Research progress of heat shock protein 90 in breast cancer / 中华内分泌外科杂志

Breast cancer has become the most common malignant tumor in the world. Heat shock protein 90 (HSP90) is a kind of molecular chaperone which can promote protein folding and maintain protein stability. HSP90 includes HSP90α, HSP90β, GRP94 and TRAP1 subtypes. Previous studies have found that the level of HSP90 is significantly increased in malignant tumors such as breast cancer, and is closely related to the occurrence and development of tumors. Meanwhile, the research on inhibitors targeting HSP90 has also attracted much attention. In this paper, we reviewed the expression of four HSP90 subtypes in breast cancer and their relationship with the clinicopathologic feature and prognosis of patients, discussed the research progress of specific inhibitors of HSP90 subtypes in breast cancer, and analyzed the application prospect of HSP90 as biomarkers for breast cancer prognosis monitoring and therapeutic targets.

Clinicopathologic analysis of 38 male breast cancers / 中国实用外科杂志

OBJECTIVE: To analyze the clinicopathologic characteristics and molecular subtype in male breast cancer(MBC). METHODS: The clinical features, histological features and molecular subtype of 38 cases of male breast cancers admitted from January 2013 to March 2019 in Clinical Pathology Diagnostic Center of Ningbo were analyzed retrospectively. RESULTS: Thirty-eight patients were diagnosed with MBC, accounting for 0.83% of all the breast cancer in the same term. The median age was 68.5(range from 24 to 88). Tumor were located in left side in 20 cases, right side in 18 cases. Twenty-nine cases were diagnosed as invasive ductal carcinoma, two cases of secretory breast cancer, one case of invasive solid papillary carcinoma, two cases of intraductal papillary carcinoma with microinvasive, and four cases of encapsulated papillary carcinoma(two of them with microinvasive). Sixteen patients had lymphatic metastasis when the tumor was diagnosed. Imunohistochemically, ER was positive in 36 cases, while PR was positive in 35 cases.Eighteen cases were Luminal A type, while sixteen were Luminal B type and two cases were basal-like subtype.CONCLUSION: MBC is a rare malignant neoplasm, and most patients are diagnosed older and at advanced clinical stage,what is more, there is more possibility of second non-breast primary cancer. All suggesting that early diagnosis,treatment and more intensive surveillance are important. MBC needs further study.

The clinicopathologic and immunohistochemical features of villoglandular adenocarcinoma of uterine cervix

Aim: Villoglandular adenocarcinoma (VGA) of the uterine cervix is a variant of endocervical adenocarcinoma. However, the clinicopathologic and immunohistochemical features of VGA are still unclear. The aim of this study was to investigate the clinicopathologic and immunohistochemical features of VGA. Materials and Methods: A total of 20 VGA patients were identified among 852 patients diagnosed with cervical cancer and enrolled in this study. The immunohistochemical levels of Ki-67, P53, P16, progesterone receptor (PR), carcinoembryonic antigen (CEA), vimentin (Vim), and estrogen receptor (ER) were measured by immunohistochemistry. Results: VGA was prevalent in younger women and presented favorable prognosis. Ki-67, P16, and CEA were highly expressed in VGA tissues, while PR expression was hardly to be detected. The positive rates of Ki-67, CEA, and P16 were 90.0%, 90.0%, and 85.0%, respectively, which were significantly higher compared with PR (5.0%, P < 0.001). In addition, the positive rates of P53, Vim, and ER in VGA tissues were 55.0%, 50.0%, and 40.0%, respectively. However, the expression levels of Ki-67, P53, P16, PR, CEA, Vim, and ER were not significantly associated with clinical features (P > 0.05). Conclusion: These data indicate that VGA is a rare cervical adenocarcinoma, which is prevalent in younger women, and presents favorable prognosis. Detection of Ki-67, P53, P16, PR, CEA, Vim, and ER would be beneficial for the diagnosis of VGA.

