Min Gew Choi

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.

Molecular analysis of gastric cancer identifies subtypes associated with distinct clinical outcomes

Gastric cancer, a leading cause of cancer-related deaths, is a heterogeneous disease. We aim to establish clinically relevant molecular subtypes that would encompass this heterogeneity and provide useful clinical information. We use gene expression data to describe four molecular subtypes linked to distinct patterns of molecular alterations, disease progression and prognosis. The mesenchymal-like type includes diffuse-subtype tumors with the worst prognosis, the tendency to occur at an earlier age and the highest recurrence frequency (63%) of the four subtypes. Microsatellite-unstable tumors are hyper-mutated intestinal-subtype tumors occurring in the antrum; these have the best overall prognosis and the lowest frequency of recurrence (22%) of the four subtypes. The tumor protein 53 (TP53)-active and TP53-inactive types include patients with intermediate prognosis and recurrence rates (with respect to the other two subtypes), with the TP53-active group showing better prognosis. We describe key molecular alterations in each of the four subtypes using targeted sequencing and genome-wide copy number microarrays. We validate these subtypes in independent cohorts in order to provide a consistent and unified framework for further clinical and preclinical translational research.

Predictive factors for lymph node metastasis in early gastric cancer with submucosal invasion: analysis of a single institutional experience.

Objective:An accurate assessment of a potential lymph node metastasis is an important issue for the appropriate treatment of early gastric cancer. Minimizing the amount of invasive procedures used in cancer treatment is critical for improving the patients quality of life. Therefore, this study analyzed the predictive risk factors for a lymph node metastasis in early gastric cancer with a submucosal invasion. Methods:The data from 1043 patients surgically treated for early gastric cancer with submucosal invasion between 2002 and 2005 were reviewed retrospectively. The patients were divided into 3 layers according to their depth: SM1, SM2, and SM3. The clinicopathological variables predicting a lymph node metastasis were evaluated. Results:A lymph node metastasis was observed in 19.4% of patients. The tumor size, histologic type, Lauren classification, tumor depth, and perineural invasion showed a positive correlation with the rate of lymph node metastasis and N category by univariate analysis. Multivariate analyses revealed the tumor size (≥2 cm) and lymphatic involvement to be significantly and independently related to lymph node metastasis. The presence of lymphatic involvement was the strongest predictive factor for a lymph node metastasis, being observed in 43.8% of cases in which a lymph node metastasis had been revealed. No lymph node metastasis was observed in the 12 cases with no lymphatic involvement, SM1 invasion, and tumor size <1 cm. Conclusions:Lymphatic involvement and tumor size are independent risk factors for a lymph node metastasis in early gastric cancer with submucosal invasion. Minimal invasive treatment, such as endoscopic mucosal resection, may be possible in highly selective submucosal cancers with no lymphatic involvement, SM1 invasion, and tumor size <1 cm.

Phase III Trial to Compare Adjuvant Chemotherapy With Capecitabine and Cisplatin Versus Concurrent Chemoradiotherapy in Gastric Cancer: Final Report of the Adjuvant Chemoradiotherapy in Stomach Tumors Trial, Including Survival and Subset Analyses

PURPOSE The Adjuvant Chemoradiotherapy in Stomach Tumors (ARTIST) trial tested whether the addition of radiotherapy to adjuvant chemotherapy improved disease-free survival (DFS) in patients with D2-resected gastric cancer (GC). PATIENTS AND METHODS Between November 2004 and April 2008, 458 patients with GC who received gastrectomy with D2 lymph node dissection were randomly assigned to either six cycles of adjuvant chemotherapy with capecitabine and cisplatin (XP) or to two cycles of XP followed by chemoradiotherapy and then two additional cycles of XP (XPRT). This final update contains the first publication of overall survival (OS), together with updated DFS and subset analyses. RESULTS With 7 years of follow-up, DFS remained similar between treatment arms (hazard ratio [HR], 0.740; 95% CI, 0.520 to 1.050; P=.0922). OS also was similar (HR, 1.130; 95% CI, 0.775 to 1.647; P=.5272). The effect of the addition of radiotherapy on DFS and OS differed by Lauren classification (interaction P=.04 for DFS; interaction P=.03 for OS) and lymph node ratio (interaction P<.01 for DFS; interaction P<.01 for OS). Subgroup analyses also showed that chemoradiotherapy significantly improved DFS in patients with node-positive disease and with intestinal-type GC. There was a similar trend for DFS and OS by stage of disease. CONCLUSION In D2-resected GC, both adjuvant chemotherapy and chemoradiotherapy are tolerated and equally beneficial in preventing relapse. Because results suggest a significant DFS effect of chemoradiotherapy in subsets of patients, the ARTIST 2 trial evaluating adjuvant chemotherapy and chemoradiotherapy in patients with node-positive, D2-resected GC is under way.

