Young Suk Park

Salvage Chemotherapy for Pretreated Gastric Cancer: A Randomized Phase III Trial Comparing Chemotherapy Plus Best Supportive Care With Best Supportive Care Alone

PURPOSE When designing this trial, there was no evidence that salvage chemotherapy (SLC) in advanced gastric cancer (AGC) resulted in substantial prolongation of survival when compared with best supportive care (BSC). However, SLC is often offered to pretreated patients with AGC for anecdotal reasons. PATIENTS AND METHODS Patients with AGC with one or two prior chemotherapy regimens involving both fluoropyrimidines and platinum and with an Eastern Cooperative Oncology Group performance status (PS) 0 or 1 were randomly assigned in a ratio of 2:1 to SLC plus BSC or BSC alone. Choice of SLC-either docetaxel 60 mg/m(2) every 3 weeks or irinotecan 150 mg/m(2) every 2 weeks-was left to the discretion of investigators. Primary end point was overall survival (OS). RESULTS Median OS was 5.3 months among 133 patients in the SLC arm and 3.8 months among 69 patients in the BSC arm (hazard ratio, 0.657; 95% CI, 0.485 to 0.891; one-sided P = .007). OS benefit for SLC was consistent in most of the prospectively defined subgroups, including age, PS, number of prior treatments, metastatic sites, hemoglobin levels, and response to prior chemotherapy. SLC was generally well tolerated, and adverse events were similar in the SLC and BSC arms. We found no median OS difference between docetaxel and irinotecan (5.2 v 6.5 months; P = .116). CONCLUSION To our knowledge, this is the largest phase III trial comparing SLC plus BSC with BSC alone in AGC. In pretreated patients, SLC is tolerated and significantly improves OS when added to BSC.

Phase III Trial Comparing Capecitabine Plus Cisplatin Versus Capecitabine Plus Cisplatin With Concurrent Capecitabine Radiotherapy in Completely Resected Gastric Cancer With D2 Lymph Node Dissection: The ARTIST Trial

PURPOSE The ARTIST (Adjuvant Chemoradiation Therapy in Stomach Cancer) trial was the first study to our knowledge to investigate the role of postoperative chemoradiotherapy therapy in patients with curatively resected gastric cancer with D2 lymph node dissection. This trial was designed to compare postoperative treatment with capecitabine plus cisplatin (XP) versus XP plus radiotherapy with capecitabine (XP/XRT/XP). PATIENTS AND METHODS The XP arm received six cycles of XP (capecitabine 2,000 mg/m2 per day on days 1 to 14 and cisplatin 60 mg/m2 on day 1, repeated every 3 weeks) chemotherapy. The XP/XRT/XP arm received two cycles of XP followed by 45-Gy XRT (capecitabine 1,650 mg/m2 per day for 5 weeks) and two cycles of XP. RESULTS Of 458 patients, 228 were randomly assigned to the XP arm and 230 to the XP/XRT/XP arm. Treatment was completed as planned by 75.4% of patients (172 of 228) in the XP arm and 81.7% (188 of 230) in the XP/XRT/XP arm. Overall, the addition of XRT to XP chemotherapy did not significantly prolong disease-free survival (DFS; P = .0862). However, in the subgroup of patients with pathologic lymph node metastasis at the time of surgery (n = 396), patients randomly assigned to the XP/XRT/XP arm experienced superior DFS when compared with those who received XP alone (P = .0365), and the statistical significance was retained at multivariate analysis (estimated hazard ratio, 0.6865; 95% CI, 0.4735 to 0.9952; P = .0471). CONCLUSION The addition of XRT to XP chemotherapy did not significantly reduce recurrence after curative resection and D2 lymph node dissection in gastric cancer. A subsequent trial (ARTIST-II) in patients with lymph node-positive gastric cancer is planned.

Impact of MET amplification on gastric cancer: possible roles as a novel prognostic marker and a potential therapeutic target.

