English version of Japanese Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) issued by the Japan Society of Clinical Oncology.

The Japan Society of Clinical Oncology Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) have been published in accordance with the Minds Manual for Guideline Development 2014 and 2017. A specialized team independent of the working group for the revision performed a systematic review. Since GIST is a rare type of tumor, clinical evidence is not sufficient to answer several clinical and background questions. Thus, in these guidelines, we considered that consensus among the experts who manage GIST, the balance between benefits and harms, patients' wishes, medical economic perspective, etc. are important considerations in addition to the evidence. Although guidelines for the treatment of GIST have also been published by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO), there are some differences between the treatments proposed in those guidelines and the treatments in the present guidelines because of the differences in health insurance systems among countries.

Early Changes in Alpha-Fetoprotein Are a Useful Predictor of Efficacy of Atezolizumab plus Bevacizumab Treatment in Patients with Advanced Hepatocellular Carcinoma.

INTRODUCTION: The aim of this study was to investigate the early changes in alpha-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) levels in patients with advanced hepatocellular carcinoma (HCC) treated with atezolizumab plus bevacizumab and to evaluate the relationship between changes in these tumor markers and treatment efficacy. METHODS: Of 58 consecutive patients who started atezolizumab plus bevacizumab at our institution, 50 patients with information on antitumor response obtained at 6 weeks after therapy were enrolled in this study and their treatment outcomes were retrospectively evaluated. RESULTS: According to the Response Evaluation Criteria in Solid Tumors at 6 weeks, the objective response (OR) rate was 22.0% and the disease control (DC) rate was 78.0%. In patients who achieved OR at 6 weeks, median AFP and DCP ratios at weeks 1, 2, 3, and 6 were significantly lower than those in patients who did not achieve OR. AFP ratios in patients who did not achieve DC at 6 weeks (Non-6W-DC group) were significantly higher than in those who achieved DC at week 6 (6W-DC group). Median overall survival in the Non-6W-DC group was significantly shorter than in the 6W-DC group (156 days vs. not reached, p = 0.0008). An AFP ratio of 1.4 or higher at 3 weeks had a specificity of 88.0% and a sensitivity of 88.9% for predicting Non-6W-DC. Median progression-free survival was significantly shorter in patients with an AFP ratio of 1.4 or higher at 3 weeks than in those with an AFP ratio of <1.4 (42 days vs. 210 days, p = 0.0003). CONCLUSION: Early changes in AFP might be useful for predicting the antitumor efficacy of atezolizumab plus bevacizumab in patients with advanced HCC. An AFP ratio of 1.4 or higher at 3 weeks might be an early predictor of refractoriness to atezolizumab plus bevacizumab therapy.

Correlation between immune-related adverse events and prognosis in patients with various cancers treated with anti PD-1 antibody.

BACKGROUND: Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) are used for the treatment of various cancer types. However, immune-related adverse events (irAEs) occur in patients treated with ICIs. Several small-scale studies have reported the onset of irAEs and therapeutic effects of ICIs. Here we report a large-scale retrospective study covering a wide range of cancers. We evaluated irAEs and the therapeutic effects of ICIs and determined whether irAEs could be predicted. METHODS: This study included patients treated with the anti-PD-1 antibodies nivolumab or pembrolizumab at Fujita Health University Hospital between December 2015 and March 2019. We retrospectively reviewed the electronic medical records for age, cancer type, pre-treatment blood test data, presence or absence of irAE onset, type and severity of irAEs, outcome of irAE treatment, response rate, progression-free survival and overall survival. RESULTS: Two hundred-eighty patients received ICIs. The overall incidence of irAEs was 41.1% (115 patients), and the incidence of severe irAEs of grade 3 and higher was 2.8% (eight patients). The most common irAEs were skin disorders, thyroid disorders and interstitial pneumonitis. Patients with irAEs were significantly older than those without irAEs (69.7 versus 66.0 years, P = 0.02). The objective response rate (ORR) in patients with irAEs was 30.4%, which was significantly higher than in patients without irAEs (12.7%; P < 0.01). Both the median overall and progression-free survival were significantly longer in patients with irAEs (P < 0.01, p < 0.01). Based on the blood test data obtained before ICI therapy, hypothyroidism, thyroid-stimulating hormone levels and thyroglobulin antibody levels were associated with the onset of irAEs. In many patients with irAEs of Common Terminology Criteria for Adverse Events Grade 3 or higher, re-administration of ICIs was difficult, and their outcomes were poor. In contrast, many patients with irAEs of a lower grade were able to resume ICI therapy. CONCLUSION: Although the onset of irAEs was difficult to be predicted based on pre-treatment tests. It appeared that the continuation of ICI therapy, along with early detection and adequate control of irAEs, might contribute to the improved prognosis of patients.

