Biomedical subjects

Hong-Jo Choi

Publications and source records attributed to Hong-Jo Choi.

12 recordsLinked to original sources

PubMed2007

Tumor budding as a prognostic marker in stage-III rectal carcinoma.

BACKGROUND AND AIM: Tumor budding along the invasive margin is known to be associated with biological behavior in colorectal carcinoma. The aims of this study were to explore if the semiquantitative assessment of tumor budding in rectal cancers correlates with oncological behavior and to appraise if the tumor budding is valid as a pathological parameter in distinguishing tumors with higher malignancy potential from those with lower one for prognostic stratification. MATERIALS AND METHODS: Surgical specimens from 244 patients with well- or moderately differentiated rectal carcinoma were retrieved to assess the intensity of tumor budding at the invasive margin. Intensities were divided semiquantitatively into four groups based on quartiles, and the 5-year disease-free survivals (DFS) were analyzed to search for a cutoff point of prognostic stratification. RESULTS: The cutoff of the intensity considered to be the best indicator for dividing patients into subgroups with different DFS was between quartiles 3 and 4, but this survival difference in subgroups in either side of the cutoff was significant only in stage-III disease [5-year DFS, 62.1 vs 35.1%; p = 0.0023; 95% confidence interval (CI), 0.1824-0.6919]. Based on multivariate analysis, the intensity of budding proved to be an independent variable associated with DFS (hazard ratio, 2.005; p = 0.0086; 95% CI, 1.021-3.934). When scores were given to grade of budding (lower, 0; higher, 1) and N stage (N1, 0; N2, 1) in stage III, a better prognostic stratification in terms of the 5-year DFS was obtained than the American Joint Committee on Cancer nodal staging only (0 vs 1 vs 2, 66.5 vs 42.6 vs 29.2%; p = 0.0101). CONCLUSIONS: Quantitative assessment of tumor budding is a reliable biological prognostic variable to identify higher malignancy potential. Scoring system using tumor budding and N stage showed better prognostic stratification in stage-III rectal carcinoma. A prospective evaluation would confirm the clinical significance of tumor budding for prognostic stratification.

Adult↗

PubMed2006

Sigmoidorectal intussusception of adenoma of sigmoid colon treated by laparoscopic anterior resection after sponge-on-the-stick-assisted manual reduction.

We present herein a case report of sigmoidorectal intussusception as an unusual case of sigmoid adenomatous polyp. The patient was a 56-year-old man who suffered from rectal bleeding for one day. He initially visited his general practitioner and was diagnosed as having an intraluminal mass of 15 cm from the anal verge. Several hours after admission to our coloproctology clinic, he suddenly presented with lower abdominal cramping pain with rectal bleeding during his bowel preparation using polyethylene glycol electrolyte solution. An emergency colonoscopy revealed that the invaginated colon with polypoid mass was protruded to the lower rectum. Gastrograffin enema showed that the invaginated bowel segment was 3 cm from the anal verge. CT scan showed the typical finding of intussusception. We performed laparoscopic anterior resection and anastomosis after the sponge-on-the-stick-assisted manual reduction. The permanent pathologic finding showed villotubular adenoma of the sigmoid colon.

Adenoma↗

PubMed2006

[Sphincter-preserving surgery for rectal cancer].

Although optimal treatment of tumors at mid and distal rectum continues to be a matter of great debate to oncologic surgeons, a surgical goal of sphincter preservation should be considered in all patients with an intact sphincter. There are growing evidences and indications that sphincter-preserving procedure might be a valid alternative to conventional modality in tumors of the mid or lower rectum. Traditionally, an abdominoperineal resection with permanent colostomy would be the sole surgical option. Recently, a variety of sphincter-preserving procedures are performed in majority of distal rectal cancers with acceptable oncologic and optimal functional results. Several recent advances may further influence future treatment strategies and many issues are, at present, under evaluation. Here, some of the most relevant topics regarding current methods of sphincter-preserving procedures with their oncologic and functional results are discussed to establish the guideline of surgical treatment in rectal cancer.

Anal Canal↗

PubMed2005

Expression of double-stranded RNA-activated protein kinase (PKR) and its prognostic significance in lymph node negative rectal cancer.

