[Experience of Introduction of Robotic-Assist Surgery at Regional Hospital].

Our hospital introduced the da Vinci Xi Surgical System in April 2022. At the same time, laparoscopic surgery was also introduced to produce endoscopic surgical skill qualification system: qualified surgeon. Open surgery for trainees was also continued as before, and young surgeons were instructed to always keep their motivation high. After the introduction of robotic surgery, conferences that were accessible to trainees were held on a regular basis. In addition, the environment was designed to allow anyone to train da Vinci Surgical System. The introduction of robotic surgery has certainly reduced the number of procedures performed by trainees, especially in rectal cancer. However, surgical outcomes were better after the introduction of robotic surgery. The trend was similar for both open and laparoscopic surgery. We report on our efforts to introduce robot-assisted surgery and the actual situation in which surgeons at various stages of their education can work together to achieve a win-win situation.

The updated five-year overall survival and long-term oxaliplatin-related neurotoxicity assessment of the FACOS study.

PURPOSE: We previously reported the first evidence of oncological benefits from a Japanese phase II trial of oxaliplatin-based adjuvant chemotherapy in patients with stage III colon cancer (the FACOS study). We herein report the long-term survival and persistent oxaliplatin-related peripheral sensory neuropathy (PSN) for patients enrolled in this trial. METHODS: Patients were scheduled to receive the mFOLFOX6 or CAPOX regimen in the adjuvant setting. The five-year overall survival (OS) rate and persistent PSN were evaluated. RESULTS: A total of 130 patients (mFOLFOX6, n = 73; CAPOX, n = 57) were eligible. The 5-year OS rate was 91.4%. No significant difference in the OS rate was observed between regimens (mFOLFOX6, 94.4%; CAPOX, 87.4%; P = 0.25). The incidence of PSN during adjuvant treatment was 55.4% in grade 1 (G1), 30.0% in G2, and 4.6% in G3. No patients showed G3 PSN at 12 months, but G1 or G2 residual PSN after 5 years was observed in 21.8% (G1, 20%; G2, 1.8%). CONCLUSIONS: Updated results from the FACOS study support the benefits of oxaliplatin-based adjuvant chemotherapy in terms of the long-term survival among Japanese patients with stage III colon cancer. However, long-term persistent PSN occurs in about 20% of survivors, counterbalancing the favorable OS.

Oxaliplatin-induced increase in splenic volume: experiences from multicenter study in Japan.

BACKGROUND: Chemotherapy with oxaliplatin is known to induce sinusoidal obstruction syndrome (SOS). In a previous single-center study, we reported that oxaliplatin-induced increase in splenic volume (SV) is strongly indicative of SOS, and that this increase in SV persisted for > 1 year after completing chemotherapy. The aim of this study was to confirm the oxaliplatin-induced SV change in a multicenter study in patients with stage III colon cancer in Japan. METHODS: We enrolled 59 patients who underwent curative resection for stage III colon cancer in the FACOS study in a phase II multi-center clinical study. Participants received mFOLFOX6 or CAPOX as adjuvant chemotherapy. SV change was assessed three times by computed tomographic volumetry: before surgery, on completion of adjuvant chemotherapy, and 1 year after completing adjuvant chemotherapy. RESULTS: SV on completing and 1 year after chemotherapy was significantly higher than that before surgery (P < 0.001). Oxaliplatin-induced SOS persisted for > 1 year after the completion of adjuvant chemotherapy in half of the patients. There was no difference in 3-year disease-free survival with respect to the presence or absence of increased SV. An increase in SV was observed in 72% of patients treated with mFOLFOX6 and 94% of patients treated with CAPOX (P = 0.13). CONCLUSION: This study can be verified the findings observed in our previous single-center study, oxaliplatin-based adjuvant chemotherapy was associated with an increase in SV. Furthermore, this increase can persist for > 1 year. The continuous presence of SOS may have a negative impact on prognosis in patients that develop recurrent disease.

A Japanese multicenter phase II study of adjuvant chemotherapy with mFOLFOX6/CAPOX for stage III colon cancer treatment after D2/D3 lymphadenectomy.