Correction to: Phase II study of sunitinib in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor.

In the original publication of this article, the license subtype should be CC BY and not CC BY-NC.

Efficacy and safety of sunitinib in Japanese patients with progressive, advanced/metastatic, well-differentiated, unresectable pancreatic neuroendocrine tumors: final analyses from a Phase II study.

BACKGROUND: In an interim analysis of a Phase II trial in Japanese patients with pancreatic neuroendocrine tumors (panNETs), sunitinib demonstrated antitumor activity with an objective response rate (ORR) of 50% (95% confidence interval [CI], 21-79) and a median progression-free survival (PFS) of 16.8 months (95% CI, 9.3-26.2). Here, we report the final analyses of efficacy and safety, as well as additional analyses, from this Phase II study. METHODS: This was a multicenter, open-label, Phase II trial (NCT01121562) of sunitinib in Japanese patients with panNETs. Patients received oral sunitinib 37.5 mg/day on a continuous daily dosing schedule. Dose modifications were permitted. The primary endpoint was clinical benefit rate (CBR). Secondary endpoints included ORR, PFS, overall survival (OS), safety and pharmacokinetics. RESULTS: Of 12 patients enrolled and treated, all discontinued treatment-the majority (n = 8) owing to disease progression. Most patients were male (n = 8), <65 years of age (n = 11) and had a non-functional tumor (n = 10). The median (range) number of days on drug was 323.5 (22-727). The CBR (95% CI) was 75.0% (42.8-94.5). ORR (95% CI) was 50.0% (21.1-78.9). Median (95% CI) PFS was 16.8 (9.3-26.2) months; however, median (95% CI) OS was not reached (22.0-not estimable). Most common adverse events (AEs; all-causality) were diarrhea (n = 10; 83.3%), hand-foot syndrome (n = 8; 66.7%) and hypertension (n = 8; 66.7%). CONCLUSIONS: These results support the efficacy and safety of sunitinib in Japanese patients with panNETs. Appropriate AE management through dose reduction and interruption may prolong sunitinib treatment and maximize its efficacy.

Regional differences in advanced gastric cancer: exploratory analyses of the AVAGAST placebo arm.

BACKGROUND: AVAGAST was an international, randomized, placebo-controlled phase III study of chemotherapy with or without bevacizumab as first-line therapy for patients with advanced gastric cancer. We performed exploratory analyses to evaluate regional differences observed in the trial. METHODS: Analyses were performed in the placebo plus chemotherapy arm (intention-to-treat population). Chemotherapy was cisplatin 80 mg/m2 for six cycles plus capecitabine (1000 mg/m2 orally bid days 1-14) or 5-fluorouracil (800 mg/m2/day continuous IV infusion days 1-5) every 3 weeks until disease progression or unacceptable toxicity. RESULTS: Overall, 387 patients were assigned to placebo plus chemotherapy (eastern Europe/South America, n = 118; USA/western Europe, n = 81; Korea/other Asia, n = 94; Japan, n = 94). At baseline, poor performance status, liver metastases, and larger tumors were most frequent in eastern Europe/South America and least frequent in Japan. Patients received subsequent chemotherapy after disease progression as follows: eastern Europe/South America (14%); USA/western Europe (37%); Korea/other Asia (61%); and Japan (77%). Hazard ratios for overall survival versus USA/western Europe were 1.47 (95% CI, 1.09-1.99) for eastern Europe/South America, 0.91 (95% CI, 0.67-1.25) for Korea/other Asia, and 0.87 (95% CI, 0.64-1.19) for Japan. CONCLUSIONS: Regional differences in the healthcare environment may have contributed to the differences in overall survival observed in the AVAGAST study.