Expressions and clinical significance of Cyr61 andβ-catenin in gallbladder carcinoma / 西安交通大学学报(医学版)

Objective To evaluate the expressions of Cyr61 and β‐catenin protein in gallbladder carcinoma tissues and investigate their association with the clinicopathologic features of gallbladder carcinoma patients . Methods The expressions of Cyr61 and β‐catenin protein in 50 cases of gallbladder carcinoma and 19 cases of normal tissue were detected by immunohistochemical S‐P method .Results ① The positive expression rate of Cyr61 in gallbladder carcinoma tissues was 66 .0% (33/50) ,which was significantly higher than that in the normal tissues group (26 .3% ) .The expression of Cyr61 was related to tumor differentiation ,TNM stage and lymph node metastasis of gallbladder carcinoma (P=0 .010 ,P=0 .014 ,P=0 .007;P<0 .05) .② The positive expression rate ofβ‐catenin in gallbladder carcinoma tissues was 84 .0% (42/50) ,which was significantly higher than that in the normal tissues group 15 .7% (3/19);the expression of β‐catenin was related to tumor differentiation ,TNM stage and lymph node metastasis of gallbladder carcinoma (P=0 .018 ,P=0 .002 ,P=0 .024;P<0 .05) .③ Correlation test showed that Cyr61 andβ‐catenin were positively correlated in gallbladder carcinoma and adjacent normal tissues (r=0 .378 , P< 0 .05) .Conclusion Cyr61 and β‐catenin are highly expressed in gallbladder carcinoma tissues . Cyr61 andβ‐catenin expressions are closely related to the clinicopathologic features (tumor differentiation ,TNM staging and lymph node metastasis) in gallbladder carcinoma .Cyr61 and β‐catenin may have a synergistic effect in promoting progression and development of gallbladder carcinoma .Combined detection of Cyr61 and β‐catenin in gallbladder carcinoma tissues will contribute to the clinical diagnosis and prognosis .

C3 glomerulonephritis in 7 children / 中华实用儿科临床杂志

Objective To analyze the clinical characteristics of 7 pediatric patients with C3 glomerulonephritis (C3-GN).Methods The clinical manifestations,pathological features,therapies,prognosis of patients from Jun.2006 to Nov.2011 were analyzed retrospectively.Results All of the patients were presented as acute nephritic syndrome,and 4 patients with macroscopic hematuria,other 3 cases with severe proteinuria.Five patients with eyelid edema.All the patients showed decreased level of serum complement C3,while serum complement C4 was normal.Investigations showed elevation of 24 h urine protein,5 patients with elevated antistreptolysin O titers.Three patients with renal dysfunction.Isolated C3 deposition in mesangial and endothelial areas(+ +-+ + +) was confirmed by immunofluorescence.Light microscope revealed membrane proliferative glomerulonephritis and mesangial proliferative glomerulonephritis.Electron microscope showed swelling and hyperplasia of endothelial cells without electron-dense deposition or podocyte foot fusion.Based on conventional treatment,administration of immunosuppressant was performed in 3 patients with severe pathological changes.After a follow-up of 2 months to 5 years,the prognosis seems to be benign.Conclusions Children with C3-GN are usually presented as acute nephritic syndrome,characterized by isolate C3 deposition in immunofluorescence.Electron microscope showed lesion of endothelial cells,while no electron-dense deposits in mesangial and endothelial areas.The mechanism may be associated with dysregulation of alternative complement pathway,and seems had a good short-term prognosis.

Clinicopathological Feature and Recurrence Pattern of Triple Negative Breast Cancer

PURPOSE: Triple-negative breast cancers (TNBC; estrogene receptor-negative, progesterone receptor-negative, and human epidermal growth factor receptor-2-negative) are very aggressive tumors with high risk of recurrence and poor prognosis. We have compared the clinical characteristics, recurrence rate and pattern between TNBC and nonTNBC. METHODS: A study was done among 879 patients who were diagnosed with breast cancer and received surgery from January 1999 to December, 2005 at Kyungpook National University Hospital. Medical records and pathological reports were reviewed. TNBC was defined as ER(-), PR(-), HER2(-). NonTNBC was defined as having any one of them positive. RESULTS: Of the 879 patients, 81 (9.2%) cases were TNBC. As compared with nonTNBC, TNBC had no significant difference in age of diagnosis (P=0.478), tumor size (P=0.961), axillary lymph node metastasis (P=0.398), stage (P=0.341), histological type (P=0.550), operation method (P=0.053) and chemotherapy (P=0.971). In histological classification TNBC had significantly a high histologic grade, compared to nonTNBC (P<0.001). The median follow-up period was 53 months. There have been 56 local recurrences, 70 distant metastases, 10 distant metastasis with local recurrence and 66 deaths. There was no significant difference in recurrence rate and mortality rate between the two groups. But, average time to recurrence was significantly shorter in TNBC than nonTNBC. CONCLUSION: TNBC had shorter time interval to recurrence compared to nonTNBC and had higher histological grade (mostly grade 3). Therefore, in TNBC, careful treatment and follow-up are important. Further long-term investigations with larger groups of patients will be necessary.

