Surgical resection of brain and adrenal gland metastases from gastric cancer: a case report and literature review.

The prognosis of recurrent gastric cancer is generally poor, and aggressive surgical treatment is rarely performed. Herein, we present the case of a patient who underwent resection of cerebellar and adrenal gland metastases from gastric cancer. The patient was treated for gastric cancer with distal gastrectomy at 23 years and for remnant gastric cancer with completion gastrectomy at 48 years. At 59 years old, she experienced vertigo and nausea and was diagnosed with cerebellar and left adrenal gland tumours. First, the cerebellar tumours were resected and diagnosed as metastases of gastric cancer. After 1 month, the adrenal gland tumour was resected and diagnosed as metastatic. She underwent whole-brain radiotherapy and subsequent chemotherapy with S-1. One year after the surgery, the patient died of meningitis carcinomatosa. There are few reports on long-term survival after the resection of brain metastases. Herein, we report our experience along with a review of the literature.

Pancreatic acinar cell carcinoma with extension into the main pancreatic duct: a case report.

BACKGROUND: Pancreatic acinar cell carcinoma (PACC) is a rare exocrine malignant tumor. Its widespread intraductal extension into the main pancreatic duct (MPD) is also rare. CASE PRESENTATION: We report the case of a 71-year-old man with PACC with MPD extension. The patient was assessed with laboratory and radiographic investigations that facilitated a preoperative diagnosis. Endoscopic ultrasonography (EUS) and dynamic thin-slice multi-detector row computed tomography (MDCT) were useful for determining the resection line of the pancreas. EUS-guided fine needle aspiration (EUS-FNA) was also helpful in determining the tumor biology and treatment strategy. Distal pancreatectomy was performed. The MPD was occupied by the tumor 35 mm downstream and 5 mm upstream. Histopathologically, the pancreatic tail tumor extended continuously into the MPD. The tumor was solid with cells showing eosinophilic and granular cytoplasm, indicating the diagnosis of PACC. This is an interesting case of PACC with intraductal extension into the MPD. We discuss the possible mechanisms of tumor extension in this rare case together with a review of the literature. CONCLUSIONS: We describe a rare pancreatic acinar cell carcinoma that could be adequately treated using preoperative precise imaging and histopathological evaluations. When an intraductal tumor extension in the MPD is encountered, the diagnosis of a rare pancreatic tumor should be considered, as in our case.

A Case of Duodenal Neuroendocrine Tumor Accompanied by Gastrointestinal Stromal Tumors in Type 1 Neurofibromatosis Complicated by Life-Threatening Vascular Lesions.

BACKGROUND Type 1 neurofibromatosis (NF1) is known to be associated with not only neurogenic tumors but also gastrointestinal (GI) neoplasms. However, there are few reports on vascular lesions and the incidence is unknown. CASE REPORT We report here the case of a 45-year-old woman with a history of NF1 referred to our hospital for the purpose of detailed examination for positive fecal occult blood test. On the basis of the investigation reports, she was diagnosed with a neuroendocrine tumor (NET)-G1. We planned a subtotal stomach-preserving pancreaticoduodenectomy. The abdominal structures, including the vascular system, were abnormally fragile, and it was very difficult to achieve satisfactory hemostasis. The total amount of intraoperative blood loss was 7580 mL. Fulminant intra-abdominal bleeding occurred on postoperative day (POD) 3. Urgent angiography showed a rupture of the gastroduodenal artery. Transarterial embolization was performed, but the patient died of multiorgan failure on POD5. On histological examination, neurofibroma cells proliferating into the surrounding blood vessels were seen; moreover, immunohistochemistry staining with S-100 antibody showed positive neurofibroma cells surrounding the vascular wall. The pathological diagnosis was duodenal NET-G1 with multinodal involvement. CONCLUSIONS This case is a rare presentation of a NET with multiple gastrointestinal stromal tumors associated with NF1, which led to a fatal outcome due to the extreme fragility of the vessel walls. Since patients with NF1 might have vulnerable vessel walls, adequate surgical preparation for major surgical treatment is necessary.

