Search

Background: Intraperitoneal chemotherapy is promising for gastric cancer with peritoneal metastasis. Although a phase III study failed to show a statistically significant superiority of intraperitoneal paclitaxel combined with S-1 and intravenous paclitaxel, the sensitivity analysis suggested clinical efficacy. Thus, attempts to combine intraperitoneal paclitaxel with other systemic therapies with higher efficacy have been warranted. We sought to explore the efficacy of intraperitoneal paclitaxel with S-1 and cisplatin., Patients and Methods: Gastric cancer patients with peritoneal metastasis were enrolled in the phase II trial. In addition to the established S-1 and cisplatin regimen every 5 weeks, intraperitoneal paclitaxel was administered on days 1, 8, and 22 at a dose of 20 mg/m 2 . The primary endpoint was overall survival rate at 1 year after treatment initiation. Secondary endpoints were progression-free survival and toxicity., Results: Fifty-three patients were enrolled and fully evaluated for efficacy and toxicity. The 1-year overall survival rate was 73.6% (95% confidence interval 59.5-83.4%), and the primary endpoint was met. The median survival time was 19.4 months (95% confidence interval, 16.1-24.6 months). The 1-year progression-free survival rate was 49.6% (95% confidence interval, 34.6-62.9%). The incidences of grade 3/4 hematological and non-hematological toxicities were 43% and 47%, respectively. The frequent grade 3/4 toxicities included neutropenia (25%), anemia (30%), diarrhea (13%), and anorexia (17%). Intraperitoneal catheter and implanted port-related complications were observed in four patients. There was one treatment-related death., Conclusions: Intraperitoneal paclitaxel combined with S-1 and cisplatin is well tolerated and active in gastric cancer patients with peritoneal metastasis., (© 2023. Society of Surgical Oncology.)

Background: The lipid scavenger receptor cluster of differentiation 36 (CD36) has been shown to have a pro-metastatic function in several cancers. Adipose tissue, a favorable site for peritoneal metastasis (PM) from gastric cancer (GC), promotes this process by providing free fatty acids (FFAs); however, the role of CD36 in PM progression from GC remains to be elucidated., Materials and Methods: We evaluated CD36 expression in the GC cells under various conditions. CD36 overexpressing (CD36OE) MKN45 cells were prepared and their migration and invasive properties were assessed. A PM mouse model was used to investigate the biological effects of palmitic acid (PA) and CD36. Furthermore, we examined the clinical role of CD36 expression in 82 human PM samples by immunohistochemical staining., Results: Hypoxia markedly increased CD36 expression in GC cells. In normoxia, only CD36OE MKN45 cells treated with PA showed an increase in migration and invasion abilities. An increased expression of active Rac1 and Cdc42 was observed, which decreased following etomoxir treatment. Conversely, hypoxia increased those capacities of both vector and CD36OE MKN45 cells. In a mouse model transplanted with CD36OE MKN45 cells, more peritoneal tumors were observed in the high-fat diet group than those in the normal diet group. In clinical samples, 80% of PM lesions expressed CD36, consistent with hypoxic regions, indicating a significant association with prognosis., Conclusion: Our findings indicate that a hypoxia in the peritoneal cavity induces CD36 expression in GC cells, which contributes to PM through the uptake of FFAs., (© 2022. The Author(s).)

Background: Peritoneal metastasis (PM) is one of the most common causes of noncurative surgery and the most frequent recurrence pattern in gastric cancer (GC). During the process of PM, GC cells detached from primary tumor interact with human peritoneal mesothelial cells (HPMC) overlapped with adipose tissues such as the omentum or mesentery. Although the interaction with HPMC promotes the malignancy of GC, the role of adipose tissues remains unclear., Aims: We aimed to clarify how adipose tissue are affected by adjacent primary tumors during the expression of adipokines and to elucidate whether GC cells transform adipocytes into CAFs in vitro. In addition, we investigated whether GC cells are affected by adipocytes in their ability to infiltrate., Methods: We investigated the phenotypic conversion of adipocytes during the malignant process of GC cells in vivo and in vitro. We evaluated the expression levels of adiponectin in the omental adipose tissue of gastric cancer patients by western blotting. Following adipocytes/gastric cancer cells coculture, adipocyte markers, adiponectin receptors, and inflammatory cytokine markers were detected by real-time PCR and/or western blotting in the single-cultured and co-cultured adipocytes; cancer-associated fibroblast (CAF) markers were detected by immunofluorescence and western blotting in the single-cultured and co-cultured adipocytes; invasion assays were performed in single cultured and co-cultured MKN45 and OCUM., Results: In omental adipose tissues that are situated close to the primary tumors, the expression of adiponectin tended to decrease in patients with subserosal or serosal invasion. By co-culturing with GC cells, adipocytes were dedifferentiated and the expression levels of CAF marker FSP1 and inflammatory cytokines, PAI-1 and IL-6, significantly increased (p < 0.05). Furthermore, GC cells co-cultured with adipocytes showed enhanced invasion ability., Conclusion: Our findings suggest that the phenotypic conversion of adipocytes may promote the malignancy of GC in the construction of the cancer microenvironment of PM., (© 2022 The Authors. Cancer Reports published by Wiley Periodicals LLC.)

Background: The role of tumor-stroma interactions in tumor immune microenvironment (TME) is attracting attention. We have previously reported that cancer-associated fibroblasts (CAFs) contribute to the progression of peritoneal metastasis (PM) in gastric cancer (GC), and M2 macrophages and mast cells also contribute to TME of PM. To elucidate the role of CAFs in TME, we established an immunocompetent mouse PM model with fibrosis, which reflects clinical features of TME. However, the involvement of CAFs in the immunosuppressive microenvironment remains unclear. In this study, we investigated the efficacy of Tranilast at modifying this immune tolerance by suppressing CAFs., Methods: The interaction between mouse myofibroblast cell line LmcMF and mouse GC cell line YTN16 on M2 macrophage migration was investigated, and the inhibitory effect of Tranilast was examined in vitro. Using C57BL/6J mouse PM model established using YTN16 with co-inoculation of LmcMF, TME of resected PM treated with or without Tranilast was analyzed by immunohistochemistry., Results: The addition of YTN16 cell-conditioned medium to LmcMF cells enhanced CXCL12 expression and stimulated M2 macrophage migration, whereas Tranilast inhibited the migration ability of M2 macrophages by suppressing CXCL12 secretion from LmcMF. In PM model, Tranilast inhibited tumor growth and fibrosis, M2 macrophage, and mast cell infiltration and significantly promoted CD8 + lymphocyte infiltration into the tumor, leading to apoptosis of cancer cells by an immune response., Conclusion: Tranilast improved the immunosuppressive microenvironment by inhibiting CAF function in a mouse PM model. Tranilast is thus a promising candidate for the treatment of PM., (© 2022. The Author(s).)

Background: Tumor-infiltrating lymphocytes (TILs) and other immune cells have been reported as a prognostic factor in several tumors, including gastric cancer, and they play an important role in antitumor effect at the primary site. There were few reports on the immune status in peritoneal metastatic lesions for gastric cancer., Aims: The aims of this study were to assess the prognostic significance of TILs (CD4, CD8, CD19, regulatory T cells [Tregs]), and myeloid-derived suppressor cells (MDSCs) in peritoneal metastatic lesions., Methods: We retrospectively investigated 60 patients for gastric cancer with peritoneal metastasis who were treated between 2009 and 2016 in our institute. Immunohistochemistry for CD4, CD8, CD19, FOXP3, and CD33 was performed in the peritoneal metastatic lesions. The absolute numbers of immune cells and ratios were evaluated, and the relationship between immune-related marker and overall survival (OS) was investigated., Results: A high infiltration of CD8 + lymphocytes or high CD8/CD33 ratio was a better prognosis for OS in univariate analysis using all immunologic variables (P = .012, P = .001). In multivariate analysis for clinical and immunologic variables, high CD8/CD33 ratio was identified as an independent prognostic factor for OS (Hazard ratio: 0.291, 95% confidence interval: 0.126-0.670, P = .004)., Conclusion: High CD8/CD33 ratio and high infiltration of CD8 + lymphocytes in peritoneal metastatic lesions were favorable prognoses for gastric cancer patients with peritoneal metastasis. It is necessary to modify the immune microenvironment result to increase the level of CD8 + lymphocytes in the peritoneal metastatic lesions., (© 2021 The Authors. Cancer Reports published by Wiley Periodicals LLC.)

