Suguru Hasegawa

Surgical resection of hilar cholangiocarcinoma: analysis of survival and postoperative complications.

BackgroundSurgery is the only potentially curative treatment for hilar bile duct cancer. This study sought to evaluate the efficacy and feasibility of surgical management of hilar bile duct carcinoma, including radical hepatectomy, at a single institution.MethodsWe performed a retrospective review of 49 consecutive patients who underwent surgery at our hospital between 1990 and 2003.ResultsAltogether, 44 of 49 patients underwent radical hepatectomy combined with caudate lobectomy and lymphadenectomy. One and four patients underwent partial hepatectomy or bile duct resection, respectively. No patients underwent preoperative portal vein embolization. The 5-year survival rate was 39.7%, with a median survival time of 3.75 years. The postoperative morbidity and mortality rates were 46.8% and 2.0%, respectively. Cox’s proportional hazard model revealed that lymph node status and the residual tumor factor were independent prognostic factors. Multivariate analysis revealed that preoperative hyperbilirubinemia, postoperative complications, and extended surgical procedures were independently associated with postoperative hyperbilirubinemia. After potentially curative resection, 39.4% of patients suffered from disease recurrence. In 60% of the total cases, the sites of recurrence were distant metastases.ConclusionSurgery, including radical hepatectomy combined with caudate lobectomy and lymph node dissection, is a feasible, effective treatment for hilar bile duct cancer.

Usefulness of quantitative real-time PCR assay for early detection of cytomegalovirus infection in patients with ulcerative colitis refractory to immunosuppressive therapies

Background: Studies suggest that cytomegalovirus (CMV) infection exacerbates ulcerative colitis (UC) refractory to immunosuppressive therapies. Early and accurate diagnosis of CMV infection is important for the treatment of UC. We evaluated the usefulness of quantitative real‐time polymerase chain reaction (PCR) for detecting CMV infection in inflamed colonic mucosa of patients with UC refractory to immunosuppressive therapies. Methods: From 2003 to 2006, 30 patients (mean age: 41 ± 18 years; 14 men, 16 women) with UC refractory to immunosuppressive therapies were enrolled in the study. We evaluated CMV infection by CMV antigenemia, histologic examination, and quantitative real‐time PCR for CMV using colonic mucosa and investigated the clinical outcomes of antiviral therapy. Results: CMV‐DNA was detected only in the inflamed colonic mucosa in 17 (56.7%) of 30 patients. Of the 17 CMV‐DNA‐positive patients, 4 were positive for CMV antigenemia or inclusion bodies on histologic examination; of the 13 CMV‐DNA‐negative patients none was positive for CMV antigenemia or inclusion bodies. Of the 17 CMV‐DNA‐positive patients, 12 (70.6%) were treated with ganciclovir for 2 weeks and 10 patients went into remission. Two other patients required colectomy after antiviral therapy. In contrast, of the 13 CMV‐DNA‐negative patients 12 (92.3%) achieved remission after intensifying their immunosuppressive therapies. Conclusions: Quantitative real‐time PCR assay for detecting CMV‐DNA is useful for early, accurate diagnosis of CMV infection in patients with UC refractory to immunosuppressive therapies, enabling prompt and appropriate treatment. (Inflamm Bowel Dis 2007)

Comparison of gene-expression profiles between diffuse- and intestinal-type gastric cancers using a genome-wide cDNA microarray

Gastric cancer is the fourth leading cause of cancer-related death in the world. Two histologically distinct types of gastric carcinoma, ‘intestinal’ and ‘diffuse’, have different epidemiological and pathophysiological features that suggest different mechanisms of carcinogenesis. A number of studies have investigated intestinal-type gastric cancers at the molecular level, but little is known about mechanisms involved in the diffuse type, which has a more invasive phenotype and poorer prognosis. To clarify the mechanisms that underlie its development and/or progression, we compared the expression profiles of 20 laser-microbeam-microdissected diffuse-type gastric-cancer tissues with corresponding noncancerous mucosae by means of a cDNA microarray containing 23 040 genes. We identified 153 genes that were commonly upregulated and more than 1500 that were commonly downregulated in the tumors. We also identified a number of genes related to tumor progression. Furthermore, comparison of the expression profiles of diffuse-type with those of intestinal-type gastric cancers identified 46 genes that may represent distinct molecular signatures of each histological type. The putative signature of diffuse-type cancer exhibited altered expression of genes related to cell–matrix interaction and extracellular-matrix (ECM) components, whereas that of intestinal-type cancer represented enhancement of cell growth. These data provide insight into different mechanisms underlying gastric carcinogenesis and may also serve as a starting point for identifying novel diagnostic markers and/or therapeutic targets for diffuse-type gastric cancers.