Analysis of Clinicopathologic Features in Papillary Thyroid Carcinoma Patients Younger than Thirty

PURPOSE: This study analyzed clinicopathologic features in patients with thyroid papillary carcinoma, who were younger than thirty, compared with patients aged thirty and forty-five. METHODS: The clinical records of 337 patients who underwent thyroidectomy because of papillary thyroid carcinoma were reviewed. Among them, 62 patients who were younger than thirty were placed in group I. And 275 patients between thirty and forty-five were placed in to group II. Clinicopathologic features between the two groups were analyzed. RESULTS: There was no significant difference between two groups in age, gender, tumor extension, and multifocality. Symptoms before detection of papillary thyroid carcinoma such as palpable mass, compressive symptoms or hoarseness were significantly higher in group I (P=0.008). In tumor size, rate of microcarcinoma is significantly higher in group II (P=0.024). Lymph node metastasis was found to be more significant in group I (P=0.010). The operative methods were different between the two groups. Rate of total thyroidectomy was increased in group I (P=0.021). CONCLUSION: This study shows that patients with thyroid papillary carcinoma, younger than thirty have more clinical symptoms and more large sized masses, more lymph node metastases at the time of surgery compared with those aged between thirty and forty-five.

The Pure and Follicular Variants of Papillary Thyroid Carcinoma: A Comparative Study of the Clinicopathologic Features / 대한내분비외과학회지

PURPOSE: Pure papillary thyroid carcinoma (PPTC) and the follicular variant of papillary thyroid carcinoma (FVPTC) are the most common subtypes of papillary thyroid carcinoma (PTC). The aim of this study was to investigate if there are any differences in clinicopathological features of these two subgroups. METHODS: We performed a retrospective chart review of patients who were treated for PPTC and FVPTC between September 2003 and April 2008. Four hundred fifty patients were shown to have PPTC (91.8%) and forty (8.2%) had FVPTC after a histologic review. The two groups were compared in terms of the clinicopathologic features and the results of preoperative ultrasonography (USG), the fine needle aspiration cytology (FNAC), the frozen section biopsy and the surgical treatment. RESULTS: The tumor size was significantly larger in the FVPTC group than in the PPTC group (1.47 cm versus 1.08 cm, respectively P=0.024). However, both groups had similar clinicopathologic features in terms of age, gender, capsular invasion, multifocality, lymph node metastasis, the MACIS score and the TNM stage. Further, the operative method did not differ between the two groups. The sensitivities of USG and frozen section biopsy for diagnosing FVPTC were significantly lower than those for PPTC (53.85% versus 72.95%, respectively, P=0.045, 81.58% versus 97.25%, respectively, P=0.049). CONCLUSION: The FVPTC group presented with a larger tumor size, and the clinicopathologic features of the FVPTC group did not significantly differ from those of the PPTC group. Although further studies with longer follow-up are required, these results suggest that the patients in both groups should be treated identically.

Clinicopathologic Features of the Superficial Spreading Type of Early Gastric Cancer

PURPOSE: The superficial spreading type of early gastric cancer (SSE) has unique features such as its growth pattern and histologic aggressiveness. But its incidence rate is very low, so the clinicopathologic features of SSE are not well known. The aim of this study is to clarify the clinicopathologic features of the superficial spreading type of gastric cancer and we propose an appropriate treatment strategy with the proper treatment modality. METHODS: A retrospective study was conducted on 894 surgically resected patients with early gastric cancer. The superficial spreading type was defined as a lesion more than 20 cm(2). The demographic features and histopathological features were analyzed by using the hospital records. The survival rate was analyzed by the Kaplan-Meier method and the other statistics were analyzed using the chi-square test. RESULTS: For the superficial and common groups, there were no significant differences in the rates of submucosal layer invasion, the histologic types and differentiation and the tumor location. But the ratio of lymph node metastasis was significantly different (P<0.05). There were some differences concerning the operative methods between the groups. For the superficial spreading type, the portion of total gastrectomy was greater than that of the common type. The average distance between the upper portion of the tumor and the proximal resection margin was shorter for the superficial spreading type than that for the common type (3.78+/-2.79 cm vs 5.58+/-2.79 cm, respectively). The 5 year survival rate and the recurrence rate between the two types were not significantly different. CONCLUSION: Because of the higher rate of lymph node metastasis and the higher rate of an indistinct tumor margin, wide resection with adequate lymph node dissection (D1+beta or more) seems to be a proper operative method for the superficial spreading type of early gastric cancer.