The patient was a 61‒year‒old man who had an advanced gastric cancer with peritoneal dissemination. After chemotherapy, intraoperative findings during a total gastrectomy revealed the disappearance of the dissemination nodules. Although adjuvant chemotherapy was performed, the presence of massive ascites led to the recurrence of the peritoneal dissemination 5 months after the surgery. While the chemotherapy regimen was altered, we observed no reduction in malignant ascites. The patient complained of abdominal distention and was admitted to our hospital for symptom management. We performed a cell‒free and concentrated ascites reinfusion therapy(CART)several times. However, symptom management proved difficult; therefore, the patient underwent a peritoneovenous shunt(Denver shunt)placement. After the shunting, we observed no organ injury and improved abdominal distention; however, an asymptomatic coagulopathy was present in the course. Additionally, blood examinations showed increased FDP‒DD and thrombin‒antithrombin complex(TAT). However, 6 months after the shunting, coagulopathy improved and the patient reported the absence of abdominal distention. This report describes a patient with an asymptomatic coagulopathy after Denver shunt placement and evaluated the clinical course by using TAT values.

Objectives: Interleukin-17A (IL-17A) is pro-inflammatory cytokine and acts as profibrotic factor in the fibrosis of various organs. Fibrosis tumor-like peritoneal dissemination of gastric cancer interferes with drug delivery and immune cell infiltration because of its high internal pressure. In this study, we examined the relationship between IL-17A and tissue fibrosis in peritoneal dissemination and elucidated the mechanism of fibrosis induced by IL-17A using human peritoneal mesothelial cells (HPMCs) and a mouse xenograft model., Methods: Seventy gastric cancer patients with peritoneal dissemination were evaluated. The correlation between IL-17A and fibrosis was examined by immunofluorescence and immunohistochemistry. A fibrosis tumor model was developed based on subcutaneous transplantation of co-cultured cells (HPMCs and human gastric cancer cell line MKN-45) into the dorsal side of nude mice. Mice were subsequently treated with or without IL-17A. We also examined the effect of IL-17A on HPMCs in vitro., Results: There was a significant correlation between IL-17A expression, the number of mast cell tryptase (MCT)-positive cells, and the degree of fibrosis (r = 0.417, P < 0.01). In the mouse model, IL-17A enhanced tumor progression and fibrosis. HPMCs treated with IL-17A revealed changes to a spindle-like morphology, decreased E-cadherin expression, and increased α-SMA expression through STAT3 phosphorylation. Moreover, HPMCs treated with IL-17A showed increased migration., Conclusions: IL-17A derived from mast cells contributes to tumor fibrosis in peritoneal dissemination of gastric cancer. Inhibiting degranulation of mast cells might be a promising treatment strategy to control organ fibrosis.

Background: Peritoneal metastasis (PM) in gastric cancer (GC) is characterized by diffusely infiltrating and proliferating cancer cells accompanied by extensive stromal fibrosis in the peritoneal space. The prognosis of GC with PM is still poor regardless of the various current treatments. In order to elucidate the cause of difficulties in PM treatment, we compared the tumor immune microenvironment (TME) in primary and PM lesions in GC. In addition, a PM model with fibrous stroma was constructed using immunocompetent mice to determine whether its TME was similar to that in patients., Methods: Immuno-histochemical analyses of infiltrating immune cells were performed in paired primary and PM lesions from 28 patients with GC. A C57BL/6 J mouse model with PM was established using the mouse GC cell line YTN16 either with or without co-inoculation of mouse myofibroblast cell line LmcMF with α-SMA expression. The resected PM from each mouse model was analyzed the immunocompetent cells using immunohistochemistry., Results: The number of CD8 + cells was significantly lower in PM lesions than in primary lesions (P < 0.01). Conversely, the number of CD163 + cells (M2 macrophages) was significantly higher in PM lesions than in primary lesions (P = 0.016). Azan staining revealed that YTN16 and LmcMF co-inoculated tumors were more fibrous than tumor with YTN16 alone (P < 0.05). Co-inoculated fibrous tumor also showed an invasive growth pattern and higher progression than tumor with YTN16 alone (P = 0.045). Additionally, YTN16 and LmcMF co-inoculated tumors showed lower infiltration of CD8 + cells and higher infiltration of M2 macrophages than tumors with YTN16 alone (P < 0.05, P < 0.05). These results indicate that LmcMF plays as cancer-associated fibroblasts (CAFs) by crosstalk with YTN16 and CAFs contribute tumor progression, invasion, fibrosis, and immune suppression., Conclusions: This model is the first immunocompetent mouse model similar to TME of human clinical PM with fibrosis. By using this model, new treatment strategies for PM, such as anti-CAFs therapies, may be developed.

Peritoneal Surface Oncology Group International(PSOGI)proposed a novel treatment, named comprehensive treatment for peritoneal metastasis(PM)from colorectal cancer(CRC). The present study demonstrated the efficacies of the treatment regarding the peritoneal sectors and organs involved with PM from CRC., Materials and Methods: Among 365 patients received laparotomy, 278 CRC patients with PM underwent complete cytoreductive surgery(CC-0)., Results: After CC-0 resection Grade 3, Grade 4, and Grade 5 postoperative complication were found in 20(7.2%), 26(9.3%), and 6(2.2%). Five- and 10-year survival rate(YSR)of CC-0 resection were 24.5%, and 11.6% with median survival time(MST)of 42.0 months. Regarding the peritoneal cancer index(PCI)of small bowel(SB-PCI), all patients of PCI B3 died of the disease. In contrast, 10-YSR of patients with SB-PCI of 0, 1, and 2 were 26.1%, 19.5%, and 6.2%, respectively. Ten-YSR of patients with the number of involved peritoneal sectors C9 ranged from 6.9% to 29.8%. MST of patients with PM in each peritoneal sector(sector 0 to sector 8)ranged from 26.4 months to 49.2 months, and 10-YSR ranged from 4.2%to 17.2%. Ten-YSR of patients with involvement of rectum, stomach, liver capsule, seminal vesicle, ureter, uterus, or ovary ranged from 0% to 16.9%., Conclusions: From the present data, PM should be removed aggressively to achieve complete cytoreduction, when the patients with PCIC26, involved peritoneal sectorsC9 and SB-PCIC2 are supposed to receive complete cytoreduction of PM.