Laparoscopic versus open intersphincteric resection and coloanal anastomosis for low rectal cancer: intermediate-term oncologic outcomes.

Objective:To compare the surgical outcome and intermediate oncological outcomes for laparoscopic versus open intersphincteric resection (ISR). Background:Intersphincteric resection has been proposed as an alternative to abdominoperineal resection for selected low rectal cancer cases, but the oncological adequacy of laparoscopic ISR has not been established. Methods:A total of 210 consecutive patients with low rectal cancer who underwent ISR between 1997 and 2009 in 2 institutions were evaluated retrospectively. Patients were classified into an open surgery (OS, n = 80) group and a laparoscopy (LAP, n = 130) group. The primary endpoint was 3-year disease-free survival. Results:The major complication rates were similar in the LAP and OS groups (5.4% vs 3.8%, respectively; P = 0.428). However, the LAP group had a shorter hospital stay and time to bowel movement compared with the OS group. In the LAP group, operating time was 16 minutes shorter (P = 0.230) and intraoperative blood loss was less (P = 0.002). Median follow-up was 34 months (interquartile range: 20.0–42.5 months). The local recurrence rates were similar in the 2 groups (LAP, 2.6% vs OS, 7.7%; P = 0.184). The combined 3-year disease-free survival for all stages was 82.1% (95% CI: 73.7–90.2%) in the LAP group and 77.0% (95% CI: 66.9%–86.9%) in the OS group (P = 0.523). Conclusions:Laparoscopic ISR can be performed safely and offers a minimally invasive sphincter-sparing alternative. The oncological adequacy of laparoscopic ISR requires long-term follow-up data, but the intermediate-term outcomes seem equivalent to those achieved with OS.

Identification of secernin 1 as a novel immunotherapy target for gastric cancer using the expression profiles of cDNA microarray

Despite the discovery of multiple TAAs, only a limited number is available for clinical application, particularly against epithelial malignancies. In this study we searched for novel TAAs using expression profiles of gastric cancer examined with cDNA microarray, and identified the SCRN1 gene as a candidate. SCRN1 was confirmed to be expressed in five out of seven gastric cancers with semiquantitative RT‐PCR. With Northern blot analysis, it was detected abundantly in the testis and ovary, but it was barely detectable in 14 other normal human adult organs. Colony formation assay revealed that its augmented expression is associated with promoted cell growth. As these expression profiles and functional features of SCRN1 appeared to be compatible with the characteristics of the hypothesized ideal TAAs, we examined whether SCRN1 protein contains antigenic epitope peptides restricted to HLA‐A*0201. We synthesized the candidate peptides derived from SCRN1, and tried to induce CTLs with each peptide. The CTL clones were successfully induced with a peptide SCRN1‐196 (KMDAEHPEL), and they lyzed not only the peptide‐pulsed targets but also the tumor cells expressing both SCRN1 and HLA‐A*0201 endogenously. These results strongly suggest that SCRN1‐196 is an epitope peptide restricted to HLA‐A*0201. Furthermore, we synthesized an anchor‐modified peptide SCRN1–9 V (KMDAEHPEV), in which leucine at position 9 was substituted for valine to increase the binding affinity to the HLA‐A*0201 molecules. The CTL clones induced by SCRN1–9 V also recognized tumor cells expressing its natural SCRN1 protein endogenously. These results strongly suggest that SCRN1 is a novel TAA and these peptides, both native and modified, may be applicable for cancer vaccines to treat gastric cancer. (Cancer Sci 2006; 97: 411–419)

