Cancer-associated fibroblast senescence and its relation with tumour-infiltrating lymphocytes and PD-L1 expressions in intrahepatic cholangiocarcinoma.

BACKGROUND: Caveolin-1 (CAV1) in cancer-associated fibroblasts (CAFs) has pro- or anti-tumourigenic effect depending on the cancer type. However, its effect in intrahepatic carcinoma (ICC) remains unknown. Therefore, this study aimed to investigate the relationship between CAV1 in CAFs and tumour-infiltrating lymphocyte (TIL) numbers or PD-L1 levels in ICC patients. METHODS: Consecutive ICC patients (n = 158) were enrolled in this study. The levels of CAV1 in CAFs, CD8 + TILs, Foxp3+ TILs and PD-L1 in cancer cells were analysed using immunohistochemistry. Their association with the clinicopathological factors and prognosis were evaluated. The correlation between these factors was evaluated. RESULTS: CAV1 upregulation in CAFs was associated with a poor overall survival (OS) (P < 0.001) and recurrence-free survival (P = 0.008). Clinicopathological factors were associated with high CA19-9 levels (P < 0.001), advanced tumour stage (P = 0.046) and lymph node metastasis (P = 0.004). CAV1 level was positively correlated with Foxp3+ TIL numbers (P = 0.01). There were no significant correlations between CAV1 levels and CD8 + TIL numbers (P = 0.80) and PD-L1 levels (P = 0.97). An increased CD8 + TIL number and decreased Foxp3+ TIL number were associated with an increased OS. In multivariate analysis, positive CAV1 expression in CAFs (P = 0.013) and decreased CD8 + TIL numbers (P = 0.021) were independent poor prognostic factors. CONCLUSION: Cellular senescence, represented by CAV1 levels, may be a marker of CAFs and a prognostic indicator of ICC through Foxp3+ TIL regulation. CAV1 expression in CAFs can be a therapeutic target for ICC.

Prognostic significance of preoperative PNI and CA19-9 for pancreatic ductal adenocarcinoma: A multi-institutional retrospective study.

BACKGROUND: The aim of this study was to investigate the clinical value of nutritional and immunological prognostic scores as predictors of outcomes and to identify the most promising scoring system for patients with pancreatic ductal adenocarcinoma (PDAC) in a multi-institutional study. METHODS: Data were retrospectively collected for 589 patients who underwent surgical resection for PDAC. Prognostic analyses were performed for overall (OS) and recurrence-free survival (RFS) using tumor and patient-related factors, namely neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, Prognostic Nutritional Index (PNI), Glasgow Prognostic Score (GPS), modified GPS, C-reactive protein-to-albumin ratio, Controlling Nutritional Status score, and the Geriatric Nutritional Risk Index. RESULTS: Compared with PDAC patients with high PNI values (≥46), low PNI (<46) patients showed significantly worse overall survival (OS) (multivariate hazard ratio (HR), 1.432; 95% CI, 1.069-1.918; p = 0.0161) and RFS (multivariate HR, 1.339; 95% CI, 1.032-1.736; p = 0.0277). High carbohydrate antigen 19-9 (CA19-9) values (≥450) were significantly correlated with shorter OS (multivariate HR, 1.520; 95% CI, 1.261-2.080; p = 0.0002) and RFS (multivariate HR, 1.533; 95% CI, 1.199-1.961; p = 0.0007). Stratification according to PNI and CA19-9 was also significantly associated with OS and RFS (log rank, P < 0.0001). CONCLUSIONS: Our large cohort study showed that PNI and CA19-9 were associated with poor clinical outcomes in PDAC patients following surgical resection. Additionally, combining PNI with CA19-9 enabled further classification of patients according to their clinical outcomes.

Long-Term Outcome of Definitive Chemoradiotherapy and Induction Chemoradiotherapy Followed by Surgery for T4 Esophageal Cancer with Tracheobronchial Invasion.

