Biomedical subjects

Shung-Haur Yang

Publications and source records attributed to Shung-Haur Yang.

24 records · Page 2Linked to original sources

PubMedDate not supplied

CA19-9 as the most significant prognostic indicator of metastatic colorectal cancer.

BACKGROUND/AIMS: Colorectal cancer is the third leading cause of cancer-related mortality in Taiwan. We became interested in searching for the factors predictive of survival. Serum CA19-9 (carbohydrate antigen 19-9) level has been reported as a factor predictive of survival in patients with colorectal cancer. A few articles have reported that patients with metastatic colorectal cancer who have normal (< or = 37 U/mL) serum CA19-9 levels survived significantly longer than those with higher serum CA19-9 levels. However, these reports are contradictory and lack definite conclusions. This study was carried out in an effort to evaluate the prognostic significance of serum CA19-9 levels in patients with metastatic colorectal cancer in Taiwan. METHODOLOGY: Between 1991 and 1994, a total of 128 patients with histologically confirmed metastatic colorectal cancers were evaluated retrospectively at Veterans General Hospital-Taipei. All patients had measurable metastatic lesions and life expectancies of more than 3 months. 5-Fluorouracil-based chemotherapy, either in a weekly bolus regimen or a monthly 5-day bolus schedule, were administered to all of them. Data on age, sex, performance status, location of primary tumor, extent of metastases, site of metastases, histological differentiation, serum CEA (carcinoembryonic antigen) and CA19-9 levels were analyzed before chemotherapy to determine their association with survival. Blood samples for CEA and CA19-9 measurement were analyzed using the radioimmunoassay method. Multivariate analysis by the Cox's proportional hazards regression model was performed to determine independent prognostic factors among all of the possible variables. RESULTS: By univariate analysis, serum CA19-9 levels (P < 0.001) and performance status of the patients (P = 0.022) were identified as prognostic factors, while age, sex, location of primary tumor, site of metastasis, histological differentiation, and pre-treatment serum CEA levels were not considered significant. By multivariate analysis, serum CA19-9 levels (P < 0.001) and performance status of the patients (P = 0.014) were still found as independent prognostic factors of these patients. CONCLUSIONS: The data from our study indicate that serum CA19-9 level is the most significant prognostic indicator of patients with metastatic colorectal cancer. It is recommended that stratification for further clinical trials for patients with metastatic colorectal cancer should be carried out according to serum CA19-9 levels.

Adenocarcinoma↗

PubMedDate not supplied

Tumor marker CEA in monitoring of response to tegafur-uracil and folinic acid in patients with metastatic colorectal cancer.

BACKGROUND/AIMS: The assessment of response to chemotherapy of solid tumors is generally made by measurement of tumors visualized by imaging, commonly computed tomography scanning. However, response assessment based on imaging is not always feasible because patients often have disease not measurable by imaging study, such as diffuse peritoneal dissemination. Furthermore, response assessment by imaging is expensive and time consuming. This study was carried out in an effort to evaluate the correlation between serial change on imaging and on CEA (carcinoembryonic antigen) levels for assessing chemotherapeutic response of patients with metastatic colorectal cancer. METHODOLOGY: Between May 1998 and August 1999, a total of 40 patients with metastatic colorectal carcinoma were enrolled in this study. All the patients had to have measurable lesions. Oral tegafur-uracil 300 mg/m2/day and folinic acid 60 mg/day were administered concurrently for four weeks, repeated every five weeks, as the first-line treatment. Tumor marker CEA was examined before and during the whole course of treatment. Response based on CEA assessment was defined as a more-than 50% drop in serum CEA level for more than four weeks. The correlation between serial change on CEA and on imaging for assessing chemotherapeutic response was evaluated. RESULTS: Forty patients received a total of 318 courses of treatment and a response rate of 32.5% (95% confidence interval, 18.0% to 47.0%), including five complete responses and eight partial responses, was achieved by imaging studies. The pretreatment CEA levels were elevated beyond the normal cut-off value in 34 (85%) patients. The response rate evaluated by CEA assessment was 42.5% (17/40). Nine responders (22.5%) based on CEA had no remission on imaging. Agreement in assessment by imaging study and by CEA was observed in 20 patients (50%), including eight responders, five stable diseases, and seven progressive diseases. The sensitivity of falling CEA levels in the prediction of true responders on imaging was 62%. The sensitivity of elevated CEA levels for the prediction of progressive disease was 70%. Concerning the diagnostic accuracy, change in CEA levels in the prediction of true responders and progressive disease on imaging were 65% and 85%, respectively. On a follow-up of 24 months, patients with remarkable falling CEA levels survived significantly longer than non-responders (P = 0.0184, log-rank test). CONCLUSIONS: The measurement of CEA levels might be useful in monitoring chemotherapeutic response and in predicting the prognosis of patients with metastatic colorectal cancer. Serum CEA level may be used as a means of monitoring chemotherapeutic response when imaging study is unsuitable for assessing the response in clinical practice.