A case of midgut volvulus related to adult intestinal malrotation found with weight loss after streptococcus infection: A case report and literature review.

INTRODUCTION AND IMPORTANCE: The incidence of intestinal malrotation is 1 in 6000 births, and 90% of cases occur within the first year of life. Adult cases are rare, with a reported incidence of 0.2%-0.5% of all cases. The significance of reporting this case is to recognize that some adult-onset cases require surgery even in the absence of intestinal necrosis. CASE PRESENTATION: A 36-year-old man was infected with streptococcus and treated with antibiotics. He developed appetite loss and his weight decreased 12 kg in 4 months. His abdomen was flat and soft with no tenderness. A computed tomography scan showed that the horizontal duodenal leg was not anchored to the retroperitoneum. Rotation of the mesentery, which was wrapped around the superior mesenteric artery in a clockwise direction, was observed, suggesting midgut volvulus. We performed emergency surgery and Ladd's procedure. CLINICAL DISCUSSION: A previous study reported that the most common symptom in the chronic course of intestinal malrotation was abdominal pain in 41.2% of cases, and weight loss was observed in only 2.6% of patients. The high degree of intestinal adhesion suggests that repeated torsion and release and the development of collateral vessels may have contributed to the asymptomatic course. CONCLUSION: Adult-onset intestinal malrotation should be considered as a differential diagnosis in the presence of weight loss and gastrointestinal symptoms. The timing of surgery is still controversial. In chronic cases, severe adhesion might be expected and laparoscopic surgery should be considered carefully.

[A Case of Chemotherapy with Low-Dose Paclitaxel and Bevacizumab for Elderly Recurrent Breast Cancer Patient].

An 86-year-old woman underwent mastectomy with sentinel lymph node biopsy for cStage ⅡA breast cancer. The subtype of tumor was triple negative breast cancer. Pulmonary metastasis was found 1 month after surgery. Chemotherapy was done because of her good performance status(PS)and her hope. Administration of S-1 produced SD status of tumor for 8 months. However, NCC-ST-439 was increased and tumor size was enlarged. Therefore, the second line of chemotherapy by low-dose- biweekly paclitaxel and bevacizumab was planned because of her high age and good PS. Thereafter, tumor maker levels dramatically decreased and lung metastasis turned to be small. This therapy had been continued without any severe adverse events for 9 months. Unfortunately, this therapy was failed because of proteinuria, but pulmonary metastasis kept favorable efficacy during administration. Biweekly low-dose paclitaxel and bevacizumab therapy can be safe and effective therapy even for elderly patient with recurrent and metastatic breast cancer.

Recurrent biliary dissemination of colon cancer liver metastasis: a case report.