The difficult choice between total and proximal gastrectomy in proximal early gastric cancer

BACKGROUND Surgical results including postoperative complications, prognoses, body weight changes, and nutritional statuses were compared in patients with early gastric cancer in the upper third of the stomach who were treated by total gastrectomy or proximal gastrectomy. METHODS The authors reviewed clinicopathologic features, postoperative complications, survivals, body weight changes, and biochemical markers after surgery in 423 patients who underwent total or proximal gastrectomy for early gastric cancer in the upper third of the stomach. RESULTS The proximal gastrectomy group (n = 89) had smaller tumors, shorter resection margins, and smaller numbers of retrieved lymph nodes than the total gastrectomy group (n = 334). N stages and 5-year survival rates were similar after total and proximal gastrectomy. Postoperative complication rates after total gastrectomy and proximal gastrectomy were 12.6% and 61.8%, respectively, which was significant (P < .001). Rates of anastomotic stenosis and reflux esophagitis were 6.9% and 1.8% after total gastrectomy and 38.2% and 29.2% after proximal gastrectomy, respectively. The parameters that reflect nutritional status (ie, body weight, serum hemoglobin, total protein, albumin, glucose, and cholesterol) were similar in the proximal and total gastrectomy groups at 6, 12, 24, and 36 months postoperatively. CONCLUSION Although the surgical safeties and curabilities of proximal and total gastrectomy were similar, proximal gastrectomy was found to be associated with a markedly higher rate of complications such as anastomotic stenosis and reflux esophagitis and to provide no benefit in terms of postoperative weight loss. The authors conclude that proximal gastrectomy is not a better option for upper-third early gastric cancer than total gastrectomy.

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.

Long-Term Outcome of Endoscopic Resection vs. Surgery for Early Gastric Cancer: A Non-inferiority-Matched Cohort Study

OBJECTIVES:Few studies have compared the long-term outcomes of endoscopic resection and surgery. The aim of this study was to compare the long-term outcomes of endoscopic resection with those of surgery for early gastric cancer (EGC).METHODS:We reviewed prospectively collected data of patients who had undergone endoscopic resection (1,290 patients) or surgery (1,273 patients) for EGC. To reduce the effect of selection bias, we performed a propensity score-matching analysis between the two groups. The primary outcome was overall survival (OS). The secondary outcomes were disease-specific survival, disease-free survival (DFS), recurrence-free survival (RFS), occurrence of metachronous gastric cancer, treatment-related complications, length of hospital stay, and 30-day outcomes. The study was designed as a non-inferiority study and tested in an intention-to-treat analysis.RESULTS:In a propensity-matched analysis of 611 pairs, the 10-year OS proportion was 96.7% in the endoscopic resection group and 94.9% in the surgery group (P=0.120) (risk difference −1.8%, 95% confidence interval (CI) −4.04–0.44, Pnon-inferiority=0.014), which met the non-inferiority criterion. In contrast, the 10-year RFS proportion was 93.5% in the endoscopic resection group and 98.2% in the surgery group (P<0.001) (risk difference 4.7%, 95% CI 2.50–6.97, Pnon-inferiority=0.820), which did not meet the non-inferiority criterion, mainly because of metachronous recurrence in the endoscopic resection group. The rate of early complications was higher in the endoscopic resection group than in the surgery group (9.0 vs. 6.6%, P=0.024), whereas the rate of late complications was higher in the surgery group than in the endoscopic resection group (0.5 vs. 2.9%, P<0.001). In the multiple Cox regression analysis, patient’s age, the comorbidity index, the performance index, sex, tumor morphology, and depth of invasion were predictors of OS in patients with EGC.CONCLUSIONS:Endoscopic resection might not be inferior to surgery with respect to OS in patients with EGC lesions that meet the absolute or expanded criteria. However, DFS, RFS, and metachronous RFS might be lower after endoscopic resection than after surgery.