Background and Objectives: The current standard of treatment for malignant peritoneal mesothelioma(MPM)is cytoreductive surgery(CRS)plus perioperative intraperitoneal or systemic chemotherapy(comprehensive treatment), The present study was performed to clarify the prognostic factors of PMP after comprehensive treatment., Methods: Among 63 patients with MPM, male and female patients were 34 and 29. CRSwas performed in 47 patients and complete cytoreduction(CC-0) was performed in 14(22%)patients. Mean numbers of resected peritoneal sectors and organs were 5.2(1-13), and 2.9(0- 9), respectively. Hyperthermic intraperitoneal chemoperfusion(HIPEC)was performed in 27 patients. Grade 1/2, Grade 3, and Grade 4 complications were experienced in 5, 6, and 3 patients, respectively. One patient died of sepsis, and the mortality rate was 2.3%. Independent prognostic factors for favorable prognosis were performance of HIPEC, peritoneal cancer index (PCI)score C12, no distant metastasis and histologic epithelial type. Relative risk of no HIPEC, PCI score B13, presence of distant metastasis and non epithelial type were 7.69, 22.1, 3.6 and 3.9, respectively., Conclusions: Risk factors for death after comprehensive treatment were no HIPEC, PCI score B13, and non epithelial type. However, only 11(17%)patients showed PCI score C12. Accordingly, PCI score should be reducedC12 before CRSby neoadjuvant chemotherapy.

Background and Objectives: Treatment failure after complete cytoreduction for appendiceal mucinous carcinoma peritonei (AMCP)has not been fully investigated. The present study was performed to clarify the risk factor for recurrence after complete cytoreduction for AMCP., Methods: A total of 400 patients with AMCP who underwent complete cytoreductive surgery combined with perioperative chemotherapy were investigated., Results: Documented recurrence was developed in 135 (33.8%)patients. The 5- and 10-year progression-free survival was 51% and 49%, respectively. By multivariate analysis, histological subtype of peritoneal disease(high-grade AMCP[AMCP-H]and AMCP-H with signet ring cells), serum CA19- 9 level, and PCIB20 were significantly associated with reduced progression-free survival. In contrast, histologic subtype of mucin without epithelial cells(MWEC)showed the lowest risk for recurrence. Eighty-six patients had localized intra-abdominal recurrence, and 42 patients had diffuse peritoneal recurrence. Recurrence was found in the various peritoneal sectors. Eighty-one patients underwent complete cytoreduction for the recurrence, and the overall survival 5-year survival rate after secondary cytoreduction was 49%., Conclusions: Risk factors for recurrence were histologic subtype, PCI cutoff level, and serum CA19-9 levels. Aggressive second attempt of cytoreduction in patients with localized recurrence improved the survival.

Background: The clinical prognosis of gastric cancer with peritoneal dissemination is poor because of its chemoresistance and rich fibrosis. While several gastric cancer cell lines have been used to establish models of peritoneal dissemination by intraperitoneal injection, most peritoneal tumors that form adopt a medullary pattern in microscopic appearance. This histological finding for the model differs from that in the clinical situation. This study was performed to demonstrate the contribution of human peritoneal mesothelial cells (HPMCs) to fibrotic tumor formation and to establish a new xenograft model with high potential for peritoneal dissemination with organ invasion and extensive fibrosis., Methods: We established four types of xenograft model: i) intraperitoneal injection of MKN45-P cells alone (control group), ii) injection of MKN45-P cells co-cultured with HPMCs (co-cultured group), iii) scratching the parietal peritoneum (parietal group), and iv) scratching the visceral peritoneum (visceral group) with a cotton swab before injection of co-cultured cells. Fibrosis, α-smooth muscle actin expression, and organ invasion by tumor cells were all assessed by immunohistochemical examination., Results: All mice developed abdominal swelling with peritoneal tumors and bloody ascites. Tumors of the control and co-cultured groups were not invasive or fibrotic. Contrastingly, tumors of the scratch groups exhibited rich stromal fibrosis and possessed increased α-smooth muscle actin (α-SMA) expression. In particular, the visceral group showed edematous and spreading tumors invading the intestinal wall., Conclusion: We established a model of peritoneal dissemination with organ invasion and stromal fibrosis. Formation of peritoneal dissemination required a favorable environment for cell adhesion, invasion, and growth. This model may be useful for analyzing the pathogenesis and treatment of peritoneal dissemination of gastric cancer.

Treatment failure after complete cytoreduction for peritoneal metastasis(PM)from colorectal cancer(CRC)has not been fully investigated. The present study was performed to clarify the risk factors for recurrence after complete cytoreduction for CRC with PM and the role of repeat surgery for recurrence., Materials and Methods: A total of 205 patients with CRC who underwent complete cytoreductive surgery combined with perioperative chemotherapy were investigated., Results: Recurrence occurred in 149(73%)patients. The 5-year overall and progression-free survival rates were 26%and 7%, respectively. By multivariate analysis, positive cytology, serum CEA level higher than normal range, and small bowel peritoneal cancer index B3 were significantly associated with reduced progression-free survival. Blood-borne recurrence was found in 62 (44%)of 149 patients. Repeat surgery was performed in 44(30%), and complete removal was performed in 28(64%) patients. Long-term survival after repeat surgery was experienced in patients with localized peritoneal recurrence and/or liver recurrence., Conclusions: This study showed that a second attempt at cytoreduction in patients with localized intra-abdominal and liver recurrence is of benefit. Blood-borne recurrence was found in 44% of recurrent patients. The prophylaxis of recurrence should therefore be performed using systemic chemotherapy after CRS plus HIPEC.

Paclitaxel (PTX) which easily elutes into ascites is widely used to treat gastric cancer patients with peritoneal carcinomatosis (PC), but clinical outcomes are suboptimal. Increased concentrations of α1-acid glycoprotein (AGP), an important drug-binding protein, have been reported in the plasma and ascites of cancer patients. This study sought to clarify whether AGP binds to PTX and alters its anticancer effects. AGP concentrations were measured in the serum and ascites of gastric cancer patients with PC and in the serum of healthy volunteers. The in vitro effects of AGP and AGP plus erythromycin (EM) on PTX were evaluated by MTT assays in the gastric cancer cell lines. We also measured AGP concentrations in the ascites of PC model mice and examined the effects of EM plus PTX on PC. The mean AGP concentrations in the serum and ascites of gastric cancer patients with PC were 1524 and 834 μg/mL, respectively, higher than the mean AGP concentration of 650 μg/mL observed in the sera of healthy volunteers. AGP > 400 μg/mL significantly suppressed the cell growth inhibitory effect of PTX in vitro, but the co-administration of EM restored it. Elevated AGP concentrations were observed in the ascites of PC model mice. Administration of PTX alone did not markedly diminish PC, whereas co-administration of PTX and EM significantly reduced PC (p = 0.011). AGP is an important regulatory factor modulating the anticancer activity of intraperitoneal PTX. The co-administration of PTX and EM may be effective in treating gastric cancer patients with PC., Competing Interests: The authors declare that they have no conflict of interest. Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Human and animal rights All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional review board at Kanazawa University and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All procedures performed in studies involving animals adhere to the Standard Guidelines for Animal Experiments at Kanazawa University. Informed consent Informed consent was obtained from all individual participants included in the study.

Background: Tumor-associated macrophages (TAMs) of the M2 phenotype are known to promote tumor proliferation and to be associated with a poor prognosis in numerous cancers. Here, we investigated whether M2 macrophages participate in the development of peritoneal dissemination in gastric cancer., Methods: The characteristics of peritoneal macrophages in gastric cancer patients with or without peritoneal dissemination were examined by flow cytometry and the real-time quantitative polymerase chain reaction. The effects of M2 macrophages on phenotypic changes of the gastric cancer cell line MKN45 were assessed with a direct or indirect co-culture system in vitro and an in vivo mouse xenograft model., Results: The number of peritoneal macrophages with the M2 phenotype (CD68(+)CD163(+) or CD68(+)CD204(+)) was significantly higher in gastric cancer patients with peritoneal dissemination than in those without peritoneal dissemination. Higher expression of the M2-related messenger RNAs (IL-10, vascular endothelial growth factor A, vascular endothelial growth factor C, matrix metalloproteinase 1, and amphiregulin) and lower expression of M1-related messenger RNAs (TNF-α, CD80, CD86, and IL-12p40) were also confirmed in the TAMs. Macrophage co-culture with gastric cancer cells converted M1 phenotype into M2 phenotype. Moreover, the coexistence of MKN45 cells with M2 macrophages resulted in cancer cell proliferation and an acceleration of tumor growth in the xenograft model., Conclusions: Intraperitoneal TAMs in gastric cancer patients with peritoneal dissemination were polarized to the M2 phenotype, and could contribute to tumor proliferation and progression. Therefore, intraperitoneal TAMs are expected to be a promising target in the treatment of peritoneal dissemination in gastric cancer., Competing Interests: The authors declare that they have no conflict of interest. Human rights statement and informed consent All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. Informed consent or substitute for it was obtained from all patients for their being included in the study (study number 1463). Animal studies All institutional and national guidelines for the care and use of laboratory animals were followed. Animals were treated in accordance with the Fundamental Guidelines for Proper Conduct of Animal Experiment and Related Activities in Academic Research Institutions, under the jurisdiction of the Ministry of Education, Culture, Sports, Science and Technology of Japan. All animal experiments were approved by the Committee on Animal Experimentation of Kanazawa University.