BACKGROUND: Most colorectal cancer liver metastases form nodules within the hepatic parenchyma, and hepatectomy is the only radical treatment for synchronous metastases. There is concern about intrabiliary tumor growth which may affect the surgical margin, resulting in local recurrence after hepatectomy for colorectal cancer liver metastasis; however, there has been no report of the dissemination in the bile duct after hepatectomy. Here, we report an unusual case of biliary dissemination of colorectal cancer that caused recurrent intrabiliary growth after hepatectomy, and discuss the management of intrabiliary metastasis of colorectal cancer. CASE PRESENTATION: A 69-year-old Japanese man underwent treatment for liver dysfunctions 3 years after aortic valve replacement. Computed tomography revealed an enhanced tumor within the hilar bile duct and dilatation of the left hepatic duct, typical of hilar cholangiocarcinoma. Endoscopic retrograde cholangiopancreatography revealed tumor shadow in his bile duct, and the cytology confirmed malignant cells in the bile. We performed extended left hepatectomy with bile duct resection; his postoperative course remained good without acute complications. After 3 months postoperatively, he was readmitted for subacute cholangitis and obstructive jaundice. Immediately, percutaneous transhepatic cholangiography drainage was performed, followed by cholangiography that exhibited intrabiliary tumor growth in the remnant liver. On immunohistochemical examination, tumor cells were positive for cytokeratin 20 and CDX2 but negative for cytokeratin 7. Then, computed tomography revealed an enhanced tumor-like lesion at the descending colon. After 3 months, left hemicolectomy was performed. Meanwhile, the percutaneous transhepatic cholangiography drainage fluid turned bloody, which was considered to be bleeding from a residual bile duct tumor. Accordingly, radiotherapy was initiated to prevent tumor bleeding around the hilar bile duct, but, unfortunately, the effects were short-lived, and cholangitis rebooted after 1 month leading to our patient's death due to septic liver failure. Autopsy revealed a remnant tumor in the bile duct, but no noticeable nodular metastasis was observed, except for a single small metastasis in the lower lobe of the left lung. CONCLUSIONS: The intrabiliary growth of metastatic colorectal cancer mimics cholangiocarcinoma occasionally. To date, as the effect of chemotherapy or radiotherapy remains uncertain, the complete resection of a bile duct tumor is the only method which could result in a better prognosis.

Adenocarcinoma in a Blind Loop of the Ileum 53 Years After an Ileotransversostomy Procedure.

BACKGROUND Primary small bowel cancer is a rare malignancy; the common histopathological types are carcinoid and adenocarcinoma. Inflammatory bowel diseases and familial adenomatous polyposis are known risk factors for small bowel cancer. Additionally, cases of surgery-induced small bowel adenocarcinoma are sometimes reported after ileostomy. CASE REPORT A 84-year-old woman, who had undergone ileotransversostomy for intestinal obstruction due to postoperative adhesion following appendectomy at the age of 31 years, was referred to our hospital for further examination after experiencing abdominal pain in the right lower quadrant for 2 weeks. Laboratory data showed elevated serum levels of carcinoembryonic antigen (CEA, 102.9 ng/ml) and carbohydrate antigen 19-9 (CA19-9, 104 U/ml). Enhanced computed tomography (CT) revealed a 10-cm mass in the terminal ileum and a distention of the ileum and colon in the blind loop, with retention of feces. The patient was suspected of having ileal cancer by preoperative examination; therefore, right hemicolectomy with en bloc resection was performed. The tumor was histopathologically diagnosed as a well-differentiated and mucinous adenocarcinoma of the ileum. At over 12 months after surgery, tumor recurrence had not been observed. CONCLUSIONS Difficulties in diagnosis can cause delays in treatment and lead to poor prognosis, mainly because tumors in the small bowel rarely cause clinical symptoms. Adenocarcinoma of the ileum should be considered in postoperative patients with ileotransversostomy.

[A Study of Patients with Regional Lymph Node Recurrence after Breast Surgery].

Regional lymph node recurrence without distant metastasis after the initial treatment of breast cancer is a relatively rare event. The optimal management for regional lymph node recurrence is poorly understood. We retrospectively evaluated 21 patients who developed regional lymph node recurrence between January 1, 2003 and December 31, 2014. The median interval between regional lymph node recurrence and distant metastasis was 1.0 years(range, 0.4 to 2.5 years). On followup, 15 cases(71.4%)were found to eventually develop distant metastases. Median follow-up time after lymph node recurrence was 1.8 years(range, 0.4 to 20.3 years). The 2-year survival rate after regional lymph node recurrence was 65.5%. The mean distant-disease-free interval was 2.2 years in patients with estrogen receptor(ER)-positive tumor(n=10)and 0.7 years in patients with ER-negative tumor(n=11). The distant-disease-free interval after regional lymph node recurrence was significantly shorter in patients with ER-negative tumor than in patients with ER-positive tumor(p=0.008). The 2-year survival rate after regional lymph node recurrence was significantly lower in patients with ER-negative tumor(33.3%)than in patients with ER-positive tumor(100%, p=0.016). This study revealed that regional lymph node recurrence after initial treatment is associated with an increased risk of distant metastasis and death and ER-negative tumors are indicative of a poor prognosis.

