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.

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.

Pimitespib in patients with advanced gastrointestinal stromal tumor (CHAPTER-GIST-301): a randomized, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Prognosis of advanced gastrointestinal stromal tumors (GIST) refractory to tyrosine kinase inhibitors (TKIs) is poor. This randomized, placebo-controlled, phase 3 trial evaluated the efficacy and safety of pimitespib, a novel heat shock protein 90 inhibitor, in advanced GIST refractory to standard TKIs.

PATIENTS AND METHODS

Patients with histologically confirmed GIST refractory to imatinib, sunitinib, and regorafenib were randomized 2:1 to oral pimitespib 160 mg/day or placebo for five consecutive days per week in 21-day cycles. Following disease progression by blinded central radiological review (BCRR), crossover to open-label pimitespib was permitted. The primary endpoint was progression-free survival (PFS) by BCRR in the full analysis set. Secondary endpoints included overall survival (OS) adjusted using the rank preserving structural failure time method to reduce the expected confounding impact of crossover.

RESULTS

From Oct 31, 2018 to Apr 30, 2020, 86 patients were randomized to pimitespib (n=58) or placebo (n=28). Median PFS was 2.8 months (95% CI 1.6-2.9) with pimitespib versus 1.4 months (0.9-1.8) with placebo (hazard ratio [HR] 0.51 [95% CI 0.30-0.87]; one-sided p=0.006). Pimitespib showed an improvement in crossover-adjusted OS compared with placebo (HR 0.42 [0.21-0.85], one-sided p=0.007). Seventeen (60.7%) patients receiving placebo crossed-over to pimitespib; median PFS after crossover was 2.7 (95% CI 0.7-4.1) months. The most common (≥30%) treatment-related adverse events (AEs) with pimitespib were diarrhea (74.1%) and decreased appetite (31.0%); the most common (≥10%) grade ≥3 treatment-related AE was diarrhea (13.8%). Treatment-related AEs leading to pimitespib discontinuation occurred in 3 (5.2%) patients.

CONCLUSION

Pimitespib significantly improved PFS and crossover-adjusted OS compared with placebo and had an acceptable safety profile in patients with advanced GIST refractory to standard TKIs.

Republication: A Prospective Observational Study of Adoptive Immunotherapy for Cancer Using Zoledronate-Activated Killer (ZAK) Cells - An Analysis for Patients With Incurable Pancreatic Cancer

BACKGROUND/AIM

Adoptive immunotherapy (AIT) using autologous zoledronate-activated killer (ZAK) cells has been performed for developing a novel modality of cancer treatment. In this study, data series from incurable pancreatic cancer were analyzed.

PATIENTS AND METHODS

Patients were treated with AIT using intravenous administration of ZAK cells every 3 to 4 weeks in combination with standard chemotherapy and possible clinical benefits were examined.

RESULTS

Seventy-five patients were treated. A median overall survival (OS) time of 6.7 months was achieved for all patients and 13.1 months for those treated 5 times or more, that increased to 14.6 and 18.3 months, respectively, when the previous treatment period of chemotherapy alone was included in the analysis. The disease control rate was 58.5 %. Multivariate regression analysis showed a significant positive correlation between the survival and baseline value of lymphocyte percentage in white blood cell counts (p=0.031).

CONCLUSION

The data suggest that AIT using ZAK cells in combination with chemotherapy is safe and feasible and may be effective in prolonging survival for patients with incurable pancreatic cancer. The lymphocyte percentage at baseline may be a good biomarker for predicting the survival benefit of ZAK cell AIT.

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.