PURPOSE: A phase II trial was conducted to investigate the benefit of oxaliplatin-based adjuvant chemotherapy in Japanese stage III colon cancer patients. METHODS: Eligible patients were scheduled to receive 12 cycles of mFOLFOX6 or 8 cycles of CAPOX in adjuvant settings. The primary endpoint was the 3-year disease-free survival (DFS). Cox proportional hazards regression was performed to identify risk factors for a worse DFS. RESULTS: A total of 130 patients, including 73 patients receiving mFOLFOX6 and 57 patients receiving CAPOX, were enrolled from 16 institutions between April 2010 and April 2014. The 3-year DFS was 82.2%, exceeding the expected primary endpoint of 81.7%. The 3-year DFS tended to be higher in patients receiving mFOLOFOX6 than in those receiving CAPOX (mFOLFOX6, 86.3%; CAPOX, 76.9%; P = 0.06). The 3-year DFS rates did not differ markedly based on the risk stratification (T1/T2/T3 N1 vs. T4 or N2) indicated by the IDEA COLLABORATION study (P = 0.22). In the multivariate analysis, stage IIIC (P = 0.046) and early discontinuation (P < 0.01) were identified as independent significant risk factors for a worse DFS. CONCLUSION: Our findings represent the first positive results in a Japanese phase II trial of adjuvant chemotherapy with mFOLFOX6/CAPOX. Early discontinuation within 2 months was an independent risk factor for a shorter DFS.

Histopathologic study from a colorectal cancer screening in Chile: results from the first 2 years of an international collaboration between Chile and Japan.

A national colorectal cancer (CRC) screening program began in Chile in 2012, which is an international collaboration between Japan and Chile and is based on a standardized protocol supported by Tokyo Medical and Dental University. We describe the results from the first 2 years of screening at one public hospital in Punta Arenas, Chile. Of 4124 asymptomatic individuals aged between 50 and 75 years, 485 participants with immunological fecal occult blood test values of at least 100 ng/ml and/or those with family histories of CRC underwent colonoscopies. Lesions were found in 291 participants, and 642 histologic samples were obtained. Chilean pathologists made the initial histologic diagnoses, and a Japanese pathologist reviewed the histologic slides and analyzed the results. Of the 291 participants with lesions, 60 (20.6%) were diagnosed with adenocarcinomas, of which 50 (83.3%) were early-phase adenocarcinomas (pTis or pT1), and 163 (56.0%) were diagnosed with conventional adenomas, of which 96 (58.9%) were high-risk adenomas. The cancer prevalence within the screened population was 1.5% (60 of 4124). The colonoscopy cancer detection rate was 12.4% (60 of 485). Notably, we detected one flat-depressed (0-IIc) lesion that measured 5 mm and had invaded the submucosa. The findings from this screening program are the first to show the histopathologic distributions of consecutive lesions and the high incidence of CRC in Chile. The high detection rates for high-risk adenomas and cancer support the feasibility of early CRC screening and its potential to reduce the mortality associated with CRC.

Intraperitoneal Administration of Paclitaxel Followed by Paclitaxel, Cisplatin, and S-1 Chemotherapy for Cytology-positive Gastric Cancer: A Feasibility Study.

BACKGROUND/AIM: A preliminary study evaluating the feasibility of single intraperitoneal (IP) administration of paclitaxel followed by paclitaxel and cisplatin with S-1 (PCS) systemic chemotherapy for cytology-positive (CY1) gastric cancer. PATIENTS AND METHODS: Staging laparoscopy was performed to confirm CY1 and P0 status. Initially, patients received IP paclitaxel. Beginning 7 days later PCS was given every 3 weeks followed by second-look laparoscopy. RESULTS: Nine patients were enrolled. The toxic effects of IP and systemic chemotherapy were acceptable. After chemotherapy, 8 patients converted from CY1P0 to CY0P0 and 1 patient from CY1P0 to CY1P1. Gastrectomy was performed on 8 patients except for the CY1P1 patient. Four patients were alive without recurrence. The 2-year overall and progression-free survival rates were 76% and 65%, respectively. CONCLUSION: Combination chemotherapy with IP paclitaxel and sequential PCS is safe and may be effective for CY1 gastric cancer.

