Toshikazu Moriwaki

Impacts of excision repair cross-complementing gene 1 (ERCC1), dihydropyrimidine dehydrogenase, and epidermal growth factor receptor on the outcomes of patients with advanced gastric cancer

Using laser-captured microdissection and a real-time RT–PCR assay, we quantitatively evaluated mRNA levels of the following biomarkers in paraffin-embedded gastric cancer (GC) specimens obtained by surgical resection or biopsy: excision repair cross-complementing gene 1 (ERCC1), dihydropyrimidine dehydrogenase (DPD), methylenetetrahydrofolate reductase (MTHFR), epidermal growth factor receptor (EGFR), and five other biomarkers related to anticancer drug sensitivity. The study group comprised 140 patients who received first-line chemotherapy for advanced GC. All cancer specimens were obtained before chemotherapy. In patients who received first-line S-1 monotherapy (69 patients), low MTHFR expression correlated with a higher response rate (low: 44.9% vs high: 6.3%; P=0.006). In patients given first-line cisplatin-based regimens (combined with S-1 or irinotecan) (43 patients), low ERCC1 correlated with a higher response rate (low: 55.6% vs high: 18.8%; P=0.008). Multivariate survival analysis of all patients demonstrated that high ERCC1 (hazard ratio (HR): 2.38 (95% CI: 1.55–3.67)), high DPD (HR: 2.04 (1.37–3.02)), low EGFR (HR: 0.34 (0.20–0.56)), and an elevated serum alkaline phosphatase level (HR: 1.00 (1.001–1.002)) were significant predictors of poor survival. Our results suggest that these biomarkers are useful predictors of clinical outcomes in patients with advanced GC.

Predictive factors of lymph node metastasis in patients with undifferentiated early gastric cancers.

Background For intramucosal differentiated early gastric cancer that has little risk of lymph node metastasis, local treatment such as endoscopic mucosal resection has been generally accepted as an adequate treatment. We studied clinicopathological characteristics of undifferentiated early gastric cancer at our institution to identify the predictive factors for lymph node metastasis and qualify lesions that should be referred for gastrectomy and not endoscopic mucosal resection. Methods We retrospectively analyzed the clinicopathological features (patient age and gender, tumor size, location, macroscopic type and histological type, presence of ulceration, depth of tumor invasion, and lymphatic-vascular involvement) in 332 patients with undifferentiated early gastric cancer who underwent gastrectomy with regional lymph node dissection. Results Lymph node metastasis was observed in 45 patients (14%). Univariate analysis revealed that depth of tumor invasion (submucosa), tumor size (>30 mm), and lymphatic-vascular involvement (positive) were associated with lymph node metastasis. Only lymphatic-vascular involvement (positive) was found to have a significant association (odds ratio, 7.4; 95% confidence interval, 2.9–19.0) by multivariate analysis. Conclusions Lymphatic-vascular involvement was the only independent predictive risk factor for lymph node metastasis. This pathologic factor was not useful for identifying patients at high risk of lymph node metastasis who should be offered gastrectomy rather than endoscopic mucosal resection.

Biweekly irinotecan plus cisplatin versus irinotecan alone as second-line treatment for advanced gastric cancer: a randomised phase III trial (TCOG GI-0801/BIRIP trial).

PURPOSE We compared biweekly irinotecan plus cisplatin (BIRIP) with irinotecan alone as the second-line chemotherapy (SLC) for advanced gastric cancer (AGC). METHODS Patients with metastatic or recurrent gastric cancer refractory to S-1-based first-line chemotherapy were randomly assigned to receive BIRIP (irinotecan 60mg/m(2) plus cisplatin 30mg/m(2), every 2weeks) or irinotecan alone (irinotecan 150mg/m(2), every 2weeks). The primary end-point was to show the superiority of BIRIP to irinotecan in terms of progression free survival (PFS). RESULTS 130 patients were enrolled. PFS was significantly longer in the BIRIP group (3.8months [95% confidence interval (CI) 3.0-4.7]) than in the irinotecan group (2.8months [2.1-3.3]; hazard ratio 0.68, 95% CI 0.47-0.98; P=0.0398). Median overall survival was 10.7months in the BIRIP group and 10.1months in the irinotecan group (HR 1.00, 95% CI 0.69-1.44, P=0.9823). The objective response rate was 22% in the BIRIP group and 16% in the irinotecan group (P=0.4975). However, the disease control rate was significantly better in the BIRIP group (75%) than in the irinotecan group (54%, P=0.0162). The incidences of grade 3 or worse adverse events did not differ between the two groups. Any grade elevation of serum creatinine was more common in the BIRIP group (25% versus 8%, P=0.009), but any grade diarrhoea (17% versus 42%, P=0.002) was more common in the irinotecan group. CONCLUSION BIRIP significantly prolonged PFS as compared with irinotecan alone and was tolerated as SLC, but did not demonstrate the survival benefit in this trial.

