Combination chemotherapy of i.v. and i.p. PTX with S-1 is well tolerated and active in gastric cancer patients with peritoneal metastasis.

Complete nodal clearance along the distal portion of the stomach offers marginal survival benefits for patients with EGJ cancers less than 4 cm in diameter. The optimal extent of esophageal resection and the benefits of mediastinal node dissection remain issues to be addressed in managing patients with esophagus-predominant EGJ cancers.

Cancer cells use PD-L1 to evade antitumor immunity through interaction with programmed cell death protein 1 (PD-1) on T cells. Recent whole-genome sequence studies revealed frequent gene amplification of PD-L1 in Epstein-Barr virus-associated gastric cancer (EBVaGC). To investigate the significance of PD-L1 in cancer cells and their microenvironment in EBVaGC, we studied PD-L1 expression by analysis of the public database and immunohistochemistry with fluorescent in situ hybridization (FISH) of the PD-L1 gene. Analysis of the database from The Cancer Genome Atlas also disclosed high expression of PD-L1 in EBVaGC compared with other molecular subtypes of GC. Expression of PD-L1 was frequently detected in cancer cells of EBVaGC (33/96; 34%), with infiltration of PD-L1 immune cells in its stroma (43/96; 45%). Both expression of PD-L1 in cancer cells and PD-L1 immune cell infiltration in EBVaGC were significantly correlated with diffuse histology according to Lauren's classification and tumor invasion (pT1b or more). As a prognostic indicator, PD-L1 expression in cancer cells correlated with poor outcomes in both overall survival and disease-specific survival (P=0.0498, 0.007). PD-L1-positive cancers had dense infiltration of PD-L1 immune cells as well as CD8 and PD-1 cells in EBVaGC. FISH analysis of representative samples of the tumor demonstrated gene amplification of PD-L1 in 11% of cases. PD-L1-amplified cells corresponded to PD-L1-positive cells showing high-intensity immunohistochemical staining among cancer cells showing weak or moderate intensities. Taken together, PD-L1 expression in cancer cells and their microenvironment may contribute to the progression of EBVaGC, and gene amplification occurs as clonal evolution during progression. This specific subtype of GC infected with EBV is potentially a good candidate for immunotherapy targeting of the PD-L1/PD-1 axis.

To determine the clinical efficacy of Roux-en-Y reconstruction (RY) after distal gastrectomy, we compared postoperative outcomes of patients who underwent RY or conventional Billroth I reconstruction (B-I). A total of 50 patients were prospectively randomized to either B-I or RY reconstruction, and complications, postoperative course, and nutritional status were compared. Bile reflux and inflammation in the remnant stomach and lower esophagus were evaluated by postoperative follow-up endoscopy at 6 months. Operative time and blood loss as well as postoperative nutrition did not show significant differences between the two groups. As anticipated, 5 of 24 patients with RY reconstruction developed gastrojejunal stasis in the early postoperative period, which led to a longer postoperative hospital stay as compared with the B-I group (mean +/- S.D; B-I; 19.0 +/- 6.2, RY; 31.8 +/- 21.7 days) (P < 0.05). Endoscopic examination revealed that the frequency of bile reflux (P < 0.01) and degree of inflammation in the remnant stomach (P < 0.05) were less in the RY group than in the B-I group. However, inflammatory findings in the lower esophagus were observed in 7 (27%) of B-I, and 8 (35%) of the RY group, suggesting that late phase esophagitis was not improved in the RY group. Roux-en-Y reconstruction was effective in preventing duodenogastric reflux and resulting gastritis, but it did not prevent esophagitis. Because RY reconstruction induces the frequent complication of Roux-en-Y stasis, causing longer postoperative hospital stay, this method has limited advantages over B-I anastomosis after distal gastrectomy.

BACKGROUND:The prognosis of patients with gastric cancer with peritoneal metastasis is extremely poor. This phase 2 study evaluated the benefits and tolerability of weekly intravenous and intraperitoneal paclitaxel (PTX) treatment combined with oral S-1 in patients with gastric cancer who had macroscopic peritoneal metastasis. METHODS: Patients with gastric cancer who had primary tumors with macroscopic peritoneal metastasis were enrolled. PTX was administered intravenously at 50 mg/m 2 and intraperitoneally at 20 mg/m 2 on days 1 and 8, respectively. S-1 was administered at 80 mg/m 2 per day for 14 consecutive days, followed by 7 days of rest. The primary endpoint was the 1-year overall survival (OS) rate. The secondary endpoints were the response rate, efficacy against malignant ascites, and safety. RESULTS: Thirty-five patients were enrolled. The median number of treatment courses was 11 (range, 2-35). The 1-year OS rate was 77.1% (95% confidence interval, 60.5-88.1). The overall response rate was 71% in 7 patients with target lesions. Malignant ascites disappeared or decreased in 15 of 22 (68%) patients. The frequent grade 3/4 toxic effects were neutropenia (34%), leukopenia (23%), and anemia (9%). CONCLUSIONS: Combination chemotherapy consisting of intravenous and intraperitoneal PTX with S-1 is well-tolerated and effective in patients with gastric cancer who have macroscopic peritoneal metastasis. Cancer 2013;119:3354-8. V C 2013 American Cancer Society.KEYWORDS: phase 2 study; paclitaxel; S-1; gastric cancer; peritoneal metastasis; intraperitoneal chemotherapy. INTRODUCTIONGastric cancer is the fourth most common cancer worldwide and the second leading cause of cancer-related deaths. 1 Multimodal therapy combined with systemic chemotherapy, radiation therapy, and surgery has been developed in the treatment of advanced gastric cancer. 2 Even for noncurable gastric cancer, many clinical trials have been conducted using various newly developed anticancer drugs. In a phase 3 study using docetaxel (DTX), cisplatin, and fluorouracil for recurrent or metastatic gastric cancer patients, the 1-year overall survival (OS) rate and median survival time (MST) were 40% and 9.2 months, respectively. 3 In another phase 3 study using S-1 and cisplatin for unresectable or recurrent gastric cancer, the 1-year OS rate and MST were 54.1% and 13.0 months, respectively. 4 Among patients with noncurable gastric cancer, the prognosis of patients with peritoneal metastasis is extremely poor, 5 and no standard treatment for peritoneal metastasis has been established.One potential treatment approach is the introduction of paclitaxel (PTX), which has been shown to produce a high response rate (29%-36%) for undifferentiated-type adenocarcinoma 6,7 and can be expected to show high efficacy for peritoneal dissemination. The intraperitoneal (IP) administration of PTX was developed to reinforce the drug's effect on peritoneal metastasis. This would be accomplished by making the drug act directly on the nodules at a high concentration. In ...