Efficacy and safety of axitinib in combination with gemcitabine in advanced pancreatic cancer: subgroup analyses by region, including Japan, from the global randomized Phase III trial.

OBJECTIVE: Axitinib is a potent and selective inhibitor of vascular endothelial growth factor receptors 1-3. This analysis compared efficacy and safety of axitinib plus gemcitabine in patients with advanced pancreatic cancer from Japan, North America and the European Union, enrolled in a randomized Phase III study. METHODS: Patients (n = 632), stratified by disease extent, were randomly assigned (1:1) to receive axitinib/gemcitabine or placebo/gemcitabine. Axitinib was administered at a starting dose of 5 mg orally twice daily and gemcitabine at 1000 mg/m(2) once weekly for 3 weeks in 4 week cycles. Primary endpoint was overall survival. RESULTS: Among Japanese patients, median overall survival was not estimable (95% confidence interval, 7.4 months-not estimable) with axitinib/gemcitabine (n = 58) and 9.9 months (95% confidence interval, 7.4-10.5) with placebo/gemcitabine (n = 56) (hazard ratio 1.093 [95% confidence interval, 0.525-2.274]). Median survival follow-up (range) was 5.1 months (0.02-12.3) with axitinib/gemcitabine vs. 5.4 months (1.8-10.5) with placebo/gemcitabine. Similarly, no difference was detected in overall survival between axitinib/gemcitabine and placebo/gemcitabine in patients from North America or the European Union. Common adverse events with axitinib/gemcitabine in Japanese patients were fatigue, anorexia, dysphonia, nausea and decreased platelet count. Axitinib safety profile was generally similar in patients from the three regions, although there were differences in incidence of some adverse events. An exploratory analysis did not show any correlation between axitinib/gemcitabine-related hypertension and overall survival. CONCLUSIONS: Axitinib/gemcitabine, while tolerated, did not provide survival benefit over gemcitabine alone in patients with advanced pancreatic cancer from Japan or other regions.

Regorafenib for advanced gastrointestinal stromal tumors following imatinib and sunitinib treatment: a subgroup analysis evaluating Japanese patients in the phase III GRID trial.

BACKGROUND: The randomized, double-blind, placebo-controlled GRID trial tested the oral multikinase inhibitor regorafenib in 199 patients with advanced gastrointestinal stromal tumors (GIST) following failure of at least imatinib and sunitinib, and showed a significant improvement in progression-free survival (PFS) versus placebo [hazard ratio (HR) 0.27; 95 % confidence interval (CI) 0.19-0.39; p < 0.0001]. METHODS: A subgroup analysis of Japanese patients in the GRID study was performed to compare the efficacy and safety of oral regorafenib 160 mg once daily with matching placebo, in combination with best supportive care. The primary study endpoint was progression-free survival (PFS); safety was evaluated through the incidence of adverse events (AEs). RESULTS: Seventeen Japanese patients were randomized to regorafenib (n = 12) or placebo (n = 5). Patient demographics were consistent with those of the overall study population. PFS was significantly longer with regorafenib than placebo (HR 0.08; 95 % CI 0.02-0.45; p = 0.000164). Centrally assessed disease control rates were 58 % and 20 % in the regorafenib and placebo groups, respectively (p = 0.080796). Treatment-related adverse events (AEs) were reported in all regorafenib-treated patients and 60 % of placebo recipients; the most frequent AE was hand-foot skin reaction (HFSR) (92 % versus 20 %, respectively). CONCLUSION: Regorafenib showed efficacy and a manageable safety profile in Japanese patients with advanced GIST, consistent with the overall GRID study population. AEs, such as HFSR and maculopapular rash, were observed more frequently in Japanese patients. Although dose modification was frequently reported, only one patient with hepatic failure discontinued regorafenib because of AEs.