BACKGROUND: T4 esophageal cancer (EC) that invades the trachea or bronchus often has poorer prognosis than other T4 ECs. We investigated the long-term results of definitive chemoradiotherapy (dCRT) or induction chemoradiotherapy followed by surgery (iCRT-S) in patients with T4 EC with tracheobronchial invasion (TBI). PATIENTS AND METHODS: From 2003 to 2013, 71 patients with T4 EC with TBI were treated in our institution; 58 underwent dCRT, and 13 underwent iCRT-S. The long-term results associated with survival were retrospectively analyzed, and prognostic factors were examined by univariable and multivariable analysis. RESULTS: The 1-, 2-, and 5-year overall survival for all patients with T4 EC with TBI treated by dCRT or iCRT-S was 57, 29, and 19%, respectively. Multivariable analysis revealed that clinical lymph node (LN) metastasis and the treatment period were significant prognostic factors. Clinical LN positivity had significantly poorer prognosis than LN negativity. The treatment outcome in the later period was significantly better than that in the earlier period. In particular, the outcome after dCRT revealed significantly better prognosis in the later compared with the earlier period, whereas the outcome after iCRT-S did not show such a difference. With respect to treatment modality, no significant difference in survival was observed between dCRT and iCRT-S. CONCLUSIONS: Clinical LN negativity and later treatment period were significantly good prognostic factors for T4 EC with TBI. The recent improvements in dCRT outcomes may help to achieve survival comparable to that of iCRT-S.

Prognostic Significance of Preoperative Controlling Nutritional Status (CONUT) Score in Patients Undergoing Hepatic Resection for Hepatocellular Carcinoma: A Multi-institutional Study.

BACKGROUND: The Controlling Nutritional Status (CONUT) score is an objective tool that is widely used to assess the nutritional status in patients, including those with cancer. The relationship between the CONUT score and prognosis in patients who have undergone hepatic resection has not been evaluated in a multi-institutional study. METHODS: Data were retrospectively collected for 2461 consecutive patients with hepatocellular carcinoma (HCC) who had undergone hepatic resection with curative intent at 13 institutions between January 2004 and December 2015. Patients were assigned to two groups: preoperative CONUT scores ≤ 3 (low CONUT score) and ≥ 4 (high CONUT score). Clinicopathological characteristics, surgical outcomes, and long-term survival were compared using propensity score matching analysis. RESULTS: Of the 2461 patients, 540 (21.9%) had high (≥ 4) and 1921 (78.1%) had low (≤ 3) preoperative CONUT scores. Overall, a high CONUT score was significantly associated with older age, female sex, low body mass index, low serum albumin, high serum total bilirubin, low lymphocyte count, low serum cholesterol, shorter prothrombin time, higher indocyanine green retention test at 15 min, Child-Pugh B (vs. A), liver cirrhosis, minor resection, shorter operation time, massive blood loss, blood transfusion, and postoperative complications. After propensity score matching, a higher CONUT score was significantly associated with poor overall survival (OS) and recurrence-free survival (RFS) using multivariate analysis. CONCLUSIONS: This retrospective, multi-institutional analysis showed that, in patients who undergo curative hepatectomy for HCC, the preoperative CONUT score is predictive of worse OS and RFS, even after propensity score matching analysis.

Ileum preserving expanded jejunectomy and pancreaticoduodenectomy with combined resection of the superior mesenteric artery for huge retroperitoneal solitary fibrous tumor.

We encountered a patient with a large retroperitoneal solitary fibrous tumor, in whom we could preserve approximately 150 cm of the ileum even after pancreaticoduodenectomy combined with resection of the superior mesenteric artery, thus preventing short bowel syndrome.

Postoperative Neutrophil-to-Lymphocyte Ratio as a Predictor of Long-Term Prognosis after Pancreatectomy for Pancreatic Carcinoma: A Retrospective Analysis.

To clarify the prognostic value of the postoperative blood neutrophil-to-lymphocyte ratio (NLR) in patients undergoing pancreatectomy for pancreatic carcinoma (PAC). A high preoperative NLR has been reported to be a predictor of poor survival in patients with various cancers including PAC. However, it has not been extensively examined in postoperative NLR after pancreatectomy for PAC. This retrospective study enrolled 86 patients who underwent pancreatectomy without preoperative therapy for PAC from 2005 to 2013. Clinicopathological parameters, including postoperative NLR, were evaluated to identify predictors of the overall and recurrence-free survival of patients after pancreatectomy. Univariate and multivariate analyses were performed, using the Cox proportional hazards model. Univariate and multivariate analyses showed that postoperative NLR at one month was an independent prognostic factor in the overall and recurrence-free survival of patients. The 3-year survival rate after pancreatectomy was as follows: 33.9 per cent in patients with a postoperative NLR of less than 3.0 at one month; and 7.3 per cent in those with a postoperative NLR of 3.0 or more at one month (P < 0.001). The overall survival rate after pancreatectomy in the NLR at one month ≥3.0 group was significantly lower than in the NLR at one month <3.0 group: one year, 42.6 versus 81.9 per cent; three year, 7.3 versus 33.9 per cent (P < 0.001). The results of the study suggest that the postoperative NLR at one month is an independent predictor of survival after pancreatectomy in patients with PAC.

