Prognostic value of mismatch repair deficiency in patients with advanced gastric cancer, treated by surgery and adjuvant 5-fluorouracil and leucovorin chemoradiotherapy.

OBJECTIVE: The predictive value of mismatch repair protein deficiency (MMRD) for chemoradiotherapeutic outcome has rarely been reported in gastric cancer. This study investigated the clinical significance of MMRD as a prognostic factor for tumor recurrence, and as a predictor of response to adjuvant chemoradiotherapy in advanced gastric cancer patients. METHODS: Between 1995 and 2008, tissue specimens of 881 patients who underwent radical gastrectomy for stage II and III gastric cancer were analyzed. MMRD was assessed using immunohistochemical stains for MLH1, PMS2, MSH2, and MSH6. Patients were divided into two groups according to adjuvant treatment: a 5-fluorouracil/leucovorin (FL) adjuvant chemoradiotherapy group and a surgery alone group. Disease-free survival (DFS) was compared between the two groups correlated to MMRD. Risk factors for tumor recurrence were analyzed using multivariate analysis. RESULTS: Of the 881 gastric cancer patients, 88 (10.0%) exhibited MMRD and 398 (45.2%) patients received adjuvant FL chemoradiotherapy. The multivariate analysis revealed that MMRD was a good independent prognostic factor (hazard ratio, 0.572; 95% confidence interval, 0.370-0.883; P = 0.012). For stage III gastric cancer displaying mismatch repair protein proficiency (MMRP), adjuvant FL chemoradiotherapy after surgery resulted in better DFS than surgery alone (P = 0.001). Among the stage II gastric cancer patients, adjuvant FL chemoradiotherapy did not show survival benefit, regardless of MMRD. CONCLUSION: MMRD is a good independent prognostic factor in advanced gastric cancer. Adjuvant FL chemoradiotherapy was beneficial in patients with stage III gastric cancer with MMRP but not in those with MMRD.

Adjuvant Chemotherapy Versus Chemoradiotherapy Versus Surgery Alone for Early Gastric Cancer with One or Two Lymph Node Metastasis.

BACKGROUND: Limited studies exist comparing clinical outcomes by adjuvant treatment for pT1N1 gastric cancer. This study compared the disease-free survival (DFS) of patients with pT1N1 gastric cancer according to the type of adjuvant treatment-surgery alone, chemotherapy (CTx), and chemoradiotherapy (CCRTx)-and evaluated risk factors for tumor recurrence. METHODS: Between 1995 and 2015, 738 patients underwent radical gastrectomy for pT1N1 gastric cancer and were divided into three groups: surgery alone (n = 355), CTx (n = 214), and CCRTx (n = 169). Chronological changes in adjuvant treatment type and chemotherapeutic regimens were evaluated and DFS was compared. Risk factors for tumor recurrence were analyzed. RESULTS: The proportion of patients who underwent surgery alone was more than 50% until 2001, and the proportion of those who had either CTx or CCRTx was more than 50% from 2002 to 2011, after which the proportion who underwent surgery alone increased again. The main chemotherapeutic agent was 5-fluorouracil with leucovorin. The 5-year DFS was 96.5% in the surgery-alone group, 96.0% in the CTx group, and 95.8% in the CCRTx group (no significant difference). The various chemotherapeutic regimens did not show differences in DFS. In univariate and multivariate analyses, adjuvant CTx and CCRTx showed no beneficial effect with regard to tumor recurrence. CONCLUSIONS: Because adjuvant CTx and CCRTx did not show any benefit with regard to tumor recurrence, these treatment strategies might be unnecessary for pT1N1 gastric cancer after gastrectomy. Further studies are necessary to reveal pT1N1 gastric cancer patient subgroups who might benefit from adjuvant treatments.

Deep Learning-Based Survival Analysis Identified Associations Between Molecular Subtype and Optimal Adjuvant Treatment of Patients With Gastric Cancer.

PURPOSE: Gastric cancer (GC) is the third-leading cause of cancer-related deaths. Several pivotal clinical trials of adjuvant treatments were performed during the previous decade; however, the optimal regimen for adjuvant treatment of GC remains controversial. PATIENTS AND METHODS: We developed a novel deep learning-based survival model (survival recurrent network [SRN]) in patients with GC by including all available clinical and pathologic data and treatment regimens. This model uses time-sequential data only in the training step, and upon being trained, it receives the initial data from the first visit and then sequentially predicts the outcome at each time point until it reaches 5 years. In total, 1,190 patients from three cohorts (the Asian Cancer Research Group cohort, n = 300; the fluorouracil, leucovorin, and radiotherapy cohort, n = 432; and the Adjuvant Chemoradiation Therapy in Stomach Cancer cohort, n = 458) were included in the analysis. In addition, we added Asian Cancer Research Group molecular classifications into the prediction model. SRN simulated the sequential learning process of clinicians in the outpatient clinic using a recurrent neural network and time-sequential outcome data. RESULTS: The mean area under the receiver operating characteristics curve was 0.92 ± 0.049 at the fifth year. The SRN demonstrated that GC with a mesenchymal subtype should elicit a more risk-adapted postoperative treatment strategy as a result of its high recurrence rate. In addition, the SRN found that GCs with microsatellite instability and GCs of the papillary type exhibited significantly more favorable survival outcomes after capecitabine plus cisplatin chemotherapy alone. CONCLUSION: Our SRN predicted survival at a high rate, reaching 92% at postoperative year 5. Our findings suggest that SRN-based clinical trials or risk-adapted adjuvant trials could be considered for patients with GC to investigate more individualized adjuvant treatments after curative gastrectomy.