[Current Cancer Immunotherapy Using Activated Lymphocytes - Do Lymphocytes Actually Recognize Cancer Cells ?].

Molecular cloning of interleukin-2(IL-2)has enabled adoptive cell therapy(ACT)to be established by using autologous activated lymphocytes. The low of regenerative medicine will promote the active development of ACT for public use, and ACTs that utilize tumor-infiltrating lymphocytes(TIL), in vitro tumor-sensitized lymphocytes, natural killer T cells, and gammadelta T cells are being evaluated as advanced medical treatments in Japan. In addition, chimeric antigen receptor genemodified T(CAR-T)cells and T cell receptor gene-modified T(TCR-T)cells are available for investigational clinical use. CART and TCR-T cells have been associated with serious adverse events as well as drastic clinical efficacies, indicating the importance of choosing the antigens to be targeted. Presently, it is accurate to state that lymphocytes do recognize cancer cells. Clinical ACT research focusing on TIL and mutated cancer antigens will be initiated for the development of personalized immunotherapy for cancer in the future.

Imatinib plasma levels during successful long-term treatment of metastatic-gastrointestinal stromal tumors.

BACKGROUND/AIMS: To investigate whether imatinib dosage correlated with effective plasma levels and clinical characteristics for Japanese patients undergoing long-term (≥2 years) imatinib therapy for GISTs. METHODOLOGY: Twenty-five patients who received imatinib for a metastatic pathologically diagnosed GISTs at our hospital were enrolled. Imatinib response was assessed according to Choi's criteria. Blood samples were collected 22­26 h after the previous imatinib dose before the next scheduled dose. Results: Fourteen patients were male and the median age was 65 years. The median duration of imatinib therapy was 3.8 years (range, 2.0­11.5 years). The median plasma level of imatinib was 1098 ng/ml and the minimal plasma level after ≥5 years of therapy was 789 ng/ml. Imatinib dosage was significantly correlated with history of gastrectomy. The minimum body surface area of patients who received 400-mg/day imatinib dosage was 1.560 m2. CONCLUSIONS: The minimum level in all patients showing response for ≥5 years of treatment was 789 ng/ml, suggesting an effective plasma imatinib level of ≥800 ng/ml. Our results suggest that imatinib dosage of 400 mg/day is recommended for a patient with a large BSA (≥1.56 m2) and that of 300 mg/day might be sufficient for patients who have undergone a gastrectomy.

Capecitabine and cisplatin with or without cetuximab for patients with previously untreated advanced gastric cancer (EXPAND): a randomised, open-label phase 3 trial.