Randomized, double-blind, placebo (PL)-controlled, phase III trial of pimitespib (TAS-116), an oral inhibitor of heat shock protein 90 (HSP90), in patients (pts) with advanced gastrointestinal stromal tumor (GIST) refractory to imatinib (IM), sunitinib (SU) and regorafenib (REG)

11524

Background: Pimitespib (PIM) is a novel class of orally active selective HSP90 inhibitors. KIT and PDGFRA are clients of HSP90 for their functional stability; therefore, HSP90 is a rational therapeutic target on GIST in pts with acquired resistance, such as secondary mutation in KIT, to approved tyrosine kinase inhibitors. A phase II trial showed clinical activity of PIM in pts with advanced GIST refractory to standard treatments whose medical need remains unmet. This phase III trial evaluated the efficacy and safety of PIM for this unmet clinical need. Methods: Eligible pts had histologically confirmed advanced GIST refractory to IM, SU, and REG, ≥1 measurable lesion, and ECOG performance status 0 or 1. Pts were randomized 2:1 to receive either PIM 160 mg once daily on a 5-days-on/ 2-days-off schedule or PL. Pts eligible for unblinding at the time of progressive disease were allowed to crossover to open-label PIM. The primary endpoint was progression-free survival (PFS) by blinded central radiological review based on modified RECIST 1.1. Secondary endpoints included overall survival (OS), PFS in the pts crossed over to PIM (secondary PFS), and safety. Crossover-adjusted OS was derived using the rank preserving structural failure time (RPSFT) model. Exploratory endpoints included pharmacogenomics (PGx). Results: From Oct 2018 to Apr 2020, 86 pts were randomized to receive either PIM (n = 58) or PL (n = 28). Baseline characteristics were well balanced between the two arms. Median PFS was 2.8 months (mo) (95% CI: 1.6–2.9) for PIM vs. 1.4 mo (95% CI: 0.9–1.8) for PL. The hazard ratio (HR) for PFS was 0.51 (95% CI: 0.30–0.87) ( p = 0.006, stratified log-rank test). Median OS was 13.8 mo (95% CI: 9.2–not reached) for PIM vs. 9.6 mo (95% CI: 5.5–not reached) for PL (HR for OS 0.63; p = 0.081), with 60.7 % of PL pts crossed over to PIM; secondary PFS was 2.7 mo (95% CI: 0.7–4.1). The RPSFT-adjusted median OS of PL was 7.6 mo (adjusted HR for OS 0.42; p = 0.007). Furthermore, the results of PGx analysis suggested that PIM was also effective in pts with secondary KIT mutation detected from blood samples. The most common ( > 5%) grade 3 or higher adverse events (AEs) in PIM/PL were diarrhea (13.8%/0%), anemia (6.9%/10.7%), decreased appetite (6.9%/0%), and tumor hemorrhage (5.2%/0%). AEs leading to PIM/PL study discontinuation were observed in 4/2 pts (6.9%/7.1%), respectively. Conclusions: This randomized trial demonstrated that PIM significantly improved PFS with OS prolongation in pts with advanced GIST refractory to IM, SU, and REG, as a HSP90 inhibitor for the first time. PIM was tolerated and AEs were manageable. With a mechanism of action different from that of standard therapies, PIM has the potential to be a new standard treatment in GIST. Clinical trial information: JapicCTI-184094.

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.

Efficacy and safety of TAS-116, an oral inhibitor of heat shock protein 90, in patients with metastatic or unresectable gastrointestinal stromal tumour refractory to imatinib, sunitinib and regorafenib: a phase II, single-arm trial

AIM

We evaluated the efficacy and safety of TAS-116, a novel class of an orally active selective inhibitor of heat shock protein 90, in patients with advanced gastrointestinal stromal tumour (GIST) after failure of three or more lines of standard treatment with imatinib, sunitinib and regorafenib.

METHODS

In this single-arm phase II study, patients received 160 mg/day oral TAS-116 for five consecutive days, followed by a 2-day rest. The primary end-point was centrally assessed progression-free survival (PFS). The secondary end-points were objective response rate, disease control rate, overall survival (OS), metabolic response rate, safety, pharmacokinetics and pharmacogenomics.