Identification of critical genes which play pivotal roles in controlling tumor growth and survival will establish the basis for developing therapeutic targets. With the aim of establishing personalized medicine for treatment of solid tumors, we focused on MET amplification in gastric cancer patients, given the extreme sensitivity to c-Met inhibitor in MET amplified gastric cancer cell lines. We tested MET amplification and activation of c-Met in various gastric cancer cell lines and tissue samples from 482 gastric cancer patients who underwent curative surgery. Gastric cancer cell lines with MET amplification by quantitative real-time PCR (qPCR) and FISH predicted sensitivity to PHA-665,752, a selective c-Met kinase inhibitor. Of the 472 patients who had DNA sample available for qPCR analysis, 100 patients (21.2%) had a MET copy number greater than 4.0 copies and demonstrated poorer survival following curative surgery with statistical significance (5-year OS; 50.0 vs. 59.1%; MET amplification (+) vs. MET amplification (-); P = 0.0134). These results suggest that the increased MET copy number measured by qPCR plays an important role in determining prognosis in gastric cancer patients. However, the predictive role of MET amplification for treatment response should be further explored in upcoming clinical trials.

Gefitinib (ZD1839) Monotherapy as a Salvage Regimen for Previously Treated Advanced Non-Small Cell Lung Cancer

Purpose: A worldwide compassionate-use program has enabled >42,000 patients with advanced non-small cell lung cancer (NSCLC) to receive gefitinib treatment. Here we report the outcome of gefitinib therapy in patients who enrolled in the “Iressa” Expanded Access Program at the Samsung Medical Center. Experimental Design: Patients with advanced or metastatic NSCLC who had progressed after prior systemic chemotherapy and for whom no other treatment option was available were eligible to receive gefitinib treatment as part of the Expanded Access Program. A post hoc assessment of potential prognostic factors for response and survival was performed by multivariate analysis. Results: All 111 evaluable patients had stage IV disease; most patients had a baseline performance status of 2 [n = 52 (47%)] or 3 [n = 18 (16%)] and had received ≥2 prior chemotherapy regimens (56%). The objective response rate was 26%, the disease control rate (measured over ≥8 weeks) was 40%, and the 1-year survival rate was 44%. Adenocarcinoma histology was associated with better response and disease control rates, and a performance status of 0–2 was also associated with a better disease control rate. Both of these factors, as well as female gender, were significantly associated with longer survival. Gefitinib was well tolerated; the most common adverse event was grade 1 skin rash. Conclusions: Gefitinib demonstrated significant antitumor activity and a favorable tolerability profile in this series of NSCLC patients with poor prognosis.

Impact of KRAS Mutations on Clinical Outcomes in Pancreatic Cancer Patients Treated with First-line Gemcitabine-Based Chemotherapy

Although erlotinib has become an important therapeutic option in addition to gemcitabine, the high frequency of KRAS mutations in pancreatic cancer probably limits the benefits. We retrospectively studied 136 pancreatic cancer patients with available formalin-fixed paraffin-embedded tumor blocks from 2003 to 2009 to understand the clinical significance of KRAS mutations in pancreatic cancer patients treated with gemcitabine-based chemotherapy. KRAS mutations were analyzed by sequencing codons 12, 13, and 61. In this study, 71 (52.2%) of the 136 pancreatic adenocarcinomas examined harbored a point mutation in codons 12 (n = 70) and 61 (n = 1) of KRAS. KRAS mutation was not associated with clinicopathologic parameters. Patients with KRAS mutations showed a worse response (11.3%) than those with wild-type KRAS (26.2%) and poor survival (mutant KRAS, 5.8 months vs. wild-type KRAS, 8.0 months; P = 0.001). Multivariate analysis revealed good prognostic factors for overall survival as well to moderately differentiated histology (P < 0.001; HR = 0.437, 95% CI: 0.301–0.634), locally advanced disease (P < 0.001; HR = 0.417, 95% CI: 0.255–0.681), response to first-line chemotherapy (P = 0.003; HR = 0.482, 95% CI: 0.297–0.780), and wild-type KRAS (P = 0.001; HR = 0.523, 95% CI: 0.355–0.770). However, the observed survival advantage is derived from the subgroup of patients treated with gemcitabine/erlotinib (9.7 vs. 5.2 months; P = 0.002), whereas no survival difference based on KRAS mutation status is obvious in the other subgroup of patients treated without erlotinib (7.0 vs. 7.0 months; P = 0.121). These results need to be further explored in upcoming prospective studies to provide a rationale for personalized medicine in pancreatic cancer. Mol Cancer Ther; 10(10); 1993–9. ©2011 AACR.