OBJECTIVE: The interferon-induced, double-stranded RNA-activated, protein kinase (PKR) is a key regulator of translational initiation, and plays an important role in the regulation of cell proliferation, apoptosis and transformation. The aim of this study was to evaluate the prognostic significance of PKR in lymph node negative rectal cancer. METHODS: Forty-three patients with stage II rectal carcinoma who underwent potentially curative resection followed by post-operative adjuvant chemoradiation and 5-fluorouracil-based chemotherapy were investigated immunohistochemically using the monoclonal antibody TJ4C4. Overall scores for PKR expression were calculated based on staining intensity and immunoreactive tumor cell fraction. Clinical information, including tumor grade, carcinoembryonic antigen (CEA), disease-free survival (DFS) and overall survival (OS) was evaluated and compared with the degree of PKR expression. RESULTS: The median follow-up duration was 53.2 months, and median patient age was 55 years (range 33-73). No relationships were found between PKR score and age, sex, tumor grade or CEA level; however, smaller tumors (< or =5 cm) were associated with high PKR score (P = 0.025). When patients were subdivided into two groups based on the PKR score, the relapse rate was lower for those with a high PKR score (7.4 versus 43.8%, P = 0.008), and a significant difference was found between these two groups in terms of 5 year DFS (92.6 versus 55.6%, P = 0.0072) and 5 year OS (92.6 versus 57.7%, P = 0.0459). Other clinicopathologic variables were not related to clinical outcome. CONCLUSION: PKR expression levels were associated with disease recurrence, DFS and OS in lymph node negative rectal cancer patients.

Adenocarcinoma↗

PubMed2005

Intensity of tumor budding and its prognostic implications in invasive colon carcinoma.

PURPOSE: The aim of this study was to assess the intensity of tumor budding in colon carcinoma quantitatively and to determine its correlation with malignancy potential. METHODS: The intensities of tumor budding at the invasive front of surgical specimens from 174 patients with well-differentiated or moderately differentiated colon carcinoma were investigated. Differences in intensity among clinicopathologic parameters were compared, and recurrences and survivals were analyzed in accordance with degree of the intensity. RESULTS: Tumor budding was identified in 155 patients (89 percent) and the mean intensity (+/- standard deviation) of budding was, on the whole, 6.6 +/- 5.6. Intensity was significantly higher in tumors with lymphatic and vascular invasion than in those without (9.1 +/- 6.6 vs. 4.8 +/- 3.9 and 9.8 +/- 6.1 vs. 5.4 +/- 4.9; P < 0.0001, respectively). It became significantly higher with increasing T and N stage (P = 0.0013 and < 0.0001, respectively). Both the Cox model and the linear logistic regression indicated that higher intensity was significantly associated with higher risk of postoperative recurrence (P = 0.017 and 0.0001, respectively). When patients were stratified into four groups based on the quartiles of the distribution of intensity, the group of higher quartiles showed significantly less favorable outcome in terms of both five-year disease-free (P = 0.0039) and overall survival (P = 0.0263). The cutoff of the intensity considered to be the best indicator for separating patients with regard to survival was third quartiles (intensity, 9). Based on multivariate analysis, the intensity of budding proved to be a significant covariate associated with disease-free survival (hazard ratio, 2.061; P = 0.0066). CONCLUSIONS: The intensity of tumor budding at the invasive margin is suggested to be a significant pathologic index, indicating higher malignancy potential and the intensity greater than nine may be considered an adverse prognostic indicator in patients with colon carcinoma.

Adult↗

PubMed2005

Sutureless intestinal anastomosis with the biofragmentable anastomosis ring: experience of 632 anastomoses in a single institute.