BACKGROUND: Patients with advanced gastric cancer have a poor prognosis and few efficacious treatment options. We aimed to assess the addition of cetuximab to capecitabine-cisplatin chemotherapy in patients with advanced gastric or gastro-oesophageal junction cancer. METHODS: In our open-label, randomised phase 3 trial (EXPAND), we enrolled adults aged 18 years or older with histologically confirmed locally advanced unresectable (M0) or metastatic (M1) adenocarcinoma of the stomach or gastro-oesophageal junction. We enrolled patients at 164 sites (teaching hospitals and clinics) in 25 countries, and randomly assigned eligible participants (1:1) to receive first-line chemotherapy with or without cetuximab. Randomisation was done with a permuted block randomisation procedure (variable block size), stratified by disease stage (M0 vs M1), previous oesophagectomy or gastrectomy (yes vs no), and previous (neo)adjuvant (radio)chemotherapy (yes vs no). Treatment consisted of 3-week cycles of twice-daily capecitabine 1000 mg/m(2) (on days 1-14) and intravenous cisplatin 80 mg/m(2) (on day 1), with or without weekly cetuximab (400 mg/m(2) initial infusion on day 1 followed by 250 mg/m(2) per week thereafter). The primary endpoint was progression-free survival (PFS), assessed by a masked independent review committee in the intention-to-treat population. We assessed safety in all patients who received at least one dose of study drug. This study is registered at EudraCT, number 2007-004219-75. FINDINGS: Between June 30, 2008, and Dec 15, 2010, we enrolled 904 patients. Median PFS for 455 patients allocated capecitabine-cisplatin plus cetuximab was 4.4 months (95% CI 4.2-5.5) compared with 5.6 months (5.1-5.7) for 449 patients who were allocated to receive capecitabine-cisplatin alone (hazard ratio 1.09, 95% CI 0.92-1.29; p=0.32). 369 (83%) of 446 patients in the chemotherapy plus cetuximab group and 337 (77%) of 436 patients in the chemotherapy group had grade 3-4 adverse events, including grade 3-4 diarrhoea, hypokalaemia, hypomagnesaemia, rash, and hand-foot syndrome. Grade 3-4 neutropenia was more common in controls than in patients who received cetuximab. Incidence of grade 3-4 skin reactions and acne-like rash was substantially higher in the cetuximab-containing regimen than in the control regimen. 239 (54%) of 446 in the cetuximab group and 194 (44%) of 436 in the control group had any grade of serious adverse event. INTERPRETATION: Addition of cetuximab to capecitabine-cisplatin provided no additional benefit to chemotherapy alone in the first-line treatment of advanced gastric cancer in our trial. FUNDING: Merck KGaA.

Phase II study of sunitinib in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor.

BACKGROUND: Pancreatic neuroendocrine tumors (NETs) are rare but are frequently diagnosed at advanced stages and require systemic therapy. PATIENTS AND METHODS: This multicenter, open-label, phase II study evaluated sunitinib in Japanese patients with well-differentiated pancreatic NET. Patients received sunitinib 37.5 mg/day on a continuous daily dosing (CDD) schedule. The primary endpoint was clinical benefit rate (CBR; percentage of complete responses [CRs] plus partial responses [PRs] plus stable disease [SD] ≥ 24 weeks). Secondary endpoints included objective response rate (ORR), tumor shrinkage, progression-free survival (PFS) probability, safety, pharmacokinetics, and biomarkers. RESULTS: Twelve patients received treatment. The CBR was 75 % (95 % confidence interval [CI], 43-94) and included 6 patients with a PR and 3 with SD. The ORR was 50 % (95 % CI, 21-79). PFS probability was 91 % (95 % CI, 54-99) at 6 months and 71 % (95 % CI, 34-90) at 12 months. Commonly reported treatment-emergent (all-causality), any-grade adverse events included diarrhea (n=10), hand-foot syndrome and hypertension (both n=8), fatigue and headache (both n=7), and neutropenia (n=6). No deaths on study were reported; one death due to disease progression occurred >28 days after end of treatment. Sunitinib on a CDD schedule resulted in sustained drug concentrations without accumulation across cycles. Tumor responses in all 12 patients did not appear to correlate with decreases in chromogranin A levels. CONCLUSIONS: Sunitinib 37.5 mg/day on a CDD schedule demonstrated antitumor activity in Japanese patients with unresectable, well-differentiated pancreatic NET. Commonly reported adverse events were consistent with the known safety profile of sunitinib.

Efficacy and safety of capecitabine plus cisplatin in Japanese patients with advanced or metastatic gastric cancer: subset analyses of the AVAGAST study and the ToGA study.

