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1.
J Thorac Dis ; 16(5): 3493-3502, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38883652

ABSTRACT

Background: Pneumothorax is a rare but serious complication of septic pulmonary embolism (SPE). SPE is a life-threatening disorder wherein infected thrombi bring infarction of the terminal and small caliber parts of the pulmonary vasculature and develop multiple nodular and cavitary lesions. Interventions other than conservative chest tube drainage for pneumothorax due to SPE have rarely been reported. Here, we present a case of bilateral pneumothorax due to SPE treated with intrapleural minocycline pleurodesis. Case Description: A 72-year-old male patient previously diagnosed as esophageal carcinoma developed metachronous bilateral pneumothorax while treated for brain metastases. Based on blood cultures and chest computed tomography images, he was diagnosed with pneumothorax secondary to SPE due to methicillin-susceptible Staphylococcus aureus bacteremia. Bilateral chest tube drainage was instituted. Continuous air leakage was found bilaterally after chest tube placement. He was treated with broad-spectrum antibiotics based on the susceptibility profile and supportive treatment for sepsis. Approximately 3 weeks later, air leakage significantly reduced. We performed intrapleural minocycline pleurodesis bilaterally to prevent the recurrence of pneumothorax; the left side was firstly treated and the right side was treated 2 weeks later. Both chest tubes were successfully removed two days after procedures. Although the patient finally died of brain metastases 1 month after pleurodesis, he never recurred pneumothorax. Conclusions: Intrapleural minocycline pleurodesis may be one of the useful and efficacious options in terms of treating intractable pneumothorax associated with SPE. Intrapleural minocycline pleurodesis could be a consideration for intractable pneumothorax related to SPE.

2.
Int J Surg Case Rep ; 102: 107805, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36502658

ABSTRACT

INTRODUCTION AND IMPORTANCE: Esophageal perforation due to stereotactic body radiotherapy (SBRT) is rare, and there is no consensus on the treatment strategy. Here, we report two cases of esophageal perforation caused by CyberKnife irradiation managed with distinct surgical approaches. CASE PRESENTATION: Case 1 was a 54-year-old woman who was administered chemotherapy including bevacizumab and underwent CyberKnife SBRT for postoperative ovarian cancer (pStage IIIc) with metastasis in the eighth thoracic vertebra. Thirteen months after irradiation, she suddenly developed right back and anterior thoracic pain and was diagnosed with esophageal perforation. Despite open chest drainage and intercostal muscle (ICM) flap coverage, the fistula could not be closed, leading to pyogenic spondylitis and epidural abscess. Case 2 was of a 58-year-old woman with mediastinal lymph node metastasis 5 years after uterine cancer surgery (pStage Ia) who underwent CyberKnife SBRT. Six months after irradiation, she experienced back pain and was diagnosed with esophageal perforation. After curative esophagectomy, the patient was discharged on postoperative day 22 without any adverse effects. CLINICAL DISCUSSION: Esophageal perforation by SBRT with vascular endothelial growth factor inhibitors (VEGFI) such as bevacizumab has rarely been reported. Considering the impaired wound healing system and blood perfusion caused by radiation therapy and VEGFI, difficulty closing the perforation covered with an ICM flap was hypothesized. CONCLUSION: Late esophageal toxicity from irradiation may cause impaired blood flow and wound healing; therefore, curative esophagectomy, including at the perforation site, is effective.

3.
Diagn Mol Pathol ; 18(4): 219-25, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19861895

ABSTRACT

Currently, surgical treatment for colorectal hepatic metastasis is performed with low mortality and morbidity rates. However, there is no definitive marker that predicts patient outcome. The aim of this study is to identify the molecular predictor of survival along with its clinical properties. Fifty-six patients were surgically treated for colorectal cancer and synchronous hepatic metastasis from January 1994 to December 2004. Clinicopathologic and molecular factors were reviewed in association with overall survival (OS) and disease-free survival (DFS). Chromosome 18q deletion in the primary tumor was a molecular predictor that affected OS (P=0.021). Decreased expression of the Smad4 protein tended to affect the outcome; however, no statistical significance was observed (P=0.29:OS, P=0.45:DFS). Preoperative carcinoembryonic antigen (P=0.013) and carbohydrate antigen 19-9 (CA19-9) (P<0.0001) levels were poor clinical predictors of OS. The number of primary lymph nodes was the only pathologic factor that affected DFS (P=0.0052). The number and diameter of hepatic metastasis had no influence on survival. In conclusion, we demonstrated that chromosome 18q deletion, in conjunction with high carcinoembryonic antigen and CA19-9 levels, is an unfavorable prognostic factor. This novel molecular predictor is helpful in identifying patients who would benefit from surgical resection.