Post-hepatectomy Refractory Ascites in Cirrhotic Patients with Hepatocellular Carcinoma: Risk Factor Analysis to Overcome this Problematic Complication.

BACKGROUND: Refractory ascites is a serious post-hepatectomy complication in cirrhotic patients with hepatocellular carcinoma (HCC). In order to avoid this complication, surgeons should preserve as much liver parenchyma as possible in performing hepatectomy in such patients. However, we still occasionally encounter refractory ascites even after limited or small hepatectomy. The aim of this study was to identify risk factors for post-hepatectomy refractory ascites in cirrhotic patients, focusing on limited or small hepatectomy. PATIENTS AND METHODS: The data of 73 cirrhotic patients with HCC who underwent limited or small hepatectomy were analyzed. Limited or small hepatectomy was defined as hepatectomy equal to or of less than subsegmentectomy. We compared the clinicopathological factors between patients with and without postoperative refractory ascites. RESULTS: Fourteen cirrhotic patients suffered postoperative refractory ascites. Total cholesterol, duration of operation, duration of Pringle maneuver, resection of segment VII, intraoperative blood loss, and intraoperative blood transfusion were found to be significant risk factors for postoperative refractory ascites in univariate analyses. Multivariate analysis revealed that resection of segment VII was an independent risk factor. CONCLUSION: Resection of segment VII necessitates extensive dissection of the right triangular or coronary ligaments, which could explain that it was an independent risk factor for post-hepatectomy refractory ascites. Surgeons should avoid extensive dissection of these ligaments in order to avoid this detrimental complication.

Neuroendocrine carcinoma of the esophagus: Clinicopathological and immunohistochemical features of 14 cases.

BACKGROUND: Neuroendocrine carcinoma (NEC) of the esophagus is a rare and highly aggressive disease but the biological features are poorly understood. The objective of this study was to analyze the clinicopathological and immunohistochemical features of NEC of the esophagus. METHODS: Fourteen patients diagnosed with NEC of the esophagus from 1998 to 2013 were included in this study. Clinicopathologic features, therapeutic outcomes and immunohistochemical results were analyzed. RESULTS: Eleven out of 14 cases showed protruding or localized type with or without ulceration. Only three patients were negative for both lymph node and organ metastasis and seven cases were positive for metastases to distant organs and/or distant lymph nodes. Of the six patients with limited disease (LD), three patients were treated by surgery. Three patients with LD and seven patients with extensive disease (ED) were initially treated with chemotherapy, except for one who underwent concurrent chemo-radiotherapy due to passage disturbance. The median survival of patients with LD was 8.5 months, whereas that of patients with LD was 17 months. Among the 14 cases, 12 cases (83.3%), 13 cases (91.7%) and 12 cases (83.3%) showed positive immunostaining for choromogranin A, synaptophysin and CD56, respectively. Nine of 14 cases (64.2%) presented positive staining for c-kit and most (8/9, 88%) simultaneously showed p53 protein abnormality. Two cases were negative for c-kit and p53, and positive for CK20. CONCLUSION: Consistent with previous reports, the prognosis of NEC of esophagus is dismal. From the results of immunohistochemical study, NEC of esophagus might be divided into two categories due to the staining positivity of c-kit and p53. This study provides new insight into the biology of NEC of the esophagus.

Surgical Results of Pancreaticoduodenectomy for Pancreatic Ductal Adenocarcinoma: a Multi-institutional Retrospective Study of 174 patients.

BACKGROUND: Postoperative pancreatic fistula (POPF) remains a major complication after pancreaticoduodenectomy (PD), and the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC) after PD is poor. PATIENTS AND METHODS: A multi-institutional retrospective study was performed in 174 patients who underwent PD for PDAC from 2007 to 2012. The details of clinical data were examined, and risk factors for POPF and poor prognostic factors after PD were identified. RESULTS: POPF occured in 26 patients (15%), and 18 patients (10%) were diagnosed as Grade B/C POPF. The independent risk factors for Grade B/C POPF were body mass index (BMI) ≥25 (Odds Ratio [OR]=21.1, p=0.006) and absence of post-operative enteral nutrition (EN) (OR=10.2, p=0.04). The 1-, 3-, and 5-year overall survivals of patients with PDAC after PD were 76%, 35%, and 18%, respectively. R1/2 operation was identified as the only independent poor prognostic factor (Hazard Ratio=3.66; p=0.0002). CONCLUSION: Patients with BMI ≥25 should be closely monitored for POPF after PD. Post-operative EN might help prevent POPF. Performing R0 resection is an important goal for ensuring patient survival after PD for PDAC.

