• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1545-1551
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• 2015

Purpose: Rectal cancers with high microsatellite-instable have clinical and pathological features that differentiate them from microsatellite-stable or low-frequency carcinomas, which was studied rarely in stage II rectal cancer, promoting the present investigation of the usefulness of microsatellite-instability status as a predictor of the benefit of adjuvant chemotherapy with fluorouracil in stage II rectal cancer. Patients and Methods: Data of 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2008 to 2012 were retrospectively collected. All patients experienced a total mesorectal excision (TME) operation. Survival analysis were analyzed using the Cox regression method. Results: Five-year rate of disease-free survival (DFS) was noted in 390 (84.8%) of 460 patients with stage II rectal cancer. Of 460 tissue specimens, 97 (21.1%) exhibited high-frequency microsatellite instability. Median age of the patients was 65 (50-71) and 185 (40.2%) were male. After univariate and multivariate analysis, microsatellite instability (p= 0.001), female sex (p<0.05) and fluorouracil-based adjuvant chemotherapy (p<0.001), the 3 factors were attributed to a favorable survival status independently. Among 201 patients who did not receive adjuvant chemotherapy, those cancers displaying high-frequency microsatellite instability had a better 5-year rate of DFS than tumors exhibiting microsatellite stability or low-frequency instability (HR, 13.61 [95% CI, 1.88 to 99.28]; p= 0.010), while in 259 patients who received adjuvant chemotherapy, there was no DFS difference between the two groups (p= 0.145). Furthermore, patients exhibiting microsatellite stability or low-frequency instability who received adjuvant chemotherapy had a better 5-year rate of DFS than patients did not (HR, 5.16 [95% CI, 2.90 to 9.18]; p<0.001), while patients exhibiting high-frequency microsatellite instability were not connected with increased DFS (p= 0.696). It was implied that female patients had better survival than male. Conclusion: Survival status after anterior resection of rectal carcinoma is related to the microsatellite instability status, adjuvant chemotherapy and gender. Fluorouracil-based adjuvant chemotherapy benefits patients of stage II rectal cancer with microsatellite-stable or low microsatellite-instable, but not those with high microsatellite-instable. Additionally, free of adjuvant chemotherapy, carcinomas with high microsatellite-instable have a better 5-year rate of DFS than those with microsatellite-stable or low microsatellite-instable, and female patients have a better survival as well.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8027-8034
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• 2014

Genetic instability contributes to the development and progression of gastric cancer, one of the leading causes of cancer death worldwide. Microsatellite instability (MSI) has been hypothesized to be involved in carcinogenesis, althgough its mechanisms and exact roles in gastric cancer remain largely unknown. Our aim was to identify associated clinicopathological characteristics and prognostic value of MSI in gastric cancer and precancerous lesions including gastritis, metaplasia, dysplasia, and adenoma. Because mitochondrial DNA has a different genetic system from nuclear DNA, the results of both nuclear MSI and mitochondrial MSI in gastric cancer were reviewed. This review provides evidence that genetic instability of nuclear and mitochondrial DNAs contributes to early stages of gastric carcinogenesis and suggests possible roles in predicting prognosis.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.260-265
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• 2005

Purpose: The protein kinase Chk1 is required for cell cycle arrest in response to DNA damage and is shown to play an important role in the G2/M checkpoint. The aim of this study was to investigate the relationship between microsatellite instability and frameshift mutation of the Chk1 gene in gastric cancers. Materials and Methods: The microsatellite instability was analyzed in 95 primary gastric carcinomas by using microdissection and 6 microsatellite markers. We also peformed single strand conformational polymorphism and sequencing to detect frameshift mutation of the Chk1 gene. Results: We found positive microsatellite instability in 19 (20%) of the 95 gastric cancers, 13 high- and 6 low-frequency microsatellite instability cases. The frameshift mutation of Chk1, which resulted in a truncated Chk1 protein, was detected in two high-frequency microsatellite instability cases. Conclusion: These data suggest that the microsatellite instability may contribute to the development of gastric carcinomas through inactivation of Chk1.

• Journal of Digestive Cancer Research
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• v.10 no.2
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• pp.117-119
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• 2022

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.180-190
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• 2000