Subject(s)
Adenocarcinoma/genetics , Chromosome Deletion , Chromosomes, Human, Pair 18 , Colorectal Neoplasms/genetics , Liver Neoplasms/genetics , Adenocarcinoma/mortality , Adenocarcinoma/secondary , Adenocarcinoma/surgery , Biomarkers, Tumor/analysis , CA-19-9 Antigen/blood , Carcinoembryonic Antigen/blood , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Colorectal Neoplasms/surgery , Disease-Free Survival , Female , Humans , Japan/epidemiology , Liver Neoplasms/mortality , Liver Neoplasms/secondary , Liver Neoplasms/surgery , Loss of Heterozygosity , Male , Microsatellite Instability , Middle Aged , Prognosis , Survival Rate
4.
Hepatogastroenterology ; 55(85): 1265-8, 2008.
Article in English | MEDLINE | ID: mdl-18795670

ABSTRACT

BACKGROUND/AIMS: The epigenetic pathway of colorectal carcinogenesis has recently become the focus of attention. The most common epigenetic change is the promoter hypermethylation of tumor suppressor genes. Secreted frizzled-related proteins have been identified and are reported to act as inhibitors of the Wnt signaling pathway. It has also been reported that microsatellite unstable cancers show more frequent hypermethylation in tumor suppressor genes and less frequent APC mutation. METHODOLOGY: Fifty-one sporadic colorectal cancers were investigated, of which 22 were MSI-H and 29 were MSI-L/MSS. Methylation-specific polymerase chain reaction was performed to detect the methylation status of SFRP1, 2 and 5 genes. RESULTS: All of the samples showed hypermethylation in the promoter region of SFRP1. MSI-H cancers showed more frequent hypermethylation in SFRP2 than MSI-L/MSS cancers, though there was no statistical significance. SFRP5 promoter hypermethylation was significantly more frequent in MSI-H cancers than in MSI-L/MSS cancers. CONCLUSIONS: SFRPs may act as an important inhibitor of the Wnt signaling pathway in MSI-H cancers.


Subject(s)
Carcinoma/metabolism , Colonic Neoplasms/metabolism , Eye Proteins/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Membrane Proteins/metabolism , Microsatellite Instability , Adaptor Proteins, Signal Transducing , Aged , Carcinoma/genetics , Carcinoma/pathology , Case-Control Studies , Colonic Neoplasms/genetics , Colonic Neoplasms/pathology , DNA Methylation , Eye Proteins/genetics , Female , Gene Silencing , Humans , Intercellular Signaling Peptides and Proteins/genetics , Male , Membrane Proteins/genetics , Middle Aged , Polymerase Chain Reaction
5.
J Surg Oncol ; 97(3): 278-83, 2008 Mar 01.
Article in English | MEDLINE | ID: mdl-18161865

ABSTRACT

BACKGROUND: Extensive genetic and epigenetic analysis of poorly differentiated colorectal adenocarcinomas (Por) has been difficult, as the number of cases is too small. METHODS: We investigated genetic and epigenetic alterations of 53 cases of Por and 53 cases of well-differentiated colorectal adenocarcinomas (WD) to clarify their differences. The cases of WD were matched with the cases of Por for T classification and tumor location, which influence genetic and epigenetic alterations. We evaluated microsatellite instability (MSI) status and loss of heterozygosity (LOH) of four loci (2p, 5q, 17p, 18q), and defined "MSI tumors" as those that showed MSI-H, and "chromosomal instability (CIN) tumors" as those that showed LOH but not MSI-H. Further, we evaluated the methylation status of the hMLH1 and p16 promoter region. RESULTS: MSI tumors were significantly more frequent in Por (22.6%) than in WD (3.8%; P = 0.0041). CIN tumors were significantly less frequent in Por (64.2%) than in WD (83.0%; P = 0.046). Further, methylation of the p16 and hMLH1 promoter region was significantly more frequent in Por than in WD (P = 0.037, P = 0.047, respectively). CONCLUSIONS: Our results indicate that Por tumorigenesis strongly correlates with MSI and methylation of the p16 and hMLH1 promoter region.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Genes, p16/physiology , Nuclear Proteins/genetics , Aged , Case-Control Studies , DNA Methylation , Female , Humans , Male , Microsatellite Instability , Middle Aged , MutL Protein Homolog 1 , Promoter Regions, Genetic/physiology
6.
J Surg Oncol ; 97(1): 69-73, 2008 Jan 01.
Article in English | MEDLINE | ID: mdl-17786972

