福嶋 敬宜

Our previous studies of pancreatic tumors have demonstrated that invasive ductal carcinoma (IDC) usually showed expression of MUC1 (membrane bound type mucin) detected by monoclonal antibody DF3, whereas intraductal papillary-mucinous neoplasm (IPMN) showed no expression of MUC1. In the present study, we examined 50 IDCs, and 63 IPMNs which were morphologically classified into two histological subtypes, "dark cell type" (IPMN-D, 27 cases) and "clear cell type" (IPMN-C, 36 cases). Patients with either type of IPMN showed significantly better survival than those with IDC. To clarify the relationship of the expression patterns of mucins with their biological behavior, we examined the expression profiles of various glycoforms of membrane mucin (MUC1) and secretory mucin (MUC2, MUC5AC and MUC6) in the neoplasms using immunohistochemistry. IDCs showed high expression of all the glycoforms of MUC1 (66%-98%). In contrast, IPMNs-D showed no or low expression of all the glycoforms of MUC1 (0%-4%), while IPMNs-C showed low expression of poorly glycosylated MUC1 (3%-6%), but expression of sialylated MUC1 (41%) and fully glycosylated MUC1 (69%). Expression of MUC2 was negative (0%) in IDC, high (96%) in IPMN-D and low (3%) in IPMN-C. MUC5AC was highly expressed in all types. MUC6 expression was higher in IPMNs-C (92%) than in IDCs (56%) and IPMNs-D (37%). In conclusion, the present study demonstrated that IDCs showed high expression of all the glycoforms of MUC1, and also that two types of IPMNs showed different expression patterns of glycosylated MUC1 as well as MUC2 and MUC6. These different expression patterns of mucins may be related with the malignancy potential of pancreatic neoplasms.<br>

The suppressor of cytokine signalling-1 (SOCS-1) gene is frequently silenced in human hepatocellular carcinoma by aberrant methylation. The aim of this study was to determine if SOCS-1 is inactivated in pancreatic ductal neoplasms, and to investigate if aberrant methylation of this gene affected the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway. Aberrant methylation in the CpG island of the SOCS-1 gene was detected in six of 19 (31.6%) human pancreatic cancer cell lines using methylation-specific PCR, and was associated with a loss or reduction of gene expression in five of the six methylated cell lines. Thirteen of 60 pancreatic ductal adenocarcinomas (21.7%) and two of 34 intraductal papillary mucinous neoplasms (IPMNs) (5.9%) had methylated SOCS-1. In contrast, SOCS-1 methylation was not seen in pancreatic normal ductal epithelia (zero out of 15), in pancreatic intraepithelial neoplasia (PanINs) (zero out of 49) or in the IPMNs without infiltrating cancer (zero out of 20). 5-Aza-2'-deoxycytidine treatment of the SOCS-1-methylated pancreatic cancer cell lines led to restoration of SOCS-1 gene expression. Interleukin-6, which has been shown to act through the JAK/STAT pathway to increase cell growth, induced modest time and dose-dependent cell proliferation in a SOCS-1-methylated cell line (PL10, P = 0.015) but not in two unmethylated cell lines. These results indicate that loss of SOCS-1 gene is associated with transcriptional silencing and may have growth-promoting effects, and that its methylation is a useful marker of pancreatic cancer.

PURPOSE: We describe a rare case of an alpha-fetoprotein-producing carcinoma originating in the transverse colon of a 59-year-old Japanese male. METHODS: The patient reported an abdominal mass and weight loss. On examination, a tumor of the transverse colon and multiple masses in the liver were found. The serum alpha-fetoprotein level was extremely high (12,873 ng/ml). The patient underwent right hemicolectomy and intraoperative biopsy of a liver mass. RESULTS: Histologically, the colon cancer was composed of three different components: a well-differentiated tubular adenocarcinoma, a tubulopapillary carcinoma consisting of cells with clear cytoplasms, and a "hepatoid carcinoma." The hepatoid carcinoma was composed of large polygonal cells with abundant eosinophilic or clear cytoplasms, arranged in a trabecular or solid pattern, and showing marked vascular invasion. Immunohistochemically, alpha-fetoprotein was strongly expressed, largely in the hepatoid carcinoma and partially in the tubulopapillary carcinoma. The liver biopsy specimen showed morphologic and immunohistochemical features similar to those of the hepatoid carcinoma of the colon and was therefore diagnosed as a metastasis. The patient died of the cancer two months after surgery. CONCLUSION: Based on our experience of this patient and a review of the literature, alpha-fetoprotein-producing colorectal carcinomas are generally associated with a poor prognosis because of the frequent occurrence of blood-borne metastases.

