Biomedical subjects

Joong Bae Ahn

Publications and source records attributed to Joong Bae Ahn.

5 recordsLinked to original sources

PubMed2006

Paclitaxel and leucovorin-modulated infusional 5-fluorouracil combination chemotherapy for metastatic gastric cancer.

As no standard chemotherapy regimen has been established for advanced gastric cancer, this study sought to evaluate the efficacy and safety of combination chemotherapy that included paclitaxel and leucovorin (LV)-modulated infusional 5-fluorouracil (5-FU) in metastatic gastric cancer. Patients received a three-hour infusion of 175 mg/m2 of paclitaxel on day 1. A bolus of 20 mg/m2 of LV was then administered, followed by a 24-h infusion of 1,000 mg/m2 of 5-FU on days 1 through 3. The treatment cycle was re-peated every 3 weeks until disease progression. Response evaluation was performed according to the RECIST criteria, with toxicity determined by NCI-CTC (version 2.0). A total of 66 patients, including 21 (31.8%) with a history of prior chemotherapy, were enrolled. Fifteen (71.4%) of the 21 patients with prior chemotherapy received prolonged infusional 5-FU. In the 56 evaluable patients (37 in the chemotherapy-naïve group and 19 in the prior chemotherapy group), tumor responses according to prior exposure to chemotherapy were as follows: 17 (45.9%) partial response (PR), 6 (16.2%) stable disease (SD) and 14 (37.8%) progressive disease (PD) in the chemotherapy-naïve group; 1 (7.1%) complete response, 3 (15.8%) PRs, 8 (42.1%) SDs and 7 (36.8%) PDs in the prior chemotherapy group. The overall median response duration was 20 weeks (range, 8-61 weeks), with a median progression-free survival of 20 weeks [95% confidence interval (CI), 13.4-26.6 weeks] and 12 weeks (95% CI, 5.7-18.3 weeks) in the chemotherapy-naïve and prior chemotherapy groups, respectively. The median overall survival was 48 weeks (95% CI, 38-58 weeks) in the chemotherapy-naïve group and 28 weeks (95% CI, 22-34 weeks) in the prior chemotherapy group. The most frequent grade III/IV toxicity was neutro-penia. Non-hematological toxicity of grade III/IV was rare. Paclitaxel in combination with 5-FU/LV is clinically beneficial for patients with advanced gastric cancer and is a feasible salvage regimen for 5-FU-refractory gastric cancer patients.

Adult↗

PubMed2006

[Chemotherapy in rectal cancer].

Until mid-1990s, fluorouracil was the only chemotherapeutic agent available for the treatment of colorectal cancer. The treatment of advanced colorectal cancer has evolved considerably over the last decade. Considerable improvements in survival as well as quality of life have been achieved with the application of oxaliplatin and irinotecan with fluoropyrimidine as a first and subsequent line therapy for colorectal cancer. Development of oral fluoropyrimidines as an alternative to intravenous administration provides an additional option for combination cytotoxic therapy, which is currently being assessed in phase III trials in advanced settings. The appearance of biologic agents in mid-2000s, namely cetuximab and bevacizumab, and their integration with conventional cytotoxic therapy for the treatment of colorectal cancer has additionally expanded the options for the treatment. Their dramatic success has led to further clinical studies of targeted therapy in colorectal cancer, making it one of the most promising areas of cancer research. Although considerable improvement was achieved by incorporating oxaliplatin in adjuvant chemotherapy for the treatment of colon cancer, there has been no phase III trial incorporating new agents in adjuvant setting for rectal cancer. However, many phase II trials on the efficacy of new agents in the setting of concurrent chemoradiation are in progress. Based on their results, randomized phase III clinical trials evaluating new agents in preoperative or postoperative setting will be carried out.

Antineoplastic Agents↗

PubMed2005

A pilot study of trans-arterial injection of 166Holmium-Chitosan complex for treatment of small hepatocellular carcinoma.

