Outcome of Proton Beam Therapy for Primary Hepatocellular Carcinoma with "Unfavorable" Macroscopic Classification

PURPOSE/OBJECTIVE(S)

Transcatheter arterial chemoembolization (TACE) is the standard treatment for early to intermediate-stage hepatocellular carcinoma (HCC) unfit for hepatectomy or radiofrequency/microwave ablation (RFA/MWA). Putting aside its hepatic toxicity, local control of TACE is far from satisfactory, especially with non- "simple nodular type" appearances, to an extent where systemic therapy is suggested to be more beneficial. We here analyzed the outcome of proton beam therapy (PBT) for primary HCC by macroscopic classification.

MATERIALS/METHODS

Primary HCC treated with PBT between 2010 and 2018 were extracted from an all-in treatment database. The macroscopic classification was defined by CT or MRI prior to PBT. Local recurrence was defined as tumor re-enlargement or the appearance of arterial phase hyperenhancement. Adverse events were evaluated by CTCAE v5.0. Overall survival, local control, intrahepatic recurrence-free survival, and extrahepatic recurrence-free survival were determined by the Kaplan-Meier method, and the association with treatment factors was analyzed by log-rank and cox regression model.

RESULTS

A total of 202 primary HCC cases were extracted, all not a candidate for hepatectomy nor RFA/MWA. Out of them, 75 cases were simple nodular type, 79 were simple nodular type with extranodular growth, 38 were confluent multinodular type, and 10 were infiltrative type. 26 cases were HBV positive, and 84 cases were HCV positive. 35 cases had macroscopic vascular invasion (MVI). With a median follow-up period of 3.72 years (IQR: 1.79-5.85years), the 3-year overall survival rate was 68.1% (95% CI 61.0 - 74.3%), the 3-year local control rate was 89.6% (95% CI 83.4-93.5), the 3-year intrahepatic recurrence-free survival rate was 53.7% (95% CI 45.9-60.8%), and the 3-year extrahepatic recurrence-free survival rate was 87.4% (95% CI: 81.5-91.6%). Simple nodular type had better overall survival (73.2% vs 65.2% p = 0.012) and extrahepatic recurrence free survival (96.9% vs 81.9% p<0.01), but there was no statistically significant difference in local control (92.7% vs 87.6% p = 0.06) and intrahepatic recurrence-free survival (62.0% vs 48.5% p = 0.114). Multivariate analysis of risk factors against OS, including age, sex, AFP, MVI, and macroscopic classification, revealed age and macroscopic classification as independent risk factors. Adverse events of grade 3 included 2 cases of gastrointestinal bleeding, 7 cases of liver function disorder, 1 cases of biliary hemorrhage, and 1 case of pleural effusion. Other than one case of early death (2 weeks after treatment) with an unknown causal relationship, there were no adverse events of grade 4 or severe.

CONCLUSION

PBT for non- "simple nodular type" primary HCC appears to be safe and effective, whilst suppression of out-of-field recurrence is needed for further survival prolongment.

Abstract 18: Transcriptomic analysis of mucinous adenocarcinoma in genetically-engineered mouse model

Background and Aim: The nature and characteristic of human mucinous colorectal adenocarcinomas have not been well elucidated yet. We previously reported a genetically-engineered mouse model for colonic neoplasia producing mucin based on inactivation of Transforming Growth Factor β Receptor Type II (Tgfbr2) and Apc (CDX2P-G19Cre;Apc flox/+;Tgfbr2flox/flox), which is useful to investigate the mechanism of tumor formation. This mouse model developed colonic neoplasia from 12 weeks of age. Despite the same genotype, 40% of the tumors were found mucinous adenocarcinoma and 28% were high-grade adenoma. For further investigation, we herein perform transcriptomic analysis to clarify the molecular differences in these two histologically different tumors.

Method: Total RNA were extracted from mucinous adenocarcinomas and high-grade adenomas in CDX2P-G19Cre;Apcflox/+;Tgfbr2 flox/flox mice from fresh frozen tumors (n=3, each). Then, RNA-seq and Gene Set Enrichment Analysis were performed. Samples were sequenced on NovaSeq 6000, and gene sets queried included the Hallmark.

Results: Mucinous adenocarcinoma and high-grade dysplasia were differentially clustered in principal component analysis despite the same genotype. Gene set enrichment analysis showed 19 upregulated signaling pathways including KRAS signaling and epithelial mesenchymal transition, and 8 suppressed signaling pathways including E2F targets and MYC targets in mucinous adenocarcinoma compared to high-grade dysplasia (FDR &lt; 0.05).

Conclusions: By comparing transcriptome of mucinous adenocarcinoma with high-grade adenoma in our mouse model, 27 differential signal pathways were detected. Some of these pathways are presumably associated with the nature and the characteristics of mucinous adenocarcinoma. We are further investigating the effects of these differences in signal pathways and the correlation with human mucinous adenocarcinoma.

Citation Format: Haruki Sada, Hiroaki Niitsu, Hikaru Nakahara, Masashi Miguchi, Naoya Sakamoto, Naohide Oue, Hirotaka Tashiro, Hideki Ohdan, Takao Hinoi. Transcriptomic analysis of mucinous adenocarcinoma in genetically-engineered mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 18.

Development of Pluoronic nanoparticles of fluorocoxib A for endoscopic fluorescence imaging of colonic adenomas

Significance

Current white light colonoscopy suffers from many limitations that allow 22% to 32% of preneoplastic lesions to remain undetected. This high number of false negatives contributes to the appearance of interval malignancies, defined as neoplasms diagnosed between screening colonoscopies at a rate of 2% to 6%.

Aim

The shortcomings of today's white light-based colorectal cancer screening are addressed by colonoscopic fluorescence imaging of preneoplastic lesions using targeted fluorescent agents to enhance contrast between the lesion and the surrounding normal colonic epithelium.

Approach

We describe the development of Pluronic® nanoparticles of fluorocoxib A (FA), a fluorescent cyclooxygenase-2 (COX-2) inhibitor that enables targeted imaging of inflammation and cancer in numerous animal models, for endoscopic florescence imaging of colonic adenomas.

Results

We formulated FA, a fluorescent COX-2 inhibitor, or fluorocoxib negative control (FNC), a nontargeted fluorophore and a negative control for FA, in micellar nanoparticles of FDA approved Pluronic tri-block co-polymer using a bulk solvent evaporation method. This afforded FA-loaded micellar nanoparticles (FA-NPs) or FNC-loaded micellar nanoparticles (FNC-NPs) with the hydrodynamic diameters (D h ) of 45.7 ± 2.5    nm and 44.9 ± 3.8    nm and the zeta potentials ( ζ ) of - 1.47 ± 0.3    mV and - 1.64 ± 0.5    mV , respectively. We intravenously injected B6;129 mice bearing colonic adenomas induced by azoxymethane and dextran-sodium sulfate with FA-loaded Pluronic nanoparticles (FA-NPs). The diffusion-mediated local FA release and its binding to COX-2 enzyme allowed for clear detection of adenomas with high signal-to-noise ratios. The COX-2 targeted delivery and tumor retention were validated by negligible tumor fluorescence detected upon colonoscopic imaging of adenoma-bearing mice injected with Pluronic nanoparticles of FNC or of animals predosed with the COX-2 inhibitor, celecoxib, followed by intravenous dosing of FA-NPs.

Conclusions

These results demonstrate that the formulation of FA in Pluronic nanoparticles overcomes a significant hurdle to its clinical development for early detection of colorectal neoplasms by fluorescence endoscopy.

Abstract 6035: Genetically-engineered mouse model for colonic neoplasia presenting mucinous and microsatellite unstable phenotype

Background and Aim: Mucinous colorectal adenocarcinoma (CRC) is characterized by abundant extracellular mucin which occupies more than 50% of the tumor volume. Mucinous CRCs account for 10% of all CRCs and are likely to be microsatellite unstable including Lynch syndrome. Mucinous CRCs metastasize less frequently. However, once they metastasize, they exhibit resistance to cytotoxic chemotherapeutics, and are associated with poorer prognosis. Although there are some issues to be addressed in mucinous CRCs, mouse models are lacking for mucinous CRCs. Here, we report genetically-engineered mouse models (GEMMs) for mucin-producing colonic tumors with microsatellite instability (MSI), resembling human mucinous CRCs.