Adult↗

PubMedDate not supplied

Prospective study of the functional results of transanal endoscopic microsurgery.

BACKGROUND/AIMS: Most clinical research addresses the technological advances and oncological outcomes of transanal endoscopic microsurgery. Our aim was to examine the functional results. METHODOLOGY: From August 1999 to November 2000, 22 Taiwanese patients (14 men, 8 women; median age, 68 years) undergoing transanal endoscopic microsurgery were prospectively examined. Functional questionnaires and anorectal manometry were assessed before surgery and at 2 weeks, 6 weeks, 3 months, and 1 year. RESULTS: The median distance from the anal verge to the tumor was 10 cm. The median tumor diameter was 2.0 cm. The median duration of surgery was 120 minutes. No surgical mortality or morbidity and no local recurrence occurred during a median follow-up of 23 months. The mean stool frequency and consistency were significantly better at 3 months after surgery than before surgery. The maximal resting pressure significantly decreased after surgery. The maximal contraction pressure and maximal tolerated volume were significantly lower at 2 and 6 weeks than before surgery; these values recovered at 1 year. CONCLUSIONS: Transanal endoscopic microsurgery is safe for the cure of benign tumors and the palliative excision of malignant tumors in middle and upper rectum. Anorectal function was preserved and improved, though some anorectal manometric parameters changed over time.

Adenocarcinoma↗

PubMedDate not supplied

EIA versus RIA in detecting carcinoembryonic antigen level of patients with metastatic colorectal cancer.

BACKGROUND/AIMS: Little literature exists comparing the differences between enzyme immunoassay (EIA) and radioimmunoassay (RIA) in the detection of serum carcinoembryonic antigen (CEA) levels of patients with metastatic colorectal cancer. Because EIA has the advantage of avoiding the use of radioisotopes, the potential of using EIA instead of RIA in detecting CEA of patients with colorectal cancer is of interest to us. METHODOLOGY: Between March and August 2001, a total of 120 blood specimens, including 60 specimens from patients with metastatic colorectal cancer and another 60 from patients with non-malignant diseases, were examined in this study. Serum CEA levels were examined by EIA and RIA methods in parallel. The CEA-EIA tests were done using EIA kits manufactured by Abbott Laboratories at Illinois in the United States. Comparison was done with the conventional CEA-RIA tests using RIA kits manufactured by CIS laboratory at France. The blood samples were sent to Veterans General Hospital-Taipei for EIA and RIA determination. The cut-off value for CEA was set at 5.0 ng/mL. RESULTS: The correlation between the Abbott-EIA and the CIS-RIA methods in detecting serum CEA levels was high. The results give a correlation coefficient of 0.992 with a linear regression line y=0.975 x + 0.215 (p<0.0001). Agreement in the Abbott-EIA and CIS-RIA tests in diagnosis was observed in 113 patients (94%), including 53 positive (>5 ng/mL) and 60 negative (<5 ng/mL) in both tests. The sensitivity was similar in both assays (83% vs. 80%) at a cut-off level of 5 ng/mL. The ability to discriminate between colorectal cancer and non-malignant diseases was good in both assays (p<0.001). The specificity and positive predictive value were slightly higher with the Abbott-EIA method compared with CIS-RIA assay (92% vs. 83% and 91% vs. 83%, respectively). The Abbott-EIA method achieved a similar diagnostic accuracy to CIS-RIA method (88% vs. 82%). CONCLUSIONS: These data suggest that the Abbott-EIA has similar diagnostic power to CIS-RIA in the measurement of CEA levels of patients with metastatic colorectal cancer, with an additional advantage of avoiding the use of radioisotopes. We believe that ELA has the potential to replace RIA in the measurement of CEA in clinical practice.