BACKGROUND: Capecitabine plus cisplatin (XP) is recognized as one of the global standard first-line chemotherapy regimens for patients with metastatic gastric cancer (mGC). Recent multinational phase III trials in mGC have been conducted with XP as the control arm, although no data on XP in Japanese patients with mGC have been published to date. The AVAGAST (XP ± bevacizumab in mGC) and ToGA (XP ± trastuzumab in human epidermal growth factor receptor 2 [HER2]-positive mGC) studies were the first two global studies including Japanese mGC patients. The aim of this analysis was to investigate the efficacy and safety of XP in Japanese mGC patients, using AVAGAST and ToGA subgroup data. METHODS: Efficacy and safety analyses were carried out in Japanese patients with mGC receiving XP alone, based on results from the AVAGAST and ToGA studies. There were differences in the target populations between the two studies; for example, the ToGA study limited patients to those with HER2-positive tumors; therefore, efficacy was evaluated separately. RESULTS: Ninety-four Japanese patients in the AVAGAST study and 50 in the ToGA study received XP alone. Median overall and progression-free survivals were 14.2 and 5.7 months, respectively, in the AVAGAST study, and 17.7 and 5.6 months, respectively, in the ToGA study. Overall response rates were 49.2 % in the AVAGAST and 58.5 % in the ToGA study. Adverse events were generally mild; the most common grade 3/4 events were neutropenia, anemia, anorexia, and nausea. CONCLUSIONS: XP is effective and well tolerated in Japanese patients with mGC, and could be one of the standard regimens for the first-line treatment in this cohort.

A retrospective comparison of S-1 plus cisplatin and capecitabine plus cisplatin for patients with advanced or recurrent gastric cancer.

BACKGROUND: Based on the results of the SPIRITS trial, combination chemotherapy of S-1 plus cisplatin (SP) is now considered the standard treatment for patients with advanced gastric cancer (AGC) in Japan. On the other hand, several non-Japanese studies have shown the efficacy of capecitabine plus cisplatin (XP), which has been used as the reference arm in recent global studies of AGC. METHODS: We retrospectively compared the efficacy and safety of SP and XP in first-line treatment for patients with AGC. RESULTS: From August 2006 to November 2008, 26 AGC patients received XP in the context of 2 global trials (AVAGAST and ToGA), and 50 patients received SP during the same period. The objective response rate was 43.2 % in the SP group and 50 % in the XP group, with no significant difference (p = 0.62). There were also no significant differences in progression-free survival (median 5.8 vs. 5.2 months; p = 0.91) and overall survival (median 13.8 vs. 13.5 months; p = 0.97) between the SP and XP groups. The frequencies of hematological toxicities of grade 3 or more and non-hematological toxicities were not significantly different between the 2 groups. Although grade 1 or 2 hand-foot syndrome was more common in the XP group, no patients experienced grade 3 or more. CONCLUSIONS: Although the retrospective nature of this study and the small number of patients is a major limitation, SP and XP were associated with similar efficacy and safety in patients with AGC.

Adjuvant therapy with imatinib mesylate after resection of primary high-risk gastrointestinal stromal tumors in Japanese patients.

BACKGROUND: Imatinib mesylate, a small-molecule tyrosine kinase inhibitor, is currently used for adjuvant therapy of patients who have undergone resection of high-risk gastrointestinal stromal tumors (GISTs). There are no data concerning the efficacy and safety of postoperative adjuvant therapy with imatinib for Japanese or East Asian patients with GIST. METHODS: A single-arm, open-label, multicenter trial was conducted in 17 hospitals in Japan. The eligibility criteria included histologically proven primary high-risk GISTs with macroscopic complete resection. Patients were treated with imatinib at a dose of 400 mg/day for 1 year after surgery. The primary endpoint was recurrence-free survival as assessed by Kaplan-Meier analysis. The secondary endpoints were overall survival and safety. This study was registered with ClinicalTrials.gov, number NCT00171977. RESULTS: A total of 64 patients were enrolled between September 2004 and July 2006. The median age of the patients was 59.5 years. Forty-nine (76.6%) patients completed the 1-year treatment, whereas 15 (23.4%) patients did not complete the treatment owing to recurrence, toxicities, and consent withdrawal. At the median follow-up period of 109 weeks, 20 patients had recurrence. The 3-year recurrence rate was 42.7% (95% confidence interval 29.2-56.3%), which exceeded the expected recurrence rate in this trial. The recurrence-free and overall survival rates at 2 years were 71.1 and 93.7%, respectively. The most frequent adverse drug reaction of any grade was eyelid edema (48.4%), followed by neutropenia (40.6%), leukopenia (39.1%), nausea (39.1%), rash (37.5%), and peripheral edema (37.5%), most of which were mild and manageable. CONCLUSIONS: Adjuvant therapy with imatinib at 400 mg/day for 1 year is well tolerated by Japanese patients and possibly reduces the risk of early recurrence of high-risk GISTs.