The Prognostic Value of CA19-9 in Patients with Colorectal Cancer

PURPOSE: There has been much debate about the significance of the CA19-9 level for predicting the prognosis of colorectal cancer patients. This study aimed to evaluate the prognostic value of the preoperative serum CA19-9 level and the CA19-9 expression in the tumor tissues of colorectal cancer patients METHODS: One hundred patients with colorectal cancer and who had been treated by resection were studied. We assessed the correlations of the preoperative serum CA19-9 level and the status of the CA19-9 immunohistochemical staining with the clinicopathologic features, including the prognosis of the patients. RESULTS: The preoperative serum CA19-9 level had significant correlation with the status of CA19-9 immunohistochemical staining. The presence of distant metastasis was significantly correlated with an elevated level of serum CA19-9. The depth of tumor, the presence of lymph node metastasis, the TNM stage and tumor cell differentiation were significantly correlated with the status of the CA19-9 immunohistochemical staining. In addition, the gross morphology, depth of tumor, the presence of lymph node metastasis, the TNM stage, the status of the CA19-9 immunohistochemical staining and the serum CEA level were correlated with survival on univariate analysis. However, multivariate analysis did not validate the status of CA19-9 immunohistochemical staining as a significantly independent predictor of the prognosis. CONCLUSION: The CA19-9 expression was frequently observed in advanced stage tumor tissue, yet its expression in tumor tissue or the preoperative CA19-9 serum level did not show independent prognostic value for colorectal cancer patients.

Comparison of the Clinicopathologic Features and the Survival Rates in Young and Elderly Patients with Gastric Cancer

PURPOSE: We analyzed the clinicopathologic features, including treatment and outcome, and the survival rates between young and elderly patients with gastric cancer. MATERIALS AND METHODS: Clinical information was reviewed for 1086 patients who had undergone a gastrectomy for gastric cancer during a 10-year period from 1990 to 1999, and the patients were assigned to one of two groups: the A group ( or =70 years of age, 85 patients). RESULTS: Compared to the B group, the A group had more females (47.3% vs 32.9%), a greater frequency of family history of cancer (15.4% vs 3.5%), and greater proportions of histologically poorly differentiated tumors (84.5% vs 40.2%) and Lauren diffuse-type tumors (69.1% vs 35.1%)(P<0.05). There was no difference in TNM stage. Cardiopulmonary co-morbidities were more in the B group, respectively, 1.1% (A group) and 11.8% (B group)(P<0.01), but the morbidity and the mortality were similar. Although there was no difference in curability, the B group underwent less aggressive operations in lymph-node dissection above D3 and had a shorter operation time, a smaller number of retrieved lymph nodes, and less adjuvant chemotherapy (P<0.001). However, there were no differences in the disease-specific 5-year survival rates, 67.6% and 67.0% respectively. CONCLUSION: Young and elderly patients with gastric cancer had different clinicopathological features. Especially, elderly patients underwent relatively less aggressive treatment. In spite of these facts, the outcome of treatment and the disease-specific survival rates were not different.

Neuroendocrine Carcinoma of the Stomach: A Clinicopathologic Study of 18 Cases

PURPOSE: Neuroendocrine carcinomas of the stomach account for only about 0.3% of all gastric tumors. The prognosis of this disease is very poor compared with the common type of gastric adenocarcinoma. The purpose of this retrospective study was to review the clinicopathologic features of 18 cases of this unusual gastric tumor and to establish a treatment strategy for this tumor. MATENRIALS AND METHODS: Excluding 2 cases of non-curative resection and 1 case of operative mortality, 18 cases of typical neuroendocrine carcinoma who had curative resection from January 1991 to December 2000 at Asan Medical Center were analyzed; 6841 gastric cancer patient were treated surgically during the same period. RESULTS: The mean age at the time of diagnosis was 58.6 years (range: 35~75 yr). Sixteen patients were male, and two were female. Eleven tumors (61.1%) developed in the lower part of the stomach, three (16.7%) in the middle part, and three (16.7%) in the upper part. One tumor involved the entire stomach. Eight cases (44.4%) were Borrmann type 2, and six case (33.3%) were Borrmann type 3. The mean tumor size was 6.94 cm (range: 0.6~15 cm). Nine cases (50%) showed recurrence of the disease, and eight of them died within 20 months. Of the nine recurred cases, 7 cases (77.8%) showed liver metastasis. The mean disease-free interval was 6.8 months (range: 2.5~11 months) after surgical resection, and the mean survival was 17.9 months (range: 8~40 months) for recurrence cases. One patient with liver metastasis was treated with a liver-wedge resection just after diagnosis and was still alive for 37.5 months postoperatively. There were 9 deaths after the median follow-up period of 40 months (range: 8~72 months). CONCLUSION: Gastric neuroendocrine carcinomas frequently recur at the liver, even in early stage cancer, and have a poor prognosis. We experienced a case of successful control of hepatic metastasis by surgical resection and a case of a small cell carcinoma which was successfully controlled with systemic chemotherapy.