ABSTRACT

PURPOSE: Chromosome 18q21 deletion and Smad4 protein inactivation have been reported as molecular markers predicting unfavorable outcome in colorectal cancers and, in a previous report, we recently revealed that these molecules are closely associated with distant metastasis, which is one of the clinical factors affecting postoperative survival. However, there has been no discussion as to how these molecules influence another clinical factor, namely, lymph node metastasis. In this report, we studied the significance of chromosome 18q deletion and loss of Smad4 protein expression in association with lymph node metastasis. METHOD: Forty pairs of colorectal cancer specimens were studied; one group was positive for lymph node metastasis while the other was negative. We examined Smad4 protein expression level and chromosome 18q deletion in the two groups. RESULTS: Immunohistochemical staining revealed that more cases showed a weaker stain for Smad4 protein in the lymph node positive group compared with the negative group (P = 0.00075). Furthermore, a higher ratio of 18q21 deletion was observed in the lymph node positive group (P = 0.029). CONCLUSION: We revealed that chromosome 18q deletion and Smad4 protein inactivation are the essential molecular events in the process of lymph node metastasis.


Subject(s)
Chromosomes, Human, Pair 18 , Colorectal Neoplasms/pathology , Loss of Heterozygosity , Smad4 Protein/analysis , Aged , Colorectal Neoplasms/chemistry , Colorectal Neoplasms/genetics , Female , Humans , Immunohistochemistry , Lymphatic Metastasis , Male , Middle Aged
7.
J Surg Oncol ; 96(7): 611-8, 2007 Dec 01.
Article in English | MEDLINE | ID: mdl-17786961

ABSTRACT

CONDENSED ABSTRACT: We compared the methylation status of several loci between right-sided and left-sided colorectal cancers (CRCs). To the best of our knowledge, this is the first to report that left-sided CRCs show significantly less frequent methylation at several loci and CpG island methylator phenotype (CIMP) than right-sided ones. BACKGROUND AND OBJECTIVES: MSI CRC occurs in 10-20% of unselected series of patients with CRC. Somatic hMLH1 promoter methylation is reported to cause MSI in sporadic cases. Many researchers report that MSI CRCs are more frequently located in the right-side colon than MSS CRCs. Though the number is very small, some MSI CRCs are located in the left-side colorectum. We focused on the existence of left-sided MSI CRCs and investigated whether they arise through hMLH1 methylation as they do in right-sided ones. METHODS: Thirty-eight sporadic MSI CRCs were included in the study. The methylation status of the promoter of hMLH1, p16, MINT1, 2 and 31 were examined and the proportions of methylated samples for each locus were compared. RESULTS: The left-sided group showed significantly less frequent methylation in hMLH1, p16, MINT1, 2 and 31. The frequency of CIMP+ samples in the left-sided group was significantly lower than the right-sided group. CONCLUSIONS: Left-sided MSI CRCs show significantly less frequent methylation of hMLH1. They also showed significantly less frequent occurrence of CIMP+ than right-sided ones. It is possible that left-sided MSI CRCs differ from the right-sided ones in the way of acquiring MSI.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Colorectal Neoplasms/genetics , CpG Islands , DNA Methylation , Microsatellite Instability , Nuclear Proteins/genetics , Adult , Aged , Female , Humans , Male , Middle Aged , MutL Protein Homolog 1 , Phenotype
8.
J Clin Pathol ; 60(6): 701-4, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17557871