Changes of quality of life in gastric cancer patients after curative resection: a longitudinal cohort study in Korea.

Objective:Little is known about how quality of life (QOL) changes over time after gastrectomy. We prospectively examined changes of QOL in Korean patients with gastric cancer after curative resection. Background:As early detection and improved treatment have led to higher survival rates and an increasing number of long-term survivors, the importance of QOL has increased. Methods:Patients newly diagnosed with gastric cancer, who were expected to undergo curative resection, were studied. QOL was assessed, using the European Organization for Research and Treatment of Cancer QLQ-C30 and its gastric module QLQ-STO22, before and after 3 and 12 months of gastrectomy. Results:In total, 465 patients were included in the study, and 377 and 88 patients underwent subtotal gastrectomy and total gastrectomy, respectively. For most of the functional or symptom scales, the mean score deteriorated at 3 months and generally improved during follow-up period. Patients with total gastrectomy had more functional and symptomatic problems related to QOL than those with subtotal gastrectomy during the follow-up. For both groups, there were temporal, unrecovered, improved, and unchanged problems in QOL. Fatigue; digestive symptoms such as diarrhea, dysphagia, and eating restrictions; body image disturbance; and cognitive functioning were the representative unrecovered problems, which persisted at 12 months after surgery. Conclusions:Our findings show that there are various functional and symptomatic problems, which health care providers need to manage during the postsurgical period. We need to continuously address fatigue, diarrhea, dysphagia, eating restrictions, body image disturbance, and cognitive functioning. In addition, it would be necessary to inform patients about possible QOL outcomes while they are receiving information about surgery and signing informed consent for surgery.

Deregulation of Immune Response Genes in Patients With Epstein-Barr Virus-Associated Gastric Cancer and Outcomes

BACKGROUND & AIMS Patients with Epstein-Barr virus-associated gastric carcinoma (EBVaGC) have a better prognosis than those with gastric cancer not associated with EBV infection (EBVnGC). This is partly because EBV infection recruits lymphocytes, which infiltrate the tumor. A high degree of tumor heterogeneity is likely to be associated with poor response. We investigated differences in gene expression patterns between EBVaGC and EBVnGC. METHODS We used gene expression profile analysis to compare tumor and nontumor gastric tissues from 12 patients with EBVaGC and 14 patients with EBVnGC. Findings were validated by whole transcriptome RNAseq and real-time quantitative polymerase chain reaction analyses. CD3(+) primary T cells were isolated from human blood samples; migration of these cells and of Jurkat cells were measured in culture with EBV-infected and uninfected gastric cancer cells. RESULTS Based on Pearson correlation matrix analysis, EBVaGCs had a higher degree of homogeneity than EBVnGCs. Although 4550 genes were differentially expressed between tumor and nontumor gastric tissues of patients with EBVnGC, only 186 genes were differentially expressed between tumor and nontumor gastric tissues of patients with EBVaGC (P < .001). This finding supports the concept that EBVaGCs have fewer genetic and epigenetic alterations than EBVnGCs. Expression of major histocompatibility complex class II genes and genes that regulate chemokine activity were more often deregulated in EBVaGCs compared with nontumor tissues. In culture, more T cells migrated to EBV-infected gastric cancer cells than to uninfected cells; migration was blocked with a neutralizing antibody against CXCR3 (a receptor for many chemokines). CONCLUSIONS Fewer genes are deregulated in EBVaGC than in EBVnGC. Most changes in EBVaGCs occur in immune response genes. These changes might allow EBVaGC to recruit reactive immune cells; this might contribute to the better outcomes of these patients compared with those with EBVnGC.

The relationships between perioperative CEA, CA 19-9, and CA 72-4 and recurrence in gastric cancer patients after curative radical gastrectomy.

The correlation between perioperative CEA, CA 19‐9, and CA 72‐4 and recurrence of gastric cancer has not been clarified. The aim of this study was to investigate the relationships between perioperative CEA, CA 19‐9, and CA 72‐4 and recurrence of gastric cancer.