-HT3 antagonist were administered to the other 48 patients (aprepitant group). The vomiting control rates in the fosaprepitant and aprepitant groups were 100% and 85.4% in the acute phase, and were 75.0% and 64.6% in the delayed phase. The incidences of toxicity were similar comparing the two groups. CONCLUSIONS Triplet therapy using an increased-dose of DEX is suggested to be safe and effective for patients receiving HEC.

Efficacy and safety analysis of chemotherapy for advanced colitis-associated colorectal cancer in Japan.

Chemotherapy for advanced colitis-associated colorectal cancer (CAC) has been insufficiently evaluated. The goal of this study was to clarify the efficacy and safety of chemotherapy for CAC in Japan. CAC patients who were treated with chemotherapy between 2005 and 2015 were retrospectively examined. Twenty-nine patients (median age, 48 years; 23 men) were assessed. Eighteen patients had ulcerative colitis, and 11 had Crohn’s disease. Three ulcerative colitis and four Crohn’s disease patients were in the active disease phase. Primary tumors were located in the rectum/anus (n=16), the left colon (n=9), or the right colon (n=4). Palliative or adjuvant chemotherapy was performed in 13 and 16 patients, respectively. First-line palliative chemotherapy regimens were as follows: fluorouracil, leucovorin, and oxaliplatin (FOLFOX; n=6), FOLFOX+bevacizumab (n=3), and others (n=4). Adjuvant chemotherapy regimens were S-1 (n=7), oxaliplatin-based (n=4) and others (n=5). In palliative chemotherapy, the objective response rate was 15%, and the median progression-free survival and overall survival were 182 and 315 days, respectively. In adjuvant chemotherapy, the 5-year relapse-free survival rate was 78%. Grade 3/4 adverse events (AEs) were observed in 16 patients (55%). Active and remission inflammatory bowel disease patients suffered grade 3/4 nonhematological AEs at an incidence of 71 and 23%, respectively (P<0.01). Dose reduction was required in 11 patients (38%), eight of whom required it for hematological AEs. Adjuvant chemotherapy for CAC exhibited sufficient efficacy, whereas modest efficacy was shown for palliative chemotherapy for CAC. AEs, particularly nonhematological AEs, were closely associated with disease activity of colitis.

E-cadherin regulates proliferation of colorectal cancer stem cells through NANOG

Cancer stem cells (CSCs) possess a self-renewal ability and display tumorigenic potential in immunodeficient mice. Colorectal CSCs are thought to be a uniform population and no functionally distinct subpopulations have been identified. Because E-cadherin is an essential molecule for self-renewal of embryonic stem cells, we examined E-cadherin expression, which may play a role in maintaining the properties of CSCs, in EpCAMhigh/CD44+ colorectal CSCs from human primary colorectal cancers. We obtained 18 surgical specimens of human primary colorectal cancer. CD44, EpCAM, and E-cadherin expression were analyzed by fluorescence-activated cell sorting. Sorted EpCAMhigh/CD44+ colorectal CSCs were injected into immunodeficient mice to estimate the tumorigenic potential. Genetic profiles were analyzed by cDNA microarray. Notably, colorectal CSCs could be divided into two populations based on the E-cadherin expression status, and they exhibited different pathological characteristics. Compared to E-cadherin-negative colorectal CSCs, E-cadherin-positive (EC+) colorectal CSCs demonstrated higher tumor growth potential in vivo. EC+ colorectal CSCs revealed a higher expression of the pluripotency factor NANOG, which contributed to the higher tumor growth potential of EC+ colorectal CSCs through control of cyclin D1 expression. These findings are the first demonstration of functionally distinct subpopulations of colorectal CSCs in human clinical samples.

Dedifferentiation process driven by TGF-beta signaling enhances stem cell properties in human colorectal cancer

Cancer stem cells (CSCs) possess the capacity for self-renewal and the potential to differentiate into non-CSCs. The recent discoveries of dynamic equilibrium between CSCs and non-CSCs revealed the significance of acquiring CSC-like properties in non-CSCs as an important process in progression of cancer. The mechanism underlying acquisition of CSC-like properties has mainly been investigated in the context of epithelial–mesenchymal transition. Here, we demonstrate the dedifferentiation process may be an alternative mechanism in acquisition of CSC-like properties in human colorectal cancer cells. By exploring the single-cell gene expression analysis of organoids developed from CD44+ CSCs, we identified TWIST1 as a key molecule for maintaining the undifferentiated state of cancer cells. Consistent with the finding, we found that TGF-beta signaling pathway, a regulator of TWIST1, was specifically activated in the undifferentiated CD44+ CSCs in human colorectal cancer using microarray-based gene expression analysis and quantitative pathology imaging system. Furthermore, we showed that external stimulation with TGF-beta and the induction of TWIST1 converted CD44− non-CSCs into the undifferentiated CD44+ CSCs, leading to the significant increment of CSCs in xenograft models. This study strongly suggests dedifferentiation driven by TGF-beta signaling enhances stem cell properties in human colorectal cancer.