S-1 Adjuvant Chemotherapy Earlier After Surgery Clinically Correlates with Prognostic Factors for Advanced Gastric Cancer.

BACKGROUND: S-1 adjuvant chemotherapy is commonly administered postoperatively for stage II and III advanced gastric cancer. METHODS: This study included 113 patients treated with S-1 adjuvant chemotherapy after surgery for stage II and III advanced gastric cancer. These patients were divided into 4 groups: group A (n = 63), who had a longer duration (≥6 months) and earlier S-1 administration (≤6 weeks) after surgery; group B (n = 16), who had a longer and later S-1 administration (>6 weeks) after surgery; group C (n = 27), who had a shorter duration (<6 months) and earlier S-1 administration after surgery; and group D (n = 7), who had a shorter and later S-1 administration after surgery. RESULTS: The recurrence rates in groups A, B, C, and D were 15.7, 43.8, 44.4, and 57.1 %, respectively (A vs. B, p < 0.05, A vs. C and D, p < 0.01). The survival time of group A was significantly longer than that of other groups (p < 0.005). In addition, the survival time of patients with severe complications was significantly shorter than that of patients with non-severe complications (p < 0.05). An earlier S-1 administration after surgery was the only independent prognostic factor in the multivariate analysis. CONCLUSIONS: The prognosis of advanced gastric cancer was significantly related to the start of S-1 adjuvant treatment within 6 weeks after surgery.

Hepatic resection of hepatocellular carcinoma after proton beam therapy: A case report.

Despite the widespread use of proton beam therapy (PBT) as locoregional therapy, there is currently a lack of histological evidence about the therapeutic effect of PBT for hepatocellular carcinoma (HCC). We present a case of hepatectomy and histological examination of HCC initially treated by PBT. A 76-year-old man with chronic hepatitis C underwent routine ultrasound surveillance, which revealed a 22-mm HCC in segment 4 of the liver. His hepatic reserve was adequate for surgical resection of the tumor; however, he chose to undergo PBT because of his cardiac disease. The patient received 66 Gy in 10 fractions with no toxicity exceeding grade 1. Six months after completion of PBT, contrast computed tomography showed that the tumor had increased in size to 27 mm, and the marginal part of the tumor, but not the central region, was enhanced. Additionally, two new hypervascular nodules were present in segments 5 and 6. The patient underwent surgical treatment 7 months after PBT. The operation and postoperative clinical course were uneventful. Nine months later, however, computed tomography demonstrated new, small, enhanced nodules in the remnant liver (segments 3, 5 and 6) and sacrum. In conclusion, PBT is a valuable treatment for HCC; however, it is difficult to evaluate therapeutic effect of HCC during the early post-irradiation period and provide an alternative treatment if PBT is not effective, especially in HCC cases with good liver function.

Suture granuloma with false-positive finding on PET/CT after gastrectomy for gastric cancer.

This study is a case report on a 49-year-old woman who had a gastrectomy and lymphadenectomy for pStage IIIa gastric cancer. Shortly after a 12-month course of adjuvant chemotherapy, CT showed a nodule adjacent to the gallbladder. High (18) F-fluorodeoxyglucose accumulation was detected, with a standardized uptake value of 10. Therefore, laparoscopic excision was performed for diagnosis and treatment. The histopathological finding was suture granuloma. Suture granulomas with high standardized uptake values on PET scans are uncommon and often cause surgeons to provide an inaccurate diagnosis. Our study suggests that suture granuloma should be included in the differential diagnosis of a new or recurrent mass detected in patients with a history of prior surgery; however, surgeons must bear in mind that false-positive fluorodeoxyglucose-PET results can be observed in suture granuloma.

Changes in expression levels of ERCC1, DPYD, and VEGFA mRNA after first-line chemotherapy of metastatic colorectal cancer: results of a multicenter study.

