Complete response to combination therapy using nivolumab and ipilimumab for metastatic, sarcomatoid collecting duct carcinoma presenting with high expression of programmed death-ligand 1: a case report.

BACKGROUND: Collecting duct carcinoma and sarcomatoid renal cell carcinoma are tumors with poor prognosis. Immune checkpoint inhibitors have been established as the standard treatment for advanced renal cell carcinoma. Some cases of remission of collecting duct carcinoma and sarcomatoid renal cell carcinoma have been reported using immune checkpoint inhibitor interventions. Specifically, sarcomatoid renal cell carcinoma expresses high levels of programmed death-ligand 1, an immune checkpoint protein, and immune checkpoint inhibitors have been reported to be highly effective for treating sarcomatoid renal cell carcinoma. CASE PRESENTATION: We describe the case of a 70-year-old Japanese male who underwent radical right nephrectomy for a right renal mass identified on computed tomography. The pathological examination demonstrated that the renal mass was urothelial carcinoma and collecting duct carcinoma with sarcomatoid changes, and programmed death-ligand 1 was highly expressed with a tumor proportion score of more than 10%. There was no evident submucosal connective tissue invasion in the urothelial carcinoma component, and collecting duct carcinoma was diagnosed as primary cancer. The tumor-node-metastasis classification was pT3aN0, venous invasion 1, lymphovascular invasion 0, and Fuhrman nuclear grade 4. Two months after the nephrectomy, multiple metastases were observed in both lungs, the right hilar lymph node, and the S6 segment of the right liver lobe. We initiated first-line combination therapy with nivolumab (240 mg, fixed dose) and ipilimumab (1 mg/kg). One day after administration, the patient developed drug-induced interstitial pneumonia, thus we applied steroid injections. After one administration of immunotherapy, the metastatic lesion showed complete response within 6 months, which was maintained after 3 years. CONCLUSION: We report the first case of complete response to a single dose of combination therapy with nivolumab and ipilimumab for metastatic collecting duct carcinoma with sarcomatoid changes and high expression of programmed death-ligand 1. This case suggests high expectations for immune checkpoint inhibitors as treatment for sarcomatoid-transformed renal carcinoma tumors that express high levels of programmed death-ligand 1.

Immunostaining With Immunoglobulin G Subclass Antibody Cocktail for Diagnosis of Type 1 Autoimmune Pancreatitis.

BACKGROUND.: Immunoglobulin (Ig) G4-related diseases (RDs) are systemic diseases in which serum IgG4 levels are frequently elevated. They can cause diffuse or focal tumor formation, organ swelling, and tissue thickening in organs infiltrated by IgG4+ plasma cells. The diagnostic criteria for IgG4-RDs include an IgG4/IgG ratio >40%, but counting IgG+ cells can be difficult because of the weakness of IgG staining density. We hypothesized that an antibody cocktail of mixed IgG1, IgG2, IgG3, and IgG4 (AC-IgG) might give immunohistochemistry results comparable with those of IgG in IgG4-RD. METHODS.: We compared AC-IgG reactivity with IgG expression in type 1 autoimmune pancreatitis (AIP), a representative IgG4-RD. We compared immunohistochemistry results using AC-IgG and IgG-only in 10 cases of AIP. The coefficient of variation (Cv) was used to analyze differences between AC-IgG and IgG findings in AIP by 13 board-certified pathologists. RESULTS.: Although mean values for IgG+ cells did not significantly differ between AC-IgG (34.3; range = 27.4-37.1) and IgG (30.0; range = 23.0-45.6; P = .6254), Cv was lower for AC-IgG (33.4%) than for IgG (51.4%; regression equation; y[IgG] = 0.988x + 0.982; correlation coefficient = 0.907). The data showed that the results of both methods were largely consistent. CONCLUSION.: AC-IgG could replace IgG to count IgG+ cells because of its lower Cv.