Intraperitoneal and Systemic Chemotherapy for Patients with Gastric Cancer with Peritoneal Metastasis: A Phase II Trial.

AIM: To conduct a phase II study of single intraperitoneal (i.p.) administration of paclitaxel followed by paclitaxel, cisplatin, and S-1 (PCS) chemotherapy for patients with gastric cancer with peritoneal metastasis (PM). PATIENTS AND METHODS: Staging laparotomy was performed to confirm PM. Initially, patients received i.p. paclitaxel. Beginning 7 days later, PCS was given every 3 weeks followed by second-look laparoscopy. Primary and secondary endpoints were the overall survival (OS) rate, and response rate and patient safety, respectively. RESULTS: Seventeen patients were enrolled. The overall response rate was 70.5% (12/17). Grade 3/4 toxic effects included neutropenia and leukopenia. After chemotherapy, PM disappearance was confirmed in 11 patients. Gastrectomy was eventually performed in 11 patients. The 1-year OS rate was 82.4% and the median survival time was 23.9 months considering the overall cohort. CONCLUSION: Combination chemotherapy with i.p. paclitaxel and PCS is well tolerated and effective in patients with gastric cancer with PM.

[Results of a multicentric colorectal cancer screening program in Chile]. / Programa multicéntrico de cribado de cáncer colorrectal en Chile.

BACKGROUND: Colorectal Cancer Screening Programs (CRCSP) are widely accepted in developed countries. Unfortunately, financial restrictions, low adherence rate and variability on colonoscopy standardization hamper the implementation of CRCSP in developing countries. AIM: To analyze a multicentric pilot model of CRCSP in Chile. MATERIAL AND METHODS: A prospective model of CRCSP was carried out in three cities, from 2012 to 2015. The model was based on CRC risk assessment and patient education. Health care personnel were trained about logistics and protocols. The endoscopy team was trained about colonoscopy standards. A registered nurse was the coordinator in each center. We screened asymptomatic population aged between 50 and 75 years. Immunological fecal occult blood test (FIT) was offered to all participants. Subjects with positive FIT underwent colonoscopy. RESULTS: A total of 12,668 individuals were enrolled, with a FIT compliance rate of 93.9% and 2,358 colonoscopies were performed. Two hundred and fifty high-risk adenomas and 110 cancer cases were diagnosed. One patient died before treatment due to cardiovascular disease, 74 patients (67%) underwent endoscopic resection and 35 had surgical treatment. Ninety one percent of patients had an early stage CRC (0-I-II). Among colonoscopy indicators, 80% of cases had an adequate bowel preparation (Boston > 6), cecal intubation rate was 97.7%, adenoma detection rate was 36.5%, and in 94.5% of colonoscopies, withdrawal time was adequate (> 8 min). CONCLUSIONS: This CRCS pilot model was associated to a high rate of FIT return and colonoscopy quality standards. Most CRCs detected with the program were treated by endoscopic resection.

A Pilot Trial to Quantify Plasma Exosomes in Colorectal Cancer Screening from the International Collaborative Study between Chile and Japan.

BACKGROUND: In Chile, a national colorectal cancer (CRC) screening program using immunochemical fecal occult blood tests and colonoscopy was started in 2012 as an international collaboration between Chile and Japan. In the present study, we quantified exosomes in the peripheral blood and evaluated the implication of the results for CRC screening. METHODS: A total of 25 peripheral plasma samples from the participants of CRC screening in Punta Arenas, Chile, were analyzed for exosomes. RESULTS: Plasma exosomes were obtained from 5 participants with adenocarcinoma (4 pTis and 1 pT1), 8 with high-grade adenoma, 4 with low-grade adenoma, 4 with hyperplastic polyps, and 4 with normal findings. Participants with adenocarcinoma had significantly higher amounts of plasma exosomes (2.1-3.2 fold) than participants with normal findings, hyperplastic polyps, or low-grade adenoma (p = 0.016, p = 0.0034, and p = 0.0042 respectively; Tukey's multiple comparisons test). The size of the representative lesion, the number of lesions, and the sum of those 2 factors in each participant correlated significantly with the exosome amounts (r = 0.56, r = 0.58, and r = 0.72, respectively; p < 0.01; Spearman's correlation coefficient test). CONCLUSIONS: This pilot study demonstrated that quantification of plasma exosomes is a potential alternative screening method for detecting individuals with a high risk of colorectal malignancy.