Background: Genomic instability, which is manifested by the replication error(RER) phenotype, has been proposed for the promotion of genetic alterations necessary for carcinogenesis. Merlo et al. reported frequent microsatellite instability in primary small cell lung cancers. However, Kim et al. found that instability occurred in only 1% of the loci tested and did not resemble the replication error-positive phenotype. The significance of microsatellite instability in the tumorigenesis of small cell lung cancer as well as the relationship between microsatellite instability and its clinical prognosis was investigated in our study. Methods: Fifteen primary small cell lung cancers were chosen for this study. The DNAs extracted from paraffin-embedded tissue blocks with primary tumor and corresponding control tissue were investigated. Forty microsatellite markers on chromosome 1p, 2p, 3p, 5q, 6p, 6q, 9p, 9q, 13q, and 17p were used in the microsatellite analysis. Results: Thirteen(86.7%) of 15 tumors exhibited LOH in at least one of the tested microsatellite markers. Three of 13 tumors exhibiting LOH lost a larger area in chromosome 9p. LOH was shown in 72.7% on chromosome 2p, 40% on 3p, 50% on 5q, 46.7% on 9p, 69.2% on 13q, and 66.7% on 17p(Table 1). Nine(60%) of 15 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Nine cases exhibiting shifted bands showed altered loci ranging 2.5~52.5%(mean $9.4%\pm16.19$)(Table 2). Shifted bands occurred in 5.7% (34 of 600) of the loci tested(Table 2). Nine cases with shifted bands exhibited LOH ranging between 0~83.3%, and the median survival duration of those cases was 35 weeks. Six cases without shifted bands exhibited LOH ranging between 0~83.3%, and the median survival duration of those cases was 73 weeks. There was no significant difference between median survival durations of the two groups(p=0.4712). Conclusion: Microsatellite instability as well as the inactivation of several tumor suppressor genes may play important roles in the development and progression process of tumors. However, the relationship between microsatellite instability and its clinical prognosis in primary small cell lung cancer could not be established.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.2
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• pp.59-63
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• 2014

The death toll of Colorectal Carcinoma in Korea was 1,826 and 7,721 in the years 1992 and 2011, respectively. This rate of increase was shown to be more than 4.23 times higher than that of any other form of cancer. Therefore, Colorectal Carcinoma requires various diagnostic methods, and Microsatellite Instability (MSI) was applied as a new diagnostic tool. From this study with several microsatellite markers, only marker #13 was detected and observed D13S160 13% (4/30), D13S292 13% (4/30), D13S153 10% (3/30) in order. From the results of amplication with microsatellite marker, D13S292 37% (11/30), D13S153 33% (10/30), D13S160 33% (10/30) in order were shown. The appearance of a genetic mutation, which depends on the loci of Colorectal Carcinoma, was shown amplication from rectal cancer (3.77) which was higher than that of right Colorectal Carcinoma (2.08) (p<0.018). The genetic mutation with lymph node (4.13) appeared higher than normal (1.93) (p<0.001). There were no great differences in the genetic mutation dependent on disease, histological classification and increased group of serum CEA. Accordingly, it is suggested that the correct primers, which can evaluate MSI well from colorectal carcinoma, should be chosen and that MSI be considered a good prognosis and quality control tool.

• Journal of Gastric Cancer
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• v.4 no.2
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• pp.109-120
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• 2004

Purpose: Individual gastric cancers demonstrate complicated genetic alterations. The PCR-based analysis of polymorphic microsatellite sequences on cancer-related chromosomes has been used to detect chromosomal loss and microsatellite instability. For the purpose of preoperative usage, we analyzed the correspondance rate of the microsatellite genotype between endoscopic biopsy and surgical specimens. Materials and Methods: Seventy-three pairs of biopsy and surgical specimens were examined for loss of heterozygosity and microsatellite instability by using 40 microsatellite markers on eight chromosomes. Microsatellite alterations in tumor DNAs were classified into a high-risk group (baselinelevel loss of heterozygosity: 1 chromosomal loss in diffuse type and high-level loss of heterozygosity: 4 or more chromosomal losses) and a low-risk group (microsatellite instability and low-level loss of heterozygosity: 2 or 3 chromosomal losses in diffuse type or $1\∼3$ chromosomal losses in intestinal type) based on the extent of chromosomal loss and microsatellite instability. Results: The chromosomal losses of the biopsy and the surgical specimens were found to be different in 21 of the 73 cases, 19 cases of which were categorized into a genotype group of similar extent. In 100 surgical specimens, the high-risk genotype group showed a high incidence of nodal involvement (19 of 23 cases: $\leq$5 cm; 23 of 24 cases: >5 cm) irrespective of tumor size while the incidence of nodal involvement for the low-risk genotype group depended on tumor size (5 of 26 cases: $\leq$5 cm; 18 of 27 cases: >5 cm). Extraserosal invasion was more frequent in large-sized tumor in both the high-risk genotype group ($\leq$5 cm: 12 of 23 cases; >5 cm: 23 of 24 cases) and the low-risk genotype group ($\leq$5 cm: 7 of 26 cases; >5 cm: 16 of 27 cases). The preoperative prediction of tumor invasion and nodal involvement based on tumor size and genotype corresponded closely to the pathologic tumor stage (ROC area >0.7). Conclusion: An endoscopic biopsy specimen of gastric cancer can be used to make a preoperative genetic diagnosis that accurately reflect the genotype of the corresponding surgical specimen.