PURPOSE: Uncertainty with the safety of the biofragmentable anastomosis ring makes surgeons hesitate in its widespread use in intestinal surgery. This study was designed to evaluate the validity of the biofragmentable anastomosis ring as a routine anastomotic device in enterocolic surgery. METHODS: The study analyzed the nine-year experience of 632 biofragmentable anastomosis ring anastomoses performed in 617 patients: 525 (83 percent) as elective procedures and 107 (17 percent) as emergency. Three classic types of anastomosis, end-to-end (n=354), end-to-side (n=263), and side-to-side (n=15), were performed with a standard technique. RESULTS: Anastomotic sites included ileocolic/ileorectal in 283 patients (45 percent), colorectal in 148 (23 percent), enteroenteric in 101 (16 percent), and colocolic in 100 patients (16 percent). Anastomotic leakage with clinical relevance was observed in five patients (0.8 percent): three elective cases, and two emergency (2 colorectal anastomoses and 1 ileorectal required diversions). Among 13 instances (2.1 percent) with postoperative intestinal obstruction, only 1 required relaparotomy for closed-loop obstruction. Seven patients (1.1 percent; 4 elective cases, and 3 emergency) died postoperatively; no deaths were directly related to the biofragmentable anastomosis ring technique. CONCLUSIONS: Our data suggest that the anastomosis using the biofragmentable anastomosis ring is a uniform and highly reliable technique even in high-risk emergency surgery. Along with its clinical validities, clinical application of the biofragmentable anastomosis ring in different types of anastomoses in enterocolic surgery is expected to be expanded with a high level of technical safety.

Adolescent↗

PubMed2004

Gene expression profiling in lymph node-positive and lymph node-negative colorectal cancer.

PURPOSE: To identify the genes involved in the carcinogenesis and progression of colorectal cancer, we analyzed the gene-expression profiles of colorectal cancer cells from 12 tumors with corresponding noncancerous colonic epithelia using a cDNA microarray representing 4,08 genes. METHODS: We classified both samples and genes by using a two-way clustering analysis and identified genes that were differentially expressed in the cancerous and noncancerous tissues. Genes associated with lymph node metastasis were identified by means of the supervised learning technique. RESULTS: Differentially expressed genes (77 up-regulated and 45 down-regulated genes) were identified in more than 75 percent of the tumors. The functional categories of these genes belonged to signal transduction (19 percent), metabolism (17 percent), cell structure/motility (14 percent), cell cycle (13 percent), and gene protein expression (13 percent). The gene expression pattern of reverse transcriptase polymerase chain reaction (RT-PCR) results from randomly selected genes shows a pattern similar to that of cDNA microarray. Moreover, the gene expression patterns observed were similar to those reported previously, suggesting rare racial differences. Sixty genes possibly associated with lymph node metastasis in colorectal cancer were selected on the basis of clinicopathological data obtained by performing signal-to-noise calculations. "Leave-one-out" cross-validation testing correctly classified 10 of 12 patients (83.3 percent) as having colorectal cancer with lymph node metastasis vs. those without metastasis. CONCLUSIONS: These results provide not only a new molecular basis for understanding the biologic properties of colorectal cancer, including lymph node metastasis, but also provide a resource for future development of therapeutic targets and diagnostic markers for colorectal cancer.

Adenocarcinoma↗

PubMed2003

Recovery of the rectoanal inhibitory reflex after restorative proctocolectomy: does it correlate with nocturnal continence?

PURPOSE: The rectoanal inhibitory reflex has an important role in fecal sampling and discrimination of rectal contents. The aim of this study was to determine the significance of rectoanal inhibitory reflex after restorative proctocolectomy with ileal pouch-anal anastomosis for mucosal ulcerative colitis. METHODS: The medical records of 345 patients who underwent ileal pouch-anal anastomosis from September 1988 to May 1999 were retrospectively reviewed. One hundred patients who underwent double-stapled ileal pouch-anal anastomosis and had anorectal physiology testing within 3 months before surgery as well as after ileostomy closure (mean, 23.1; range, 3-77 months) were analyzed. Anorectal physiology testing included detecting the presence of the rectoanal inhibitory reflex, sensory threshold volume, and rectal or pouch capacity and compliance. Parameters to determine incontinence included daytime and nocturnal bowel movement frequency, nocturnal spotting, status of continence for solid or liquid stool, gas, use of pads, and lifestyle alteration were surveyed in 62 of the 100 patients at a mean of 3.9 (range, 1-9.1) years to determine the incontinence score. RESULTS: Whereas the rectoanal inhibitory reflex was noted in 96 (96 percent) patients before surgery, it was found in only 53 (53 percent) after ileostomy closure (P < 0.0001). Incontinence status data was available in only 62 of the 100 patients (32 RAIR-positive; 30 RAIR-negative). There were no significant differences between the rectoanal inhibitory reflex-positive and the rectoanal inhibitory reflex-negative groups relative to the interval between surgery and manometry (22 vs 25 months), postoperative threshold sensation volume (32 vs 31 ml), postoperative compliance (19 vs 12 cm H(2)O/ml), postoperative capacity (85 66 ml), daytime/nighttime stool frequency (6.2/2 vs 5.5/1.5), or postoperative incontinence score (3.9 vs 1.8). However, there were significant differences relative to the incidence of nocturnal soiling (12/30 (40 percent) 23/32 (72 percent), P = 0.0012) favoring the presence of the rectoanal inhibitory reflex. CONCLUSION: Preservation of the rectoanal inhibitory reflex correlated with a decrease in the incidence of nocturnal soiling after double-stapled ileoanal reservoir construction.