Ten‐Day Sequential Therapy as First‐line Treatment for Helicobacter pylori Infection in Korea: A Retrospective Study

Background and Aims:  The eradication rate of proton‐pump inhibitor‐based triple therapy for Helicobacter pylori infection is low due to increasing antibiotics resistance, especially clarithromycin. Recently, it was reported in Europe that a 10‐day sequential strategy produced good outcomes. The aim of this study was to assess the efficacy of sequential therapy as first‐line treatment for eradication of H. pylori in clinical practice in Korea.

Prospective blinded study of somatic mutation detection in cell-free DNA utilizing a targeted 54-gene next generation sequencing panel in metastatic solid tumor patients

Sequencing of the mutant allele fraction of circulating cell-free DNA (cfDNA) derived from tumors is increasingly utilized to detect actionable genomic alterations in cancer. We conducted a prospective blinded study of a comprehensive cfDNA sequencing panel with 54 cancer genes. To evaluate the concordance between cfDNA and tumor DNA (tDNA), sequencing results were compared between cfDNA from plasma and genomic tumor DNA (tDNA). Utilizing next generation digital sequencing technology (DST), we profiled approximately 78,000 bases encoding 512 complete exons in the targeted genes in cfDNA from plasma. Seventy-five patients were prospectively enrolled between February 2013 and March 2014, including 61 metastatic cancer patients and 14 clinical stage II CRC patients with matched plasma and tissue samples. Using the 54-gene panel, we detected at least one somatic mutation in 44 of 61 tDNA (72.1%) and 29 of 44 (65.9%) cfDNA. The overall concordance rate of cfDNA to tDNA was 85.9%, when all detected mutations were considered. We collected serial cfDNAs during cetuximab-based treatment in 2 metastatic KRAS wild-type CRC patients, one with acquired resistance and one with primary resistance. We demonstrate newly emerged KRAS mutation in cfDNA 1.5 months before radiologic progression. Another patient had a newly emerged PIK3CA H1047R mutation on cfDNA analysis at progression during cetuximab/irinotecan chemotherapy with gradual increase in allele frequency from 0.8 to 2.1%. This blinded, prospective study of a cfDNA sequencing showed high concordance to tDNA suggesting that the DST approach may be used as a non-invasive biopsy-free alternative to conventional sequencing using tumor biopsy.

Expression of activated signal transducer and activator of transcription 3 predicts poor clinical outcome in gastric adenocarcinoma

Lee J, Kang WK, Park JO, Park SH, Park YS, Lim HY, Kim J, Kong J, Choi MG, Sohn TS, Noh JH, Bae JM, Kim S, Lim DH, Kim K‐M, Park CK. Expression of activated signal transducer and activator of transcription 3 predicts poor clinical outcome in gastric adenocarcinoma. APMIS 2009; 117: 598–606.