PD-1+ TIM-3+ T cells in malignant ascites predict prognosis of gastrointestinal cancer

The liquid biopsy of ascites fluid could be an excellent source of tumor and microenvironment for the study of prognostic biomarkers because of its accessibility. Tumor‐infiltrating lymphocytes (TILs) can predict prognosis in multiple malignancies, including the response to immune checkpoint inhibitors, a breakthrough cancer therapy. However, TILs’ profiles from malignant ascites have not been extensively studied. Using flow cytometric analysis, we quantified the proportion of exhausted T cells and memory/naive/effector T‐cell subsets, among the CD4+ and CD8+ T‐cell populations of paired TILs and peripheral blood T cell samples (n = 22). The correlation between CD4+ and CD8+ subset profiles suggested that the combined analysis of CD4+ and CD8+ cells in malignant ascites was clinically significant. We found that cells positive for the exhaustion markers programmed cell death‐1 (PD‐1), and T‐cell immunoglobulin and mucin domain 3 (TIM‐3), and cells coexpressing PD‐1 and TIM‐3 abundantly exist among malignant ascites TILs. Furthermore, patients with high frequency of PD‐1+ TIM‐3+ cells among the CD4+ and CD8+ T‐cell population showed worse clinical outcome in multivariate analysis (n = 27). We propose that exhausted ascites TILs represent a clinically significant prognostic biomarker in advanced gastrointestinal cancer and represent an important target for immune checkpoint inhibitors.

Activation of central/effector memory T cells and T-helper 1 polarization in malignant melanoma patients treated with anti-programmed death-1 antibody

Human anti‐programmed death‐1 (PD‐1) antibody possesses the capability to revitalize host T cells and has been an effective therapy for metastatic malignant melanoma (MM). The precise subsets of T cells predominantly activated by anti‐PD‐1, however, have not yet been clarified. In this study, peripheral blood mononuclear cells obtained from MM patients scheduled to receive anti‐PD‐1 (nivolumab) therapy, and healthy subjects (HS), were systematically examined on flow cytometry to identify changes in the proportion of immune cell subsets. Compared with HS, MM patients prior to therapy had an increased proportion of activated CD8+ T cells with effector memory phenotypes (Tem), and PD‐1 positive subsets of CD4+ central memory T cells (Tcm) and T‐helper (Th)17 cells. After a single course of anti‐PD‐1 therapy, MM patients had an increase in activated Tem and Tcm subsets of CD4+ and CD8+ T cells, and activated Th1 plus T‐helper follicular 1 cells. There was no consistent change in the proportion of Tfh cells, B cells, natural killer cells, or dendritic cells. The observed activated phenotypes were attenuated during the course of therapy, but regulatory T cells belonging to the CD3+CD4+CD45RO+CD25high fraction increased at disease progression. Taken together, anti‐PD‐1 therapy modulates systemic immune reactions and exerts anti‐tumor effects, not only by revitalizing Tem and Tcm of CD4+ and CD8+ T cells, but also via a shift to a Th1 phenotype.

Epithelial-mesenchymal transition is activated in CD44-positive malignant ascites tumor cells of gastrointestinal cancer

Disseminated cancer cells in malignant ascites possess unique properties that differ from primary tumors. However, the biological features of ascites tumor cells (ATC) have not been fully investigated. By analyzing ascites fluid from 65 gastrointestinal cancer patients, the distinguishing characteristics of ATC were identified. High frequency of CD44+ cells was observed in ATC using flow cytometry (n = 48). Multiplex quantitative PCR (n = 15) showed higher gene expression of epithelial‐mesenchymal transition (EMT)‐related genes and transforming growth factor beta (TGF‐beta)‐related genes in ATC than in the primary tissues. Immunohistochemistry (n = 10) showed that ATC also had much higher expression of phosphorylated SMAD2 than that in the corresponding primary tissues. TGF‐beta 1 was detected in all cases of malignant ascites by enzyme‐linked immunoassay (n = 38), suggesting the possible interaction of ATC and the ascites microenvironment. In vitro experiments revealed that these ATC properties were maintained by TGF‐beta 1 in cultured ATC(n = 3). Here, we showed that ATCrevealed high frequencies of CD44 and possessed distinct EMT features from primary tissues that were mainly maintained by TGF‐beta 1 in the ascites.