Method: To induce genetic alterations specifically in colonic epithelial cells, we used CDX2P-G19Cre transgenic mice. In this mouse model, a 9.5-kb fragment in the CDX2 promoter lesion (CDX2P9.5) regulates Cre expression specifically in colonic epithelium (Hinoi et al. Cancer Research 2007). In addition, 19 guanine nucleotides are inserted just after the first ATG, and Cre only expresses in the epithelial cells in which the number of the guanine tract stochastically turns a multiple of three. This mechanism helps our GEMMs to avoid embryonic death due to the genetic events we introduce. We have also reported that tumors in CDX2P9.5-G19Cre;Apcflox/flox mice have an abnormality in two of four MSI markers, suggesting that the tumors are driven by MSI (Sasada et al. PLoS One 2015). TGFBR2 mutation is frequently seen in human MSI CRCs, and inactivation of both Tgfrbr2 and Apc by Villin-Cre results in small intestinal neoplasm producing mucin. Therefore, to test if Tgfbr2 conditional knockout affects the mucin-producing phenotype in the context of MSI-high in this mouse model, we generated CDX2P-G19Cre;Apcflox/+;Tgfbr2flox/flox.

Results: In CDX2P-G19Cre; Apcflox/+; Tgfbr2 flox/flox mice, colonic neoplasia developed in 27 out of 40 mice. Approximately 60% of the tumors are well-differentiated adenocarcinoma producing mucin, while the remaining 40% are regular colonic adenomas. In these mucinous adenocarcinomas, tumor cells invade into the muscular layer. We also confirmed the immunoreactivity of β-catenin in cytoplasm and nuclei at the invasive front of the tumors in IHC analysis, indicating that these tumors are driven by abnormal Wnt activity. Nearby to the invasive front, there were mucin that were positive for a PAS reaction.

Conclusion: Mucin-producing adenocarcinomas develop in CDX2P9.5-G19Cre;Apcflox/+; Tgfbr2flox/flox mice. This GEMM is a potential mouse model recapitulating human mucinous and microsatellite unstable colorectal adenocarcinoma. The precise mechanism in which mucinous adenocarcinoma develops needs to be elucidated by genomic and transcriptomic analyses.

Citation Format: Haruki Sada, Takao Hinoi, Hiroaki Niitsu, Masashi Miguchi, Naoya Sakamoto, Naohide Oue, Hirotaka Tashiro, Hideki Ohdan. Genetically-engineered mouse model for colonic neoplasia presenting mucinous and microsatellite unstable phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6035.

Cancer-Associated Fibroblasts and Squamous Epithelial Cells Constitute a Unique Microenvironment in a Mouse Model of Inflammation-Induced Colon Cancer

The tumor microenvironment plays a key role in the pathogenesis of colorectal tumors and contains various cell types including epithelial, immune, and mesenchymal cells. Characterization of the interactions between these cell types is necessary for revealing the complex nature of tumors. In this study, we used single-cell RNA-seq (scRNA-seq) to compare the tumor microenvironments between a mouse model of sporadic colorectal adenoma (Lrig1^CreERT2/+;Apc^2lox14/+) and a mouse model of inflammation-driven colorectal cancer induced by azoxymethane and dextran sodium sulfate (AOM/DSS). While both models develop tumors in the distal colon, we found that the two tumor types have distinct microenvironments. AOM/DSS tumors have an increased abundance of two populations of cancer-associated fibroblasts (CAFs) compared with APC tumors, and we revealed their divergent spatial association with tumor cells using multiplex immunofluorescence (MxIF) imaging. We also identified a unique squamous cell population in AOM/DSS tumors, whose origins were distinct from anal squamous epithelial cells. These cells were in higher proportions upon administration of a chemotherapy regimen of 5-Fluorouracil/Irinotecan. We used computational inference algorithms to predict cell-cell communication mediated by ligand-receptor interactions and downstream pathway activation, and identified potential mechanistic connections between CAFs and tumor cells, as well as CAFs and squamous epithelial cells. This study provides important preclinical insight into the microenvironment of two distinct models of colorectal tumors and reveals unique roles for CAFs and squamous epithelial cells in the AOM/DSS model of inflammation-driven cancer.

Translocator protein-targeted photodynamic therapy for direct and abscopal immunogenic cell death in colorectal cancer

Abscopal effect is an attractive cancer therapeutic effect referring to tumor regression at a location distant from the primary treatment site. Immunogenic cell death (ICD) offers a mechanistic link between the primary and remote therapeutic effects by activating favorable anti-tumor immune responses. In this study, we induced ICD in colorectal cancer (CRC) cell lines in vitro and in vivo by targeting the 18 kDa translocator protein (TSPO), a mitochondrial receptor overexpressed in CRC. Photodynamic therapy (PDT) using a TSPO-targeted photosensitizer, IR700DX-6T, caused effective apoptotic cell death in fourteen CRC cell lines. In a syngeneic immunocompetent CRC mouse model, the growth of tumors subjected to TSPO-PDT was greatly suppressed. Remarkably, untreated tumors in the opposing flank also showed marked growth suppression. Dendritic and CD8⁺ T cells were activated after TSPO-PDT treatment, accompanied by decreased Treg cells in both treated and non-treated tumors. In addition, a cancer vaccine developed from TSPO-PDT produced a significant tumor inhibition effect. These results indicate that TSPO-PDT could not only directly suppress tumor growth but also dramatically provoke host anti-tumor immunity, highlighting the potential of TSPO-PDT as a successful therapeutic for CRC that exhibits systemic effects. STATEMENT OF SIGNIFICANCE: Abscopal effect is an attractive cancer therapeutic effect referring to tumor regression at a location distant from the primary treatment site. Immunogenic cell death (ICD) offers a mechanistic link between the primary and remote therapeutic effects by activating favorable anti-tumor immune responses. In this study, we report a new therapeutic approach that can reduce the growth of multiple CRC cell lines by inducing ICD. Notably, a direct and abscopal effect was observed in mouse tumor-derived MC38 cells when injected into syngeneic immunocompetent mice. If comparable effects could be achieved in humans, it would establish a novel paradigm for treating micro- and macro-metastasis.

Molecular Imaging of Inflammation in Osteoarthritis Using a Water-Soluble Fluorocoxib

Clinical imaging approaches to detect inflammatory biomarkers, such as cyclooxygenase-2 (COX-2), may facilitate the diagnosis and therapy of inflammatory diseases. To this end, we report the discovery of N-[(rhodamin-X-yl)but-4-yl]-2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetamide chloride salt (fluorocoxib D), a hydrophilic analog of fluorocoxib A. Fluorocoxib D inhibits COX-2 selectively in purified enzyme preparations and cells. It exhibits adequate photophysical properties to enable detection of COX-2 in intact cells, in a mouse model of carrageenan-induced acute footpad inflammation and inflammation in a mouse model of osteoarthritis. COX-2-selectivity was verified either by blocking the enzyme's active site with celecoxib or by molecular imaging with nontargeted 5-carboxy-X-rhodamine dye. These data indicate that fluorocoxib D is an ideal candidate for early detection of inflammatory or neoplastic lesions expressing elevated levels of COX-2.

Oncogenic mutation in RAS-RAF axis leads to increased expression of GREB1, resulting in tumor proliferation in colorectal cancer

BRAF^V600E mutation accounts for up to 90% of all BRAF mutations in human colorectal cancer (CRC), and constitutively activates the MEK‐MAPK pathway. It is recognized that neutralizing mAbs for epidermal growth factor receptor alone are not effective for CRC with BRAF^V600E mutation. Therefore, there is increasing interest in identification of the possible therapeutic targets in downstream of BRAF mutation in CRCs. To address this, we studied genome engineered mouse models for colonic neoplasia that has Braf^V600E mutation on the basis of Apc inactivation, induced in 2 distinct Cre mouse models, CDX2P‐G22Cre and CDX2P‐CreER^T2 mice. We carried out oligonucleotide microarray analysis for colonic neoplasia generated in these mouse models, and compared gene expression profiles among Kras/Braf WT, Kras‐mutated, and Braf‐mutated mouse colon tumors to seek new molecular targets corresponding to the KRAS‐BRAF‐MAPK axis. We found that the expression of the growth regulation by estrogen in breast cancer protein 1 (Greb1) was the most upregulated gene in Braf‐mutated mouse tumors compared to Kras/Braf WT counterparts. The silencing of GREB1 significantly reduced the proliferation and tumorigenesis of CRC cell lines, whereas the overexpression of GREB1 promoted cell proliferation. Although GREB1 was first identified as a hormone‐responsive gene mediating estrogen‐stimulated cell proliferation in endometriosis, breast, and ovarian cancers, these results suggest that RAS‐RAF‐MAPK signaling upregulates GREB1 expression in CRC, resulting in cellular proliferation. Thus, GREB1 is a possible therapeutic target for CRCs with Braf^V600E mutation.