Programa multicéntrico de cribado de cáncer colorrectal en Chile / Results of a multicentric colorectal cancer screening program in Chile

Background: Colorectal Cancer Screening Programs (CRCSP) are widely accepted in developed countries. Unfortunately, financial restrictions, low adherence rate and variability on colonoscopy standardization hamper the implementation of CRCSP in developing countries. Aim: To analyze a multicentric pilot model of CRCSP in Chile. Material and Methods: A prospective model of CRCSP was carried out in three cities, from 2012 to 2015. The model was based on CRC risk assessment and patient education. Health care personnel were trained about logistics and protocols. The endoscopy team was trained about colonoscopy standards. A registered nurse was the coordinator in each center. We screened asymptomatic population aged between 50 and 75 years. Immunological fecal occult blood test (FIT) was offered to all participants. Subjects with positive FIT underwent colonoscopy. Results: A total of 12,668 individuals were enrolled, with a FIT compliance rate of 93.9% and 2,358 colonoscopies were performed. Two hundred and fifty high-risk adenomas and 110 cancer cases were diagnosed. One patient died before treatment due to cardiovascular disease, 74 patients (67%) underwent endoscopic resection and 35 had surgical treatment. Ninety one percent of patients had an early stage CRC (0-I-II). Among colonoscopy indicators, 80% of cases had an adequate bowel preparation (Boston > 6), cecal intubation rate was 97.7%, adenoma detection rate was 36.5%, and in 94.5% of colonoscopies, withdrawal time was adequate (> 8 min). Conclusions: This CRCS pilot model was associated to a high rate of FIT return and colonoscopy quality standards. Most CRCs detected with the program were treated by endoscopic resection.

[Laparoscopic Gastrectomy for Gastric Adenocarcinoma of the Fundic Gland Type - Report of a Case].

A 69-year-old man underwent esophagogastroduodenoscopy, which showed a slightly depressed lesion at the greater curvature of the gastric body. We diagnosed gastric adenocarcinoma of the fundic gland type(GA-FG)from examination of the biopsy specimen. Endoscopic submucosal dissection(ESD)was performed for curative resection. The pathological examination revealed a positive vertical margin. Consequently, laparoscopic gastrectomy was additionally performed. GA-FG has recently been proposed as a new entity of gastric adenocarcinoma. GA-FG mostly develops without Helicobacter pylori infection and often invades the submucosa, regardless of size. However, GA-FG rarely demonstrates lymphatic and venous invasion despite deep submucosal invasion. Since most GA-FG cases undergo ESD, few reports of surgical resection exist. Here, we report our experience of laparoscopic gastrectomy for GA-FG.

International collaboration between Japan and Chile to improve detection rates in colorectal cancer screening.