Aberrant DNA methylation associated with aggressiveness of gastrointestinal stromal tumour.

BACKGROUND AND AIMS: The majority of gastrointestinal stromal tumors (GISTs) have KIT mutations; however, epigenetic abnormalities that could conceivably potentiate the aggressiveness of GISTs are largely unidentified. Our aim was to establish epigenetic profiles associated with the malignant transformation of GISTs. METHODS: Methylation of four tumor suppressor genes, RASSF1A, p16, CDH1, and MGMT was analyzed in GISTs. Additionally, genome-wide DNA methylation profiles were compared between small, malignant-prone, and malignant GISTs using methylated GpG island amplification microarrays (MCAM) in a training set (n=40). Relationships between the methylation status of genes identified by MCAM and clinical features of the disease were tested in a validation set (n=75). RESULTS: Methylation of RASSF1A progressively increased from small to malignant GISTs. p16 was specifically methylated in malignant-prone and malignant GISTs. MCAM analysis showed that more genes were methylated in advanced than in small GISTs (average of 473 genes vs 360 genes, respectively, P=0.012). Interestingly, the methylation profile of malignant GISTs was prominently affected by their location. Two genes, REC8 and PAX3, which were newly-identified via MCAM analysis, were differentially methylated in small and malignant GISTs in the training and validation sets. Patients with methylation of at least REC8, PAX3, or p16 had a significantly poorer prognosis (P=0.034). CONCLUSION: Our results suggest that GIST is not, in epigenetic terms, a uniform disease and that DNA methylation in a set of genes is associated with aggressive clinical behavior and unfavorable prognosis. The genes identified may potentially serve as biomarkers for predicting aggressive GISTs with poor survivability.

Cutaneous Metastasis of Transverse Colon Cancer with an Aberrant Pattern of CK7/CK20/CDX2 and High Microsatellite Instability.

A 79-year-old woman was diagnosed with transverse colon cancer, moderately differentiated adenocarcinoma. She underwent surgery and postoperative adjuvant chemotherapy. At 80 years old, the patient exhibited changes in skin tone at the chest and abdomen with CK7+/CK20-/CDX2- immunostaining that was later identified as poorly differentiated adenocarcinoma. The diagnosis was cancer of unknown primary origin. The patient passed away three months after the detection of the skin lesion. Autopsy revealed recurrence at the transverse colon, multiple organ metastases, a similar postmortem immunostaining pattern, and high-frequency microsatellite instability (MSI-high). We herein report this case of CK7+/CK20-/CDX2- and MSI-high transverse colon cancer showing cutaneous metastasis.

Distinct profiles of epigenetic evolution between colorectal cancers with and without metastasis.

Liver metastasis is a fatal step in the progression of colorectal cancer (CRC); however, the epigenetic evolution of this process is largely unknown. To decipher the epigenetic alterations during the development of liver metastasis, the DNA methylation status of 12 genes, including 5 classical CpG island methylator phenotype (CIMP) markers, was analyzed in 62 liver metastases and in 78 primary CRCs (53 stage I-III; 25 stage IV). Genome-wide methylation analysis was also performed in stage I-III CRCs and in paired primary and liver metastatic cancers. Methylation frequencies of MGMT and TIMP3 increased progressively from stage I-III CRCs to liver metastasis (P = 0.043 and P = 0.028, respectively). The CIMP-positive cases showed significantly earlier recurrence of disease than did CIMP-negative cases with liver metastasis (P = 0.030), whereas no such difference was found in stage I-III CRCs. Genome-wide analysis revealed that more genes were methylated in stage I-III CRCs than in paired stage IV samples (P = 0.008). Hierarchical cluster analysis showed that stage I-III CRCs and stage IV CRCs were clustered into two distinct subgroups, whereas most paired primary and metastatic cancers showed similar methylation profiles. This analysis revealed distinct methylation profiles between stage I-III CRCs and stage IV CRCs, which may reflect differences in epigenetic evolution during progression of the disease. In addition, most methylation status in stage IV CRCs seems to be established before metastasis.