A Randomized Controlled Trial of Vagus Nerve-preserving Distal Gastrectomy Versus Conventional Distal Gastrectomy for Postoperative Quality of Life in Early Stage Gastric Cancer Patients.

OBJECTIVE: To compare the postoperative quality of life of vagus nerve preserving distal gastrectomy (VPG) vs conventional distal gastrectomy (CG) in patients with early-stage gastric cancer. DESIGN: Randomized controlled clinical trial. SETTING: Large tertiary comprehensive cancer center in Korea. PARTICIPANTS: One hundred sixty-three patients with early gastric cancer 18 years of age or older expected to undergo curative gastric resection. INTERVENTION: Patients were randomized 1:1 to VPG (n = 85) or CG (n = 78). MAIN OUTCOME MEASURES: European Organization for Research and Treatment of Cancer (EORTC) gastric module (STO22). RESULTS: Patients assigned to VPG showed less diarrhea 3 and 12 months after surgery (P = 0.040 and 0.048, respectively) and less appetite loss at 12 months (P = 0.011) compared with those assigned to CG. In both groups, fatigue, anxiety, eating restriction, and body image deteriorated at 3 months after surgery and did not regain baseline levels 12 months after surgery. There were no significant differences between the 2 groups in cancer recurrence and death over 5 years of follow-up. CONCLUSIONS: Early gastric cancer patients undergoing VPG reported significantly less diarrhea and appetite loss at 12 months postsurgery compared with those undergoing CG, with no differences in long-term clinical outcomes. VPG may improve the quality of life after gastrectomy in early gastric cancer patients compared with CG.

Adjuvant chemoradiation with 5-fluorouracil/leucovorin versus S-1 in gastric cancer patients following D2 lymph node dissection surgery: a feasibility study.

PURPOSE: We retrospectively analyzed the feasibility and adverse events for two regimens, postoperative chemoradiation (CRT) with 5-fluorouracil/leucovorin (5-FU/LV) compared to S-1 in D2-resected gastric cancer patients. PATIENTS AND METHODS: The study included 405 gastric cancer patients who underwent curative gastrectomy with D2 lymph node dissection and received adjuvant therapy between January 2008 and July 2009. Feasibility and adverse events for the CRT and S-1 regimens were analyzed. RESULTS: Out of the 405 patients, 244 (60.2%) had CRT and 161 (39.8%) had S-1 treatment. The regimen was selected based on the preferences of the physician and the patient. S-1 was more frequently administered to patients with older age (age≥70) and those with early-stage disease (stage II). The stage was significantly more advanced in the CRT group compared to the S-1 group (S-1 vs. CRT: stage II, 59.6% vs. 36.1%; stage III/IV, 28.0% vs. 48.3%, respectively; p<0.001). The completion rate of the planned therapy was significantly higher in the CRT group than in the S-1 group (95.1% vs. 72.8%, respectively; p<0.001). Regarding severe adverse events (grade 3-4), neutropenia (CRT vs. S-1; 40.2% vs. 8.7%, respectively, p<0.001), nausea (CRT vs. S-1; 5.7% vs. 0%, respectively; p=0.002) and stomatitis (CRT vs. S-1; 7.4% vs. 2.5%, respectively; p=0.034) were significantly more frequent in the CRT cohort compared to the S-1 group. CONCLUSION: Both adjuvant CRT with 5-FU/LV and adjuvant S-1 are safe and feasible in D2-resected gastric cancer patients. Patients with old age or early stage disease tend to prefer S-1 therapy to chemoradiation.

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 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 R(0)-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 R(0)-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 (M(0)) 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.

An observational study suggesting clinical benefit for adjuvant postoperative chemoradiation in a population of over 500 cases after gastric resection with D2 nodal dissection for adenocarcinoma of the stomach.

PURPOSE: The role of adjuvant chemoradiotherapy (CRT) in D2-resected gastric-cancer patients has not been defined yet. We investigated the effect of postoperative chemoradiotherapy on the relapse rate and survival rate of patients with D2-resected gastric cancer. METHODS AND MATERIALS: From August 1995 to April 2001, 544 patients received postoperative CRT after curative D2 resection. During the same period of time, 446 patients received surgery without further adjuvant treatment. The adjuvant CRT consisted of 400 mg/m2 of fluorouracil plus 20 mg/m2 of leucovorin for 5 days, followed by 4,500 cGy of radiotherapy for 5 weeks, with fluorouracil and leucovorin on the first 4 and the last 3 days of radiotherapy. Two 5-day cycles of fluorouracil and leucovorin were given 4 weeks after the completion of radiotherapy. RESULTS: The median duration of overall survival was significantly longer in the CRT group than in the comparison group (95.3 months vs. 62.6 months), which corresponds to a hazard ratio for death of 0.80 (p = 0.0200) or a reduction of 20% in the risk of death in the CRT group. The 5-year survival rates were consistently longer in the CRT group at Stages II, IIIA, IIIB, and IV than those in the comparison group. The CRT was associated with increases in the median duration of relapse-free survival (75.6 months vs. 52.7 months; hazard ratio for relapse, 0.80, p = 0.0160). CONCLUSION: Our results highly suggest that the postoperative chemoradiotherapy in D2-resected gastric-cancer patients can prolong survival and decrease recurrence.