[A Case of Gastrointestinal Stromal Tumor(GIST)Originating in the Anal Canal].

We report a case of a gastrointestinal stromal tumor(GIST)that originated in the anal canal. A 70's woman with a subcutaneous tumor reaching from the anal canal was referred to our hospital. After a thorough examination, the tumor was resected percutaneously in the jackknife position. Histopathological examination showed proliferation of spindle-shaped tumor cells arranged in irregular bundles. Immunohistochemical staining showed that the tumor was positive for c-kit and CD34, and negative for a-SMA and S-100, so the tumor was diagnosed as GIST. As a-SMA-positive smooth muscle cells were seen around the tumor, we suspected that this tumor originated from the internal sphincter muscle.

Massive pneumoretroperitoneum arising from emphysematous cholecystitis: a case report and the literature review.

BACKGROUND: Emphysematous cholecystitis is a severe variant of acute cholecystitis caused by anaerobic bacteria. Although intraperitoneal air as a complication has been described in association with emphysematous cholecystitis, pneumoretroperitoneum arising from emphysematous cholecystitis is extremely rare. Herein, we describe a rare case of pneumoretroperitoneum arising from emphysematous cholecystitis that was successfully treated with emergency surgery. CASE PRESENTATION: An 84-year-old male was transported to the Emergency Department of our hospital for acute abdomen. Computed tomography revealed acute cholecystitis accompanied by emphysematous change. Computed tomography also revealed massive pneumoretroperitoneum complicated with pneumobilia and gas in the hepatoduodenal ligament. Clinical findings fulfilled the diagnostic criteria for systemic inflammatory response syndrome and sepsis. Emergency surgery was carried out with a diagnosis of both emphysematous cholecystitis and gastrointestinal perforation. Intraoperative findings revealed acute gangrenous cholecystitis and pneumoretroperitoneum presenting with an odor-free foamy abscess along the loose connective tissue behind the ascending colon and mesocolon. No evidence of gastrointestinal perforation was found during surgery. Therefore, cholecystectomy and lavage drainage were performed. Bacterial culture examination isolated a single species of anaerobe, Klebsiella pneumoniae, which was considered to be the cause of emphysematous cholecystitis, pneumobilia, and pneumoretroperitoneum. CONCLUSIONS: Emphysematous cholecystitis should be considered as a possible cause of pneumoretroperitoneum. The present case is the first report of massive pneumoretroperitoneum extending to the dorsal side of the ascending mesocolon as a complication of emphysematous cholecystitis.

Resection of distal gastric tube cancer with sentinel node biopsy: a case report and review of the literature.

BACKGROUND: The frequency of gastric tube cancers has increased with advances in surgical techniques and improvement of survival rates in patients with esophageal cancer. However, a standard surgical treatment has not yet been established. Total resection of the gastric tube with lymphadenectomy has been considered a radical treatment, while repeat surgery with both laparotomy and thoracotomy has been associated with severe complications, including anastomotic leakage, recurrent nerve paralysis, bronchotracheal injury, and damage to other organs. CASE PRESENTATION: We present a successful case of a gastric tube cancer that was treated with surgical resection in combination with sentinel node biopsy. The tumor was diagnosed as a type 0-IIc lesion with ulceration, and was located proximal to the pyloric ring. Endoscopic submucosal dissection was not indicated because the primary lesion was submucosally invasive, and undifferentiated. By the dye-guided method, sentinel nodes were detected along the right gastroepiploic artery and vein. Intraoperative pathological examination revealed no metastasis of the sentinel nodes. Resection of the distal gastric tube was safely performed with a Roux-en-Y reconstruction, preserving the right gastroepiploic artery and vein and the perfusion of the proximal gastric tube. CONCLUSION: We suggest distal resection of the gastric tube with sentinel node biopsy as a novel surgical method for a cT1N0 gastric tube cancer located in the abdomen.