A phase I study of S-1 combined with weekly cisplatin for metastatic gastric cancer in an outpatient setting

A dose-escalation study was conducted for patients with metastatic gastric cancer to determine the recommended dose of weekly intravenous (i.v.) cisplatin combined with a fixed dose of a new oral dihydropyrimidine dehydrogenase-inhibitory fluoropyrimidine, S-1, on an outpatient basis. Secondary endpoints were to define the toxicity profile and to determine tumour responses. S-1 was fixed at a dose of 70 mg/m(2)/day and was administered for 2 weeks followed by a 1-week rest. Three dose levels of cisplatin (10, 15 and 20 mg/m(2)) were studied. Cisplatin was infused over 30 min on days 1 and 8. 20 patients were enrolled. No dose-limiting toxicities (DLTs) were recorded during the administration of cisplatin up to 20 mg/m(2), except for grade 3 diarrhoea and stomatitis in one patient at dose level 3. No grade 4 adverse events occurred. However, grade 2 gastrointestinal adverse reactions, such as nausea and anorexia, were seen in 7 of 13 patients at dose level 3 within the first two treatment cycles. This was determined to be the maximum acceptable level that would not negate the advantages observed with use of an oral drug such as S-1. An objective tumour response was seen at all dose levels, and the overall response rate in the 18 patients evaluated was 61%. A higher response rate of 78% was observed in 9 patients who had received no prior chemotherapy. Oral S-1 with weekly cisplatin is a feasible and promising combination regimen that is appropriate for an outpatient setting. A randomised phase II study comparing this combination with S-1 alone in chemo-nai;ve patients is warranted.

Randomized phase III study of bevacizumab plus FOLFIRI and bevacizumab plus mFOLFOX6 as first-line treatment for patients with metastatic colorectal cancer (WJOG4407G)

BACKGROUND FOLFIRI and FOLFOX have shown equivalent efficacy for metastatic colorectal cancer (mCRC), but their comparative effectiveness is unknown when combined with bevacizumab. PATIENTS AND METHODS WJOG4407G was a randomized, open-label, phase III trial conducted in Japan. Patients with previously untreated mCRC were randomized 1:1 to receive either FOLFIRI plus bevacizumab (FOLFIRI + Bev) or mFOLFOX6 plus bevacizumab (mFOLFOX6 + Bev), stratified by institution, adjuvant chemotherapy, and liver-limited disease. The primary end point was non-inferiority of FOLFIRI + Bev to mFOLFOX6 + Bev in progression-free survival (PFS), with an expected hazard ratio (HR) of 0.9 and non-inferiority margin of 1.25 (power 0.85, one-sided α-error 0.025). The secondary end points were response rate (RR), overall survival (OS), safety, and quality of life (QoL) during 18 months. This trial is registered to the University Hospital Medical Information Network, number UMIN000001396. RESULTS Among 402 patients enrolled from September 2008 to January 2012, 395 patients were eligible for efficacy analysis. The median PFS for FOLFIRI + Bev (n = 197) and mFOLFOX6 + Bev (n = 198) were 12.1 and 10.7 months, respectively [HR, 0.905; 95% confidence interval (CI) 0.723-1.133; P = 0.003 for non-inferiority]. The median OS for FOLFIRI + Bev and mFOLFOX6 + Bev were 31.4 and 30.1 months, respectively (HR, 0.990; 95% CI 0.785-1.249). The best overall RRs were 64% for FOLFIRI + Bev and 62% for mFOLFOX6 + Bev. The common grade 3 or higher adverse events were leukopenia (11% in FOLFIRI + Bev/5% in mFOLFOX6 + Bev), neutropenia (46%/35%), diarrhea (9%/5%), febrile neutropenia (5%/2%), peripheral neuropathy (0%/22%), and venous thromboembolism (6%/2%). The QoL assessed by FACT-C (TOI-PFC) and FACT/GOG-Ntx was favorable for FOLFIRI + Bev during 18 months. CONCLUSION FOLFIRI plus bevacizumab was non-inferior for PFS, compared with mFOLFOX6 plus bevacizumab, as the first-line systemic treatment for mCRC. CLINICAL TRIALS NUMBER UMIN000001396.