Synbiotics suppress colitis-induced tumorigenesis in a colon-specific cancer mouse model

Although synbiotics may be effective in maintaining remission of inflammatory bowel disease, their anticarcinogenic effects are still debated. To address this issue, we evaluated the effects of synbiotics, probiotics, and prebiotics on tumorigenesis using a CDX2P-Cre; Apc^+/flox mouse model harboring a colon-specific Apc knock out, which develops adenoma and adenocarcinoma of the colon. Dextran sodium sulfate (DSS)-administration promoted colonic tumor development in CDX2P-Cre; Apc^+/flox mice, and these tumors were associated with loss of Apc heterozygosity, as confirmed by observation of well-differentiated adenocarcinomas with β-catenin accumulation in tumor cell cytoplasm. Synbiotics-treatment suppressed dextran sodium sulfate-induced colitis in CDX2P-Cre; Apc^+/flox mice, thereby reducing mortality, and inhibited tumorigenesis accelerated by DSS-administration. Conversely, neither probiotics nor prebiotics had any effect on inflammation and tumorigenesis. Lactobacillus casei and Bifidobacterium breve were detected in the fecal microbiota of probiotics-treated mice. Synbiotics-treatment suppressed DSS-induced expression of IL-6, STAT-3, COX-2, and TNF-α gene transcripts in normal colonic epithelium, indicating the possibility of suppressing tumor development. Importantly, these genes may be potential therapeutic targets in inflammation-associated colon cancer.

Survival benefit of lymph node dissection in surgery for colon cancer in elderly patients: A multicenter propensity score-matched study in Japan

INTRODUCTION

In surgery for elderly patients with colorectal cancer, it is unclear whether radical lymph node (LN) dissection safely offers a survival benefit. The aim of the study was to evaluate the impact of the LN yield in elderly patients undergoing surgery for colorectal cancer.

METHODS

The subjects were selected from a surgical database of 2065 patients aged ≥80 years old who underwent surgery for colorectal cancer at 41 hospitals in Japan between 2003 and 2007. The patients were divided into groups according to the number LN harvested: <12 and ≥12. Propensity scores were subsequently matched to balance the baseline characteristics.

RESULTS

Of the 954 patients initially selected, 331 were in the <12 LN and 623 were in the ≥12 LN group. After cases were matched, 293 patients were allocated to each group, and all covariates were balanced. For short-term outcomes, the time for surgery was longer in the ≥12 LN group, but there was no significant difference in morbidity between the groups. Overall, relapse-free and cancer-specific survival rates were higher in the ≥12 LN group (P = 0.004, 0.001, and 0.02).

CONCLUSIONS

In patients aged ≥80 years old with stage II-III colon cancer, harvesting ≥12 LN provides a survival benefit, and therefore, limited LN dissection is not recommended in these patients.

Clinical Characteristics and Surgical Treatment for Inguinal Endometriosis in Young Women of Reproductive Age

AIM

To study the characteristics and surgical treatment of inguinal endometriosis (IEM), which can occur in women of reproductive age.

METHODS

Patients who underwent groin surgery at the Hiroshima City Funairi Citizens Hospital between 2004 and 2017 were retrospectively examined. Patients with IEM were divided into 3 groups based on the site of occurrence as follows: at a hernia sac or hydrocele of Nuck's canal (type I), round ligament (type II), or subcutaneous area (type III). Clinical characteristics were compared among groups.

RESULTS

Of 2,798 patients investigated, 28 were pathologically diagnosed as having IEM with 15, 10, and 3 classified as type I, II, and III respectively. All patients presented with a mass (median 20 mm) and/or bulge that mainly occurred at the right inguinal region. Sixteen patients presented with inguinal pain associated with menstruation. While the groups did not differ in terms of most clinical characteristics, the lack of a preoperative diagnosis of IEM occurred more frequently for type I than for types II and III.

CONCLUSIONS

Because IEM-type I might be underdiagnosed preoperatively, complete resection of a hernia sac or hydrocele of Nuck's canal with subsequent pathological examination is required for women of reproductive age with an inguinal disease.

Abstract 4074: Pten haploinsufficiency promotes tumor invasion and carcinogenesis in mouse colon epithelium with Apc deficiency

Background and Aim: The loss of PTEN (phosphatase and tensin homologue) expression in human colorectal cancer (CRC) is found in approximately 40% of cases, and its functional contribution is not fully understood. To address this question, the colon tumors from the Pten-deficient mice with a disruption of the Adenomatous polyposis coli (Apc) were compared with those from the mice with Apc deficiency alone.

Method: To recapitulate human CRC, mouse models carrying transgenes regulated by a 9.5-kb fragment containing sequences from the human CDX2 promoter (CDX2P9.5), which were previously shown to have tightly restricted transgene expression in the colon epithelium, were prepared. CDX2P9.5-NLSCre;Apcflox/+;Ptenflox/+ (referred to as CPC;Apc+Pten mouse) and CDX2P9.5-NLSCre;Apcflox/+(;Pten+/+) mice (referred to as CPC;Apc mouse) were generated, and the overall survival and tumor phenotypes (number, size and severity) at 4, 6, 9, 12 and 15 weeks of age were compared between the two models. In addition, the loss of heterozygosity status of the Apc and Pten wild-type alleles in tumor tissue and normal mucosa in the two mouse models were compared with multiplex polymerase chain reaction (PCR), and Pten transcripts and protein expression were evaluated by quantitative reverse transcription PCR and immunohistochemistry, respectively.

Results: CPC;Apc+Pten mice had a significantly shorter life span than CPC;Apc mice (median survival time of CPC;Apc+Pten mice and CPC;Apc mice: 14.4 weeks [n=20] vs. 21.6 weeks [n=20], respectively). The CPC;Apc+Pten mice had more tumors than CPC;Apc mice at all time points measured, but the tumor size in CPC;Apc+Pten mice was significantly larger than that in CPC;Apc mice only at 9 weeks of age. Invasion into the submucosa was more frequently observed in CPC;Apc+Pten mice than in CPC;Apc mice (CPC;Apc+Pten mice and CPC;Apc mice: 36.3%/58.3% and 4.9%/10% at 12/15 weeks of age, respectively). Regarding the findings on multiplex PCR, while the tumors from both models showed biallelic Apc inactivation, the tumors from CPC;Apc+Pten mice showed no loss of the wild-type allele of Pten. Regarding the Pten transcript levels, the levels in the tumors and mucosa from CPC;Apc+Pten mice were almost half of those in CPC;Apc mice. The Pten protein expression level in tumors from CPC;Apc+Pten mice was lower than that in tumors from CPC;Apc mice but not completely suppressed.

Conclusion: Pten promotes tumor invasion and carcinogenesis without two hits on the gene. Consistent with the previous finding that two hits on the PTEN gene was a rare event in human CRC with PTEN loss, our data strongly suggest the haploinsufficient tumor-suppressive activity of Pten. These findings show that this CPC;Apc+Pten mouse model recapitulates human CRC with PTEN loss.

Citation Format: Haruki Sada, Takao Hinoi, Hiroaki Niitsu, Masatoshi Kochi, Naoya Sakamoto, Kazuhiro Sentani, Naohide Oue, Wataru Yasui, Hideki Ohdan. Pten haploinsufficiency promotes tumor invasion and carcinogenesis in mouse colon epithelium with Apc deficiency [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4074.

Risk factors for postoperative pneumonia in elderly patients with colorectal cancer: a sub-analysis of a large, multicenter, case-control study in Japan

PURPOSE

Postoperative pneumonia affects the length of stay and mortality after surgery in elderly patients with colorectal cancer (CRC). We aimed to determine the risk factors of postoperative pneumonia in elderly patients with CRC, and to evaluate the impact of laparoscopic surgery on elderly patients with CRC.

METHODS

We retrospectively investigated 1473 patients ≥ 80 years of age who underwent surgery for stage 0-III CRC between 2003 and 2007. Using a multivariate analysis, we determined the risk factors for pneumonia occurrence from each baseline characteristic.

RESULTS

Among all included patients, 26 (1.8%) experienced postoperative pneumonia, and restrictive respiratory impairment, obstructive respiratory impairment, history of cerebrovascular events, and open surgery were determined as risk factors (odds ratio [95% confidence interval], 2.78 [1.22-6.20], 2.71 [1.22-6.30], 3.60 [1.37-8.55], and 3.57 [1.22-15.2], respectively). Furthermore, postoperative pneumonia was more frequently accompanied by increasing cumulative numbers of these risk factors (area under the receiver operating characteristic curve = 0.763).