Percutaneous approaches, such as percutaneous ethanol injection and radiofrequency ablation, have been most widely used for hepatocellular carcinoma patients who were not eligible for surgery. New technologies to improve the efficacy are currently needed. (166)Holmium is a neutron activated radionuclide, and has several beneficial radiophysical characteristics for internal radiation therapy. (166)Holmium-Chitosan complex, in which chitosan is chelated with (166)Holmium, was developed as a radiopharmaceutical for cancer therapy. We have conducted a pilot study to evaluate the clinical efficacy of transarterial administration of (166)Holmium-Chitosan complex in patients with a single and small (< 3 cm) hepatocellular carcinoma. (166)Holmium-Chitosan complex, at a dose of 20 mCi per cm of tumor mass-diameter, was administered through the artery that directly fed the tumor. Twelve patients were treated with a median follow-up duration of 26 (range: 12-61) months. The tumor diameter ranged between 1.5 and 2.5 cm. Ten patients (83%) had complete response and two (17%) had partial response. The median complete response duration was not reached. The median AFP level declined from 83.8 to 8.3 ng/mL within 2 months after treatment. No grade III/IV toxicity was observed. Grade I and II toxicities were observed in four patients (2 abdominal pain, 1 fever, and 1 AST/ALT elevation). No toxic death occurred. This preliminary study shows a promising and durable complete response rate with an acceptable safety profile. Further studies with greater accrual of patients are warranted.

Adult↗

PubMed2005

Usefulness of magnetic resonance volumetric evaluation in predicting response to preoperative concurrent chemoradiotherapy in patients with resectable rectal cancer.

PURPOSE: We performed magnetic resonance (MR) volumetry before and after neoadjuvant chemoradiation for evaluating response to therapy in T3 and T4 rectal cancer. To investigate the utility of MR volumetry for predicting the response to neoadjuvant chemoradiation, we compared results from MR volumetry before chemoradiation with those after chemoradiation. METHODS AND MATERIALS: A total 112 patients with T3 or T4 rectal cancer who successfully underwent MR volumetry and completed neoadjuvant chemoradiation followed by radical resection for cure were identified. MR volumetries were performed before and after chemoradiation. We compared pre- and postchemoradiation tumor volume and % volume reduction rates of patients whose tumors were down-staged with those of patients that were not down-staged. The same analyses were also performed between those patients having a complete histologic regression and those with residual disease in the operative specimen. We assessed the difference of % volume reduction rate according to Dworak's rectal cancer regression grades. RESULTS: Fifty-seven patients (50.9%) demonstrated a tumor down-staging after chemoradiation therapy. Both pre- and posttreatment MR tumor volumes were significantly less in patients whose tumors were down-staged than in patients that were not down-staged (p = 0.04, 0.031), and % volume reduction rates were significantly higher in patients whose tumors were down-staged (p = 0.024). Sixteen patients (14.3%) showed pathologically complete tumor regression. The differences of MR tumor volumes before and after chemoradiation and % volume reduction rates were not significantly different between patients having a complete histologic regression and those with residual disease (p = 0.688, 0.451, and 0.480). The differences of % volume reduction rates according to Dworak's grades were statistically significant (p = 0.03). CONCLUSION: The MR volumetric examinations before and after chemoradiation demonstrated the significant difference of tumor volume and % volume reduction rate between patients whose tumors were down-staged and those that were not down-staged. The volume reduction rates were significantly different among groups according to Dworak's grades. However, the MR volumetric evaluation could not identify any differences between those patients having a complete histologic regression and those with residual disease.

Adult↗

PubMed2004

The pattern of gene copy number changes in bilateral breast cancer surveyed by cDNA microarray-based comparative genomic hybridization.

The nature of genetic alterations in bilateral breast cancer (BBC) associated with the distinctive development of a second primary tumor or a metastatic lesion is not clearly established. In this study, patterns of promoter methylation and gene copy number changes were assessed for their utility in the distinction of two types of BBC (synchronous and metachronous). Seven cases of synchronous and five cases of metachronous breast cancer tissues were used in X chromosome inactivation assay to assess the methylation pattern of human androgen receptor gene. X chromosome inactivation assay alone did not provide enough information to distinguish the genetic origins of synchronous and metachronous BBC. When four pairs of paraffin-embedded BBC tissues were used in cDNA array-based CGH with placenta DNA as a reference, higher DNA copy number changes were observed from metachronous pairs (9.0%) than from synchronous pairs (3.1%). From the two cases of metachronous pairs tested, 44 genes were found to be commonly modulated in gene copy numbers in a cancer detected later.

Breast Neoplasms↗