Adolescent↗

PubMed2003

Double stapled ileal pouch anal anastomosis (DS-IPAA) for mucosal ulcerative colitis (MUC): is there a correlation between the tissue type in the circular stapler donuts and in follow-up biopsy?

PURPOSE: This study aims to assess the correlation between the tissue types found in the circular stapler donut at the time of initial double-stapled ileal pouch-anal anastomosis (DS-IPAA) and during subsequent periodic routine random biopsy. Secondarily, we sought to assess the risk of dysplasia, carcinoma or mucosal ulcerative colitis (MUC) recurrence in the retained mucosa. METHODS: The pathology reports of 91 patients (48 males, 43 females) who were operated upon for MUC from September 1988 to June 1997 and were reviewed and had two follow up visits for biopsy. The histological features of the distal donuts and biopsies of retained mucosa obtained at yearly interval follow-up were assessed in order to determine the epithelial tissue type (columnar, transitional and squamous), inflammation, recurrence of MUC and presence of dysplasia or malignancy. RESULTS: Median age at surgery was 43 (range 15-71) years and duration of MUC was 9.6 (range 0.3-42) years prior to surgery. The anastomosis was performed at a median height of 1.0 (range 0-2.5) cm cephalad to the dentate line and biopsy follow-up was undertaken at median 34 (range 2-110) months after DS-IPAA. The distal donuts were analysed in all cases, as were 305 follow-up biopsies (median 3.4; range 1-7 per patient). Although columnar epithelium (CE) was found in 62 (68%) donuts, it was absent on follow-up biopsy in 16 (26%) of these patients. Conversely, although no CE was identified in 29 (32%) donuts, it was identified in 11 (38%) of these patients during follow-up biopsy. CE in the donut was a significant predictor of CE in subsequent biopsies (P = 0.0012). The histological features consistent with MUC were seen in the biopsies from the retained mucosa in 15 (16%) patients from 0.3 to 7.6 years after DS-IPAA. While eight (9%) patients exhibited dysplasia or adenocarcinoma in the excised colon or rectum, none of the patients had either dysplastic changes or carcinoma within the retained mucosal biopsies. CONCLUSION: The correlation between CE in the circular stapler donut and at follow-up biopsy was high. However since CE developed in some patients in whom no CE was present in the distal donuts, regardless of the epithelial tissue type finding at the time of DS-IPAA, periodic follow-up biopsy should be obtained.

Adolescent↗

PubMed2002

How consistent is the anal transitional zone in the double-stapled ileoanal reservoir?

BACKGROUND AND AIMS: The double-stapled ileoanal reservoir (DSIAR) has become a preferred method for ileal pouch anal anastomosis in restorative proctocolectomy. This investigation assessed the relative ratio of epithelial tissue types within the anal transition zone after a DSIAR and reviewed functional physiological differences. PATIENTS AND METHODS: All 138 patients who underwent restorative proctocolectomy with a DSIAR for mucosal ulcerative colitis were stratified into two groups according to histological evidence of epithelium types in the distal excised rectal donut. In group I a squamous or a squamous mixed with columnar epithelium was present (n=40) whereas in group II only columnar epithelium was seen (n=98). Anal physiological parameters were measured by anal manometry preoperatively, prior to ileostomy closure, and 1 year after surgery. RESULTS: None of the preoperative resting and squeeze pressure parameters showed a significant difference between the two groups. Postoperative mean and maximal resting pressures were significantly decreased in both groups. Postoperative mean and maximum squeeze pressures were decreased in group I. Postoperative mean length of the high-pressure zone tended to be decreased in both groups. The decrease in rectoanal inhibitory reflex was significant in both groups. Postoperative functional parameters measured as maximal tolerable volume and compliance were significantly improved from preoperative values in both groups. CONCLUSION: The tissue type in the anal transitional zone after DSIAR has a wide variability at a similar level (height) of the anastomosis. However, these different epithelial types were not associated with substantial physiological functional differences. Thus, if technically feasible, it is desirable for DSIAR to construct the anastomosis as close to the dentate line as possible.