CONCLUSIONS

Laparoscopic surgery may be safely performed in elderly CRC patients, even those with respiratory impairment and a history of cerebrovascular events.

Choline Deficiency Causes Colonic Type II Natural Killer T (NKT) Cell Loss and Alleviates Murine Colitis under Type I NKT Cell Deficiency

Serum levels of choline and its derivatives are lower in patients with inflammatory bowel disease (IBD) than in healthy individuals. However, the effect of choline deficiency on the severity of colitis has not been investigated. In the present study, we investigated the role of choline deficiency in dextran sulfate sodium (DSS)-induced colitis in mice. Methionine-choline-deficient (MCD) diet lowered the levels of type II natural killer T (NKT) cells in the colonic lamina propria, peritoneal cavity, and mesenteric lymph nodes, and increased the levels of type II NKT cells in the livers of wild-type B6 mice compared with that in mice fed a control (CTR) diet. The gene expression pattern of the chemokine receptor CXCR6, which promotes NKT cell accumulation, varied between colon and liver in a manner dependent on the changes in the type II NKT cell levels. To examine the role of type II NKT cells in colitis under choline-deficient conditions, we assessed the severity of DSS-induced colitis in type I NKT cell-deficient (Jα18^-/-) or type I and type II NKT cell-deficient (CD1d^-/-) mice fed the MCD or CTR diets. The MCD diet led to amelioration of inflammation, decreases in interferon (IFN)-γ and interleukin (IL)-4 secretion, and a decrease in the number of IFN-γ and IL-4-producing NKT cells in Jα18^-/- mice but not in CD1d^-/- mice. Finally, adaptive transfer of lymphocytes with type II NKT cells exacerbated DSS-induced colitis in Jα18^-/- mice with MCD diet. These results suggest that choline deficiency causes proinflammatory type II NKT cell loss and alleviates DSS-induced colitis. Thus, inflammation in DSS-induced colitis under choline deficiency is caused by type II NKT cell-dependent mechanisms, including decreased type II NKT cell and proinflammatory cytokine levels.

Increased Calcineurin A Expression Is Associated with a Lower Relapse-Free Survival Rate after Colorectal Cancer Surgery

OBJECTIVE

Increased expression of calcineurin in colorectal cancer (CRC) has been reported. Although the oncogenic function has been suggested, the clinical relevance is still unclear. We herein studied calcineurin expression as a prognostic biomarker in patients receiving curative surgery for stages I-III CRC.

METHODS

In 121 patients with stages I-III CRC treated at Hiroshima University between 1997 and 2003, calcineurin A expression was examined using immunohistochemistry (IHC) staining of surgical specimens. Specimens were considered positive for calcineurin A if any IHC-stained cells were observed within the carcinomatous area, and clinicopathological characteristics and survival outcomes were compared between IHC-positive and -negative groups.

RESULTS

Calcineurin A was preferentially expressed in the cytoplasm of cancer cells, and a median of 8% of the cells (range: 0-80%; interquartile range: 0-22.5%) were stained within the carcinomatous areas. Of 121 cases, 81 were determined as IHC positive while 40 were determined to be negative. Positive expression of calcineurin A, as well UICC-TNM stage, was associated with low relapse-free survival (RFS) rates in multivariate analyses (hazard ratio = 2.92; 95% CI: 1.27-7.92; p = 0.010).

CONCLUSION

Increased calcineurin A expression is associated with lower RFS rates and may have clinical value in predicting recurrence.

Regulation of multidrug resistance 1 expression by CDX2 in ovarian mucinous adenocarcinoma

Epithelial ovarian cancer is an aggressive gynecological malignancy with a high mortality rate. Resistance against chemotherapeutic agents often develops in ovarian cancer patients, contributing to high recurrence rates. The multidrug resistance 1 (MDR1/ABCB1) gene encodes P‐glycoprotein, which affects the pharmacokinetic properties of anticancer agents. We previously reported that the Caudal‐related homeobox transcription factor CDX2 transcriptionally regulates MDR1 expression in colorectal cancer. CDX2 is a factor that influences cancer cell differentiation, malignancy, and cancer progression. We hypothesized that profiling of CDX2 and MDR1 expression could be an effective strategy for predicting anticancer drug resistance. We studied the expression of these factors in clinical samples from ovarian cancer patients. We found that endogenous MDR1 expression was positively associated with CDX2 expression in ovarian mucinous adenocarcinoma. Using ovarian mucinous adenocarcinoma cell lines, we also observed decreased MDR1 expression following inhibition of CDX2 by RNA interference. In addition, CDX2 overexpression in MN‐1 cells, which display low endogenous CDX2, resulted in upregulation of MDR1 expression. CDX2 induced MDR1‐dependent resistance to vincristine and paclitaxel, which was reversed by treatment with the MDR1‐specific inhibitor verapamil. Our findings show that CDX2 promotes upregulation of MDR1 expression, leading to drug resistance in ovarian mucinous adenocarcinoma. Therefore, our study demonstrates the potential of novel chemotherapy regimens based on CDX2 status and MDR1 expression in ovarian mucinous adenocarcinoma.

Laparoscopic surgery for colorectal cancer is safe and has survival outcomes similar to those of open surgery in elderly patients with a poor performance status: subanalysis of a large multicenter case-control study in Japan

BACKGROUND

It remains controversial whether open or laparoscopic surgery should be indicated for elderly patients with colorectal cancer and a poor performance status.

METHODS

In those patients aged 80 years or older with Eastern Cooperative Oncology Group performance status score of 2 or greater who received elective surgery for stage 0 to stage III colorectal adenocarcinoma and had no concomitant malignancies and who were enrolled in a multicenter case-control study entitled "Retrospective study of laparoscopic colorectal surgery for elderly patients" that was conducted in Japan between 2003 and 2007, background characteristics and short-term and long-term outcomes for open surgery and laparoscopic surgery were compared.

RESULTS

Of the 398 patients included, 295 underwent open surgery and 103 underwent laparoscopic surgery. There were no significant differences in the baseline characteristics between open surgery and laparoscopic surgery patients, except for previous abdominal surgery and TNM stage. The median operation duration was shorter with open surgery (open surgery, 153 min; laparoscopic surgery, 202 min; P < 0.001), and less blood loss occurred with laparoscopic surgery (median open surgery, 109 g; median laparoscopic surgery, 30 g; P < 0.001). An operation duration of 180 min or more (odds ratio, 1.97; 95 % confidence interval, 1.17-3.37; P = 0.011) and selection of laparoscopic surgery (odds ratio, 0.41; 95 % confidence interval, 0.22-0.75; P = 0.003) were statistically significant in the multivariate analysis for postoperative morbidity. Moreover, laparoscopic surgery did not result in an inferior overall survival rate compared with open surgery (log-rank test P = 0.289, 0.278, 0.346, 0.199, for all-stage, stage 0-I, stage II, and stage III disease, respectively).

CONCLUSIONS

Laparoscopic surgery in elderly colorectal cancer patients with a poor performance status is safe and not inferior to open surgery in terms of overall survival.

Total colectomy for multiple metachronous colon cancers in a patient with Lynch syndrome

Lynch syndrome (LS) is a disorder caused by mismatch repair gene mutations, which have been recognized to be associated with an increased frequency of colorectal and extracolorectal tumors. However, it remains controversial as to whether total or segmental colectomy should be performed to treat colorectal cancer in patients with LS. A 58-year-old male underwent total colectomy with ileostomy for advanced transverse colon cancer. He was also found to have LS based on his characteristic family history and the findings of a preoperative examination, including a microsatellite instability analysis of past multiple metachronous cancers. The postoperative histological findings showed mucinous adenocarcinoma without lymph node metastasis, and the loss of the MSH2 protein expression was confirmed on an immunohistochemical examination. The present case provided important information on the clinical management of multiple developing metachronous colorectal cancers in patients with LS.

Abstract 2301: The generation of colorectal cancer mouse model based on microsatellite instability and the identification of transforming growth factor-beta signal target

Background & Aims:

The transforming growth factor-beta (TGF-beta) signal is a tumor-suppressor pathway that is commonly inactivated in about 90% of microsatellite instability (MSI) colorectal cancer (CRC). However, there was little evidence what gene is regulated by TGF-beta signal in the multistep progression sequence of CRC. The first aim of the present study was to generate a mouse model that is null for Tgfbr2 and Apc in the colon epithelium and forms tumors in the colon. The second aim was to analyze the tumors that arose in the mice model for the purpose to identify the gene regulated by TGF-beta signal.