• Journal of Chest Surgery
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• v.33 no.1
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• pp.60-67
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• 2000

Background: Microsatellites are short-tandem repeated uncleotide sequences present throughout the human genome. Alterations of microsatellites have been termed microsatellite instability(MI). It has been generally known that microsatellite instability detected in hereditary non-polyposis colorectal cancer (HNPCC) reflects genetic instability that is caused by impairments of DNA mismatch repair system regarding as a novel tumorigenic mechanism. A number of studies reported that MI occurred at varying frequencies in non-small cell lung carcinoma (NSCLC). However It has been unproven whether MI could be a useful market of genetic instability and have a clinical significance in NSCLC. Material and Method : We have examined whether MI can be observed in thirty NCSLC using polymerase chain reaction whether such alterations are associated with other molecular changes such as p53, K-ras and c-myc oncoproteins expression detected by immunohistochemical stain,. Result: MI(+) was observed in 16.6%(5/30) and MI(-) was 83.3% (25/30) Average age was 50$\pm$7.5 year-old in MI(+) group and 57$\pm$6.6 year-old in MI(-) group. Two year survival rate in MI(=) group (20% 1/5) was worse than MI(-) group (64% 16/25) with a statistic difference. (P=0.04) The positive rate of K-ras oncoprotein expression and simultaneous expression of 2 or 3 oncoproteins expression were higher in MI(+) group than MI(-) group with a statistic difference(P=0.05, P=0.01) Conclusion: From, these results the authors can conclude that MI is found in some NSCLC and it may be a novel tumorigenic mechanism in some NSCLC. We also conclude that MI could be used as another poor prognostic factor in NSCLS.

• Journal of Gastric Cancer
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• v.3 no.4
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• pp.214-220
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• 2003

Purpose: The aim of this study was to investigate the frequency of loss of heterozygosity and the microsatellite instability at multiple tumor suppressor gene loci in gastric adenocarcinomas. Materials and Methods: Loss of heterozygosity and the microsatellite instability at several tumor suppressor gene loci were analyzed in 29 primary gastric carcinomas by using microdissection and the polymerase chain reaction. Results: Twenty-three ($79\%$) of the 29 cases demonstrated loss of heterozygosity at one or more loci. The frequency of loss of heterozygosity at the p53 locus was the highest ($63\%$) and those at the VHL, APC, p16, Rb, MEN1, BRCA1, DPC4, 3p21, and 16p13 region were $41\%,\;36\%,\;19\%,\;29\%,\;33\%,\;26\%,\;21\%,\;32\%,\;and\;11\%$, respectively. Compared with histological type, loss of heterozygosity was more common in diffuse-type gastric cancer (P<0.01). Interestingly, 9 of 10 tumors with allelic deletion at the p53 locus showed loss of heterozygosity at other tumor suppressor gene loci. The microsatellite instability was also detected in 6 ($20\%$) of the 29 cases at one or more loci. Conclusion: These data suggest that frequent loss of heterozygosity and the microsatellite instability at multiple tumor suppressor genes might be required for the development and the progression of gastric carcinomas and that p53 allelic loss may be the most frequent event in the development of gastric carcinomas.

• Journal of Gastric Cancer
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• v.19 no.4
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• pp.427-437
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• 2019

Purpose: We aimed to evaluate the clinical characteristics of microsatellite instability in early gastric cancer. Materials and Methods: The microsatellite instability status of resected early gastric tumors was evaluated using two mononucleotide repeat markers (BAT25 and BAT26) and three dinucleotide repeat markers (D5S346, D2S123, and D17S250). Tumors with instability in two or more markers were defined as microsatellite instability-high (MSI-H) and others were classified as microsatellite stable (MSS). Results: Overall, 1,156 tumors were included in the analysis, with 85 (7.4%) classified as MSI-H compared with MSS tumors. For MSI-H tumors, there was a significant correlation with the female sex, older age, tumor location in the lower gastric body, intestinal histology, lymphovascular invasion (LVI), and submucosal invasion (P<0.05). There was also a trend toward an association with lymph node (LN) metastasis (P=0.056). In mucosal gastric cancer, there was no significant difference in MSI status in tumors with LN metastasis or tumors with LVI. In submucosal gastric cancer, LVI was more frequently observed in MSI-H than in MSS tumors (38.9% vs. 25.0%, P=0.027), but there was no difference in the presence of LN metastases. The prognosis of MSI-H tumors was similar to that of MSS tumors (log-rank test, P=0.797, the hazard ratio for MSI-H was adjusted by age, sex, pT stage, and the number of metastatic LNs, 0.932; 95% confidence interval, 0.423-2.054; P=0.861). Conclusions: MSI status was not useful in predicting prognosis in early gastric cancer. However, the frequent presence of LVI in early MSI-H gastric cancer may help guide the appropriate treatment for patients, such as endoscopic treatment or limited LN surgical dissection.