Peritoneal carcinomatosis (PC) is the most frequent metastatic pattern of gastric cancer and its prognosis is extremely poor. PC is characterized by rich fibrosis and the development of obstructive disorders such as ileus, jaundice and hydronephrosis. Epithelial-mesenchymal transition (EMT) is one of the major causes of tissue fibrosis and transforming growth factor β (TGF-β) has a pivotal function in the progression of EMT. Protein-bound polysaccharide K (PSK) is a biological response modifier that can modulate the TGF-β/Smad signaling pathway in vitro. In the present study, we established a fibrotic tumor model using human peritoneal mesothelial cells (HPMCs) and a human gastric cancer cell line to evaluate whether PSK attenuates tumor fibrosis. HPMCs exposed to PSK did not undergo the morphological change from a cobblestone-like pattern to a spindle-shape pattern normally induced by treatment with TGF-β. Immunofluorescence further demonstrated that PSK suppressed TGF-β-induced overexpression of α-SMA in the HPMCs. We further showed that HPMCs contributed to the proliferation of tumor fibrosis by using a mouse xenograft model. Additionally, PSK treatment of these mice significantly reduced the area of observable tumor fibrosis. These results suggest that seeded cancer cells transformed HPMCs into myofibroblast-like cells through their release of TGF-β in the microenvironment, facilitating the development of fibrous tumors in organs covered with HPMCs. Therefore, our study indicates that PSK has potential utility as an anti-fibrotic agent in the treatment of gastric cancer patients with PC.

Tumor-associated macrophages(TAM)of the M2 phenotype(M2 macrophage)promote tumor proliferation and are associated with a poor prognosis in several tumors. We investigated the phenotype of macrophages in gastric cancer patients with peritoneal carcinomatosis(PC). Intraperitoneal macrophages were found more frequently in PC patients than in Stage I or II patients(control). CD163, an M2 macrophage surface marker, was detected in 71.7% of PC patients and 15.7% of controls. In addition, we examined whether macrophage markers were present in ascites caused by gastric cancer following intraperitoneal paclitaxel. The ratio of M2 macrophages decreased with every therapy. These findings indicate that intraperitoneal M2 macrophages may contribute to the progression of PC, and inhibition of M2 macrophages could be a promising treatment strategy.

Intraperitoneal (i.p.) chemotherapy with paclitaxel (PTX) has been shown to be a promising treatment strategy for peritoneal metastasis. The present study focused on the comparative evaluation of the therapeutic efficacy of nanoparticle albumin-bound PTX (Nab-PTX) and i.p. administration of the conventional solvent-based PTX (Sb-PTX). We also investigated the difference in antitumor activity depending on the route of administration in the Nab-PTX treatment. Nab-PTX was administered i.p. or intravenously (i.v.) and Sb-PTX was administered i.p. at equitoxic and equal doses to nude mice bearing gastric cancer OCUM-2MD3 cell subcutaneous and peritoneal xenografts. Therapeutic efficacy of Sb-PTX and Nab-PTX was evaluated as inhibition of tumor growth using a peritoneal metastatic model with subcutaneous xenografts. The survival rate was also investigated using mouse peritoneal models. For assessment of subcutaneous tumors, the change in tumor volume was measured, and for assessment of peritoneal tumors, the weight of ascitic fluid and the total peritoneal tumor burden were measured for each individual mouse. At equitoxic doses, treatment with Nab-PTX resulted in a greater reduction in the size of subcutaneous tumors and the weight of ascites and peritoneal burden as compared with i.p. Sb-PTX (p<0.05). Treatment with i.p. and i.v. Nab-PTX also achieved greater survival benefit than i.p. Sb-PTX (p<0.05). In contrast, there was no significant difference in the degree of tumor reduction and the survival time between both drugs at equal doses. With regard to the route of administration, the antitumor efficacy of Nab-PTX after i.v. administration was equivalent to the efficacy after i.p. administration. These results suggest that i.v. Nab-PTX may be another encouraging treatment option that can target peritoneal dissemination in gastric cancer.

Background: Intraperitoneal (i.p.) chemotherapy is garnering attention as an effective treatment for gastric cancer with peritoneal metastasis. We report the case of a patient who developed colonic stenosis caused by infection of an i.p. access port system during i.p. chemotherapy. It was difficult to differentiate whether the extrinsic colonic stenosis arose from a catheter infection or peritoneal metastasis of the gastric cancer., Case Presentation: A 66-year-old Japanese man underwent total gastrectomy for gastric cancer. Because the intraoperative findings revealed peritoneal metastasis, a port system was implanted for subsequent i.p. chemotherapy. Two months after initiation of chemotherapy, he complained of vomiting and abdominal pain. A computed tomography scan revealed marked thickening of the sigmoid colon wall adjacent to the catheter of the i.p. access port system. A barium enema demonstrated extrinsic irregular stenosis of the sigmoid colon. Although it was difficult to distinguish whether infection or peritoneal metastasis had caused the colonic stenosis, we removed the port system to obtain a therapeutic diagnosis. Coagulase-negative staphylococci were detected by catheter culture. The wall thickening and stenosis of the sigmoid colon completely resolved after removal of the port system., Conclusions: We report the case of a rare complication in association with an i.p. access port system. Infection of the port system should be considered as a differential diagnosis when colonic stenosis adjacent to the catheter is observed during i.p. chemotherapy.

A 56-year-old woman with advanced gastric cancer with peritoneal metastasis was successfully treated with multidisciplinary therapy. Gastrectomy and total resection of the peritoneal metastasis were performed initially. Subsequently, combined chemotherapy with S-1/polysaccharide-Kureha( PSK) and intraperitoneal infusion( IP) of docetaxel( TXT) was continued for 9 months. Because of the appearance of hepatic metastasis, the anti -cancer drug was changed to irinotecan (CPT-11) that was administered by dropping intravenously( DIV therapy) and continued for 10 months. Despite the reduction of the hepatic metastasis, ascites was increased. All metastatic lesions disappeared after 3-months of paclitaxel (TXL) DIV therapy. Five years after the operation, the peritoneal metastasis recurred. Combined DIV and IP TXL therapy was administered for 2 months. The peritoneal metastasis was reduced and the TXL DIV therapy was continued for 6 months. Due to increased levels of tumor markers, capecitabine( Xeloda)/cisplatin( CDDP) was introduced; however, it could not be continued because of the side effects. Subsequent TXT DIV therapy was not effective; chemotherapy was switched to CPT-11 DIV therapy, which was effective for 14 months. S-1 and TXL IP therapy was initiated because of the appearance of a new peritoneal tumor. This therapy effectively controlled the disease until today. The patient is in good health at 8 years after the start of therapy.