Method & Result:

Previously we have described the generation of the ‘CDX2P-G19Cre;Apcflox/flox mice’ (called Apc KO mice) which is randomly null for Apc in the colonic epithelium. By mating Tgfbr2flox/flox mice with Apcflox/flox and CDX2P9.5-G19Cre mice, we have finally generated a mouse model ‘CDX2P-G19Cre;Apcflox/flox;Tgfbr2flox/flox mice’ (called Apc+Tgfbr2 KO mice) which is null for Apc and Tgfbr2. In these model, the tumors with well differentiated adenocarcinoma arose mainly in proximal colon and most of mice died at 4 weeks age due to tumor bleeding. Therefore the mice were harvested at 3 weeks age to evaluate the development of colon tumors. Total RNAs of only cancerous tissue areas were extracted from frozen samples by the laser capture microdissection method. We compared gene expression profiles of these mice's tumors (n = 3, respectively) with Mouse Exon 1.0 ST Array (Affymetrix). Gene X expression of Apc+Tgfbr2 KO mice tumors was most highly upregurated by 9.25-fold compared with Apc KO mice (p = 0.045). The array data was validated by quantitative PCR. For human CRC samples, mutations of repetitive mononucleotide tracts in the coding regions of TGFBR2 were identified by direct sequencing. By immunohistochemical analysis, the expression of X was classified according to the percentage of stained cancer cells. The expression was considered to be ‘positive’ if ≥30% of cancer cells were stained. An analysis demonstrated that 11 (100%) of 11 mutated TGFBR2 cases were positive for X, whereas 10 (66.7%) of 15 wild type TGFBR2 cases were positive (P = 0.033), indicating that high expression of X was correlated with TGFBR2 mutation in human CRCs samples. Additionally, the cell proliferation assay revealed that silencing of X led to a significant reduction in CRC cell proliferation. Conversely, forced expression of X enhanced CRC cell proliferation in vitro.

Conclusion:

We have generated an in vivo model system that Apc and Tgfbr2 were inactivated only in the colonic epithelium and tumors with well differentiated adenocarcinoma arose mainly in proximal colon. The analysis of this model revealed that Gene X is regulated by a TGF-beta signal and likely promotes cell proliferation in CRC.

Citation Format: Masashi Miguchi, Takao Hinoi, Manabu Shimomura, Tomohiro Adachi, Yasufumi Saito, Hiroaki Niitsu, Masatoshi Kochi, Yusuke Sotomaru, Hideaki Ijichi, Tsuneo Ikenoue, Kunitoshi Shigeyasu, Kohji Tanakaya, Kazuhiro Sentani, Naohide Oue, Wataru Yasui, Hideki Ohdan. The generation of colorectal cancer mouse model based on microsatellite instability and the identification of transforming growth factor-beta signal target. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2301. doi:10.1158/1538-7445.AM2015-2301

Abstract 823: Gene expression profiling for oncogenic Kras mutation in mice and human colorectal cancer

Purpose: Oncogenic KRAS mutations are found in 40-50% of human colorectal cancers. However, specific therapeutics has not been yet available. We aimed to search new therapeutic molecular targets or biomarkers in KRAS mutated colorectal cancers.

Experimental design: We generated Apcflox/flox; CDX2P9.5-G22Cre and LSL-KrasG12D; Apcflox/flox; CDX2P9.5-G22Cre mice, that had been considered as sporadic colon cancer mouse model with Kras wild and mutant, respectively. We observed the carcinogenesis at the age of 3-4 weeks by necropsy, and harvested the tumors for gene expression profiling. We compared the gene expression by Microarray (GeneChip, Affymetrix) between each 3 tumors from these mice strains. Genes with &gt;5 fold changes between the two groups were selected as candidate genes, and subsequently narrow these down by bibliographic search for further analyses in human colorectal cancers.

Result: In macroscopic findings, extensive polyps were generated in cecum and proximal colon, but not in other site of gastrointestinal tract. Tumors occurred in the both strains were considered as well differentiated adenocarcinomas in hematoxylin-eosin staining. It was confirmed that tumors generated in Apcflox/flox; CDX2P9.5-G22Cre mice had Cre-targeted Apc 580D alleles and wild-type Kras, and that tumors generated in LSL-KrasG12D; Apcflox/flox; CDX2P9.5-G22Cre mice had both Cre-targeted Apc 580D alleles and activated oncogenic KrasG12D. In the subsequent gene expression profiling, we identified 31 genes with &gt;5 fold change in Microarray analyses. Of these, we focused on some genes that showed lower expression in Kras mutant tumor than in Kras wild type tumor. We confirmed the lower expressions of these genes in murine tumors by quantitative RT-PCR, and the lower expression in early-staged human colorectal cancers with oncogenic KRAS mutant by immunohistochemistry staining. To analyze the functions, the retroviral vectors that lead overexpression of these genes were constructed and infected to SW480 and RKO CRC cell lines. Proliferation and migration is being analyzed using these cell lines.

Conclusion: We identified novel genes associated with oncogenic KRAS mutation, using the analyses of gene expression in colon cancer mouse model.

Citation Format: Hiroaki Niitsu, Takao Hinoi, Yasuo Kawaguchi, Kazuhiro Sentani, Naohide Oue, Yusuke Sotomaru, Tomohiro Adachi, Yasufumi Saito, Masashi Miguchi, Masatoshi Kochi, Manabu Shimomura, Wataru Yasui, Hideki Ohdan. Gene expression profiling for oncogenic Kras mutation in mice and human colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 823. doi:10.1158/1538-7445.AM2015-823

Up-front systemic chemotherapy is a feasible option compared to primary tumor resection followed by chemotherapy for colorectal cancer with unresectable synchronous metastases

Background

In stage IV colorectal cancer (CRC) with unresectable metastases, whether or not resection of the primary tumor should be indicated remains controversial. We aim to determine the impact of primary tumor resection on the survival of stage IV CRC patients with unresectable metastases.

Methods

We retrospectively investigated 103 CRC patients with stage IV colorectal cancer with metastases, treated at Hiroshima University Hospital between 2007 and 2013. Of these, those who had resectable primary tumor but unresectable metastases and received any chemotherapy were included in the study. We analyzed the overall survival (OS) and short-term outcomes between the patients who received up-front systemic chemotherapy (USC group) and those who received primary tumor resection followed by chemotherapy (PTR group).

Results

Of the 57 included patients, 15 underwent USC and 42 PTR. The median survival times were 13.4 and 23.9 months in the USC and PTR groups, respectively (P = 0.093), but multivariate analysis for the overall survival showed no significant difference between the two groups (hazard ratio, 1.30; 95% confidence interval (CI), 0.60 to 2.73, P = 0.495). In the USC group, the disease control rate of primary tumor was observed in 12 patients (80.0%), but emergency laparotomy was required for 1 patient. Morbidity in the PTR group was observed in 18 cases (42.9%).

Conclusions

The overall survival did not differ significantly between the USC and PTR groups. USC may help avoid unnecessary resection and consequently the high morbidity rate associated with primary tumor resection for stage IV CRC with unresectable metastases.

Avoiding restorative proctocolectomy for colorectal cancer in patients with ulcerative colitis based on preoperative diagnosis involving p53 immunostaining: report of a case

The standard operation for colitic cancer in ulcerative colitis (UC) is restorative proctocolectomy; however, sporadic colorectal cancer (CRC) can coincidentally arise in patients with UC and the optimal procedure remains controversial. Therefore, it is crucial to preoperatively determine whether the CRC in UC is a sporadic or colitic cancer. We report a case of avoiding proctocolectomy for sporadic CRC in a patient with UC based on preoperative diagnosis involving p53 immunostaining. A 73-year-old man with CRC in UC had undergone sigmoid colectomy with lymphadenectomy because of the submucosal deep invasion pathologically after endoscopic mucosal resection. The cancer was diagnosed sporadic cancer preoperatively not only based on the endoscopic, clinical, and histological patterns but also that the colon epithelium was unlikely to develop dysplasia as the circumference and unaffected UC mucosa did not detect p53 protein overexpression. Recent reports have shown that the immunohistochemical detection of p53 protein overexpression can be useful for a differential diagnosis and as a predictor of dysplasia and colitic cancer. The analysis of p53 mutation status based on immunostaining of p53 protein expression in the unaffected UC mucosa can be useful for the decision regarding a surgical procedure for CRC in patients with UC.