BACKGROUND: In Chile, mortality from colorectal cancer (CRC) has increased rapidly. To help address this issue, the Prevention Project for Neoplasia of the Colon and Rectum (PRENEC) program was initiated in 2012 with intensive support from Tokyo Medical and Dental University (TMDU) in Tokyo, Japan, as part of an international collaboration. METHODS: From June 2012 to July 2014, a total of 10,575 asymptomatic participants were enrolled in PRENEC. Participants with positive immunochemical fecal occult blood test (iFOBT) results or a family history of CRC underwent colonoscopy. The colonoscopy results from a similar, previous project in Chile (PREVICOLON) were compared with those from PRENEC. Furthermore, the initial colonoscopies of 1562 participants in PRENEC were analyzed according to whether the colonoscopists were from TMDU or Chile. RESULTS: The complete colonoscopy, adenoma detection, and cancer detection rates were 88.0%, 26.7%, and 1.1%, respectively, in PREVICOLON, while the corresponding values were 94.4%, 41.8%, and 6.0%, respectively, in PRENEC. In PRENEC, 107 cases of CRC were detected, amounting for 1.0% of all participants. Considering initial colonoscopies in PRENEC, the complete colonoscopy, adenoma detection, and cancer detection rates were 97.4%, 45.3%, and 9.3%, respectively, for physicians at TMDU and 93.3%, 41.5%, and 5.1%, respectively for Chilean physicians. The detection rates of intramucosal cancer were 7.3% and 3.7%, respectively, for TMDU and Chilean physicians. CONCLUSIONS: Quality indicators of colonoscopy substantially improved from PREVICOLON to PRENEC. The assessments made by Chilean physicians alone were improved in PRENEC, but remained better in the TMDU group. Moreover, physicians from TMDU detected more CRCs than Chilean physicians, especially at earlier stages.

A phase II trial of perioperative chemotherapy involving a single intraperitoneal administration of paclitaxel followed by sequential S-1 plus intravenous paclitaxel for serosa-positive gastric cancer.

BACKGROUND AND OBJECTIVES: We carried out a phase II trial to evaluate the feasibility, efficacy, and tolerability of perioperative chemotherapy including single intraperitoneal(IP) administration of paclitaxel(PTX) followed by intravenous(IV) administrations of PTX with S-1 in a neoadjuvant setting for serosa-positive gastric cancer. METHODS: Patients with cT4a gastric cancer were enrolled. A laparoscopic survey was performed before study inclusion for the confirmation of serosal invasion, negative lavage cytology, and negative peritoneal metastasis. IP PTX (80 mg/m(2)) was administered, followed by systemic chemotherapy. Surgery was performed after the completion of chemotherapy. The primary endpoint was the treatment completion rate. RESULTS: 37 patients were recruited. The treatment completion rate was 67.6% (25/37; 90% CI, 52.8-80.1%), which was significantly higher than 50%; we set this as a threshold value (P = 2.4% [one-sided]). 14 patients had target lesions; of these, 10 showed a partial response (71.4%), three had stable disease (21.4%), and one had progressive disease(7.2%). The response rate was 71.4% (10/14). All patients underwent gastrectomy with D2 lymph node dissection. The 3- and 5-year OS rates were 78.0 and 74.9%, respectively. CONCLUSIONS: Perioperative chemotherapy including neoadjuvant IP PTX followed by sequential IV PTX with S-1 for serosa-positive gastric cancer is feasible, safe, and efficient.

Establishment of a novel model of peritoneal carcinomatosis of the peritoneal extension type.

AIM: Patients with scirrhous carcinoma of the gastrointestinal tract frequently develop peritoneal carcinomatosis-particularly of the peritoneal extension type (PET), which has a bad prognosis. We developed a novel animal model, suitable for testing treatments for PET. MATERIAL AND METHODS: In order to develop the model, we scraped the entire peritoneum of Fischer 344 rats with sterile cotton swabs and injected 1 × 10(6) cells of the RCN-9 cell type into the peritoneal cavity. RESULTS: In the novel experimental model, RCN-9 cells adhered only to the exposed basement membrane. The submesothelial layer and fibroblasts in the submesothelial layer grew and increased to a maximum at day 7, then decreased during late-phase peritoneal carcinomatosis. At day 14, RCN-9 cells coated the peritoneum in a manner similar to PET. CONCLUSION: We successfully established a novel animal model of peritoneal carcinomatosis that mimics clinicopathological features of PET. Fibroblasts in the submesothelial layer potentially play an important role in peritoneal carcinomatosis.

C-terminal modification of monoclonal antibody drugs: amidated species as a general product-related substance.