米国での膵癌発症数は年間約30,000人で,人種差はあるものの人口比,切除率,5年生存率などは日本とほぼ同様と見なされる.根治が難しい膵癌の現状における対膵癌戦略の要の1つに早期診断を目指したバイオマーカーの開発がある.異常検出のアプローチとしてDNAレベル,RNAレベル,タンパク質レベルがあるが,DNAマイクロアレイの出現やプロテオミクス技術の開発が膵癌早期診断に向けてのゲノムスケールでの遺伝子発現解析を可能にした.一方,これらの「ゲノム医学の導入」を活かすための研究環境の整備やネットワークの構築なども重要である.ジョンズ・ホプキンス大学の対膵癌チームの戦略はその1つのモデルである

Background: The aim of this study was to assess the implications of positive peritoneal washing cytology for management of patients with potentially resectable pancreatic cancer. Methods: Cytological examination of peritoneal washings was performed in 134 patients who underwent surgical resection for pancreatic adenocarcinoma. The clinicopathological findings and the relationship between cytology results (including cytomorphology) and survival were investigated. Results: One hundred and fourteen patients (85 per cent) had negative cytology results (group 1). Excluding one patient with atypical cells, positive cytology results were obtained in 19 patients (14 per cent): 16 patients without macroscopic peritoneal metastases (group 2) and three patients with minimal macroscopic peritoneal metastases (group 3). The patients in group 2 had significantly larger (P &lt; 0.001) and more advanced (P = 0.022) tumours than those in group 1. However, there were no significant differences in postoperative cumulative survival rates between groups 1 and 2 (P = 0.347). Two patients in group 2 are long-term survivors (40 and 58 months). In cytomorphological analyses, the presence of clusters with ragged edges and isolated carcinoma cells can be considered to indicate a high risk of peritoneal recurrence. Conclusions: Positive cytology does not directly predict peritoneal carcinomatosis and, while associated with advanced disease, does not contraindicate radical surgery.

膵管内乳頭腫瘍(IPMN)と膵粘液性嚢胞腫瘍(MCN)とは,形態的に類似している場合があり混同されてきた.ところがMCNの嚢胞壁に卵巣様間質(OS)が存在することが知られるようになり,改めて両者の違いに関心がもたれている.IPMNとMCNの病理学的鑑別には,膵管系との交通やそれに付随する所見の有無,OSの有無などが重要である.IPMN症例の蓄積に伴い,その浸潤癌への関心も高まっている.IPMNと通常の浸潤性膵管癌とは臨床病理学的に異なる疾患概念であるが,両者の発生・発育の違いに関しての分子生物学的説明は必ずしも十分にはなされておらず,形態的にも両者の中間に位置するような浸潤癌が存在する

Despite the growing awareness of intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas among clinicians, the molecular features of IPMNs have not been well characterized. Previous reports suggest that inactivation of the STK11/LKB1, a tumor-suppressor gene responsible for Peutz-Jeghers syndrome (PJS), plays a role in the pathogenesis of gastrointestinal hamartomas as weft as several cancers, including pancreatic adenocarcinoma. Using polymerase chain reaction amplification of five microsatellite markers from the 19p13.3 region harboring the STK11/LKB1 gene, we analyzed DNA from 22 IPMNs for loss of heterozygosity (LOH). LOH at 19p13.3 was identified in 2 of 2 (100%) IPMNs from patients with PJS and 5 of 20 (25%) from patients lacking features of PJS (7 of 22, 32% overall). Sequencing analysis of the STK11/LKB1 gene in these IPMNs with LOH revealed a germline mutation in one IPMN that arose in a patient with PJS and a somatic mutation in 1 of the 20 sporadic IPMNs. None of the 22 IPMNs showed hypermethylation of the STK11/LKB1 gene. These results suggest that the STK11/LKB1 gene is involved in the pathogenesis of som IPMNs.