Abstract 250: Sulindac delayed and suppressed the tumor progression, was not effective on inhibition of tumor initiation in a human colorectal cancer mouse model (CPC;Apc mouse)

Purpose

Non-steroidal anti-inflammatory drugs (NSAIDs) have shown potential as chemopreventive agents against cancer formation, especially colorectal cancers. However, the mechanisms by which these drugs act are not fully understood. In this study, CPC;Apc mice, a human colorectal cancer mouse model treated with sulindac, were evaluated according to tumor initiation and prognosis and gene expression profile of the tumors were analyzed.

Methods

CPC;Apc mice, originating from ApcFlox/wt mice harbor a Cdx2-Cre transgene in which colorectal tumorigenesis was driven by Apc allelic loss and represent a genetic model of human colorectal cancer (CRC) were treated with control (n=20) or sulindac (160ppm, n=22) for 12 weeks and their colorectal tumors were evaluated. Gene expression analysis was performed to identify genes differentially expressed in tumor cells from sulindac-treated mice. The gene expression was validated through quantitative real-time polymerase chain reaction in vivo.

Results

Body weight of mice with control or sulindac was no significantly difference ( P = 0.801). However, we observed that sulindac significantly suppressed the tumor progression relative to untreated controls (the colon tumors size per mouse: median of 4.2mm, range 2.3-5.9 versus 5.0mm, range 3.1-8.7, respectively ; P = 0.007 ), but not the initiation (the colon tumor numbers per mouse: median of 1.5, range 0-5 versus 1.0 tumors, range 0-8 respectively ; P = 0.979) in CPC;Apc mice. We identified some upregulated (n = 6, &gt;1.4 fold ) and downregulated (n = 5, &gt;1.4 fold) target genes by microarray assay. We validated expression of these candidate genes in human colorectal cancer.

Conclusion

We have identified for the first time that sulindac affected tumor progression by delayed and suppressing it, but had no effect on the initiation of tumor in CRC mice model.

Citation Format: Tomohiro Adachi, Takao Hinoi, Yuu Sasaki, Manabu Shimomura, Yasufumi Saito, Masashi Miguchi, Hiroaki Niitsu, Yuusuke Sotomaru, Naohide Oue, Wataru Yasui, Hideki Ohdan. Sulindac delayed and suppressed the tumor progression, was not effective on inhibition of tumor initiation in a human colorectal cancer mouse model (CPC;Apc mouse). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 250. doi:10.1158/1538-7445.AM2014-250

Colonoscopy as a tool for evaluating colorectal tumor development in a mouse model

PURPOSE

A sporadic colon cancer mouse model with conditional mutations in adenomatous polyposis coli (Apc) is biologically relevant for human colorectal cancer (CRC). This study aimed to determine the utility and limitations of colonoscopy for evaluating colon tumors in this mouse model.

METHODS

We compared the estimates of location, size, and miss rate of tumors detected during colonoscopy with those determined by necropsy. Sixty-six CPC-Apc mice originating from Apc (F/wt) mice harbor a Cdx2-Cre transgene in which colorectal tumorigenesis was driven by Apc allelic loss. The sensitivity and specificity of colonoscopy for detecting tumors in a mouse CRC model were investigated.

RESULTS

A strong positive correlation was found between tumor location as measured by colonoscopy and the location determined by necropsy (p < 0.001). A total of 120 tumors were graded during colonoscopy (grades 1-5: 0, 8, 20, 27, and 65 lesions, respectively), and a strong positive correlation was found between the tumor grade determined by colonoscopy and size measured by necropsy (grades 2-5: 2.08, 2.98, 4.02, and 5.09 mm, respectively; p < 0.005). Although the miss rate was 47.1 %, most of the missed tumors (96 %) were in close proximity (within 5 mm) of another tumor.

CONCLUSIONS

A colonoscopic method for the reliable measurement of colorectal tumors in vivo has been established. The application of this technique to mouse models of colon carcinogenesis will provide a better understanding of the dynamics of tumor growth.

Inguinal hernia repair with the mesh plug method is safe after radical retropubic prostatectomy

PURPOSE

We evaluated the safety and efficiency of using the mesh plug method (MP) to repair inguinal hernias in patients with a history of radical retropubic prostatectomy (RRP). We also investigated how RRP influences the development of inguinal hernias and impacts their repair.

METHODS

Among 488 adult male patients who underwent inguinal hernia repair during a recent 5-year period, 37 had a history of RRP. We compared the characteristics and surgical outcomes of the patients who had undergone RRP (post-RRP group) with those who had not (non-RRP group).

RESULTS

All post-RRP hernias were treated by MP. The 37 post-RRP patients had a collective 41 hernias, 40 of which were of the indirect type. The side affected by the hernia did not differ significantly between the groups. We compared the short-term surgical outcomes of the indirect post-RRP hernias vs. the indirect non-RPP hernias without recurrence and incarceration. The operation times, postoperative hospital stay, and mobility rates did not differ significantly between the two groups. The blood loss was almost equal in both groups.

CONCLUSION

Inguinal hernia repair after RRP may be difficult because of inflammatory changes in the preperitoneal cavity, but the surgical outcomes of MP were equivalent in patients with or without a history of RPP in this study. MP is a safe and effective method for post-RPP hernia repair.

[A case of advanced colorectal carcinoma with aggressively growing liver metastases successfully managed with the induction of cetuximab single-agent therapy]

Chemotherapy for advanced colorectal cancer has developed remarkably in recent years. However, medical practitioners are occasionally unwilling to initiate a standard multi-agent chemotherapy regimen for patients whose general condition is poor. We report the case of a patient with aggressively growing liver metastases and impending organ failure and symptoms who was successfully treated with the induction of anti-epidermal growth factor receptor( EGFR) antibody single- agent therapy. With the selection of some biomarkers, induction with anti-EGFR antibody single-agent therapy might be a beneficial therapeutic option for the treatment of colorectal cancer in patients with imminent organ failure and severe symptoms caused by local tumor progression.

Abstract 2716: Oncogenic K-ras mutation associates with GLUT1 expression in mice and human colorectal cancer

Background and aims: Somatic APC defects are present in 75% of sporadic colorectal cancer. K-ras gene mutations found in 40-50%, occur early in the progression to carcinoma, but their functional contribution remains incompletely understood. Previous study reported that GLUT1, encoding glucose transporter-1, was one of the genes consistently up-regulated in colorectal cancer cell lines with K-RAS or BRAF mutations. In this study, we have analyzed tumors from genetically modified mice carrying either mutation in the Apc gene or in combination with another mutation in the K-ras G12D allele. Subsequently, we evaluated whether K-RAS gene mutations associate GLUT1 expression in human colorectal cancer. Methods: Mice carrying transgenes regulated by CDX2 homeobox gene promoter (CDX2P9.5) showed tightly restricted transgene expression in the colon in adult tissues. Cre recombinase transgenes with 22 guanine nucleotides (G22Cre) introduced downstream of the initiating ATG codon, and CDX2P9.5-G22Cre transgenic mice homozygous for the Apc flox allele lived only for 10-27 d after birth due to the tumor in the proximal colon. Mice carrying loxP-flanked Apc alleles homozygously (ApcloxP/loxP, 580S) were intercrossed with Lox-Stop-Lox K-ras conditional mice strain (referred to as LSL-K-ras G12D) to generate CDX2P9.5-G22Cre;Apcflox/flox;LSL-K-ras G12D with K-ras G12D expression (CPC;Apc 580D;Lox-K-ras G12D). Gene expression analyses on the 3 samples from CPC;Apc 580D;Lox-K-ras G12D mice and CPC;Apc 580D;K-ras WT mice were performed with high-density oligonucleotide arrays (GeneChip Mouse Genome 430 2.0 Array). Results: Glut1 was found to be up-regulated significantly in CPC;Apc 580D;Lox-K-ras G12D mice. Immunohistochemical staining revealed that Glut1 protein was up-regulated in CPC;Apc 580D;Lox-K-ras G12D mice. 47 samples of colorectal cancer patients with K-RAS mutations in 18 patients (38.3%) showed GLUT1 expression in 12 patients of 18 K-RAS mutated patients and 8 patients of 29 K-RAS wild-type patients. Conclusions: Using mice carrying conditional solely mutant in the Apc gene or in combination with the K-ras G12D allele, we assessed the relevance of oncogenic K-ras with Glut1 in colorectal cancer. Microarray analysis, quantitative PCR, and immunohistochemistry suggested the association of the K-ras with the Glut1 (Glut1). Our clinical analysis showed K-RAS gene mutations significantly associate GLUT1 expression in human colorectal cancer.

