Suk Joong Oh

HER-2/neu amplification is an independent prognostic factor in gastric cancer.

The HER-2/neu protein is intimately involved with normal cell proliferation and tissue growth and is extensively homologous and related to the epidermal growth factor receptor. HER-2/neu protein expression has been most intensively studied in the context of breast carcinoma, in which its amplification and overexpression correlate with the overall course of disease, and with a poor prognosis, and constitute a predictive factor of poor response to chemotherapy and endocrine therapy. In this study, we investigated the relationship between the expression of HER-2/neu and the clinicopathological characteristics of tumors, including survival. This study was performed with a view toward the future introduction of Herceptin therapy for gastric cancer patients. HER-2/neu overexpression and gene amplification was examined with semiquantitative standardized immunohistochemical staining, chromogenic in situ hybridization (CISH), and fluorescence in situ hybridization (FISH) in 182 gastric cancer patients who underwent curative surgery at the Kangbuk Samsung Hospital. Twenty-nine (15.9%) of 182 patients expressed the HER-2/neu protein by immunohistochemistry. HER-2/neu gene amplification was detected in seven patients by CISH and FISH. Intestinal-type cancers exhibited higher rates of HER-2/neu amplification than did diffuse-type cancers (P < 0.05). Tumors with HER-2/neu amplification were associated with poor mean survival rates (922 vs 3243 days) and 5-year survival rates (21.4% vs 63.0%; P < 0.05). Age, TNM stage, and amplification of HER-2/neu were found to be independently related to survival by multivariate analysis. HER-2/neu amplification may constitute an independent prognostic factor in gastric cancer patients, and patients exhibiting HER-2/neu amplification might constitute potential candidates for new adjuvant therapies which involve the use of humanized monoclonal antibodies.

HER-2/neu overexpression is an independent prognostic factor in colorectal cancer

Background and aimsThe HER-2/neu protein is intimately involved with normal cell proliferation and tissue growth, as it is extensively homologous and is related to the epidermal growth factor receptor. This phenomenon has been most intensively studied in the context of breast carcinoma, in which its amplification and overexpression correlate with the overall course of disease and poor prognoses, and also constitute a predictive factor of poor response to chemotherapy and endocrine therapy. In this study, we investigated the relationships between the expression of HER-2/neu and the clinicopathological characteristics of colorectal cancer, including survival. This study was performed with a view toward the future introduction of Herceptin therapy for colorectal cancer patients.Patients and methodsHER-2/neu overexpression and gene amplification were examined via semiquantitative standardized immunohistochemical staining and fluorescence in situ hybridization (FISH) in 137 colorectal cancer patients who underwent curative surgery at the Kangbuk Samsung Hospital.ResultsSixty-five (47.4%) out of 137 patients were determined by immunohistochemistry to have overexpressed HER-2/neu protein. HER-2/neu gene amplification was detected in two patients by FISH. Tumors with HER-2/neu overexpression showed higher postoperative recurrence rate (39.3% vs 14.6%, p=0.013). Tumors with HER-2/neu overexpression were associated with poor 3-year (70.8% vs 83.7%) and 5-year survival rates (55.1% vs 78.3%, p<0.05). Advanced TNM stage, postoperative recurrence, and overexpression of HER-2/neu were found to be independently related to survival by multivariate analysis.ConclusionHER-2/neu overexpression may constitute an independent prognostic factor in colorectal cancer patients, and patients exhibiting HER-2/neu overexpression might constitute potential candidates for a new adjuvant therapy which involves the use of humanized monoclonal antibodies.

Influence of enzyme and transporter polymorphisms on trough imatinib concentration and clinical response in chronic myeloid leukemia patients

BACKGROUND This study explored the impact of genetic polymorphisms in cytochrome P450 (CYP) enzymes and transporters on the plasma trough concentration of imatinib mesylate (IM) and clinical response in chronic myeloid leukemia (CML). PATIENTS AND METHODS In total, 82 patients with CML who had been administered 400 mg IM daily for over 6 months were genotyped for 11 single-nucleotide polymorphisms in nine genes (CYP3A4, CYP3A5, CYP2C9, CYP2C19, CYP2D6, ABCB1, SLC22A1, SLC22A2 and ABCG2) using blood samples. The trough imatinib concentration and clinical responses were assessed 6 months after the initiation of IM therapy. RESULTS The CC, CA and AA genotypes in ABCG2 421C>A gave significantly different frequencies for the major molecular response (MMR) (P = 0.02). However, no significant differences were found between the genotypes of the CYP enzymes and transporters identified in this study and the imatinib plasma trough concentrations and clinical response frequencies, except for the correlation of ABCG2 with MMR. CONCLUSIONS The results of the present study may indicate that the ABCG 421C>A genetic polymorphism influences the MMR of imatinib in patients with CML.