Most intraductal papillary-mucinous carcinomas (IPMCs) of the pancreas are resectable and curable. but some develop into frankly invasive carcinomas. We studied the clinicopathologic features of eight cases of invasive carcinoma derived from IPMC (IC-IPMC) of the pancreas. The patients were aged 54-75 years (mean, 66.6 years); six were male and two were female. The mean tumor size was 7.7 cm (range 5.5-10.5 cm). Two patients without lymph node metastasis had no peripancreatic invasion, and survived longer (115 and 20 months). Three out of four patients with extrapancreatic invasion died of their tumors or developed tumor recurrence within a year. One patient with evidence of liver and lymph node metastasis at the time of first surgery again showed metastatic tumor 21 months later. One patient died of another cause. We also performed a comparative study of the immunohistochemical features of IC-IPMCs in 9 IPMCs (including minimally invasive cases) and 15 ductal adenocarcinomas. CEA cytoplasmic positivity was observed in most of the IC-IPMCs (87.5%) and ductal adenocarcinomas (93.3%), but in only I IPMC (11.1%). The frequency of p53 nuclear staining in ductal adenocarcinoma (73.3%) was higher than in IPMC (33.3%) or IC-IPMC (37.5%). In conclusion, IC-IPMC with extrapancreatic invasion should be treated as ductal carcinoma because of its aggressive behavior after resection. Some IPMCs might progress to invasive carcinoma via pathways that are different from those followed by ductal adenocarcinomas.

膵の粘液性嚢胞腫瘍(MCN)と膵管内乳頭(粘液性)腫瘍(IPMN)は臨床病理学的に区別されるべき病変である.MCNは嚢胞形成性腫瘍であり,中年女性の膵体尾部に好発する.一方,IPMNは膵管拡張を伴い膵管内を進展増殖する傾向の強い腫瘍で,高齢男性の膵頭部に多い.両者の上皮成分は類似しているが,MCNの殆どには上皮下に&quot;卵巣様間質&quot;が見られ,WHO分類ではこの所見を定義の中に取り入れている.画像診断上の両者の鑑別には,膵管枝との連絡の有無,嚢胞状病変の壁の性状,腫瘍全体の形状などが役立つ

The laminin-5-γ-2 chain is expressed in various invasive carcinoma cells. To clarify the relationship between laminin-5 expression and the development of intraductal papillary-mucinous tumors (IPMTs), we performed an immunohistochemical study of 26 IPMTs and 30 invasive ductal adenocarcinomas. Cases were classified into five groups: intraductal papillary-mucinous adenoma (Group A; n = 8), adenocarcinoma without invasion (Group B; n = 3), adenocarcinoma with minimal invasion (Group C; n = 5), adenocarcinoma with macroscopically evident invasion (Group D; n = 10), and invasive ductal adenocarcinoma (conventional type; Group E; n = 30). In the invasive components of Groups D and E, laminin-5 was expressed in 80% and 100% of cases, respectively. In the intraductal components of IPMTs, expression of laminin-5 was not seen in Groups A and B, whereas they were seen in one case in Group C (20%) and in seven in Group D (70%). Most of the staining patterns of the intraductal components were focal and scattered. Laminin-5-γ-2 expression in the intraductal components of IPMTs tends to increase as tumors develop and may be a indicator of the potential invasiveness of the tumor cells.

Most patients with pancreatic ductal carcinoma have a poor prognosis. However, in certain cases, 5-year survival can be achieved after surgical resection. Analysis of the pathologic findings associated with good survival rates will assist in identifying the optimum treatment. The clinicopathologic features of 67 patients who underwent surgical resection of ductal adenocarcinoma of the pancreas between 1990 and 1996 were reviewed and correlated with survival rates. There were 42 men and 25 women, with a mean age of 62.1 years (range, 44 to 82 years). The mean greatest diameter of the tumor was 4.3 cm (range, 1.5 to 11 cm). Nineteen patients (29.4%) survived more than 3 years, and 9 (13.2%) survived more than 5 years after surgical resection. The intraductal papillary component (IDPC) of the carcinoma was the main focus of the pathologic observations. IDPC was defined as intraductal papillary proliferative lesions seen in the tumor nodule with proliferative cells consistent with carcinomatous cellular atypia. IDPC was clearly present (++) in 24 patients and vaguely present (+) in 9 patients. Using the Mantel-Cox test, a statistically significant correlation was found between the presence of IDPC (either + or ++) and postoperative patient survival (P = .002). IDPC is a morphologic feature associated with longer patient survival and should be taken into consideration in assessing the pathway of tumor progression. Copyright © 2001 by W.B. Saunders Company.