Citation Format: Yasuo Kawaguchi, Takao Hinoi, Tatsunari Sasada, Tomohiro Adachi, Yasufumi Saito, Shinji Miguchi, Hiroaki Niitsu, Hideki Ohdan. Oncogenic K-ras mutation associates with GLUT1 expression in mice and human colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2716. doi:10.1158/1538-7445.AM2013-2716

Using the Objective Structured Assessment of Technical Skills (OSATS) global rating scale to evaluate the skills of surgical trainees in the operating room

Purpose

The education of surgical trainees should be based on an accurate evaluation of their surgical skill levels. In our hospital, the Objective Structured Assessment of Technical Skills (OSATS) is used for this purpose. We conducted this study to demonstrate the validity and accuracy of the OSATS for assessing surgical skills in the operating room (OR) setting.

Methods

Between January, 2007 and December, 2010, the OSATS global rating scale was used to assess several operations in which surgical trainees participated. We assessed ten surgical trainees who participated as the main surgeon or first assistant, and studied the correlation between their postgraduate year and their OSATS score.

Results

The median score of the global rating scale for each trainee improved with each year of experience. The median scores of all trainees in postgraduate years 3, 4, and 5 were significantly different (p < 0.001 for both the main surgeon and first assistant roles; Kruskal–Wallis test).

Conclusion

Using the OSATS global rating scale to assess the surgical skills of trainees in the OR was feasible and effective.

Idiopathic granulomatous gastritis resembling a gastrointestinal stromal tumor

A 41-year-old female presented with a 2 cm gastric submucosal tumor that was suspected to be a gastrointestinal stromal tumor or other malignancy, and local resection of the stomach was performed. However, histopathological examination showed granulomatous gastritis (GG) with a variety of chronic inflammatory cells and multinodular granulomas. Although she had a past history of tuberculosis and advanced breast cancer after surgery, there was no apparent evidence of either tuberculosis or a metastatic tumor. Other causes of GG, such as mycosis, syphilis, sarcoidosis or foreign body reaction were also excluded. There were no clinical features of Crohn's disease as the principal differential diagnosis. Therefore, she was diagnosed to have idiopathic granulomatous gastritis (IGG). IGG is rare with few reports, and this report presents a surgical case of IGG resembling a gastrointestinal stromal tumor.

Laparoscopic Hartmann's procedure for fecal peritonitis resulting from perforation of the left-sided colon in elderly and severely ill patients

BACKGROUND

Traditional treatment for fecal peritonitis resulting from perforation of the left-sided colon has been performed using Hartmann's procedure to reduce the high mortality caused by anastomotic leakage. However, the morbidity rates associated with abdominal incision (due in great part to wound infection, and dehiscence of abdominal fascia) are high. Therefore, we propose using laparoscopic Hartmann's procedure with abdominal incisions only for the port site to reduce the high morbidity associated with the laparoscopic procedure as compared to open surgery.

METHODS

Between April 2008 and July 2011, we treated 16 consecutive patients (median age, 83 years) with fecal peritonitis resulting from perforations in the left-sided colon due to various causes. The American Society of Anesthesiologists score of each patient was either IV or V. Patients underwent a four-port laparoscopic Hartmann's procedure. Specimens were extracted through the stoma site. Irrigation of the abdominal cavity with more than 10 L of saline was performed in every case, as was insertion of three 10-mm silicon drains via the port site into the left- and right subphrenic spaces or the pouch of Douglas.

RESULTS

The median total surgical time was 166 min (range, 123-250 min). There were no intraoperative complications, and there was no need to convert to open surgery. Fourteen patients survived. There was no wound infection or dehiscence of abdominal fascia. Successful laparoscopic reversals of the laparoscopic Hartmann's procedure were performed in all 14 survivors.

CONCLUSIONS

This laparoscopic Hartmann's procedure is a promising surgical strategy for treating fecal peritonitis arising from perforation of the left-sided colon.

[A case of breast cancer with multiple hepatic metastasis successfully treated with S-1/PTX and S-1 chemotherapy]

The case is a woman in her 50's. A total glandectomy was performed for her breast cancer on August 8, 1998, and subsequently chemotherapy(5'-DFUR, CMF, uracil.tegafur, CEF, and docetaxel)as well as radiation therapy and surgical resection have been performed for local recurrence. With multiple hepatic metastasis recognized in September, 2007, chemotherapy combined with S-1/paclitaxel(PTX)has been performed. In view of the side effects such as reduction in appetite and leukocyte, the dosage has been reduced as of the second course of treatment. With the disappearance of hepatic metastasis on CT, 6 courses of S-1monotherapy have been performed after completing 6 courses of chemotherapy combined with S-1/ PTX. As of March, 2009, the therapeutic effect shows that continuous CR and outpatient follow-up have been performed while maintaining QOL. Since any chemotherapy after thirdline treatment for recurrent breast cancer has not been established yet, chemotherapy combined with S-1/PTX is considered to be one of the regimens and therefore, the second and thirdphase clinical tests ahead are expected to bring better outcomes.

Application of quantitative ethanol detector (QED) test kit to measure ethanol concentration in blood samples

In this paper, the applicability of the quantitative ethanol detector (QED) test kit for screening of ethanol concentrations in blood samples was investigated. The pretreatment of blood using the sulfosalicylic acid solution and the three-way stopcock followed by membrane filtration gave satisfactory results. The ethanol concentrations in whole blood samples (n=61) determined by QED correlated well with those determined by gas chromatography; the correlation coefficient indicated 0.990. Because a high correlation coefficient (0.928) was also confirmed in trial by investigators, QED test should be highly considered for ethanol screening in forensic praxis.

Studies on the mechanisms responsible for the formation of focal swellings on neuronal processes using a novel in vitro model of axonal injury

A novel in vitro model of axonal injury using PC12 cells was designed to introduce traumatic alterations on neuronal processes and to identify mechanisms responsible for the formation of focal swellings by observation with phase-contrast and transmission electron microscopes. The injury on the processes was produced by one-dimensional, horizontal oscillation. The fluid shear stress applied by the oscillation did not exceed 380 dyne/cm2. The injured processes showed two forms. One involved an increase in the terminal diameter of the processes and the other entailed beading along the injured portions. Long-term observation of cellular responses to the mechanical insult disclosed that the terminal swelling coincided with the detachment of growth cones from the culture plate. The finding suggests that the detachment of the growth cone destroys the cytoskeletal network, which determines and maintains the cell shape, resulting in spherical deformation of the processes. When the cytoskeletal destruction occurred at non-terminal sites along the processes, spherical deformations developed slowly, and these appeared as beads. The beading also caused the detachment of the growth cones. As the most proximal bead grew, they absorbed the distal segment and their growth cones were pulled proximally with the spreading cytoskeletal destruction. The processes with terminal swellings as well as the bead segments showed regeneration with time evidence of and growth cone formation.

Forced oral opening for cadavers with rigor mortis: two approaches for the myotomy on the temporal muscles

Forensic dentistry plays an essential role in personal identification procedures. An adequate interincisal space of cadavers with rigor mortis is required to obtain detailed dental findings. We have developed intraoral and two directional approaches, for myotomy of the temporal muscles. The intraoral approach, in which the temporalis was dissected with scissors inserted via an intraoral incision, was adopted for elderly cadavers, females and emaciated or exhausted bodies, and had a merit of no incision on the face. The two directional approach, in which myotomy was performed with thread-wire saw from behind and with scissors via the intraoral incision, was designed for male muscular youths. Both approaches were effective to obtain a desired degree of an interincisal opening without facial damage.

[Application of Q.E.D. and Alco-Screen test kits to measurements of ethanol in forensic samples]

We have investigated the applicability of the Q.E.D. (Quantitative Ethanol Detector) and Aloco-Screen test kits for screening ethanol concentrations in forensic samples, such as hemolyzed/decomposed blood, urine and vitreous humor. Because both kits were based on enzymatic color reactions, direct application of the kits to hemoglobin-rich samples gave unsatisfactory results. The deproteinization of blood with trichloroacetic acid followed by membrane filtration overcame such problem. This procedure was also effective for pretreatment of urine and vitreous humor samples to suppress excessive color development in the Alco-Screen test. The ethanol concentrations in whole blood (n = 29), urine (n = 7) and vitreous humor (n = 6) samples determined by the Q.E.D. kit correlated well with those determined by gas chromatography; the correlation coefficients were 0.986, 0.975 and 0.993, respectively. Because of its high specificity and sensitivity to ethanol, Q.E.D. seems to be highly reliable for quantitative estimation of ethanol concentrations in forensic samples. Alco-Screen also had high sensitivity, the specificity to ethanol was relatively low; the color reaction was also observed in the presence of acetone, n-propanol, toluene, methanol, ethylene glycol, methamphetamine, diazepam and dichrovos. Therefore, if forensic samples are analyzed by the Alco-Screen, it is essential to confirm the positive results using other analytical methods.