Thymidylate synthase (TYMS) and dihydropyrimidine dehydrogenase (DPYD) polymorphisms in the korean population for prediction of 5-fluorouracil-associated toxicity

The important cellular proteins for 5-fluorouracil (5-FU) metabolism are the major target enzymes, thymidylate synthase, and the rate-limiting enzyme in the degradation pathway, dihydropyrimidine dehydrogenase. Adverse drug reactions to 5-FU-based chemotherapy have been reported to be in part the result of polymorphisms in the thymidylate synthase (TYMS) and dihydropyrimidine dehydrogenase (DPYD) genes. Therefore, we examined the type and frequency of polymorphisms in the TYMS and DPYD genes in 100 healthy Korean individuals and compared these findings with 21 patients with colorectal cancer who had a grade 3 or greater toxic response to 5-FU treatment. Genotyping analysis of the promotor enhancer region (TSER) and the 3′-untranslated region (3′-UTR) of the TYMS gene as well as haplotype analysis were conducted in all 121 study participants. For the TSER and the 3′-UTR of the TYMS gene, similar genotypes and allele frequencies were observed in control subjects and patients. For the haplotype analysis of the single nucleotide polymorphism G > C at the 12th nucleotide of the second repeat of the 3R allele of the TSER, different haplotype frequencies were noted in comparisons between the two groups; in addition, we found that the 3RC-del 6bp was significantly associated with severe toxicity with 5-FU treatment. Extensive polymorphisms in the DPYD gene were observed; in addition, four polymorphisms were related to the known DPYD allelic variants or to allelic variants that alter protein structure, among which the most common polymorphism was 1627A > G, observed in 20.5% of all alleles. The 496A > G allele and a novel 1774C > T allele were identified in two patients. The DPYD*2A allele, causing exon 14 skipping, was not identified in the study group. The findings, from Korean patients with colon cancer, suggest that polymorphisms of the DPYD gene are not associated with an increased risk for toxic response to 5-FU. These findings suggest that there may be an important relationship between the TYMS haplotypes examined and 5-FU toxicity. The novel variant in the DPYD gene, identified in this study, should be further investigated to confirm its functional significance. A large sample is required before DPYD or TYMS genotyping could be used as markers for individualized treatment of patients with colorectal cancer.

Impact of E2F-1 Expression on Clinical Outcome of Gastric Adenocarcinoma Patients with Adjuvant Chemoradiation Therapy

Purpose: There are no reliable prognostic markers that identify gastric cancer patients who may benefit from adjuvant chemoradiation therapy. E2F-1 was shown to be associated with radiosensitivity and chemosensitivity in certain tumor types. Therefore, we analyzed expression and prognostic significance of E2F-1 along with thymidylate synthase (TS) in R0-resected gastric adenocarcinoma patients, who underwent adjuvant chemoradiation therapy with 5-fluorouracil (5-FU) and leucovorin. Experimental Design: The chemosensitivity to 5-FU and radiosensitivity were tested in three E2F-1–overexpressed gastric cancer cell lines in vitro. The expressions of TS and E2F-1 were analyzed in 467 R0-resected primary gastric cancer patients, who received adjuvant chemoradiation therapy with 5-FU and leucovorin using tissue microarray. Results: The E2F-1 immunopositivity rate was 22.2% (103 of 465 samples) with a cutoff value of 5% immunoreactivity, whereas the TS-positive expression occurred in 19.0% of the 463 tumors tested. Using stepwise Cox proportional hazards regression modeling, multivariate analyses showed that the E2F-1 immunopositivity predicted more favorable survival as compared with the E2F-1 immunonegativity with borderline statistical significance [P = 0.050, hazard ratio (HR) = 0.702, 95% confidence interval, 0.487, 1.013]. However, the E2F-1 immunopositivity did not retain its statistical significance at multivariate analysis for predicting disease-free survival (data not shown, P = 0.270), but stage was the only influential factor for disease-free survival in stages IB to IV (M0) patients (P < 0.001). TS immunopositivity did not influence survival (P = 0.459) or disease-free survival (P = 0.447). Conclusion: E2F-1 is a potentially novel independent prognostic factor that may identify gastric cancer patients who will likely benefit from adjuvant chemoradiation therapy following curative resection.