RESULTS

Forty-one patients were enrolled in Japan, and 40 patients underwent efficacy and safety evaluation. At the cut-off date, the median PFS was 4.4 months (95% confidence interval [CI], 2.8-6.0) and 12-week progression-free rate was 73.4% (95% CI, 58.1-88.7). Thirty-four patients (85.0%) had stable disease for ≥ 6 weeks. The median OS was 11.5 months (95% CI, 7.0-not reached). All patients experienced at least one treatment-related adverse event (AE), including diarrhoea (80.0%), decreased appetite (45.0%) and increase in blood creatinine level (42.5%). Grade ≥3 AEs and treatment-related grade ≥3 AEs occurred in 23 (57.5%) and 21 (52.5%) patients, respectively. All AEs resolved after dose modification, and no TAS-116-related AEs led to treatment discontinuation.

CONCLUSION

TAS-116 showed significant activity in advanced GIST refractory to standard treatment. Further development of TAS-116 is warranted.

TRIAL REGISTRATION

JapicCTI-163182.

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.

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.

A randomized phase III clinical trial of sequential capecitabine or 5-FU plus bevacizumab (Cape/5-FU+Bmab) followed by Cape/5-FU plus oxaliplatin plus Bmab (CapeOX/mFOLFOX6+Bmab) versus combination CapeOX/mFOLFOX6+Bmab in advanced colorectal cancer: The C-cubed (C3) study

TPS872

Background: Less intensive regimens, focusing on survival and disease control, may be better first-line treatments in unresectable metastatic colorectal cancer (mCRC). Several randomized trials suggested that sequential cytotoxic agents in mCRC may improve overall survival compared with combination chemotherapy. This study investigated whether sequential treatment with Bmab-based first-line therapy with oxaliplatin has superior efficacy to combination treatment for unresectable mCRC. Methods: This study is a two-arm, multicenter, open-label, randomized phase III trial in Japan, comparing the efficacy and safety of sequential Cape/5-FU+Bmab with escalation to CapeOX/mFOLFOX6+Bmab versus combination CapeOX/mFOLFOX6+Bmab as the first-line treatment of mCRC. The primary endpoint is Time to failure of strategy (TFS). In the sequential arm (Arm A: oxaliplatin ‘wait-and-go’), treatment escalation from Cape/5-FU+Bmab to CapeOX/mFOLFOX6+Bmab is recommended for progressive disease. In the combination arm (Arm B: oxaliplatin ‘stop-and-go’), de-escalation from CapeOX/mFOLFOX6+Bmab to Cape/5-FU+Bmab is possible after 12 weeks of treatment. Re-escalation to CapeOX/mFOLFOX6+Bmab after progressive disease is considered only for patients who received de-escalation of oxaliplatin, not caused by oxaliplatin-associated toxicity, after 12 weeks of treatment. A target sample size of 304 evaluable patients is considered sufficient to detect a hazard ratio of 0.69 for the TFS of the sequential ‘wait-and-go’ approach compared with the combination ‘stop-and go’ approach with 80% power and a 2-sided significance level of 5%. From December 2014 to September 2016, 311 patients were enrolled across 81 centers in Japan. The follow-up period is until March 2018, and results are expected in 2019, and results are expected in 2019. Clinical trial information: 000015405.

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.

Rare gastrointestinal stromal tumors (GIST): omentum and retroperitoneum

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms that arise in the gastrointestinal tract and rarely elsewhere in the abdomen. GISTs that develop outside the digestive tract are called extra-GISTs (EGISTs). The incidence of EGISTs is reported to be approximately 10% of all GISTs, and the median age is younger than that of conventional GISTs. EGISTs have similar histology and immunohistochemical features as conventional GISTs, with the majority of them in the omentum and mesentery. Most GISTs harbor a kinase-activating mutation in either KIT or PDGFRA. For EGISTs, the incidence of this type of mutation is 40-50%, which is somewhat lower than for conventional GISTs. EGISTs may have a worse prognosis compared with conventional GISTs with high mitotic indices, large size, and distant metastasis including lymph node involvement. In large abdominal tumors, the visceral origin is almost impossible to discern.