ABSTRACT

BACKGROUND: Poorly differentiated adenocarcinomas of the colon and rectum (Por) feature the worst prognosis among the various types of colorectal carcinomas. Por is highly associated with microsatellite instability (MSI), although MSI is associated with an improved prognosis in colorectal cancers. AIM: To investigate the influence of MSI on clinicopathological features and survival of patients affected by Por. METHODS: 53 patients affected by Por were investigated. DNA extracted from tumour sections and the corresponding normal tissue was analysed by PCR at five microsatellite loci: BAT25, BAT26, D2S123, D5S346 and D17S250. Tumours with alterations at two or more loci were classified as MSI-Por. The others were classified as microsatellite stability (MSS)-Por. The clinicopathological features and survival of patients with MSI-Por and MSS-Por were investigated. RESULTS: Of the 53 patients who were examined, 12 (22.6%) were MSI-Por, whereas 41 (77.4%) were MSS-Por. Significant differences were found between MSI-Por and MSS-Por regarding the following clinicopathological features: age, gender, lymph-node metastasis (MSI-Por: 4/12; MSS-Por: 33/41), TNM stage (MSI-Por: T1/T2/T3/T4 = 2/6/2/2; MSS-Por: 3/3/19/16) and lymphatic invasion (MSI-Por: 4/10; MSS-Por: 27/35). Kaplan-Meier survival curves and log-rank analysis showed that MSI-Por was associated with better prognosis than MSS-Por, although no significant difference was found. CONCLUSIONS: Compared with MSS-Por, MSI-Por is significantly associated with a low incidence of lymph-node metastases and a low stage. This indicates that MSI-Por is a less aggressive subtype.


Subject(s)
Adenocarcinoma/genetics , Colorectal Neoplasms/genetics , Microsatellite Instability , Adenocarcinoma/pathology , Adenocarcinoma/secondary , Aged , Aged, 80 and over , Cell Differentiation , Colorectal Neoplasms/pathology , DNA, Neoplasm/genetics , Female , Humans , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Staging , Prognosis , Survival Analysis
9.
Clin Cancer Res ; 13(2 Pt 1): 415-20, 2007 Jan 15.
Article in English | MEDLINE | ID: mdl-17255260

ABSTRACT

PURPOSE: Ulcerative colitis (UC) is associated with a high risk of colorectal cancer. To identify genes that could predict the development of cancer in UC, we conducted a DNA microarray analysis using nonneoplastic rectal mucosa of UC patients. EXPERIMENTAL DESIGN: Gene expression in nonneoplastic mucosa of 53 UC patients were examined. Gene expression profiles were examined using human Genome U133 Plus 2.0 gene chip array (Affymetrix). Among 53 UC patients, 10 had UC-associated cancer (UC-Ca group) whereas 43 did not (UC-NonCa group). RESULTS: By comparing gene expression profiles of nonneoplastic rectal mucosae between the UC-Ca and UC-NonCa groups, we could identify 40 genes that were differentially expressed between two groups. The list of discriminating genes included low-density lipoprotein receptor-related protein (LRP5 and LRP6). Previous studies suggested that LRP5 and LRP6 expression promotes cancer cell proliferation and tumorigenesis and are considered as candidate oncogenes. In the present study, both LRP5 and LRP6 showed significantly higher expression in the UC-Ca group, which suggests the importance of these genes in the development of UC-associated colorectal cancers. With the 40 selected discriminating genes, we did class prediction of the development of colorectal neoplasms in UC patients. Using the k-nearest neighbor method and the support vector machine, we could predict the development of UC-associated neoplasms with an accuracy of 86.8% and 98.1%, respectively. CONCLUSIONS: These findings have important implications for the early detection of malignant lesions in UC and may provide directions for future research into the molecular mechanisms of UC-associated cancer.


Subject(s)
Colitis, Ulcerative/complications , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Gene Expression Regulation, Neoplastic , Oligonucleotide Array Sequence Analysis/methods , Colorectal Neoplasms/etiology , Gene Expression Profiling , Genome, Human , Humans , Intestinal Mucosa/pathology , Reproducibility of Results , Risk , Treatment Outcome
10.
Cancer Res ; 66(20): 9804-8, 2006 Oct 15.
Article in English | MEDLINE | ID: mdl-17047040