Metastatic gastric carcinoma from breast cancer mimicking primary linitis plastica: A case report.

Metastases to the gastrointestinal tract rarely occur in breast cancer except in invasive lobular carcinoma. The present study reports a rare case of metastatic gastric cancer from invasive ductal carcinoma (IDC) of the breast mimicking primary gastric linitis plastica. A 51-year-old premenopausal female, who had a history of partial mastectomy for right breast cancer at the age of 40, was referred to Toyama City Hospital (Toyoma, Japan) for an endoscopic diagnosis of gastric linitis plastica. Abdominal computed tomography (CT) revealed left hydronephrosis, while peritoneal metastasis and malignant ascites were not detected. Chest CT detected a left lung tumor, which had invaded the left upper bronchus. Biopsy specimens were obtained and the histopathological findings on both the gastric tumor and lung tumor demonstrated poorly differentiated adenocarcinoma, whereas the histology of the original breast cancer was IDC with a solid-tubular type. Immunohistochemistry revealed that the biopsied specimens of the gastric and lung tumors were positive for estrogen receptor (ER), progesterone receptor (PgR) and negative for human epithelial growth factor receptor-2 (HER2). These molecular characteristics indicated the case was metastatic gastric carcinoma from the breast cancer with lung metastasis, since the statuses of ER, PgR and HER2 were concordant with those of the original breast cancer. However, the possibility of primary gastric cancer could not be completely ruled out. Therefore, a total gastrectomy was performed for the purpose of both diagnosis and treatment. Pathological examination of the resected specimen provided a definite diagnosis of multiple metastatic gastric carcinomas from the breast. To the best of our knowledge, metastatic gastric cancer derived from the breast presenting as linitis plastica 11 years following the surgical removal of IDC has not been described previously.

[A case of malignant peritoneal mesothelioma diagnosed with laparoscopic biopsy].

A 66-year-old woman was admitted to our hospital for massive ascites of unknown origin. Peritoneal mesothelioma was suspected because of her history of asbestos exposure. Diagnostic laparoscopy with biopsy of the peritoneum and greater omentum was performed. Pathological examination with immunostaining provided a definite diagnosis of malignant peritoneal mesothelioma. The patient underwent early postoperative induction therapy with pemetrexed and carboplatin, which resulted in a reduction in ascites. Laparoscopic biopsy contributed to the definite diagnosis of malignant peritoneal mesothelioma, and thereby, early induction of chemotherapy.

Sigmoid colon cancer arising in a diverticulum of the colon with involvement of the urinary bladder: a case report and review of the literature.

BACKGROUND: Colon cancer can arise from the mucosa in a colonic diverticulum. Although colon diverticulum is a common disease, few cases have been previously reported on colon cancer associated with a diverticulum. We report a rare case of sigmoid colon cancer arising in a diverticulum with involvement of the urinary bladder, which presented characteristic radiographic images. CASE PRESENTATION: A 73-year-old man was admitted to our hospital for macroscopic hematuria. Computed tomography and magnetic resonance imaging revealed a sigmoid colon tumor that protruded into the urinary bladder lumen. The radiographs showed a tumor with a characteristic dumbbell-shaped appearance. Colonoscopy showed a type 1 cancer and multiple diverticula in the sigmoid colon. A diagnosis of sigmoid colon cancer with involvement of the urinary bladder was made based on the pathological findings of the biopsied specimens. We performed sigmoidectomy and total resection of the urinary bladder with colostomy and urinary tract diversion. Histopathological findings showed the presence of a colovesical fistula due to extramurally growing colon cancer. Around the colon cancer, the normal colon mucosa was depressed sharply with lack of the muscular layer, suggesting that the colon cancer was arising from a colon diverticulum. CONCLUSION: The present case is the first report of sigmoid colon cancer arising in a diverticulum with involvement of the urinary bladder. Due to an accurate preoperative radiological diagnosis, we were able to successfully perform a curative resection for sigmoid colon cancer arising in a diverticulum with involvement of the urinary bladder.