Efficacy and safety of radotinib in chronic phase chronic myeloid leukemia patients with resistance or intolerance to BCR-ABL1 tyrosine kinase inhibitors

Radotinib (IY5511HCL), a novel and selective BCR-ABL1 tyrosine kinase inhibitor, has shown pre-clinical and phase I activity and safety in chronic myeloid leukemia. This phase II study investigated the efficacy and safety of radotinib in Philadelphia chromosome-positive chronic phase-chronic myeloid leukemia patients with resistance and/or intolerance to BCR-ABL1 tyrosine kinase inhibitors. Patients received radotinib 400 mg twice daily for 12 cycles based on results from the phase I trial. The primary end point was rate of major cytogenetic response by 12 months. A total of 77 patients were enrolled. Major cytogenetic response was achieved in 50 (65%; cumulative 75%) patients, including 36 (47%) patients with complete cytogenetic response by 12 months. Median time to major cytogenetic response and complete cytogenetic response were 85 days and 256 days, respectively. Major cytogenetic response and complete cytogenetic response rates were similar between imatinib-resistant and imatinib-intolerant patients, but were higher in patients without BCR-ABL1 mutations. Overall and progression-free survival rates at 12 months were 96.1% and 86.3%, respectively. All newly-occurring or worsening grade 3/4 hematologic abnormalities included thrombocytopenia (24.7%) and anemia (5.2%); grade 3/4 drug-related non-hematologic adverse events included fatigue (3.9%), asthenia (3.9%), and nausea (2.6%). The most common biochemistry abnormality was hyperbilirubinemia (grade 3/4 23.4%), and 12 of 18 cases were managed with dose modification. Study findings suggest radotinib is effective and well tolerated in chronic phase-chronic myeloid leukemia patients with resistance and/or intolerance to BCR-ABL1 tyrosine kinase inhibitors and may represent a promising alternative for these patients. (clinicaltrials.gov identifier: 01602952)

Trough plasma imatinib levels are correlated with optimal cytogenetic responses at 6 months after treatment with standard dose of imatinib in newly diagnosed chronic myeloid leukemia

To investigate the correlation of trough imatinib mesylate (IM) levels with cytogenetic or molecular responses, we measured trough IM levels in patients with chronic myeloid leukemia, chronic phase (CML-CP), at 6 months of treatment with a standard dose of IM. Eighty-seven newly diagnosed patients with CML-CP were prospectively enrolled. Seventy-eight patients (89.7%) showed an optimal response (complete or partial cytogenetic response) at 6 months. Trough IM levels were 1378 ± 725 ng/mL. When categorized into two groups, there was a statistically significant difference in numbers of patients with optimal and suboptimal responses at 6 months (group with <1000: 80.6% vs. 19.4%; ≥1000: 94.6% vs. 5.4%; p = 0.032), and in numbers of patients with early major molecular response (early-MMR) and without MMR at 6 months (group with <1000: 3.2% vs. 96.8%; ≥1000: 21.4% vs. 78.6%; p = 0.047). In conclusion, the incidence of optimal cytogenetic response or early-MMR in patients with CML-CP treated with IM for 6 months was significantly higher in those with a trough level of ≥1000 compared with those with a level of <1000. Dose escalation of IM can be one option in patients with CML showing suboptimal response or resistance to the standard dose of IM, especially with low trough plasma IM levels (<1000 ng/mL).

Prognostic model to predict outcomes in nonsmall cell lung cancer patients treated with gefitinib as a salvage treatment

A prognostic model based on clinical parameters for nonsmall cell lung cancer (NSCLC) patients treated with gefitinib (250 mg/day) as a salvage therapy was devised.

Significance of Endoscopy in Asymptomatic Premenopausal Women with Iron Deficiency Anemia