Adult↗

PubMedDate not supplied

Is decrease of tumor volume correlated with stage change after preoperative concurrent chemoradiotherapy?

BACKGROUND/AIMS: The significance of tumor volume and its change after concurrent chemoradiotherapy (CCRT) was evaluated. METHODOLOGY: Standard-dose external radiation and oral UFUR plus leucovorin were used to treat 30 middle and lower rectal adenocarcinoma patients. Volume of tumor calculated from images obtained by dynamic MRI of the rectum before and after CCRT was compared to pathological results after definite resection and other clinical data. RESULTS: The T-stage in 15 patients (50%), the N-stage in 13 (72.2%), and overall, the TNM stage in 18 (60%), were downstaged, including 7 (23.3%) with complete responses (CR). Volume of tumor before CCRT (Vpre) and after CCRT (VPost) was 10.3+/-6.1cm3 and 4.2+/-2.2cm3, respectively, and VPre correlated with initial T stage, N stage, age, and location. The net decrease ratio (NDR) of tumor volume was related to Vpre and initial T stage. As to the downstaging effect, VPre was related to incidence of CR; NDR was related to the downstaging of the N stage. CONCLUSIONS: All tumors showed volume reduction after CCRT, but the downstaging benefits were not in proportion to the size change. Initially larger tumors had higher ratios of volume reduction, and smaller tumors had higher chance of CR.

Adenocarcinoma↗

PubMedDate not supplied

Metastatic potential in T1 and T2 colorectal cancer.

BACKGROUND/AIMS: Survival of patients with colorectal cancer confined to the muscularis propria (stage I) is excellent after curative resection. However, some patients are likely to develop lymph node and distant metastasis that can ultimately cause death. The purpose of this study was to identify the possible predictors of lymph node and distant metastasis in T1 and T2 colorectal cancers. METHODOLOGY: In total 208 patients with T1 and T2 colorectal cancers who underwent surgical resection in Taipei Veterans General Hospital from July 1996 to December 2001 were enrolled. The clinicopathological variables including age, gender, tumor location (rectum/colon), preoperative carcinoembryonic antibody level, depth of tumor invasion, lymphovascular invasion, and unfavored histology corresponding to the metastasis assessed pathologically were analyzed. Categorical variables were analyzed using Chi-square with Yates' correction. The independent predictor of lymph node and distant metastasis was determined with multivariate binary logistic regression. RESULTS: Of the 208 T1 and T2 colorectal cancer patients, 36 (17.3%) had lymph node metastasis and 5 (2.4%) had distant metastasis at surgery. The risk of lymph node metastasis was 14.3% (8/56) in T1 and 18.4% (28/52) in T2 colorectal cancer. The tumors with evidence of lymphovascular invasion had a significantly higher incidence of lymph node metastasis than those without lymphovascular invasion (43.6% vs. 9.4%; p<0.001). The independent risk factor for lymph node metastasis was lymphovascular invasion only (95% confidence interval, 3.37-19.97; p<0.001), whereas that for distant metastasis was preoperative carcinoembryonic antibody level >5ng/mL only (95% confidence interval, 0.03-0.21; p<0.001). The negative predictive value of possible adverse risk factors including preoperative carcinoembryonic antibody level >5ng/mL, lymphovascular invasion, and unfavored differentiation for metastasis was 93.5%. CONCLUSIONS: Considering the negative predictive value of combined possible adverse risk factors, the risk of metastasis still was 6.5%. Therefore radical surgery was recommended for all T1 and T2 stage colorectal cancer patients except if the patient had a very high surgical risk.

Adenocarcinoma↗