[A case of breast cancer treated with chemotherapy after resection of giant ovarian metastasis].

A 49-year-old female patient presented with lower abdominal pain and constipation. Computed tomography revealed left breast cancer with lymph node metastases, a peritoneal metastasis, bilateral hydronephrosis, and ovarian metastasis. The giant ovarian metastasis occupied the pelvic cavity and was responsible for her symptoms of digestive obstruction. Both ovaries were resected as a palliative measure. Three cycles of weekly paclitaxel were successfully administered, leading to the disappearance of malignant ascites. Hence, reduction surgery for ovarian metastasis in the treatment of breast cancer increased the effectiveness of the chemotherapy by improving the patient's general condition.

VEGF is a target molecule for peritoneal metastasis and malignant ascites in gastric cancer: prognostic significance of VEGF in ascites and efficacy of anti-VEGF monoclonal antibody.

BACKGROUND: In gastric cancer, poor prognosis is associated with peritoneal dissemination, which often accompanies malignant ascites. We searched for a target molecule in peritoneal metastasis and investigated its clinical utility as a biomarker. METHODS: Biopsy specimens from both primary lesions and peritoneal metastasis, and if possible, malignant ascites, were obtained from 40 patients with gastric cancer. Vascular endothelial growth factor (VEGF) expression was analyzed by immunohistochemical staining and enzyme-linked immunosorbent assay. RESULTS: VEGF expression was seen in 70% of peritoneal samples. Of the 40 patients, 35 had malignant ascites. These 35 patients were divided into two groups: 15 with ascites found beyond the pelvic cavity (large group) and 20 whose ascites were within the pelvic cavity (small group). The two groups did not significantly differ by serum VEGF levels, but ascites VEGF levels in the large group were significantly higher than in the small group (P < 0.0001). Serum VEGF and ascites VEGF levels were highly correlated in the large group (r = 0.686). A high ascites VEGF level was found to be a risk factor for survival (P = 0.045). We include a report of a patient with chemoresistant refractory gastric cancer and symptomatic ascites who obtained 8 months of palliation from systemic bevacizumab. CONCLUSION: Anti-VEGF therapies are promising, and the ascites VEGF level is an important marker in managing patients with gastric cancer and peritoneal metastasis.

Low-dose paclitaxel modulates tumour fibrosis in gastric cancer.

Various treatments have been used for peritoneal dissemination, which is the most common mode of metastasis in gastric cancer, but sufficiently good clinical outcomes have not yet been obtained because of the presence of rich fibrous components and acquired drug resistance. Epithelial-mesenchymal transition (EMT) is one of the major causes of tissue fibrosis and transforming growth factor-ß (TGF-ß) has a pivotal function in the progression of EMT. Smad proteins play an important role in the TGF-ß signalling pathway. The TGF-ß/Smad signalling pathway can be modulated by stabilising microtubules with paclitaxel (PTX). Here, we investigated whether paclitaxel can modulate TGF-ß/Smad signalling in human peritoneal methothelial cells (HPMCs). To determine the cytostatic concentrations of antineoplastic agents in HPMCs, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was performed using PTX, 5-fluorouracil and cisplatin. The minimum concentration that caused significant inhibition of TGF-ß1-induced morphological changes in human peritoneal methothelial cells on pre-treatment with PTX was 5 nM at 48 h (cell viability: 87.1±1.5%, P<0.01). The TGF-ß signalling cascade and the status of various fibrous components were evaluated by immunofluorescence staining, real-time quantitative PCR and western blotting. TGF-ß signalling induced morphological changes, α-SMA expression and collagen I synthesis in HPMCs and PTX treatment suppressed these EMT-like changes. Moreover, PTX treatment markedly suppressed Smad2 phosphorylation. These data suggest that at a low-dose, PTX can significantly suppress the TGF-ß/Smad signalling pathway by inhibiting Smad2 phosphorylation in the human peritoneum and that this can reduce stromal fibrosis.