Clinical Analysis of Stage Ib Gastric Cancer

PURPOSE: The aim of this study was to clarify the clinicopathological differences between T1N1M0 and T2N0M0, particularly the survival rates, and the role of chemotherapy in the stage Ib gastric cancer. METHODS: From January 1992 to December 1999, 118 cases were confirmed as having stage Ib gastric cancer in the Korea University Medical Center. Among them 31 patients were classified as being T1N1M0 and the other 87 cases were T2N0M0. The clinicopathological features and the prognosis were evaluated retrospectively. RESULTS: The overall 5-year survival rate of the stage Ib gastric cancer patients was 94%. Overall 5-year survival rates in T1N1M0 and T2N0M0 were 100% and 91%, respectively. Though T1N1M0 group showed better prognosis, there was no significant difference between two groups (P=0.14). D1, D2, and D2+alpha resections were performed in 28 cases (23.7%), 81 (68.6%), and 9 (7.6%), respectively, and there was no difference in the survival rate (P>0.05). The 5-year survival rates were analyzed according to whether or not they had received chemotherapy. There was a 98% 5-year survival rate with those who had chemotherapy and a 90% 5-year survival rate with those who had not had chemotherapy, but there was no significant difference between them (P=0.18). In the T2N0M0 group, the 5 year survival rates of patients with or without chemotherapy were 97% and 86%, respectively, but there was no significant difference (P=0.16). CONCLUSION: Though T1N1M0 group showed a better prognosis than the T2N0M0 group, there was no significant difference between the two groups (P=0.14). There was no significant survival difference between D1, D2, or D2+alpha procedures. It appears that post operative intravenous chemotherapy does not affect the prognosis of stage Ib gastric cancer, and the role of the chemotherapy in patients with T2N0M0 diseases is minimal.

Clinicopathological study of hereditary nonpolyposis colorectal cancer families in China / 中华消化杂志

Objective To study the clinicopathological characteristics of hereditary nonpolyposis colorectal cancer (HNPCC) in Chinese population with different criteria and guidelines. Methods Twenty four families fulfilling Amsterdam Criteria (AC), 15 additional families fulfilling Japanese Criteria (JC) and the remaining 19 patients fitting Bethesda Guidelines (BG) were analyzed. Results In the 24 AC families there were 116 malignant tumor patients including 90 colorectal cancer (CRC) subjects and in the 15 JC families there were 54 malignant tumor patients including 33 CRC cases. The two groups displayed similar clinical features. Mean age of first CRC at diagnosis was 46.1 and 51.4 years old, respectively. The proximal colonic cancers accounted for 55.4% versus 44.8%. Synchronous and metachronous multiple CRCs occurred in 25.6% and 18.2% of patients respectively. Totally there were 55 extracolonic tumors in the two groups. Gastric and endometrial carcinomas were two most common extracolonic tumor types in our series. The tumors of the 34 probands showed more frequent exophytic growth pattern, higher occurance of poorly differentiated carcinoma, A / B Dukes stage and more Crohn's like lymphoid reaction ( P

The Clinicopathologic Characteristics and Prognosis of Gastric Signet Ring Cell Carcinoma