ABSTRACT

Promoter methylation of the mismatch repair gene plays a key role in sporadic microsatellite instability (MSI) colorectal cancers. However, promoter methylation often occurs in proximal colon cancers, and molecular phenotypes underlying MSI cancers in distal colon have not been fully clarified. Our goal was to clarify the difference between MSI and microsatellite stability (MSS) cancers and, furthermore, to determine distinct characteristics of proximal and distal MSI cancers. By DNA microarray analysis of 84 cancers (33 MSI and 51 MSS), we identified discriminating genes (177 probe sets), which predicted MSI status with a high accuracy rate (97.6%). These genes were related to phenotypic characteristics of MSI cancers. Next, we identified 24 probe sets that were differentially expressed in proximal and distal MSI cancers. These genes included promoter methylation-mediated genes, whose expression was significantly down-regulated in proximal MSI cancers. Among discriminating genes between MSI and MSS, nine methylation-mediated genes showed down-regulation in MSI cancers. Of these, 7 (77.8%) showed down-regulation in proximal MSI cancers. Furthermore, methylation-specific PCR confirmed that frequency of hMLH1 promoter methylation was significantly higher in proximal MSI cancers (P = 0.0317). These results suggested that there is a difference between proximal and distal MSI cancers in methylation-mediated influence on gene silencing. In conclusion, using DNA microarray, we could distinguish MSI and MSS cancers. We also showed distinct characteristics of proximal and distal MSI cancers. The inactivation form of hMLH, per se, differed between proximal and distal MSI cancers. These results suggested that distal MSI cancers constitute a distinct subgroup of sporadic MSI cancers.


Subject(s)
Colorectal Neoplasms/genetics , Microsatellite Instability , Adaptor Proteins, Signal Transducing , Carrier Proteins/biosynthesis , Carrier Proteins/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , DNA Methylation , Gene Expression Profiling , Humans , MutL Protein Homolog 1 , Nuclear Proteins/biosynthesis , Nuclear Proteins/genetics , Oligonucleotide Array Sequence Analysis
12.
Cancer Res ; 66(7): 3370-4, 2006 Apr 01.
Article in English | MEDLINE | ID: mdl-16585155

ABSTRACT

Preoperative radiotherapy has been widely used to improve local control of disease and to improve survival in the treatment of rectal cancer. However, the response to radiotherapy differs among individual tumors. Our objective here was to identify a set of discriminating genes that can be used for characterization and prediction of response to radiotherapy in rectal cancer. Fifty-two rectal cancer patients who underwent preoperative radiotherapy were studied. Biopsy specimens were obtained from rectal cancer before preoperative radiotherapy. Response to radiotherapy was determined by histopathologic examination of surgically resected specimens and classified as responders or nonresponders. By determining gene expression profiles using human U95Av2 Gene Chip, we identified 33 novel discriminating genes of which the expression differed significantly between responders and nonresponders. Using this gene set, we were able to establish a new model to predict response to radiotherapy in rectal cancer with an accuracy of 82.4%. The list of discriminating genes included growth factor, apoptosis, cell proliferation, signal transduction, or cell adhesion-related genes. Among 33 discriminating genes, apoptosis inducers (lumican, thrombospondin 2, and galectin-1) showed higher expression in responders whereas apoptosis inhibitors (cyclophilin 40 and glutathione peroxidase) showed higher expression in nonresponders. The present study suggested the possibility that gene expression profiling may be useful in predicting response to radiotherapy to establish an individualized tailored therapy for rectal cancer. Global expression profiles of responders and nonresponders may provide insights into the development of novel therapeutic targets.


Subject(s)
Rectal Neoplasms/genetics , Rectal Neoplasms/radiotherapy , Combined Modality Therapy , Gene Expression Profiling , Humans , Oligonucleotide Array Sequence Analysis , Predictive Value of Tests , Preoperative Care , Prospective Studies , Rectal Neoplasms/metabolism , Rectal Neoplasms/surgery , Sensitivity and Specificity
13.
Diagn Mol Pathol ; 15(1): 30-4, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16531766

ABSTRACT

Colorectal cancers can progress through 2 pathways of genomic instability: microsatellite instability (MSI) and chromosomal instability (CSI). We investigated the influence of CSI and MSI on clinicopathological features and survival of 35 patients affected by mucinous colorectal cancers (MCRC). MSI status was determined by PCR amplification using 5 standard markers. Evidence for CSI was gathered by identifying loss of heterozygosity (LOH) of 4 loci (2p, 5q, 17p, 18q). We defined "MSI-MCRC" as those that showed MSI-H, and "CSI-MCRC" as those that showed LOH at 1 or more of these sites but did not show MSI-H. Among 35 cases, 18 cases (51.4%) were CSI-MCRC, whereas 11 cases (31.4%) were MSI-MCRC. Significant differences were found between CSI-MCRC and MSI-MCRC regarding the following clinicopathological features: tumor location (P=0.00026), lymph node metastasis (P=0.026), and TNM stage (P=0.026). Kaplan-Meier survival curves and log-rank analysis demonstrated that MSI-MCRC was associated with better prognosis than CSI-MCRC, although no significant difference was found (P=0.10). CSI-MCRC correlates more strongly with lymph node metastasis and advanced stage than MSI-MCRC. This indicates that CSI-MCRC is an aggressive subtype.