Induction of Cancer Stem Cell Properties in Colon Cancer Cells by Defined Factors

Cancer stem cells (CSCs) are considered to be responsible for the dismal prognosis of cancer patients. However, little is known about the molecular mechanisms underlying the acquisition and maintenance of CSC properties in cancer cells because of their rarity in clinical samples. We herein induced CSC properties in cancer cells using defined factors. We retrovirally introduced a set of defined factors (OCT3/4, SOX2 and KLF4) into human colon cancer cells, followed by culture with conventional serum-containing medium, not human embryonic stem cell medium. We then evaluated the CSC properties in the cells. The colon cancer cells transduced with the three factors showed significantly enhanced CSC properties in terms of the marker gene expression, sphere formation, chemoresistance and tumorigenicity. We designated the cells with CSC properties induced by the factors, a subset of the transduced cells, as induced CSCs (iCSCs). Moreover, we established a novel technology to isolate and collect the iCSCs based on the differences in the degree of the dye-effluxing activity enhancement. The xenografts derived from our iCSCs were not teratomas. Notably, in contrast to the tumors from the parental cancer cells, the iCSC-based tumors mimicked actual human colon cancer tissues in terms of their immunohistological findings, which showed colonic lineage differentiation. In addition, we confirmed that the phenotypes of our iCSCs were reproducible in serial transplantation experiments. By introducing defined factors, we generated iCSCs with lineage specificity directly from cancer cells, not via an induced pluripotent stem cell state. The novel method enables us to obtain abundant materials of CSCs that not only have enhanced tumorigenicity, but also the ability to differentiate to recapitulate a specific type of cancer tissues. Our method can be of great value to fully understand CSCs and develop new therapies targeting CSCs.

Relationship between 18F-Fluorodeoxyglucose Accumulation and KRAS/BRAF Mutations in Colorectal Cancer

Purpose: Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) has been widely used in the management of colorectal cancer (CRC). However, the relationship between FDG accumulation and KRAS/BRAF mutations has not yet been investigated. The purpose of this study was to investigate whether KRAS/BRAF mutations affect FDG accumulation in CRC. Experimental Design: Retrospective analysis was conducted in 51 patients with CRC who underwent FDG-PET/computed tomographic (CT) scans for staging before primary tumor resection. The maximum standardized uptake value (SUVmax) for the primary tumor and the tumor-to-liver ratio (TLR) were calculated from FDG accumulation and compared between KRAS/BRAF mutated and wild-type groups. Expression levels of glucose transporter-1 (GLUT1) and hexokinase type-II (HXK-II) were assessed by immunohistochemical analysis. Results: Both SUVmax and TLR were significantly higher in the KRAS/BRAF-mutated group compared with the wild-type group (P = 0.006 and 0.001, respectively). Multivariate analysis indicated that SUVmax and TLR remained significantly associated with KRAS/BRAF mutations (P = 0.016 and 0.01, respectively). KRAS/BRAF status could be predicted with an accuracy of 75% when a SUVmax cutoff value of 13 or 14 was used. GLUT1 expression in cancer cells was positively correlated with FDG accumulation and KRAS/BRAF status whereas HXK-II expression was not. Conclusion: FDG accumulation was higher in CRC with KRAS/BRAF mutations. FDG-PET/CT scans may be useful for predicting the KRAS/BRAF status of patients with CRC and thus aid in determination of therapeutic strategies for patients with CRC. Clin Cancer Res; 18(6); 1696–703. ©2012 AACR.