Synchronous Duodenal Cancer and Lung Cancer Harboring an Epidermal Growth Factor Receptor Mutation Treated with Erlotinib and Oral Fluoropyrimidine.

Chemotherapy for multiple primary cancers is challenging. We describe a case of synchronous duodenal cancer with lung cancer harboring an epidermal growth factor receptor (EGFR) mutation treated with erlotinib and S-1, an oral fluoropyrimidine agent. A 78-year-old woman with advanced EGFR-mutated lung adenocarcinoma was simultaneously diagnosed with duodenal adenocarcinoma. After the treatment with erlotinib, the lung cancer responded well, but her duodenal cancer showed no response. S-1 was added to erlotinib, and the duodenal cancer demonstrated a good response with tolerable toxicities. The concurrent use of erlotinib and S-1 was safe and efficacious for synchronous lung cancer harboring an EGFR mutation and duodenal cancer.

Increased phosphatidylcholine (16:0/16:0) in the folliculus lymphaticus of Warthin tumor.

Warthin tumor (War-T), the second most common benign salivary gland tumor, consists mainly of neoplastic epithelium and lymphoid stroma. Some proteins and genes thought to be involved in War-T were evaluated by molecular biology and immunology. However, lipids as an important component of many tumor cells have not been well studied in War-T. To elucidate the molecular biology and pathogenesis of War-T, we investigated the visualized distribution of phosphatidylcholines (PCs) by imaging mass spectrometry (IMS). In our IMS analysis of a typical case, 10 signals were significantly different in intensity (p < 0.01) between the War-T and non-tumor (Non-T) regions. Five specific PCs were frequently found in the War-T regions of all of the samples: [PC (16:0/16:0) + K](+) (m/z 772.5), [PC (16:0/20:4) + K](+) (m/z 820.5), [PC (16:0/20:3) + K](+) (m/z 822.5), [PC (18:2/20:4) + K](+) (m/z 844.5), and [PC (18:0/20:5) + K](+) (m/z 846.5). PC (16:0/16:0) was increased specifically in the folliculus lymphaticus of War-T lymphoid stroma, suggesting a different metabolism. Localization of PC (16:0/16:0) might reflect inflammation activity participating in the pathogenesis of War-T. Thus, our IMS analysis revealed the profile of PCs specific to the War-T region. The molecules identified in our study provide important information for further studies of War-T pathogenesis.

Effect of miR-122 and its target gene cationic amino acid transporter 1 on colorectal liver metastasis.

Control of liver metastasis is an important issue in the treatment of colorectal cancer (CRC). MicroRNAs have been shown to be involved in the development of many cancers, but little is known about their role in the process of colorectal liver metastasis. We compared miRNA expression between primary colorectal tumors and liver metastasis to identify those involved in the process of metastasis. Cancer cells were isolated from formalin-fixed paraffin-embedded primary CRC samples and their corresponding metastatic liver tumors in six patients using laser capture microdissection, and miRNA expression was analyzed using TaqMan miRNA arrays. The most abundant miRNA in liver metastasis compared with primary tumors was miR-122. Immunohistochemical analysis revealed that the expression levels of cationic amino acid transporter 1 (CAT1), a negative target gene of miR-122, were lower in liver metastases than primary tumors (P < 0.001). Expression levels of CAT1 in 132 primary tumors were negatively correlated with the existence of synchronous liver metastasis (P = 0.0333) and tumor stage (P < 0.0001). In an analysis of 121 colon cancer patients without synchronous liver metastasis, patients with CAT1-low colon cancer had significantly shorter liver metastasis-free survival (P = 0.0258) but not overall survival or disease-free survival. Overexpression of miR-122 and concomitant suppression of CAT1 in the primary tumor appears to play important roles in the development of colorectal liver metastasis. Expression of CAT1 in the primary CRC has the potential to be a novel biomarker to predict the risk of postoperative liver metastasis of CRC patients.