Twelve therapeutic mAbs, comprising 10 IgG1s and 2 IgG4s, were analyzed by a peptide mapping technique to detect and quantify C-terminal modifications. C-terminal amidated structures were found in 8 out of the 12 mAbs. An in vitro study using a commercially available peptidylglycine alpha-amidating monooxygenase (PAM) revealed that both IgG1 and IgG4 can be substrates for PAM. This study showed that C-terminal amidation is a general C-terminal modification on the heavy chains of therapeutic mAbs and that C-terminal amidation of mAbs can be catalyzed by a certain PAM(s) in the Chinese hamster ovary (CHO) cells that are widely used for manufacturing therapeutic mAbs.

Increased apoptotic neuronal cell death and cognitive impairment at early phase after traumatic brain injury in aged rats.

Progressive age-associated increases in cerebral dysfunction have been shown to occur following traumatic brain injury (TBI). Moreover, levels of neuronal mitochondrial antioxidant enzymes in the aged brain are reduced, resulting in free radical-induced cell death. It was hypothesized that cognitive impairment after TBI in the aged progresses to a greater degree than in younger individuals, and that damage involves neuronal degeneration and death by free radicals. In this study, we investigated the effects of free radicals on neuronal degeneration, cell death, and cognitive impairment in 10-week-old (young group) and 24-month-old rats (aged group) subjected to TBI. Young and aged rats received TBI with a pneumatic controlled injury device. At 1, 3 and 7 days after TBI, immunohistochemistry, lipid peroxidation and behavioral studies were performed. At 1, 3 and 7 days post-TBI, the number of 8-hydroxy-2'-deoxyguanosine-, 4-hydroxy-2-nonenal- and single-stranded DNA (ssDNA)-positive cells, and the levels of malondialdehyde around the damaged area after TBI significantly increased in the aged group when compared with the young group (P < 0.05). In addition, the majority of ssDNA-positive cells in both groups co-localized with neuronal cells around the damaged area. There was a significant decrease in the number of surviving neurons and an increase in cognitive impairment after TBI in the aged group when compared with the young group (P < 0.05). These results indicate that following TBI, high levels of free radicals are produced in the aged rat brain, which induces neuronal degeneration and apoptotic cell death around the damaged area, resulting in cognitive impairment.

Appearance of neural stem cells around the damaged area following traumatic brain injury in aged rats.

We have previously reported free radical production after traumatic brain injury (TBI), which induces neural stem cell (NSC) degeneration and death. However, the effects of aging on NSC proliferation around the damaged area following TBI have not been investigated. Therefore, in this study, we used 10-week (young group) and 24-month-old (aged group) rat TBI models to investigate the effects of aging on NSC proliferation around damaged tissue using immunohistochemical and ex vivo techniques. Young and aged rats received TBI. At 1, 3 and 7 days after TBI, immunohistochemical and lipid peroxidation studies were performed. Immunohistochemistry revealed that the number of nestin-positive cells around the damaged area after TBI in the aged group decreased significantly when compared with those in the young group (P < 0.01). However, the number of 8-hydroxy-2'-deoxyguanosine-, 4-hydroxy-2-nonenal- and single-stranded DNA (ssDNA)-positive cells and the level of peroxidation around the damaged area after TBI significantly increased in the aged group, compared with those in the young group (P < 0.01). Furthermore, almost all ssDNA-positive cells in young and aged groups co-localized with NeuN and nestin staining. Ex vivo studies revealed that neurospheres, which differentiated into neurons and glia in culture, could only be isolated from injured brain tissue in young and aged groups at 3 days after TBI. These results indicate that, although there were fewer NSCs that have the potential to differentiate into neurons and glia, these NSCs escaped free radical-induced degeneration around the damaged area after TBI in the aged rat brain.

Neuroprotective effect of (-)-epigallocatechin-3-gallate in rats when administered pre- or post-traumatic brain injury.