Asian Consensus Guidelines for the Diagnosis and Management of Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors originating in the gastrointestinal tract. With the introduction of molecular-targeted therapy for GISTs which has yielded remarkable outcomes, these tumors have become a model of multidisciplinary oncological treatment. Although Western clinical guidelines are available for GISTs, such as those published by the National Comprehensive Cancer Network (NCCN) and the European Society of Medical Oncology (ESMO), the clinical situations in Asian countries are different from those in Western countries in terms of diagnostic methods, surgical approach, and availability of new targeted agents. Accordingly, we have reviewed current versions of several GIST guidelines published by Asian countries (Japan, Korea, China, and Taiwan) and the NCCN and ESMO and discussed the areas of dissensus. We here present the first version of the Asian GIST consensus guidelines that were prepared through a series of meetings involving multidisciplinary experts in the four countries. These guidelines provide an optimal approach to the diagnosis and management of GIST patients in Asian countries.

Protocol of a randomised phase III clinical trial of sequential capecitabine or 5-fluorouracil plus bevacizumab (Cape/5-FU-Bmab) to capecitabine or 5-fluorouracil plus oxaliplatin plus bevacizumab (CapeOX/mFOLFOX6-Bmab) versus combination CapeOX/mFOLFOX6-Bmab in advanced colorectal cancer: the C-cubed (C3) study

INTRODUCTION

Results from several randomised trials suggest that the sequential use of cytotoxic agents in patients with metastatic colorectal cancer (mCRC) has the potential to improve overall survival compared with combination chemotherapy. This study is designed to investigate whether sequential treatment with bevacizumab-based first-line treatment with oxaliplatin is superior to combination treatment of mCRC.

METHODS AND ANALYSIS

The C-cubed (C(3)) study is a two-arm, multicentre, open-label, randomised phase III trial in Japan comparing the efficacy and safety of sequential capecitabine or 5-fluorouracil plus bevacizumab (Cape/5-FU-Bmab) with escalation to capecitabine or 5-fluorouracil plus oxaliplatin plus bevacizumab (CapeOX/mFOLFOX6-Bmab) versus combination CapeOX/mFOLFOX6-Bmab as the first-line treatment of mCRC. In the sequential arm (Arm A: oxaliplatin 'wait-and-go'), treatment escalation from Cape/5-FU-Bmab to CapeOX/mFOLFOX6-Bmab is recommended in the case of progressive disease. In the combination arm (Arm B: oxaliplatin 'stop-and-go'), de-escalation from CapeOX/mFOLFOX6-Bmab to Cape/5-FU-Bmab is possible after 12 weeks of treatment. Re-escalation to CapeOX/mFOLFOX6-Bmab after progressive disease is considered only for patients who received de-escalation of oxaliplatin after 12 weeks of treatment not caused by oxaliplatin-associated toxicity. A target sample size of 304 evaluable patients is considered sufficient to validate an expected HR for time to failure of strategy of the sequential approach 'wait-and-go' compared to the combination approach 'stop-and go' with 80% power and 2-sided 5% α in case of a true HR<0.69.

ETHICS AND DISSEMINATION

This study is conducted according to the standards of Good Clinical Practice and in compliance with the Declaration of Helsinki 2013 and local regulations, and has been submitted and approved by the Ethical Committee of the Non-Profit Organization MINS Institutional Review Board. The protocol and the trial results, even inconclusive, will be presented at international oncology congresses and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

UMIN000015405, Pre-results.

A Prospective Observational Study of Adoptive Immunotherapy for Cancer Using Zoledronate-Activated Killer (ZAK) Cells - An Analysis for Patients with Incurable Pancreatic Cancer

BACKGROUND/AIM

Adoptive immunotherapy (AIT) using autologous zoledronate-activated killer (ZAK) cells has been performed for developing a novel modality of cancer treatment. In this study, data series from incurable pancreatic cancer were analyzed.

PATIENTS AND METHODS

Patients were treated with AIT using intravenous administration of ZAK cells every 3 to 4 weeks in combination with standard chemotherapy and possible clinical benefits were examined.