The role of human peritoneal mesothelial cells in the fibrosis and progression of gastric cancer.

Peritoneal dissemination is the most frequent metastatic pattern of scirrhous gastric cancer. However, despite extensive research effort, disease outcomes have not improved sufficiently. Tumor progression and metastasis result from interactions between cancer and various cells in the stroma, including endothelial cells, immune cells and fibroblasts. Fibroblasts have been particularly well studied; they are known to change into carcinoma-associated fibroblasts (CAFs) and produce transforming growth factor ß (TGF-ß), which mediates cancer-stroma interactions. Here, we investigated whether TGF-ß derived from cancer cells in the peritoneal microenvironment activates human peritoneal mesothelial cells (HPMCs), leading to the progression and fibrosis of gastric cancer. We found that activated HPMCs (a-HPMCs) took on a spindle shape formation, decreased the expression of E-cadherin and increased that of α-SMA. Furthermore, a-HPMCs became more invasive and upregulated proliferation of human gastric cancer-derived MKN45 cells following direct cell-cell contact. Notably, MKN45 cells co-cultured with a-HPMCs also acquired anchorage-independent cell growth and decreased expression of E-cadherin in vitro. To measure the effects of the co-culture in vivo, we developed a mouse xenograft model into which different culture products were subcutaneously injected. The largest tumors were observed in mice that had been given MKN45 cells co-cultured with a-HPMCs. Furthermore, these tumors contained HPMC-derived fibrous tissue. Thus, the epithelial-mesenchymal transition (EMT) of HPMCs appears to drive peritoneal dissemination and tumor fibrosis.

Adiponectin receptor-1 expression is associated with good prognosis in gastric cancer.

BACKGROUND: Adiponectin is inversely related to BMI, positively correlates with insulin sensitivity, and has anti-atherogenic effects. In recent years, adiponectin has been well studied in the field of oncology. Adiponectin has been shown to have antiproliferative effects on gastric cancer, and adiponectin expression is inversely correlated with clinical staging of the disease. However, no studies have reported the correlation between serum adiponectin and receptor expression with disease progression. METHODS: In this study, we evaluated expression levels of 2 adiponectin receptors--AdipoR1 and AdipoR2--and attempted to correlate their expression with prognosis in gastric cancer patients. AdipoR1 and AdipoR2 expression in gastric cancer cell lines (MKN45, TMK-1, NUGC3, and NUGC4) was evaluated by western blotting analysis, and the antiproliferative potential of adiponectin was examined in vitro. Serum adiponectin levels were evaluated in 100 gastric cancer patients, and the expression of AdipoR1 and AdipoR2 was assessed by immunohistochemical staining. RESULTS: MKN45 and NUGC3 expressed higher levels of AdipoR1 compared to NUGC4, even though there was no significance in AdipoR2 expression. The antiproliferative effect of adiponectin was confirmed in MKN45 and NUGC3 at 10 µg/ml. No significant associations were observed between serum adiponectin levels and clinicopathological characteristics, but lymphatic metastasis and peritoneal dissemination were significantly higher in the negative AdipoR1 immunostaining group (24/32, p = 0.013 and 9/32, p = 0.042, respectively) compared to the positive AdipoR1 group (lymphatic metastasis, 33/68; peritoneal dissemination, 8/68). On the other hand, AdipoR2 expression was only associated with histopathological type (p = 0.001). In survival analysis, the AdipoR1 positive staining group had significantly longer survival rates than the negative staining group (p = 0.01). However, multivariate analysis indicated that AdipoR1 was not an independent prognostic factor on patient's survival on gastric cancer. CONCLUSIONS: In gastric cancer, adiponectin has the possibility to be involved in cell growth suppression via AdipoR1. The presence of AdipoR1 could be a novel anticancer therapeutic target in gastric cancer.