[Pulmonary complications after allogeneic hematopoietic stem cell transplantation]

We investigated the occurrence of pulmonary complications in patients who underwent allogeneic hematopoietic stem cell transplantation at our institution. Pulmonary complications were observed in 12 out of 60 patients. Interstitial pneumonia developed in 12 cases: 7 idiopathic, 2 cytomegalovirus-associated, 1 P. carinii, 1 HSV, and 1 HHV-6-associated. HSV- and HHV-6-associated pneumonias were exhibited 100 days after transplantation. PCR analysis was diagnostically useful for detection of viral DNA in bronchial alveolar lavage fluid. Respiratory disease with airway obstruction was observed in 4 patients with chronic graft-versus-host disease, and all 4 had a history of interstitial pneumonia. Three patients died of respiratory failure. Mycobacicrium avium complex was detected in 2. Exacerbation of respiratory failure may be associated with mycobacterial infection.

Modulation of allogeneic immune responses by filgrastim (recombinant human granulocyte colony-stimulating factor) in bone marrow transplantation

We examined whether the use of G-CSF would affect the outcome of allogeneic marrow transplantation in humans and mice. Retrospective analysis of 24 patients who had received allogeneic marrow grafts from HLA-identical siblings revealed that the incidence of chronic but not acute graft-versus-host disease (GVHD) was lower in the patients receiving G-CSF than in those not given G-CSF (18% vs. 80%, P = 0.02). There was a difference in serum TNF-alpha levels during the first 3 months after transplant between these two groups. Four out of the ten patients who were not given G-CSF showed elevated serum TNF-alpha levels, whereas there was only one patients with an increased TNF-alpha level among eleven patients who were given G-CSF. With the use of murine acute and chronic GVHD models, we also observed that administration of G-CSF improved the survival of minor GVHD, but not major GVHD, mice. Taken together, these findings suggest that G-CSF down-regulates allogeneic immune responses and is active in modulating alloreactivity in vivo.

Autoantibodies against 70-kDa heat shock proteins (HSP70) in allogeneic bone marrow transplant recipients

We report that autoantibodies against the 70-kDa heat shock protein family (HSP70) were detected in allogeneic bone marrow transplant recipients. Antibodies to HSP70 family proteins were detected in three out of 14 recipients of an allogeneic marrow graft but in none of the seven patients receiving autologous peripheral blood stem cell transplant (PBSCT). Immunoblotting analysis combined with two-dimensional SDS-PAGE revealed that these patients had antibodies to a constitutive 73-kDa/pI 5.5 heat shock protein (HSP73) and to a stress-inducible 72-kDa/pI 5.6 protein (HSP72). This is the first report, to our knowledge, describing the presence of autoantibody against HSP73 in allogeneic marrow transplant recipients. Our results may provide additional insight into the etiology and the pathophysiology of allogeneic transplant-related disorders.

Granulocyte colony-stimulating factor downregulates allogeneic immune responses by posttranscriptional inhibition of tumor necrosis factor-alpha production

We report downregulatory effects of granulocyte colony-stimulating factor (G-CSF) on allogeneic immune responses in vitro. G-CSF did not affect the proliferative response of peripheral blood mononuclear cells (PBMC) against allogeneic Daudi cells but did inhibit tumor necrosis factor (TNF)-alpha secretion. In contrast with G-CSF, granulocyte-macrophage (GM)-CSF and interleukin (IL)-3 enhanced alloactivation-induced TNF-alpha production. G-CSF-mediated suppression of TNF-alpha production was not affected by fixation of stimulators. G-CSF did not inhibit TNF-alpha mRNA expression or accelerate mRNA degradation, whereas pentoxifylline inhibited the expression of TNF-alpha mRNA. These results indicate that G-CSF acts directly on responder cells and modulates TNF-alpha production at posttranscriptional levels. Suppression of TNF-alpha secretion was accompanied by an increase of intracellular cyclic adenosine monophosphate (cAMP) concentration in alloactivated PBMC. The cell-permeable cAMP analogue, dibutyryl cAMP, suppressed TNF-alpha secretion without affecting TNF-alpha mRNA expression. G-CSF showed an inhibitory effect on the development of cytotoxic effector cells against allogeneic Daudi cells. Anti-TNF-alpha monoclonal antibody (MoAb) also inhibited the induction of cytolytic activity, and the inhibitory effects of G-CSF and anti-TNF-alpha MoAb on killer activity generation were overcome by adding exogenous TNF-alpha. Hence, impaired generation of cytolytic effector cells by G-CSF is believed to be the result of reduced TNF-alpha production. Collectively, the results described above suggest that G-CSF downregulates allogeneic immune responses by posttranscriptionally inhibiting TNF-alpha production.

Successful hematopoietic reconstitution with granulocyte colony-stimulating factor in a patient with hypoplastic acute myelogenous leukemia

We describe a 68-year-old Japanese male with hypoplastic acute myelogenous leukemia (AML) who achieved complete hematological reconstitution following granulocyte colony-stimulating factor (G-CSF) administration. The patient had pancytopenia and the bone marrow was hypocellular with 19 to 36% peroxidase-positive blasts without morphological abnormalities suggestive of myelodysplasia. After receiving G-CSF as a supportive therapy for pneumonia, the blood count became normal and the bone marrow was normocellular with less than 5% of blasts. Without subsequent chemotherapy, he relapsed as a form of overt leukemia and died of pneumonia. Chemotherapy may be necessary to maintain remission in hypoplastic AML after hematopoietic reconstitution by G-CSF.

Non-genetic group specific component (GC) observed in a patient with acute non-lymphocytic leukemia

This is the case of a male non-lymphocytic leukemia patient who continuously exhibited non-genetic group specific component (GC). The patient was hospitalized 10 months for treatment. The patient's GC type was GC 2-1A2 upon his admission to the hospital, which was consistent with his parents' type. The additional GC protein isoform appeared during treatment and was detected by polyacrylamide gel isoelectric focusing (PAGIEF). This acquired GC component corresponded to GC 1F in PAGIEF and was thought to have originated from GC 1A2 protein. This phenomenon most probably occurred due to a metabolic abnormality or modification of the GC molecule caused by the disease itself, or by chemotherapy.

Risk factors for hepatosplenic abscesses in patients with acute leukemia receiving empiric azole treatment

The authors retrospectively evaluated 63 febrile neutropenic episodes in 33 consecutive patients with leukemia who received empiric azole treatment for refractory or relapsing fever that occurred despite broad-spectrum antibiotics. In 8 patients (24%), hepatosplenic abscesses (HSA) developed. To identify the risk factors for the development of HSA, the authors compared various characteristics of febrile episodes in those with and without HSA. The risk factors included relapsed status of leukemia (P = 0.04) and Candida colonization of surveillance cultures from the throat (P = 0.03) and stool (P = 0.03). However, the duration of neutropenia, gastrointestinal symptoms, types of chemotherapy, and leukemia subtypes were not correlated with the development of HSA. Based on these results, the authors identified the high risk group for the development for HSA as patients with relapsed leukemia with fungal colonization of gastrointestinal tract during neutropenia despite empiric antifungal treatment with azoles.

Successful vidarabine therapy for adenovirus type 11-associated acute hemorrhagic cystitis after allogeneic bone marrow transplantation

A 36-year-old man underwent an allogeneic BMT for acute lymphoblastic leukemia. Eighteen days later the patient developed sudden onset of painful, gross hematuria due to adenovirus type 11 infection that did not respond to conservative therapy. There was an increase in serum creatinine levels and delayed recovery of the platelet count, associated with hemophagocytosis. After obtaining informed consent, vidarabine, which has been shown to be active against adenovirus in vitro, was started. The patient's symptoms improved within a few days of vidarabine therapy and urine cultures for adenovirus became negative. No serious adverse effects were observed. Vidarabine may be one therapeutic option in life-threatening adenovirus infection.