Potent in vitro and in vivo antitumor effects of MDM2 inhibitor nutlin‐3 in gastric cancer cells

The tumor suppressor gene p53 is the most frequently mutated gene in human cancers. However, its mutation rate is relatively low in gastric cancer compared with other cancers. In this study, we investigated the mechanisms underlying the antitumor effects of nutlin‐3, an inhibitor of human homolog of murine double minute 2 (MDM2). MDM2 is a negative regulator of p53. Four gastric cancer cell lines with wild‐type p53 (wt p53) and three with mutant‐type p53 (mt p53) were analyzed for MDM2 and MDM4 expression by immunoblotting, and for their gene amplification by quantitative real‐time PCR. Moreover, the viability of cells exposed to nutlin‐3 was examined by WST‐8 assay, and the expression of p53 and its downstream genes was analyzed by immunoblotting. Nutlin‐3 stabilized p53 and increased the expression of p21WAF1 and Noxa, and cleaved poly (ADP)‐ribose polymerase regardless of the pre‐expression levels of MDM2 and MDM4 in gastric cancer cells with wt p53. Flow cytometry revealed that nutlin‐3 arrested the cell cycle in G1 phase and induced apoptosis in the cell lines. These nutlin‐3 effects were not observed in the cell lines with mt p53. Nutlin‐3 exerted additive or synergistic cytotoxicity in combination with 5‐fluorouracil or cisplatin in most cell lines with wt p53. An in vivo antitumor effect of nutlin‐3 alone and its additive augmentation by 5‐fluorouracil were confirmed in an MDM2 overexpressed xenograft tumor model. Nutlin‐3 showed potent antitumor activity against human gastric cancer cells with wt p53 and shows promise as a single agent and in combination with conventional anticancer drugs. (Cancer Sci 2011; 102: 605–613)

Granular cell tumor occurring in the sigmoid colon treated by endoscopic mucosal resection using a transparent cap (EMR-C)

A case of granular cell tumor occurring in the sigmoid colon is reported. The patient, a 56-year-old man, visited our hospital for further evaluation of occult blood in his stool. Endoscopic examination revealed a yellowish, hemispheric submucosal tumor (SMT) with redness, about 6 mm in diameter, in the sigmoid colon. Endoscopic mucosal resection using a transparent cap (EMR-C) was performed, and histological examination revealed that the tumor consisted of a nested growth of large tumor cells with ample granular cytoplasm and small round nuclei. The tumor cells expressed S-100 protein and were stained with neuron-specific enolase (NSE) and periodic acid-Schiff, but were negative for desmin, vimentin, and cytokeratin. The resected tumor was diagnosed as a granular cell tumor. This may be the first report of a colorectal granular cell tumor successfully treated with EMR-C.

S-1 plus leucovorin versus S-1 plus leucovorin and oxaliplatin versus S-1 plus cisplatin in patients with advanced gastric cancer: a randomised, multicentre, open-label, phase 2 trial