A 74-year-old man was admitted to the hospital because of abdominal fullness and constipation. Endoscopy and abdominal computed tomography (CT) scans showed an advanced sigmoid colonic cancer with multiple lung and liver metastases and peritoneal dissemination. Sigmoid resection was performed to relieve ileus. Postoperative chemotherapy was administered for metastatic lesions. We administered systemic chemotherapy with tegafur-uraci(l UFT)/UZEL( 10 months), oxaliplatin with fluorouracil (5-FU) and folinic acid (FOLFOX; 11 courses), irinotecan with 5-FU and folinic acid (FOLFIRI; 13 courses), irinotecan plus S-1 (IRIS; 23 courses), bevacizumab (32 courses), cetuximab (29 courses), and peritoneal infusion of paclitaxel( 65 courses). The patient survived for 5 years after the initial treatment.

Purpose: We designed a phase I/II trial of intraperitoneal (IP) docetaxel plus S-1 to determine the maximum tolerated dose (MTD) and recommended dose (RD) and to evaluate its efficacy and safety in gastric cancer patients with peritoneal carcinomatosis (PC)., Methods: Patients with PC confirmed by laparoscopy or laparotomy received IP docetaxel on days 1 and 15 and S-1 (80 mg/m(2)) on days 1-14 every 4 weeks., Results: In the phase I part (n = 12), each cohort received escalating doses of docetaxel (35-50 mg/m(2)); the MTD was determined to be 50 mg/m(2) and the RD was determined to be 45 mg/m(2). Dose-limiting toxicities included grade 3 febrile neutropenia and grade 3 diarrhea. In the phase II part (n = 27), the median number of courses was 4 (range 2-11). The 1-year overall survival (OS) rate was 70 % (95 % confidence interval 53-87 %). The overall response rate was 22 % and peritoneal cytology turned negative in 18 of 22 (81 %) patients. The most frequent grade 3/4 toxicities included anorexia (19 %), neutropenia (7 %), and leukopenia (7 %)., Conclusion: IP docetaxel plus S-1 is active and safety in gastric cancer patients with PC.

During the last 7 years, 21 patients with DMPM were treated. Histologic types were epitheloid type in 18 patients, biphasic type in 2 patients and sarcomatoid type in 1 patient. Preoperative systemic chemotherapy, hyperthermic intraperitoneal chemotherapy(HIPEC) by laparoscopy(LHIPEC), and intraperitoneal(IP) chemotherapy were done in 14, 3 and 1 patients, respectively. Cytoreductive surgery(CRS) was done in 13 patients. Ten patients received HIPEC after CRS. Partial responses were experienced in 4 of 13 patients treated with preoperative systemic chemotherapy. One of three patients treated by LHIPEC showed complete response. Among 13 patients received laparotomy, complete removal of PC was done in 4(31%) patients. The other 9 patients who received incomplete cytoreduction had diffuse involvement on the small bowel and its mesentery. All over 5-year survival was 17%. Patients treated with HIPEC survived significantly longer than non-HIPEC group. Neoadjuvant laparoscopic HIPEC may have a great role in the preoperative control of small PC on the surface of small bowel.

Vascular endothelial growth factor (VEGF) plays an important role in proliferation of cancer cells, angiogenesis and vascular permeability in peritoneal dissemination. In addition, the release of VEGF by tumor cells has been identified as a main factor promoting the intraperitoneal secretion of fluid. Accordingly, recent evidence suggests that targeting VEGF may have the potential to suspend the ascites production resulting from peritoneal metastasis. We previously reported the effects of bevacizumab (BEV) on the growth inhabitation of peritoneal nodules and the reduction of ascites in peritoneal metastatic models. Here we present two cases of women (62 and 42 years old) with refractory peritoneal dissemination of scirrhous gastric cancer and server symptomatic ascites. They required frequent paracenteses for ascites which was resistant to systemic and intraperitoneal chemotherapy of S-1 and taxane. We treated them with intravenous BEV (5-10 mg/kg) with dramatic improvement in their ascites. BEV may have a role in the management of malignant ascites in the patient with refractory gastric cancer which should be confirmed in a larger series of well selected patients.

Purpose: Vascular endothelial growth factor (VEGF) is correlated with peritoneal metastasis of gastric cancer, increasing vascular permeability accompanied by accumulation of ascites. The aim of the current study is to investigate the biodistribution of bevacizumab in a peritoneal metastatic model of gastric cancer and to clarify which is more suited to treatment of peritoneal metastasis, systemic or regional therapy., Methods: A highly peritoneal-seeding cell line of gastric cancer, OCUM-2MD3, which exhibited high production and release of VEGF was used in this study. The biodistribution of bevacizumab was investigated using peritoneal metastatic models together with subcutaneous xenografts, and (125)I-radiolabelled bevacizumab was administrated to these models subcutaneously (s.c.) or intraperitoneally (i.p.), respectively. In addition, the anti-tumor response of bevacizumab and paclitaxel was assessed as single agents or in combination using peritoneal metastatic models., Results: In the analysis of biodistribution, (125)I-bevacizumab administrated i.p. indicated low peritoneal clearance. On the other hand, s.c. administration of (125)I-bevacizumab showed preferential accumulation in subcutaneous tumors and peritoneal nodules, with a high blood concentration. In peritoneal metastatic models, the effects of bevacizumab were found for both the growth inhibition of peritoneal nodules (P < 0.01) and the reduction of ascites (P < 0.05). These effects were more prominent by s.c. administration compared with i.p. administration and were increased in combination with i.p. paclitaxel., Conclusion: Bevacizumab should be administrated systemically compared to regionally, and the combination with i.p. paclitaxel has a potential to be useful for patients with peritoneal metastasis of gastric cancer.

A 58-year-old woman was admitted to the hospital because of abdominal fullness and anorexia. Abdominal CT scan revealed pancreatic cancer with massive ascites showing peritoneal dissemination, combined with lymph node and liver metastases. Cytology of ascites showed malignancy. Abnormally high values of CA19-9 (1,908 U/mL) and CA125 (545 U/mL) were detected in serum. Histologically, metastatic adenocarcinoma was recognized by laparoscopic biopsy of peritoneal dissemination. We performed systemic chemotherapy of S-1, gemcitabine and peritoneal infusion of paclitaxel for nonresected pancreatic cancer. After 5 courses, ascites disappeared and the serum CA19-9 and CA125 levels regained their normal value. Peritoneal seeding was not found by second laparoscopic examination 20 months after beginning chemotherapy. Thus, we consider the patient had an effective response, and performed distal pancreatectomy and proximal resection of the stomach. Histological examination of the primary lesion revealed no cancer cells where fibrosis presented.

Vascular Endothelial Growth Factor (VEGF) plays an important role in proliferation of cancer cells, angiogenesis and vascular permeability in peritoneal dissemination. Now we investigated the efficacy of anti-VEGF therapy in peritoneal dissemination of gastric cancer considering of pharmacokinetics. We investigated pharmacokinetics of bevacizumab, humanized anti-VEGF monoclonal antibody in subcutaneous xenograft and peritoneal dissemination model of OCUM-2MD3, highly peritoneal-seeding cell line of human scirrhous gastric carcinoma. In the group of intraperitoneal administration, bevacizumab remains in the intraperitoneal cavity and transits slowly to blood pool. On the other hand, in the group of subcutaneous administration, bevacizumab transits faster to blood pool and is accumulated in subcutaneous tumors and peritoneal nodules. Bevacizumab administered intraperitoneally seemed to neutralize intraperitoneal VEGF. Bevacizumab administered in subcutaneous seemed to act on peritoneal wall and control vascular permeability. Systemic administration of anti-VEGF agent will be a potential therapy in peritoneal dissemination of gastric cancer.