RESULTS

Seventy-five patients were treated. A median overall survival (OS) time of 6.7 months was achieved for all patients and 13.1 months for those treated 5 times or more, that increased to 14.6 and 18.3 months, respectively, when the previous treatment period of chemotherapy alone was included in the analysis. The disease control rate was 58.5 %. Multivariate regression analysis showed a significant positive correlation between the survival and baseline value of lymphocyte percentage in white blood cell counts (p=0.031).

CONCLUSION

The data suggest that AIT using ZAK cells in combination with chemotherapy is safe and feasible and may be effective in prolonging survival for patients with incurable pancreatic cancer. The lymphocyte percentage at baseline may be a good biomarker for predicting the survival benefit of ZAK cell AIT.

Clinicopathological features of ruptured GIST in the ReGISTry study of high risk GIST patients after complete resection in Japan

96

Background: Ruptured GIST, either preoperatively or intraoperatively, has ominous prognosis and is classified as high risk GIST in the modified Fletcher risk stratification. Although patients (pts) with these GISTs are recommended for 3-year imatinib adjuvant therapy, their clinicopathological features and compliance of guidelines are unknown. Methods: Between Dec. 2012 and Aug. 2015, 474 pts with high-risk GISTs locally diagnosed were prospectively registered. Among them, 453 pts with GISTs histologically confirmed by central review were analyzed. There were 243 males and 210 females with median age of 65 yrs. In the central review, H&E, immunohistochemistry, and genotyping were tested. Results: Disease was located in the stomach (n = 279), small intestine (n = 137), large intestine (n = 25), or others (n = 12). Median tumor size was 7.7 cm and median mitosis (local pathology) was 10/50HPF. Tumor rupture was seen in 54 pts (12%) who had preoperative rupture (28 pts) or intraoperative rupture (25 pts). After surgery, adjuvant therapy was administered for 342 pts (75%) and withheld for 89 pts (20%). Tumor rupture was frequently observed in small intestinal GIST (23.6%) other than the duodenum and in epithelioid and/or mixed features (24%). Mitosis of ruptured GIST (median = 5.0/50 HPF) was significantly lower than that of non-ruptured (11/50 HPF). Age, gender, tumor size and genotype are not related with rupture. There was no difference in postoperative complications and adhibition of adjuvant therapy in pts who have ruptures vs pts who don’t. Preoperative rupture was associated with small intestinal GIST and R1 surgery. Mitosis was significantly lower in GIST with preoperative rupture (5/50 HPF) than that without rupture (11/50 HPF). GIST with intraoperative rupture (11.8 cm) was larger than that without rupture (7.5 cm) although there was no difference in mitosis, location and genotype. Frequency of intraoperative rupture was not different between laparoscopic surgery (4.8%) and open one (6.3%). Conclusions: Tumor rupture was not infrequent in high risk GIST and half of rupture was occurred during surgery, which may be related to large tumor size but not with laparoscopic surgery. Clinical trial information: UMIN000009531.

[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.

Abstract 1757: The new molecular target therapy of Hsp90 inhibition in esophageal squamous cell carcinoma

Heat shock protein 90 (HSP90) has numerous cellular functions, including promotion of proper protein folding, and stabilizes a number of oncogenic proteins, many of which are overexpressed in cancers. The objective of this study is to evaluate an antitumor effect of HSP90 inhibitor, AUY922, in esophageal squamous cell carcinoma(ESCC) cell lines. ESCC cell lines were treated with AUY922 to examine the effect on proliferation assay, apoptosis assay, Western blotting, and chemotaxis assay. AUY922 inhibited cell proliferation in ESCC cells in a dose- and time-dependent manner. Growth inhibitory effect of AUY922 for ESCC cells was higher than CDDP. With flowcytometry and immunostaining, we showed that AUY922 induced apoptosis in ESCC cells and inhibited chemotaxis of ESCC cells. These antitumor effects of AUY922 were due to inhibition of cell proliferation through suppression of phosphorylation of the client proteins. The HSP90 inhibitor is useful as an antitumor drug in ESCC by inhibiting proliferation of ESCC cells through novel mechanism.