Identification of immunoglobulin superfamily 11 (IGSF11) as a novel target for cancer immunotherapy of gastrointestinal and hepatocellular carcinomas

We previously performed gene expression profile analyses of 20 intestinal‐type gastric cancers, and identified a set of genes whose expression levels were elevated in cancer tissues compared to their corresponding non‐cancerous tissues. In the present study we focused on the immunoglobulin superfamily 11 gene (IGSF11). Its expression was also elevated in colorectal cancers and hepatocellular carcinomas as well as intestinal‐type gastric cancers. Northern blot analysis showed that it was expressed abundantly in testis and ovary. These data suggest that IGSF11 is a good candidate of cancer‐testis antigen. Furthermore, suppression of IGSF11 by siRNA retarded the growth of gastric cancer cells. To investigate the possibility of clinical application of peptide vaccine to IGSF11, we synthesized candidate epitope peptides for IGSF11 and tested whether the peptides elicit IGSF11‐specific CTL. As a result, we successfully established oligo‐clonal CTL by stimulation with IGSF11‐9‐207 (ALSSGLYQC). In addition, we also established additional CTL using IGSF11‐9V (ALSSGLYQV), anchor‐modified peptides of IGSF11‐9‐207. These peptides showed IGSF11‐specific cytotoxic activity in an HLA‐A*0201‐restricted fashion, suggesting that these peptides may be applicable for cancer immunotherapy. These findings have provided a novel insight into carcinogenesis of the stomach, colon and liver, and will be helpful for the development of novel therapeutic strategies to a wide range of human cancers. (Cancer Sci 2005; 96: 498 –506)

Esophagojejunostomy through minilaparotomy after laparoscopic total gastrectomy

Although laparoscopic distal gastrectomy (LDG) has been accepted as a surgical option for the treatment of early gastric cancer, laparoscopic total gastrectomy (LTG) has been adopted less often, because a more difficult surgical technique is required for reconstruction. To reduce the technical difficulties, we made some modifications to the functional end-to-end anastomosis technique and performed esophagojejunal anastomosis through a minilaparotomy. First, for easier handling of the esophagus, the first application of the linear stapler to create the esophagojejunal anastomosis was performed before transection of the esophagus. Second, the jejunal limb was anastomosed to the left side of the esophagus, which, compared with the right side, made available more free space, sufficient to operate the stapling device. Third, to close the entry hole and complete the gastrectomy concurrently, a linear stapler was applied through the left lower trocar. With this technique, the closure of the access opening was performed easily and was monitored directly through the minilaparotomy. We successfully performed LTG with Roux-en-Y reconstruction using our modified procedure in seven patients without any anastomotic complications. We believe our procedure is a secure and reliable method for reconstruction after LTG and will facilitate adoption of LTG as a surgical option for patients with early upper gastric cancers.

Open versus laparoscopic resection of primary tumor for incurable stage IV colorectal cancer: a large multicenter consecutive patients cohort study.

Objective:To investigate the hypothesis that laparoscopic primary tumor resection is safe and effective when compared with the open approach for colorectal cancer patients with incurable metastases. Background:There are only a few reports with small numbers of patients on laparoscopic tumor resection for stage IV colorectal cancer. Methods:Data from consecutive patients who underwent palliative primary tumor resection for stage IV colorectal cancer between January 2006 and December 2007 were collected retrospectively from 41 institutions. Short- and long-term outcomes were compared between patients who underwent laparoscopic or open resection. Results:A total of 904 patients (laparoscopic group: 226, open group: 678) with a median age of 64 years (range: 22–95) were included in the analysis. Conversion was required in 28 patients (12.4%) and the most common reasons for conversion (23/28: 82%) were bulky or invasive tumors. There was no 30-day postoperative mortality in either group. The complication rate (NCI-CTCAE grade 2–4) after laparoscopic surgery (17%) was significantly lower than that after open surgery (24%) (P = 0.02), and the difference was greater (4% vs 12%; P < 0.001) when we limited the analysis to severe (≥grade 3) complications. The median length of postoperative hospital stay in the laparoscopic group was significantly shorter than that in the open group (14 vs 17 days; P = 0.002). In univariate analysis, overall survival for the laparoscopic group was significantly better than that for open surgery (median survival time: 25.9 vs 22.3 months, P = 0.04), although no difference was apparent in multivariate analysis. Conclusions:Compared with open surgery, laparoscopic primary tumor resection has advantages in the short term and no disadvantages in the long term. It is a reasonable treatment option for certain stage IV colorectal cancer patients with incurable disease.