This study evaluated the feasibility and pharmacology of intraperitoneal docetaxel (IP docetaxel) when administered weekly for 3 consecutive weeks, followed by 1 week without treatment. A total of 24 patients with peritoneal carcinomatosis of gastric cancer (10 preoperative, 7 postoperative and 7 recurrent) were enrolled in this study. Docetaxel was dissolved in an isotonic saline to a final 1 liter solution and was administered in a 1 h dosage of 25, 35, 45 and 60 mg/m(2) to determine the maximum tolerated dose (MTD). To measure the docetaxel concentration, blood and peritoneal fluid samples were collected 0.5, 1, 2, 3, 6 and 24 h after administering the drug to 15 patients. A total of 109 chemotherapy cycles were administered, with a median of four cycles per patient (range 2-9). The MTD of the weekly IP docetaxel was defined at 60 mg/m(2). At a docetaxel dosage of 60 mg/m(2) per week, the dose-limiting events of grade 3 abdominal pain and grade 3 diarrhea, which may be associated with local toxicity, occurred. Peak concentrations of peritoneal fluid ranged from 24.5 to 68.7 microg/ml. The mean ratio of the area under concentration (AUC) in the peritoneal fluid to the plasma concentration was 515. Furthermore, the mean of plasma AUC by IP docetaxel was 5.63 microg h/ml versus that of IV docetaxel at a dose of 60 mg/m(2). The response rate of the preoperative IP docetaxel was 80% (4 CR, 4 PR, 1 NC and 1 PD), which was judged with laparoscopy and peritoneal lavage cytology. Gastrectomy, with D2 lymph node dissection, was performed on all of the patients evaluated as CR. The weekly IP docetaxel demonstrated a low toxicity and high efficacy for peritoneal carcinomatosis with dual anti-cancer effects via the peritoneal surface and capillary blood supply due to its unique pharmacokinetic property.

To determine the safety profile and activity of IP docetaxel combined with S-1 for patients with peritoneal dissemination of gastric cancer, a multi-centric phase I/II study has started. Patients with histologically confirmed peritoneal dissemination by laparoscopy or laparotomy were eligible to participate in this study, but the patients with a large amount of malignant ascites were excluded. In phase I part, the patients received variable doses of intraperitoneal docetaxel on day 1 and day 15 and 80 mg/m2 of daily oral S-1 on days 1-14 every 4 weeks. Phase I part determines the dose-limiting toxicity (DLT), maximum-tolerated dose (MTD) and recommended dose (RD), and phase II part evaluates a safe successful execution. The response rate of peritoneal dissemination was explored as the secondary endpoint. After 2 cycles, peritoneal tumor response was assessed according to the new criteria of Society for the Study of Peritoneal Dissemination in Gastric Cancer. The response criteria included the following: a decrease in ascites and change in cytology negative; at least a 50% decrease in the sum of the longest diameter of peritoneal tumor using photographs of peritoneal lesions taken to confirm an objective response before and after the treatment.

We evaluated the effectiveness of intraperitoneal chemotherapy for peritoneal dissemination of gastric cancer. A total of 104 patients with primary gastric cancer with peritoneal dissemination were enrolled in this study. In 72 of the 104 patients with gastrectomy performed, 5 patients underwent CDDP-ip (50-100 mg/100-200 ml), 16 patients underwent CHPP (CDDP 300 mg, MMC 30 mg, ETP 150 mg/8 l/42-43 degrees C/60 min), and 17 patients underwent CMV-ip (CDDP 150 mg, MMC 20 mg, ETP 100 mg/1 l/60 min). The prognosis of patients who underwent CMV-ip was significantly better than those who received other therapies. In 26 patients with severe peritoneal dissemination who were treated with TS-1 (60 mg/m2) and taxane-ip (docetaxel 40-60 mg/body or paclitaxel 120-180 mg/body), 9 of 18 responders performed complete cytoreduction. The median survival time (MST) in these 9 patients was 944 days and a 2-year survival rate was 63%. A multimodal therapy consisting of systemic chemotherapy, intraperitoneal chemotherapy and complete cytoreductive surgery may provide good prognosis to the gastric cancer patients with peritoneal dissemination.

Background: The degree of peritoneal metastasis (PM) of gastric cancer has been classified into four grades (P0, P1, P2, and P3) in the Japanese Classification of Gastric Carcinoma, First English Edition. However, the PM category in this version was so ambiguous in terms of volumetry that it was unlikely to estimate PM status correctly. We have developed a new volume scoring system for PM, modifying Sugarbaker's classification., Methods: Eighty-five patients with gastric cancer with PM underwent surgery and/or laparoscopy at our hospital at Kanazawa University between January 1990 and December 2000. The grading (Gr) by the volume scoring system was decided according to the sum of scores for nine (in male) or ten (in female) abdominopelvic regions. These regions included left subphrenics, right subphrenics, left flank, right flank, pelvis, omenta, mesentery, small and large bowels, ovaries (only for females), and other intraabdominal organs. Volumetry for each region was carried out using the following categories: VS0, indicating the absence of cancer in a particular abdominopelvic region; VS1, indicating that tumor nodules are less than 10 mm in diameter; VS2, indicating tumors between 1 and 5 cm in diameter; and VS3, indicating that tumor is more than 5 cm in diameter or that an organ is coated by a mat of tumor (confluent disease). The scores for VS0, VS1, VS2, and VS3 were 0, 1, 2, and 3 points, respectively. Total scores of 1 to 3 were the equivalent of Gr I, total scores of 4 to 6 were equivalent to Gr II, total scores of 7 to 9 were equivalent to Gr III, and total scores of more than 9 were equivalent to Gr IV., Results: There was no significant difference between P1 and P2, or between P1 and P3 in survival curves. But the 50% survival times of Gr I, Gr II, Gr III, and Gr IV were 1.23, 0.66, 0.67, and 0.32 years, respectively. The prognosis of Gr I was significantly better than that of any other grades. Eight of the 28 patients (29%) assessed as Gr I survived more than 2 years, whereas only 2 of the 57 (4%) assessed as Gr II, Gr III, or Gr IV did so. Multivariate analysis by Cox's proportional hazard model revealed that the volume scoring, resection of primary tumor, and resection of peritoneal tumor were independent factors to predict prognosis., Conclusion: These results showed that the volume scoring system was strongly related to the prognosis, and the patients assessed as Gr I had a great probability of cure by surgery.

This study was designed to evaluate the pharmacokinetics and toxicity of paclitaxel administered via an intraperitoneal (i.p.) route for patients with gastric cancer. Fourteen patients with peritoneal dissemination were entered in the trial. Three distinct dose levels from 120 to 180 mg/body were studied. A major pharmacokinetic advantage (550-2,000 fold) for peritoneal cavity exposure compared with the systemic compartment was seen following intraperitoneal delivery of paclitaxel. The dose-limiting toxicity was found to be abdominal pain at 180 mg/body. Grade 2 toxicity included 1 episode of neutropenia and grade 1 toxicities included 1 case of finger-numbness and 2 of alopecia. We conclude that intraperitoneal paclitaxel administration is well tolerated and provides a peritoneal pharmacokinetic advantage for the treatment of peritoneal dissemination.

This study was designed to evaluate the pharmacokinetics and toxicity of docetaxel administered via an intraperitoneal (i.p.) route for patients with gastric cancer. Eleven patients with peritoneal dissemination were entered into this trial. Patients were treated with 45 mg/m2 of i.p. docetaxel administration in 1 l of saline. Peak peritoneal concentration was 40.0 +/- 14.5 micrograms/ml and peritoneal concentration at 24 hours after drug administration was 4.3 +/- 3.9 micrograms/ml. The median pharmacokinetic advantage (AUC peritoneal/AUC plasma) was 515 (range 22-1, 770). Grade 2 and 3 toxicities included 5 episodes of diarrhea; 3 of abdominal pain; 3 of ascites; 2 of alopecia; and 1 of neutropenia. We conclude that intraperitoneal docetaxel administration is well tolerated and provides a peritoneal pharmacokinetic advantage for the treatment of peritoneal dissemination.