PURPOSE: There has been considerable controversy over the prognosis of gastric signet ring cell carcinoma (SRC). To clarify the biologic behavior of SRC, we evaluated the clinicopathologic features and the prognosis of SRC. METHODS: A total of 3,104 patients with a gastric carcinoma who had undergone a gastrectomy from 1987 to 1995 were analyzed retrospectively. Among them, 556 patients with SRC were compared to 2,548 patients with non-SRC. RESULTS: Patients with SRC were younger than those with non-SRC, and female were prevalent. Incidence of EGC were higher in patients with SRC. EGC with SRC had a larger proportion of mucosa-confined lesions and a lower rate of lymph node metastasis than EGC with non-SRC. Multivariate analysis showed that SRC was a negative inde pendent risk factor for lymph node metastasis. Among advanced gastric cancers SRCs showed a higher prevalence of large-sized lesions, Borrmann type IV lesions, and advanced nodal stage, as well as a higher rate of peritoneal metastasis. The 5-year survival rate of EGC with SRC (93.8%) was higher than that of non-SRC (91.2%). However, the prognosis of advanced SRC (49.0%) was poorer than that of non-SRC (53.5%). CONCLUSION: A female preponderance, a younger age, and a higher proportion of early gastric cancer characterized the peculiar biologic behavior of gastric signet ring cell carcinoma. In addi tion, the prognosis of SRC was poor once invasion had gone beyond the submucosa. These findings suggest that signet ring cell carcinoma of the stomach should be regarded as a distinct type of gastric cancer.

Prospective Evaluation of Colorectal Polyps in 1,683 Consecutive Colonoscopies / 대한소화기내시경학회지

BACKGROUND AND AIMS: The colorectal polyp, particularly the adenoma, has been regarded as a precursor of cancer. The incidence of colorectal polyps has been reported at various rates according to investigation centers in foreign countries. In Korea, the incidence of colorectal polyps has been reported as very low according to the few reports, which was involved a few cases and were partial. Therefore, the aim of this study is to evaluate prospectively the incidence and the clinicopathologic features of colorectal polyps. METHODS: A colonoscope was inserted up into the cecum in 1,889 patients among 2,001 trials from Oct. 1996 to Aug. 1997 (success rate: 94.4%). Of the 1,889 full colonoscopies, the following were excluded; 1) referred patients with suspicious colorectal cancer or polyps, 2) patients with suspicious rectal cancer determined by rectal examination, 3) patients who had follow-up colonoscopy after a polypectomy or cancer surgery, and 4) patients who had periodic colonoscopy due to FAP or HNPCC. There were a total of 1,683 full colonoscopies in this study. The majority of the total cases involved a colonoscopy due to benign anal disease, irritable bowel syndrome, or routinechecks for health. RESULTS: There were 946 men (56.2%) and 737 women (43.8%). The mean age was 48.2 yrs (13~88 yrs) for men and 48.1 yrs (18~89 yrs) for women. 422 patients were found to have 645 colorectal polyps (1.52 polyps per patient). The incidence of polyps was 25.1% (32.0% for men, 16.1% for women) and increased after the 6th decade in men (44.0%) and in women (23.0%). 281 patients were found to have 426 colorectal adenomas. The incidence of adenomas was 16.6% (21.9% for men, 9.9% for women) and increased after the 6th decade, 32.0% in men, and 15.9% in women. Solitary polyps were present in 277 patients (65.6%) while 94 patients (22.3%) had two polyps and 51 patients (12.1%) had between 3 and 8 polyps. The polyp retrieval rate was 96.9%. There were 426 adenomas (66.0%), 75 hyperplastic (11.7%), 120 inflammatory (18.6%), and 24 miscellaneous (3.7%) polyps. Of the 426 adenoma, there were 397 tubular adenoma (93.2%), 18 tubulovillous adenoma (4.3%), 4 villous adenoma (0.9%), 6 in situ carcinoma (1.4%), and 1 invasive carcinoma (0.2%). 6 in situ carcinoma's were detected in tubular adenoma and 1 invasive carcinoma in tubulovillous adenoma. Of 645 polyps, the sessile type was 87.9%. The polyp size varied from 1 mm to 25 mm and 79.2% were under 5mm. Also, 85.7% of adenomas were sessile and 74.7% were under 5mm. 22.0% of polyps were located in rectum, 35.4% in sigmoid colon, 9.5% in descending colon, 13.3% in transverse colon, 19.8% in ascending colon and cecum. The distribution of adenoma was similar to that of polyp. 40.1% of adenoma showed moderate to severe dysplasia. CONCLUSIONS: This study revealed that the incidence of polyp in Korea was higher than that in previous reports and 42.6% of polyps were proximal to rectosigmoid colon. Therefore, we suggest that we should try to detect and remove colorectal polyps by more active colonoscopy.