Adolescent↗

PubMed2002

Incidence and prognostic implications of isolated tumor cells in lymph nodes from patients with Dukes B colorectal carcinoma.

PURPOSE: Lymph node metastasis in colorectal carcinoma is an important prognostic factor, yet the prognostic relevance of occult tumor cells in lymph nodes has not elucidated. This study was performed to investigate the correlation between isolated tumor cells in lymph nodes and malignancy potential in patients with Dukes B colorectal carcinoma and, thus, to determine whether presence of isolated tumor cells in lymph nodes has a prognostic significance. METHODS: To evaluate the incidence of isolated tumor cells in lymph nodes in patients with Dukes B colorectal carcinoma, 1,808 lymph nodes taken from 93 patients (19.4 per case) were assessed by immunohistochemical technique using a monoclonal antihuman cytokeratin (MNF 116). Clinicopathologic parameters and prognosis were compared between patients with and without isolated tumor cells. RESULTS: Isolated tumor cells were identified in 54 lymph nodes from 29 patients (31.2 percent) by the immunostaining. No correlations were observed between the incidence of positive isolated tumor cells and various clinicopathologic parameters, including preoperative carcinoembryonic level, tumor site and size, histologic differentiation, pT stage, vascular invasion and lymphatic invasion, and perineural invasion. There was no difference in five-year survival estimated by Kaplan-Meier life-table method between positive and negative groups for isolated tumor cells (82.8 and 85.9 percent, respectively). Multivariate analyses showed that sex (P = 0.0236), serum carcinoembryonic level (>or= 5 ng/ml, P = 0.0002), and lymphatic vessel invasion (P = 0.0002) were significant factors in the survival time. CONCLUSION: Immunohistochemical staining with an anticytokeratin antibody is useful in identifying isolated tumor cells in lymph nodes missed in routine hematoxylin-eosin staining, but clinically it seems to be of little prognostic value in patients with Dukes B colorectal carcinoma. Thus, this immunostaining technique does not offer a significant benefit of different strategies for additional therapy or follow-up during conventional pathologic staging using hematoxylin-eosin staining.

Adult↗

PubMedDate not supplied

Occurrence and prognostic implications of micrometastases in lymph nodes from patients with submucosal gastric carcinoma.

BACKGROUND: The aims of this study were to assess the incidence of micrometastases of lymph nodes in patients with early gastric cancer invading the submucosal layer and to investigate the correlation between nodal micrometastases and malignancy potential to determine whether micrometastases of lymph nodes have prognostic significance, by use of an anticytokeratin immunohistochemical technique. METHODS: A total of 2272 lymph nodes taken from 88 patients (25.8 per case) were assessed by immunohistochemical technique by use of monoclonal anti-human cytokeratin 8 antibodies. Clinicopathologic parameters and prognosis were compared between patients with and without micrometastases. RESULTS: The incidence of nodal involvement by tumor cells in 88 patients with submucosal gastric cancer increased from 19.3% (17 patients) by hematoxylin-eosin (H&E) staining to 31.8% (28 patients) by cytokeratin immunostaining. The rate of positive node in this study increased from 1.0% (23 of 2272 nodes) by H&E staining to 2.5% (57 of 2272 nodes) by immunostaining (P = .0002). No correlation was observed between the incidence of lymph node micrometastases and various clinicopathologic parameters, including tumor site and size, histological differentiation, Lauren classification, gross tumor type, vascular and lymphatic invasion, and perineural invasion. There was no difference in disease-free survival, estimated by the Kaplan-Meier life-table method, between the micrometastasis-negative and -positive groups (95% and 92.9%, respectively). Multivariate analyses showed that tumor size and diffuse subtype by the Lauren classification were significant factors for survival time (P = .0042 and .014, respectively). CONCLUSIONS: Immunohistochemical staining with an anticytokeratin antibody seems to be of little prognostic value in patients with submucosal gastric carcinoma. Thus, this immunostaining technique does not offer a significant benefit of different strategies for additional therapy or follow-up over conventional pathologic staging with H&E staining.

Adult↗