We report the long-term survival of a patient with primary papillary serous carcinoma of the peritoneum, treated by subtotal peritonectomy combined with continuous hyperthermic peritoneal perfusion. After subtotal peritonectomy and continuous hyperthermic peritoneal perfusion, early postoperative intraperitoneal chemotherapy with cisplatin and three cycles of cisplatin-based intravenous chemotherapy were administered. The patient currently remains alive 23 months after surgery. This long-term survival suggests that treatment of primary papillary serous carcinoma of the peritoneum requires aggressive cytoreduction surgery followed by chemotherapy using adequate methods to enhance chemosensitivity.

Background and Study Aims: Peritoneal metastasis is a crucial factor for the prognosis in gastric cancer, but its diagnosis is difficult before laparotomy. We report on the utility of laparoscopy and its indications in the detection of peritoneal metastasis in gastric cancer., Patients and Methods: A total of 39 patients with gastric cancer underwent laparoscopy and peritoneal cytology investigation in our department, between April 1992 and April 2000. Laparoscopic diagnosis for peritoneal metastasis (LP-P) was determined through macroscopic, pathological and cytological diagnoses. All the patients underwent diagnostic imaging with computed tomography (CT) and ultrasound before laparoscopy. Carcinoembryonic antigen, carbohydrate antigen (CA) 19-9, and CA125 levels in serum and peritoneal fluid were measured using enzyme immunoassay., Results: Laparoscopic diagnosis for peritoneal metastasis gave negative results in 21 patients and positive results in 18. All the patients with negative LP-P findings underwent surgery; 18 of the 21 patients showed no peritoneal metastasis, but three were diagnosed as having peritoneal metastasis, one at the pouch of Douglas and two at the mesentery. The diagnosis of all the patients with positive LP-P findings was finally confirmed as correct. The specificity, sensitivity, and accuracy of laparoscopy for peritoneal metastasis were 100 % (18/18, 95 % CI 0.82 - 1), 86 % (18/21, 95 % CI 0.64 - 0.97), and 92 % (36/39, 95 % CI 0.79 - 0.98), respectively. The specificity, sensitivity, and accuracy of diagnostic imaging for peritoneal metastasis were 100 % (18/18, 95 % CI 0.82 - 1), 38 % (8/21, 95 % CI 0.18 - 0.62), and 67 % (26/39, 95 % CI 0.50 - 0.81), respectively. All of the 11 patients showing high levels of serum CA125 (equal to or more than 35 U/ml) had peritoneal metastasis whereas 17 of the 26 patients with low levels of serum CA125 (less than 35 U/ml) did not ( P < 0.001)., Conclusions: The sensitivity of laparoscopy for peritoneal metastasis was much higher than that of diagnostic imaging. Laparoscopy and serum CA125 level both predicted peritoneal metastasis, but the degree, volume, or distribution of peritoneal metastasis was disclosed only by laparoscopy. Laparoscopy is a useful way of detecting peritoneal metastasis in gastric cancer, and patients with an elevated level of serum CA125 are the best candidates for laparoscopy.

Background/aims: Although the most frequent cause of death after curative resection of advanced gastric cancer is peritoneal recurrence, there was no effective therapy for the prevention of peritoneal recurrence. This randomized trial sought to determine whether intraoperative chemohyperthermic peritoneal perfusion could eliminate microscopic residual disease and thereby improve survival of patients with advanced gastric cancer., Methodology: One-hundred and thirty-nine patients with T2-4 gastric cancer underwent curative gastrectomy with extended lymphadenectomy. These patients were randomly allocated into the following three groups. Patients in the CHPP group received surgery + chemohyperthermic peritoneal perfusion, and those in the CNPP group underwent surgery + chemonormothermic peritoneal perfusion. The third group was surgery alone group. In the CHPP and CNPP groups, peritoneal cavity was perfused with 6-8 liters of heated saline at, respectively, 42-43 degrees C and 37 degrees C with 30 mg of mitomycin C and 300 mg of cisplatin by a extracorporeal circulation machine., Results: Major operative complication occurred in 19% (9/48), 14% (6/44) and 19% (9/47) of the CHPP, CNPP and surgery alone group, respectively. Complication which uniquely developed after chemohyperthermic peritoneal perfusion was bowel perforation. Mortality rates of each group were 4% (2/48), 0% (0/44) and 4% (2/47) in the CHPP, CNPP and surgery alone group, respectively. Overall 5-year survival rates of CHPP, CNPP and surgery alone groups were 61%, 43% and 42%, respectively. In a subset analysis, patients with gastric cancer having serosal invasion or lymph node metastasis have shown a statistically significant improvement in survival when treated with chemohyperthermic peritoneal perfusion. However, chemonormothermic peritoneal perfusion had no survival benefit. By analyzing with Cox proportional hazard model, chemohyperthermic peritoneal perfusion emerged as an independent prognostic factor for good survival. Surgery alone had three-fold higher risk of death than chemohyperthermic peritoneal perfusion., Conclusions: Chemohyperthermic peritoneal perfusion had an efficiency for the prophylaxis of recurrence after curative resection of advanced gastric cancer, and is indicated for patients with tumor infiltrating beyond serosal layer and node positive tumor.

Background: This study examined the clinical value of intraoperative peritoneal lavage for cytological examination in patients with gastric cancer. Peritoneal dissemination is the most frequent mode of recurrence for this tumor., Methods: A retrospective of lavage findings, other factors, and outcome was performed in 1,297 patients with gastric cancer who underwent intraoperative peritoneal lavage., Results: The 5-year survival rate of patients with positive lavage cytology was only 2%. Patients who underwent curative resection and had negative cytology had a significantly better 5-year survival rate (P < 0.001). Even among patients with macroscopic peritoneal dissemination, the survival rate was significantly better with negative cytology, which reflected fewer free cancer cells in the peritoneal cavity. Serum concentrations of carcinoembryonic antigen and carbohydrate antigen 19-9 were significantly higher in patients with positive cytology. Multivariate analyses indicated that intraoperative cytological findings was an independent prognostic factor for survival, and was the most important factor for predicting peritoneal recurrence., Conclusions: Intraoperative peritoneal lavage cytology is important in predicting survival and peritoneal recurrence in gastric cancer.

Background/aims: Despite the improvements of chemotherapy and surgical techniques, treatment results of peritoneal dissemination still remain pessimistic., Methodology: During a 10-year period, 106 patients with peritoneal dissemination from gastric cancer were treated with chemo-hyperthermic peritoneal perfusion (CHPP), peritonectomy + CHPP, systemic PMUE therapy, and surgery alone in 51, 15, 13, and 27 patients, respectively. In peritonectomy, disseminated nodules were resected as much as possible in combination with the combined resection of the abdominal organs and parietal peritoneum covering diaphragm, pelvis and abdominal wall. After resection, the abdominal cavity was treated with heated saline at 42-43 degrees, containing cisplatinum (CDDP), Mitomycin C (MMC), and etoposide for 1 hour. PMUE therapy was administered with one course of i.v. infusion of 75 mg/m2 of CDDP and 30 mg/body of MMC on the 1st day, followed by etoposide 50 mg/body on the 3rd, 4th, and 5th day, and with oral intake of 400 mg/body of UFT every day from the 1st day., Results: No post-operative or chemotherapeutic deaths were observed. Systemic PMUE therapy showed no survival improvement, and survival of the peritonectomy + CHPP group was the best, following CHPP, systemic PMUE and surgery alone., Conclusions: Peritonectomy and CHPP may be the best choice for the treatment of peritoneal dissemination.