Subject(s)
Adenocarcinoma, Mucinous/diagnosis , Chromosomal Instability/genetics , Colorectal Neoplasms/diagnosis , Microsatellite Repeats/genetics , Adenocarcinoma, Mucinous/classification , Adenocarcinoma, Mucinous/secondary , Colorectal Neoplasms/classification , Colorectal Neoplasms/pathology , Disease-Free Survival , Female , Humans , Lymphatic Metastasis , Male
17.
J Gastroenterol ; 40(12): 1155-7, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16378180

ABSTRACT

A case of life-threatening lower gastrointestinal hemorrhage from Crohn's disease is reported. Several promising studies have recently been published that describe superselective embolization for the treatment of massive lower gastrointestinal hemorrhage in patients with bleeding colonic diverticular disease and angiodysplasia, and success rates of 74%-93% have been reported. But in patients with Crohn's disease, successful superselective embolization has rarely been reported. This is a report of successful superselective embolization in a patient with Crohn's disease; this should be the initial treatment of choice in Crohn's disease in an attempt to avoid surgical resection, because repeated resections predispose patients to the development of short-bowel syndrome.


Subject(s)
Crohn Disease/complications , Embolization, Therapeutic/methods , Gastrointestinal Hemorrhage/therapy , Ileal Diseases/therapy , Female , Gastrointestinal Hemorrhage/diagnostic imaging , Humans , Ileal Diseases/diagnostic imaging , Middle Aged , Radiography
18.
Cancer ; 103(10): 2023-9, 2005 May 15.
Article in English | MEDLINE | ID: mdl-15812832

ABSTRACT

BACKGROUND: The clinicopathologic significance of mucinous carcinomas (Muc) of the colon and rectum has been widely discussed, but there have been few studies on Muc regarding genetic and epigenetic alterations. The current study analyzed genetic and epigenetic alterations of Muc to clarify their differences from well differentiated adenocarcinomas (WD). METHODS: Thirty-nine cases of Muc and 39 cases of WD were investigated. Cases of WD were matched with cases of Muc for T classification and tumor location. Microsatellite instability (MSI) status and loss of heterozygosity (LOH) of four loci (2p, 5q, 17p, 18q) were evaluated. The methylation status of the hMLH1 promoter region in Muc was also examined. RESULTS: "MSI tumors" were defined as those that showed MSI-high, and "chromosomal instability (CIN) tumors" were defined as those that showed LOH but not MSI-high. MSI tumors were significantly more frequent in Muc (30.8%) than in WD (5.1%). CIN tumors were significantly less frequent in Muc (53.8%) than in WD (87.2%). In Muc, MSI tumors were significantly more frequent in the proximal colon (55.6%) than in the distal colon (9.5%). Also, methylation of the hMLH1 promoter region in Muc was significantly more frequent in MSI tumors (83.3%) than in CIN tumors (27.8%) (P = 0.0077). CONCLUSIONS: When matched for T classification and tumor location, Muc shows higher rates of MSI and lower rates of CIN than WD.. Muc shows different characteristics according to tumor location, and methylation of the hMLH1 promoter region strongly correlates with Muc tumors showing MSI.


Subject(s)
Adenocarcinoma, Mucinous/genetics , Chromosomal Instability/genetics , Colonic Neoplasms/genetics , Microsatellite Repeats/genetics , Rectal Neoplasms/genetics , Adaptor Proteins, Signal Transducing , Adenocarcinoma, Mucinous/pathology , Base Pair Mismatch/genetics , Carrier Proteins , Case-Control Studies , Chromosomes, Human, Pair 17/genetics , Chromosomes, Human, Pair 18/genetics , Chromosomes, Human, Pair 2/genetics , Chromosomes, Human, Pair 5/genetics , Colonic Neoplasms/pathology , Epigenesis, Genetic/genetics , Female , Humans , Loss of Heterozygosity/genetics , Male , Methylation , Middle Aged , MutL Protein Homolog 1 , Neoplasm Proteins/genetics , Neoplasm Staging , Nuclear Proteins/genetics , Promoter Regions, Genetic/genetics , Rectal Neoplasms/pathology
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