Our previous study showed that administering oxaliplatin as first-line chemotherapy increased ERCC1 and DPD levels in liver colorectal cancers (CRCs) metastases. Second, whether the anti-VEGF monoclonal antibody bevacizumab alters tumoral VEGFA levels is unknown. We conducted this multicenter observational study to validate our previous findings on ERCC1 and DPD, and clarify the response of VEGFA expression to bavacizumab administration. 346 CRC patients with liver metastases were enrolled at 22 Japanese institutes. Resected liver metastases were available for 175 patients previously treated with oxaliplatin-based chemotherapy (chemotherapy group) and 171 receiving no previous chemotherapy (non-chemotherapy group). ERCC1, DPYD, and VEGFA mRNA levels were measured by real-time RT-PCR. ERCC1 mRNA expression was significantly higher in the chemotherapy group than in the non-chemotherapy group (P = 0.033), and were significantly correlated (Spearman's correlation coefficient = 0.42; P < 0.0001). VEGFA expression level was higher in patients receiving bevacizumab (n = 51) than in those who did not (n = 251) (P = 0.007). This study confirmed that first-line oxaliplatin-based chemotherapy increases ERCC1 and DPYD expression levels, potentially enhancing chemosensitivity to subsequent therapy. We also found that bevacizumab induces VEGFA expression in tumor cells, suggesting a biologic rationale for extending bevacizumab treatment beyond first progression.

Comparison of Neoadjuvant Chemotherapy to Surgery Followed by Adjuvant Chemotherapy in Japanese Patients with Peritoneal Lavage Cytology Positive for Gastric Carcinoma.

BACKGROUND: Therapeutic strategies for positive peritoneal lavage cytology [CY(+)] findings have not yet been established. The aim of the present study was to compare the effects of neoadjuvant systemic chemotherapy and surgery followed by S-1 adjuvant chemotherapy for treating gastric carcinoma in patients with CY(+) status without peritoneal metastasis. PATIENTS AND METHODS: Twenty-three patients with CY(+) status without peritoneal metastasis who underwent curative surgery for gastric carcinoma between October 1999 and December 2014 were included in the study. Ten patients received neoadjuvant systemic chemotherapy followed by surgery, whereas 13 patients underwent surgery, in nine cases followed by S-1 adjuvant chemotherapy. RESULTS: The 5-year survival in both groups was 15%, and no significant difference was observed. However, the prognosis for patients with CY(-) status after neoadjuvant systemic chemotherapy was significantly better than that of patients who were still CY(+) after neoadjuvant systemic chemotherapy (p<0.01). Among all patients, the prognosis of those with less than clinical N2 disease was significantly better than that of patients with clinical N3 (p<0.01). In multivariate analysis, clinical lymph node metastasis was the only independent prognostic factor for CY(+) patients without peritoneal metastasis (p<0.05). CONCLUSION: The prognosis of gastric carcinoma with CY(+) without peritoneal metastasis is still stage IV disease and is dependent on the degree of clinical lymph node metastasis, in spite of therapeutic treatment.

Effect of sustained virological response to interferon therapy for hepatitis C to the hepatectomy for primary hepatocellular carcinoma.

BACKGROUND/AIMS: Interferon (IFN) therapy improves the prognosis of the patients with HCV-related hepatocellular carcinoma (HCC). However, the effects of IFN therapy for hepatectomy (Hx) for primary HCC have not been established. Several published reports investigating the effects of IFN therapy on survival and tumor recurrence after curative resection of HCC have been inconclusive. METHODOLOGY: Subjects included 470 patients who underwent Hx for HCV related primary HCC. One hundred and fifty nine patients received IFN therapy past or postoperatively of the first Hx. Seventy-four of those patients attained a sustained viral response (SVR group). The other 396 patients, including 85 were no responders (NR) and 311 patients who had not received IFN therapy (non-IFN) were classified as the control group. RESULTS: Overall survival (SVR group vs. control group: 5-yr, 93.2 vs. 61.9%; p<0.0001) and disease-free survival (SVR group vs. control group: 5-yr, 56.0 vs. 27.4%; p<0.0001) rates were significantly different. By multivariate analysis, NR/non-IFN was the independent risk factor for overall survival (p=0.0002) and disease-free survival (p=0.0053) after Hx. CONCLUSIONS: SVR achieved past or postoperatively to the Hx of HCV-related HCC significantly inhibits recurrence and consequently improves patient survival after Hx for HCC.

Practical management and treatment of pancreatic neuroendocrine tumors.