Background and Objectives: The most reliable method for the diagnosis of peritoneal dissemination of gastric cancer at the present time is cytological examination of ascitic fluid, which is unavailable to patients without ascites or may be inadequate for those with ascites containing few cancer cells. It has been reported recently that human gastric cancer immunoreacted with a monoclonal antibody against pancreatic trypsinogen. We therefore examined the expression of trypsinogen as a new marker for the early diagnosis of peritoneal dissemination of gastric cancer., Methods: Pancreatic trypsinogen protein was immunohistochemically stained with a three-step indirect immunoperoxidase method and cationic trypsinogen (trypsinogen-1) mRNA expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in gastric cancer. Twenty-nine of 30 primary tumors (97%) and all 12 tumors (100%) of the peritoneal seedings immunohistochemically reacted with trypsinogen. Preliminary study for early diagnosis of peritoneal dissemination was carried out for eight more recent patients who showed positive immunoreactivity to trypsinogen protein and expressed trypsinogen- mRNA in the primary tumor. The expression of trypsinogen-1 mRNA was detected by using peritoneal lavage fluid preoperatively collected in these patients., Results: All three patients in whom peritoneal dissemination was diagnosed at the time of their operation(s) expressed trypsinogen-1 mRNA. One patient, who did not show peritoneal dissemination at the operation but was positive for trypsinogen-1 mRNA detection, later died of the recurrence of peritoneal dissemination., Conclusions: These results indicated that trypsinogen protein and trypsinogen-1 mRNA frequently expressed in peritoneal dissemination as well as primary tumors in gastric cancer and detection of trypsinogen-1 mRNA expression was a useful method for early diagnosis in peritoneal dissemination of gastric cancer.

Background: The most common cause of noncurative resection and recurrence is gastric cancer is peritoneal seeding. However, the results of treatment of peritoneal dissemination with chemotherapy have been poor with 5-year survival rates of 0%., Methods: A new in vitro thermochemosensitivity test was performed on gastric cancer cells obtained from 19 surgically resected specimens by using tetrazolium-based colorimetric assay (MTT assay). A novel treatment of the intraoperative chemohyperthermia was undertaken in 83 patients with gastric cancer with peritoneal dissemination. After aggressive resection of primary tumor, lymph nodes, and peritoneal metastases, warmed saline solution containing mitomycin C 30 mg, etoposide 150 mg, and cisplatin 300 mg was introduced into the peritoneal cavity via a closed circuit continuous hyperthermic peritoneal perfusion (CHPP) for 60 minutes to keep the abdominal temperature at 42 degree to 43 degrees C by means of a heat exchange mechanism., Results: The in vitro thermochemosensitivity test that 43 degrees C enhanced the cytotoxin effects on gastric cancer cells under clinically achievable drug concentrations. During CHPP, drug concentrations of cisplatin, mitomycin C, and etoposide in the perfusate remained statistically higher than in the peripheral venous circulation. Among 43 evaluable patients with residual peritoneal seeding, eight (19%) and nine (21%) exhibited complete response and partial response, respectively. The overall 1- and 5-year survival rates were 43% and 11%, respectively. Patients who underwent complete resection survived significantly longer than those with residual disease, and those with complete response had a significantly better prognosis than did those with partial response, and nonresponders. One-year survival rates with complete response, partial response or nonresponders were 88%, 27% and 22%, respectively. Five patients survived longer than 5 years., Conclusions: Our triple treatment combining surgery and CHPP is an effective therapy for selected patients with gastric cancer with peritoneal dissemination.

A new operative procedure, called subtotal peritonectomy (SP), in combination with chemohyperthermic peritoneal perfusion, was developed for the treatment of peritonitis carcinomatosa in gastrointestinal cancer. SP includes resection of primary lesion, colon, small bowel, spleen, and gall bladder and parietal peritonectomy. Six patients with gastric cancer and two patients with colon cancer underwent these procedures. A great deal of discharge from the peritoneal cavity, an increase in systemic vascular resistance index, and a decrease in central venous pressure represented much decrease in circulatory volume on days 1 to 2 postoperatively. This state improved at 3 to 4 days after operation. Histopathological study revealed multiple peritoneal seedings with negative surgical margins in all patients. There were no related deaths though bleeding, perforation, and abscess occurred in two patients each. One patient died of peritoneal recurrence after one year, but the other have survived.

Continuous hyperthermic peritoneal perfusion (CHPP) combined with administration of anticancer drugs was performed in eight colorectal cancer patients with peritoneal dissemination. An overall response rate of 50 percent was achieved in the eight patients. Two of three complete responders are long, recurrence-free survivors for 15 and 30 months. The two-year survival has been achieved in 18.8 percent of the patients receiving CHPP, and this rate is significantly higher than the rates in P2 and P3 patients who did not receive CHPP. The complications of CHPP with administration of anticancer drugs were mild bone marrow suppression in two (25 percent) of the eight patients and also a mild grade of renal dysfunction in one (12.5 percent), though not lethal. The results suggest that the combination of CHPP with the administration of anticancer drugs is a safe and effective therapy for peritoneal dissemination of colorectal cancers.

Continuous hyperthermic peritoneal perfusion (CHPP) with anticancer agents (mitomycin C and cisplatin) in warm saline was performed in patients with peritoneal dissemination of gastric cancer following resection of the primary lesion. The effect of CHPP was examined by a second-look operation. This study includes 41 cases of gastric cancer with peritoneal dissemination but without liver metastasis treated during the past 6 years. The overall median survival was 14.6 months to 64.2 months from CHPP to death and the 3-year survival rate was 28.5%. Second look surgery revealed a remarkable diminution in the degree of peritoneal dissemination in 7 (50%) of 14 patients with disappearance of ascites after only one course of CHPP in 7 (77.8%) of 9 patients. Long-term 3 year-survival was noted in 4 (9.8%) patients on CHPP. Side effects were renal insufficiency in 2 (5%) patients, leukopenia in 2 (5%) patients, and perforation of the small intestine in 1 (2%) patient. These results suggest the effectiveness of CHPP in the treatment of gastric cancer with peritoneal dissemination.

A total of 31 patients with gastric cancer showing peritoneal dissemination received continuous hyperthermic peritoneal perfusion (CHPP) in combination with the administration of cisplatin (CDDP) and mitomycin C (MMC). The authors developed a new special device named the peritoneal cavity expander (PCE) for sufficient perfusion and direct temperature measurement in the peritoneal cavity. As complications of CHPP three patients presented with bone marrow suppressions (leukocytes less than or equal to 3000/mm3 and/or platelets less than or equal to 30,000/mm3): one, leakage of intestinal anastomosis; one, intestinal perforation; and one, acute renal failure. But none of them was lethal. Twelve of 31 patients who had received CHPP during the initial operation underwent second-look operation (SLO) for the assessing the effects of CHPP and for resecting residual or recurrent tumors. Among 12 patients who received SLO complete response (CR) was observed in four patients, partial response (PR) in one, no change (NC) in three, and progressive disease (PD) in four, with the overall response rates (%CR + %PR) standing at 41%. Two-year survival rate of the complete and partial responders was 50%, which was significantly higher than 0% of the other responders (NC + PD). The survival curves of the two groups were significantly different (P less than 0.05, generalized Wilcoxon test). These results supported that CHPP was well tolerated and effective for the treatment of patients with peritoneal dissemination in gastric cancer when combined with anti-cancer drugs having synergism with hyperthermia. Since the outcome of SLO was one of prognostic factors it was important to follow up these patients by SLO.