Our previous study indicated that consuming (-)-epigallocatechin gallate (EGCG) before or after traumatic brain injury (TBI) eliminated free radical generation in rats, resulting in inhibition of neuronal degeneration and apoptotic death, and improvement of cognitive impairment. Here we investigated the effects of administering EGCG at various times pre- and post-TBI on cerebral function and morphology. Wistar rats were divided into five groups and were allowed access to (1) normal drinking water, (2) EGCG pre-TBI, (3) EGCG pre- and post-TBI, (4) EGCG post-TBI, and (5) sham-operated group with access to normal drinking water. TBI was induced with a pneumatic controlled injury device at 10 weeks of age. Immunohistochemistry and lipid peroxidation studies revealed that at 1, 3, and 7 days post-TBI, the number of 8-Hydroxy-2'-deoxyguanosine-, 4-Hydroxy-2-nonenal- and single-stranded DNA (ssDNA)-positive cells, and levels of malondialdehyde around the damaged area were significantly decreased in all EGCG treatment groups compared with the water group (P < 0.05). Although there was a significant increase in the number of surviving neurons after TBI in each EGCG treatment group compared with the water group (P < 0.05), significant improvement of cognitive impairment after TBI was only observed in the groups with continuous and post-TBI access to EGCG (P < 0.05). These results indicate that EGCG inhibits free radical-induced neuronal degeneration and apoptotic death around the area damaged by TBI. Importantly, continuous and post-TBI access to EGCG improved cerebral function following TBI. In summary, consumption of green tea may be an effective therapy for TBI patients.

High expression of epithelial cellular adhesion molecule in peritoneal metastasis of gastric cancer.

Intraperitoneally administrated epithelial cellular adhesion molecule (EpCAM) monoclonal antibody is a therapeutic agent in patients with malignant effusion in several types of carcinoma. However, the role of EpCAM in peritoneal metastasis (PM) lesions and primary lesions of gastric cancer (GC) is still unclear. Therefore, in this study, we investigated EpCAM expression in GC patients with PM. We investigated the expression of EpCAM in 35PM lesions and 104 biopsy samples as primary lesions. Immunohistochemical staining was performed using the Ventana Benchmark XT (Roche Diagnostics) system. EpCAM expression was evaluated by calculating the total immunostaining score, which is the product of the proportion score and the intensity score. Overexpression was defined as a total score greater than 4. All PM specimens showed overexpression of EpCAM, and GC cells in both the surface layer and the deep layer of the PM showed a high expression of EpCAM. Meanwhile, in the biopsy sample, the expression of EpCAM ranged from none to strong. The EpCAM score results for PM specimens and biopsy samples were 11.0 ± 2.0 and 6.9 ± 3.9, respectively. The difference between the scores was statistically significant (P < 0.05). The intraperitoneally administrated EpCAM antibody might have a anti-cancer effect in PM lesions of GC. Additionally, it can be assumed that only GC cells which express a high level of EpCAM might metastasize to the peritoneum.

Phase II study of single intraperitoneal chemotherapy followed by systemic chemotherapy for gastric cancer with peritoneal metastasis.

BACKGROUND: We conducted a phase II study involving a single administration of intraperitoneal chemotherapy with paclitaxel followed by sequential systemic chemotherapy with S-1+ paclitaxel for advanced gastric cancer patients with peritoneal metastasis. METHODS: Gastric cancer patients with peritoneal metastasis were enrolled. Paclitaxel (80 mg/m(2)) was administered intraperitoneally at staging laparoscopy. Within 7 days, patients received systemic chemotherapy with S-1 (80 mg/m(2)/day on days 1-14) plus paclitaxel (50 mg/m(2) on days 1 and 8), followed by 7-days rest. The responders to this chemotherapy underwent second-look laparoscopy, and gastrectomy with D2 lymph node dissection was performed in patients when the disappearance of peritoneal metastasis had been confirmed. The primary endpoint of the study was overall survival rate. RESULTS: Thirty-five patients were enrolled. All patients were confirmed as having localized peritoneal metastasis by staging laparoscopy. Eventually, gastrectomy was performed in 22 patients. The median survival time of the total patient population and those patients in which gastrectomy was performed was 21.3 and 29.8 months, respectively. The overall response rate was 65.7 % for all patients. The frequent grade 3/4 toxic effects included neutropenia and leukopenia. CONCLUSIONS: Sequential intraperitoneal and intravenous paclitaxel plus S-1 was well tolerated in gastric cancer patients with peritoneal metastasis.