There is, currently, no consensus with regard to the role of endoscopy in the etiologic investigation of asymptomatic pemenopausal women suffering from iron deficiency anemia (IDA). We conducted a retrospective case-control study to evaluate the contribution of esophagogastroduodenoscopy (EGD) and colonoscopy to the etiologic diagnosis of a group of asymptomatic premenopausal women suffering from IDA. One hundred eight consecutive asymptomatic premenopausal women who fulfilled our entry criteria were included in our patient group between January 1998 and December 2004. One hundred thirty-five age-matched asymptomatic premenopausal women without anemia who had undergone EGD and colonoscopy for medical checkups were included in the control group. Clinically relevant lesions were detected in 7 of 108 (6.5%) of the patients and in 8 of 135 (5.9%) of the controls. There were no differences with regard to the frequency of clinically relevant lesions between the two groups (P > 0.05). Concomitant upper and lower GI lesions were not detected in any patients. In the upper GI tract, the only lesion found to be potentially causative of IDA anemia was a severe erosive gastritis, which was found in both the patient and the control groups. A source consistent with chronic bleeding was detected in the lower GI tract in 6 (5.6%) of the patients and 7 (5.2%) of the controls. Bleeding hemorrhoids represented the most frequently detected lesions in both the patient and control groups. Only one case of colon cancer was detected in the patient group. As IDA in the premenopausal women could not be attributed consistently to GI blood loss in this study, prospective studies should be conducted to validate our findings and to identify which subgroup of asymptomatic premenopausal women would benefit from a diagnostic endoscopic evaluation.

CTRP1 protects against diet-induced hyperglycemia by enhancing glycolysis and fatty acid oxidation.

Complement-C1q/tumor necrosis factor-α related protein 1 (CTRP1) is a 35-kDa glycoprotein that is secreted from various tissues. Although CTRP1 is highly increased in patients with type II diabetes and obesity, the metabolic roles of CTRP1 remain largely unknown. To unveil the physiological roles of CTRP1 in vivo, CTRP1 transgenic (TG) mice were challenged by a high-fat diet (HFD) and a high-sucrose drink (HS). Homeostatic model assessment-estimated insulin resistance values were decreased in HFD- or HS-fed CTRP1 TG mice compared with wild-type control mice. In this context, CTRP1 stimulated glucose uptake through the glucose transporter GLUT4 translocation to the plasma membrane and also increased glucose consumption by stimulating glycolysis. To analyze the roles of CTRP1 in lipid metabolism, acetyl-CoA carboxylase (ACC) and hormone-sensitive lipase levels were determined in CTRP1 TG mice, and the effect of CTRP1 on fatty acid oxidation was assessed in C2C12 myotubes. CTRP1 was found to inhibit ACC by phosphorylation and to stimulate fatty acid oxidation in C2C12 myotubes. Taken together, CTRP1 performs active catabolic roles in vivo. Therefore, CTRP1 seems to perform a defensive function against nutritional challenges.

Phase III Clinical Trial (RERISE study) Results of Efficacy and Safety of Radotinib Compared with Imatinib in Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia

Purpose: Radotinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor (TKI) approved in Korea for chronic phase chronic myeloid leukemia (CML-CP) in patients newly diagnosed or with insufficient response to other TKIs. This study was conducted to evaluate the efficacy and safety of radotinib as first-line therapy for CML-CP. Experimental Design: This multinational, open-label study assigned patients (1:1:1) to one of two twice-daily radotinib doses, or imatinib daily. The primary endpoint was major molecular response (MMR) by 12 months. Results: Two hundred forty-one patients were randomized to receive radotinib 300 mg (n = 79) or 400 mg twice-daily (n = 81), or imatinib 400 mg daily (n = 81). MMR rates by 12 months were higher in patients receiving radotinib 300 mg (52%) or radotinib 400 mg twice-daily (46%) versus imatinib (30%; P = 0.0044 and P = 0.0342, respectively). Complete cytogenetic response (CCyR) rates by 12 months were higher for radotinib 300 mg (91%) versus imatinib (77%; P = 0.0120). Early molecular response at 3 months occurred in 86% and 87% of patients receiving radotinib 300 mg and radotinib 400 mg, respectively, and 71% of those receiving imatinib. By 12 months, no patients had progression to accelerated phase or blast crisis. Most adverse events were manageable with dose reduction. Conclusions: Radotinib demonstrated superiority over imatinib in CCyR and MMR in patients newly diagnosed with Philadelphia chromosome–positive CML-CP. This trial was registered at www.clinicaltrials.gov as NCT01511289. Clin Cancer Res; 23(23); 7180–8. ©2017 AACR.

Phase II study of S‐1 and irinotecan combination chemotherapy as a first‐line therapy for patients with advanced gastric cancer. Korean Cancer Study Group Protocol ST05‐02

Background:  Irinotecan plus intravenous 5‐fluorouracil (5‐FU) with leucovorin is effective against gastrointestinal cancer. S‐1 is an oral fluoropyrimidine derivative and has a high response rate of about 40% for patients with advanced gastric cancer (AGC). We evaluated the antitumor activity and toxicities of an S‐1 and irinotecan combination as a first‐line therapy for patients with AGC.