BACKGROUND Although leucovorin enhances the efficacy of fluorouracil, the anti-tumour activity of S-1 and leucovorin and their combination with oxaliplatin for patients with advanced gastric cancer is unknown. We compared the activity and safety of S-1 plus leucovorin, S-1 plus leucovorin and oxaliplatin, and S-1 plus cisplatin as first-line chemotherapy for advanced gastric cancer. METHODS In this multicentre, randomised, open-label, phase 2 trial, we recruited chemotherapy-naive patients with unresectable or recurrent gastric cancer with measurable lesions aged 20 years or older from 25 general hospitals and specialist centres in Japan. Patients were randomly assigned (1:1:1) centrally to receive S-1 plus leucovorin (S-1 40-60 mg orally plus oral leucovorin 25 mg twice a day for 1 week, every 2 weeks), S-1 plus leucovorin and oxaliplatin (S-1 plus leucovorin and intravenous oxaliplatin 85 mg/m(2) on day 1, every 2 weeks), or S-1 plus cisplatin (S-1 40-60 mg orally twice a day for 3 weeks, plus intravenous cisplatin 60 mg/m(2) on day 8, every 5 weeks). Randomisation was done with the minimisation method using performance status (0 vs 1) and tumour stage (stage IV vs recurrent) as stratification factors. The primary endpoint was independently reviewed overall response in the full analysis set. This trial is registered with Japic CTI, number 111635. FINDINGS Between Oct 20, 2011, and Dec 17, 2012, we enrolled and randomly assigned 145 patients: 49 patients were assigned to S-1 plus leucovorin, 47 to S-1 plus leucovorin and oxaliplatin, and 49 to S-1 plus cisplatin. An objective response assessed by the independent review committee was achieved in 20 (43% [95% CI 28·3-57·8]) of the 47 patients in the S-1 plus leucovorin group, 31 (66% [50·7-79·1]) of the 47 patients in the S-1 plus leucovorin and oxaliplatin group, and 22 (46% [31·4-60·8]) of the 48 patients in the S-1 plus cisplatin group (Fishers exact test, p=0·84 for S-1 plus leucovorin vs S-1 plus cisplatin, p=0·063 for S-1 plus leucovorin and oxaliplatin vs S-1 plus cisplatin, and p=0·038 for S-1 plus leucovorin and oxaliplatin vs S-1 plus leucovorin). The most common grade 3-4 adverse events were neutropenia (three [6%] of 48 patients in the S-1 plus leucovorin group vs 12 [26%] of 47 patients in the S-1 plus leucovorin and oxaliplatin group vs 17 [35%] of 49 patients in the S-1 plus cisplatin group), decreased appetite (six [13%] vs 14 [30%] vs 12 [24%]), anaemia (five [10%] vs seven [15%] vs 13 [27%]), and hyponatraemia (two [4%] vs two [4%] vs nine [18%]). INTERPRETATION S-1 plus leucovorin and oxaliplatin was more active than S-1 plus leucovorin or S-1 plus cisplatin with acceptable toxic effects for patients with advanced gastric cancer. A phase 3 trial comparing S-1 plus leucovorin and oxaliplatin with S-1 plus cisplatin is underway. FUNDING Taiho Pharmaceutical.

Randomized study of FOLFIRI plus either panitumumab or bevacizumab for wild-type KRAS colorectal cancer-WJOG 6210G

This randomized phase II trial compared panitumumab plus fluorouracil, leucovorin, and irinotecan (FOLFIRI) with bevacizumab plus FOLFIRI as second‐line chemotherapy for wild‐type (WT) KRAS exon 2 metastatic colorectal cancer (mCRC) and to explore the values of oncogenes in circulating tumor DNA (ctDNA) and serum proteins as predictive biomarkers. Patients with WT KRAS exon 2 mCRC refractory to first‐line chemotherapy containing oxaliplatin and bevacizumab were randomly assigned to panitumumab plus FOLFIRI or bevacizumab plus FOLFIRI. Of 121 randomly assigned patients, 117 were eligible. Median overall survival (OS) for panitumumab plus FOLFIRI and bevacizumab plus FOLFIRI were 16.2 and 13.4 months [hazard ratio (HR), 1.16; 95% CI, 0.76–1.77], respectively. Progression‐free survival (PFS) was also similar (HR, 1.14; 95% CI, 0.78–1.66). KRAS, NRAS, and BRAF status using ctDNA was successfully examined in 109 patients, and mutations were identified in 19 patients (17.4%). Panitumumab plus FOLFIRI showed favorable survival compared with bevacizumab plus FOLFIRI in WT patients and unfavorable survival in those with mutations (P for interaction = 0.026 in OS and 0.054 in PFS). OS with bevacizumab plus FOLFIRI was better than panitumumab plus FOLFIRI in patients with high serum vascular endothelial growth factor‐A (VEGF‐A) levels and worse in those with low levels (P for interaction = 0.016). Second‐line FOLFIRI plus panitumumab and FOLFIRI plus bevacizumab showed a similar efficacy in patients with WT KRAS exon 2 mCRC. RAS and BRAF mutation in ctDNA could be a negative predictive marker for panitumumab.

Propensity Score Analysis of Regorafenib Versus Trifluridine/Tipiracil in Patients with Metastatic Colorectal Cancer Refractory to Standard Chemotherapy (REGOTAS): A Japanese Society for Cancer of the Colon and Rectum Multicenter Observational Study

This article compares the efficacy between regorafenib and trifluridine/tipiracil in patients with metastatic colorectal cancer refractory to standard chemotherapy, who had access to both drugs, to determine whether a further prospective comparative trial should be conducted.