Pancreatic neuroendocrine tumors (NETs) are uncommon disease, about which little is known. Pancreatic NETs are usually slow growing and their malignant potential are often underestimated. The management of this disease poses a challenge because of the heterogeneous clinical presentation and varying degrees of aggressiveness. Recently, several guidelines for the management of pancreatic NETs have been established and help to devise clinical strategy. In the treatment algorithms, however, a lot of uncertain points are included. Practical treatment decisions of pancreatic NETs are still sometimes made in a patient- and/or physicians-oriented manner. The tumor grading system proposed by the European Neuroendocrine Tumor Society (ENETS) gives important prognostic information, however, the implication of grading regarding medical treatment strategies to choose has not yet been clarified. Moreover, the place of surgical treatment is unclear in the overall management course of advanced pancreatic NETs. In some cases, practical management and treatment have to be individualized depending on predominant symptoms, tumor spread, and general health of the patients. Current issues and a few points to make a strategy in the management of pancreatic NETs would be reviewed.

Late-type port-site recurrence of unexpected gallbladder carcinoma 11 years after laparoscopic cholecystectomy.

A 55-year-old man had laparoscopic cholecystectomy for acute cholecystitis and unexpected gallbladder cancer, followed by a liver bed resection and lymph node dissection. Eleven years later, he had a port-site recurrence of gallbladder cancer requiring resection; at that time, no other site of recurrence was observed. The patient has survived for 20 months without another recurrence. Although a rare finding, clinicians should be alert to the possibility of such a recurrence even 11 years after complete cure of the primary tumor, particularly in patients who have undergone laparoscopic cholecystectomy for unexpected gallbladder cancer.

Role of resection of the primary pancreatic neuroendocrine tumor in the multidisciplinary treatment of patients with unresectable synchronous liver metastases: a case series.

CONTEXT: Liver metastases have often existed in patients who have pancreatic neuroendocrine tumors (pNETs) at the time of diagnosis. In the management of patients of pNETs with unresectable liver metastases, the clinical efficacy of surgery to primary pancreatic tumor has been controversial. We presented four patients who were treated with resection of primary pancreatic tumor, trans-arterial hepatic treatment and systemic therapies. We reviewed literatures and discussed about role of resection of primary pancreatic tumor in the multidisciplinary treatment. METHODS: We retrieved medical records of patients who had been histopathologically diagnosed as pNETs at our institution between April 2000 and March 2006, and found 4 patients who had pNETs with unresectable synchronous liver metastases and no extrahepatic metastases. All patients received resection of primary tumor. Patients' demographics, pathology, treatment, short- and long-term outcome were examined. RESULTS: In short-term outcome analysis, delayed gastric emptying was developed in one patient who received pancreaticoduodenectomy. There were no other significant postoperative complications. As for long-term outcome, two patients who received distal pancreatectomy, sequential trans-arterial treatments and systemic therapies could survive for long time relatively. They died 92 and 73 months after the first treatment, respectively. One patient who received distal pancreatectomy and trans-arterial treatment died from unrelated disease 14 months after the first treatment. Another patient who received preoperative trans-arterial treatments and pancreaticoduodenectomy rejected postoperative trans-arterial treatment, was treated with systemic therapies and died 37 months after the initial treatment. CONCLUSIONS: Resection of primary pNETs would be considered as an optional treatment for the selected patients who had unresectable synchronous liver metastases in the process of the multidisciplinary approach.

Significant prognostic factors in patients with Stage IV gastric cancer with special reference to the curability of surgery.

PURPOSES: The purpose of this study was to determine an effective treatment strategy for patients with Stage IV gastric cancer. METHODS: We analyzed the significant prognostic factors in 74 patients who underwent surgery between 1989 and 2005, and were finally determined to have Stage IV gastric cancer. These patients were classified as curability A (n = 0), B (n = 29) and C (n = 45) according to the criteria outlined by Japanese Gastric cancer society. Anti-tumor drugs were used after surgery in some cases. There were 32 patients who received either no treatment or an oral anti-tumor drug, and 42 patients who received new chemotherapeutic regimens. RESULTS: According to a univariate analysis, the postoperative mean survival times were significantly different; tumor size ≤ 12 cm, a tumor without lymphatic involvement, more than D2 lymphadenectomy, and classification as curability B were favorable prognostic factors. The multivariate analysis revealed that tumor size, lymphadenectomy and curability were independent prognostic factors. In curability B patients, venous involvement was an independent prognostic factor. In curability C patients, both the tumor size and postoperative chemotherapy affected their prognosis. CONCLUSIONS: In patients with curable Stage IV gastric cancer, at least a D2 gastrectomy to reduce the absolute volume of tumor cells, followed by adjuvant chemotherapy, may be essential to improve their prognosis. In incurable cases, aggressive new chemotherapeutic regimens should be the treatment of choice for the prolongation of survival.