Clinical impact of K-ras mutation analysis in EUS-guided FNA specimens from pancreatic masses.

BACKGROUND: EUS-guided FNA (EUS-FNA) is considered optimal for differentially diagnosing pancreatic masses. However, the sensitivity of EUS-FNA ranges from 65% to 95%, respectively, which requires improvement. OBJECTIVE: To evaluate clinical impact of K-ras mutation analysis in EUS-FNA specimens from pancreatic masses. DESIGN: Prospective registration, single-center study. SETTING: Tertiary referral center. PATIENTS: This study involved 394 consecutive patients with pancreatic masses (307 pancreatic ductal adenocarcinomas [PDACs], 47 pancreatic inflammatory lesions, and 40 other types of tumors) who underwent EUS-FNA and analysis of K-ras mutations. INTERVENTION: EUS-FNA, Cycleave polymerase chain reaction. MAIN OUTCOME MEASUREMENTS: Improvement of the diagnostic accuracy by K-ras mutation analysis; absence of K-ras mutations in non-PDAC masses. RESULTS: K-ras mutations were detected in 266 of 307 PDAC aspirates (87%) and in 3 of 87 non-PDAC masses (3%). K-ras mutations were detected in 18 of 39 patients (46%) who remained cytohistopathologically undiagnosed. The sensitivity, specificity, positive and negative predictive values, and accuracy of cytohistopathological and K-ras mutation analyses alone were 87%, 100%, 100%, 54%, and 89%, respectively, and, when combined, were 93%, 100%, 100%, 68%, and 94%, respectively. Adding K-ras mutation analysis to standard cytohistopathological assessment increased the sensitivity and accuracy of EUS-FNA by 6% (P < .001) and 5% (P < .001), respectively. LIMITATIONS: Single-center study. CONCLUSIONS: K-ras mutation analysis may be helpful in patients with suspected PDAC yet inconclusive EUS-FNA findings. K-ras mutations were extremely rare in pancreatic inflammation and other pancreatic tumors.

Efficacy of trastuzumab in Japanese patients with HER2-positive advanced gastric or gastroesophageal junction cancer: a subgroup analysis of the Trastuzumab for Gastric Cancer (ToGA) study.

BACKGROUND: The Trastuzumab for Gastric Cancer (ToGA) study is the first international trial to include Japanese patients with human epidermal growth factor 2 (HER2) positive advanced/metastatic gastric or gastroesophageal junction cancer. ToGA showed that trastuzumab plus chemotherapy (capecitabine/cisplatin or 5-fluorouracil/cisplatin) improved overall survival in the overall population (hazard ratio 0.74). Regional differences in outcome in favor of Japanese populations were observed in other studies; therefore, subgroup analyses of ToGA may contribute to the evaluation of the potential benefits of this regimen in Japanese patients. METHODS: We performed subgroup analyses on 101 Japanese patients enrolled into ToGA (trastuzumab plus chemotherapy, n = 51; chemotherapy, n = 50). RESULTS: Median overall survival in the Japanese subgroup was 15.9 months (95% confidence interval 12-25) for trastuzumab plus chemotherapy and 17.7 months (95% confidence interval 12-24) for chemotherapy (hazard ratio 1.00; 95% confidence interval 0.59-1.69). After adjusting for prespecified covariates, the estimated hazard ratio for overall survival was 0.68 (95% confidence interval 0.36-1.27). Further post hoc and exploratory examinations supported the robustness of the adjusted hazard ratios. CONCLUSIONS: After adjusting for imbalanced patient backgrounds between arms, overall survival of Japanese patients with human epidermal growth factor 2 positive advanced/metastatic gastric or gastroesophageal junction cancer who received trastuzumab plus chemotherapy was improved compared with patients who received chemotherapy alone.