Citation Format: Masahiro Yamamura, Tsutomu Nohno, Akira Yamauchi, Naoki Katase, Makoto Okawaki, Akira Sawaki, Hideo Matsumoto, Toshihiro Hirai, Yoshiyuki Yamaguchi. The new molecular target therapy of Hsp90 inhibition in esophageal squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1757. doi:10.1158/1538-7445.AM2015-1757

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/m² 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.

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 22–26 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, 2.0–11.5 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.

Impact of rechallenge with imatinib in patients with advanced gastrointestinal stromal tumor after failure of imatinib and sunitinib

Purpose. This retrospective, nonrandomized study investigated the effect of imatinib rechallenge plus best supportive care (BSC) on overall survival after imatinib and sunitinib treatment for patients with locally advanced or metastatic gastrointestinal stromal tumor (GIST). Methods. Twenty-six patients who had previously been exposed to both imatinib and sunitinib were enrolled in this study. The treatment regimen was BSC with or without imatinib, based on the patient's choice after discussion with his or her physician. The primary endpoint was overall survival, and secondary endpoints were time to treatment failure, clinical response rate assessed by Choi criteria, and safety. Results. Fourteen patients were treated with imatinib plus BSC and 12 received BSC alone. Median overall survival was greatly improved for the imatinib group, although differences were not significant (22 months for imatinib plus BSC versus 4 months for BSC; P = 0.058). Three patients (21%) had a clinical response in the imatinib group, and one had a clinical response in the BSC alone group. Imatinib was well tolerated. Conclusions. Rechallenge with imatinib may be associated with improvement in overall survival without deteriorating performance status in patients who failed imatinib and sunitinib. A prospective study should be considered to confirm the efficacy of rechallenge with imatinib.

Imatinib plasma concentrations during long-term effective treatment of metastatic gastrointestinal stromal tumor

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Background: Imatinib concentrations at one month after the start of imatinib have shown an association with clinical benefit in pts with gastrointestinal stromal tumors (GISTs) and a significant decrease of 30% within twelve months. This retrospective study investigated imatinib plasma concentrations in pts with metastatic GISTs in a long-term (≥2 years) effective treatment. Methods: 31 metastatic GIST pts, who had been treated with imatinib for two or more years in our hospital, were enrolled in this study. 11 pts were excluded because of adjuvant setting (n=5) and rejection to concentration testing (n=6). 20 pts were included in this study. GISTs were immunohistochemically diagnosed, and radiologically assessed as effective GIST by Choi’s criteria without relapse. Results: 10 pts were male, median age was 63 years (range, 31-84), and median imatinib exposure time was 3.5 year (range, 2-12). The median plasma concentration was 1093 ng/ml (range, 417-2091) and minimal level after at least five years was 789 ng/ml. imatinib concentration has no significant correlation with age, gender, gastrectomy, leukocyte count, platelet count, serum albumin, serum creatinine, cholesterol, and duration of imatinib exposure. Body surface area (BSA) isn’t directly associated with imatinib dose; median BSA of pts taking 300mg imatinib was 1.560 m2 and that of 400mg 1.595 m2, but minimal BSA of 400mg imatinib was 1.560 m2, which is higher than the minimum of 300mg. Conclusions: Plasma concentrations of long-term (≥2 years) response pts was scattered, but one of longer-term (≥5 years) response pts were more than 789 ng/ml. Effective imatinib plasma level might be more than 789 ng/ml and 400mg imatinib may be recommended for a pt with BSA(≥1.56 m2).

Clinical outcome according to tumor HER2 status and EGFR expression in advanced gastric cancer patients from the EXPAND study

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Background: In the EXPAND study adding cetuximab to first-line capecitabine and cisplatin chemotherapy (CT) failed to improve clinical outcome in patients (pts) with advanced gastric or gastroesophageal junction cancer. This analysis assessed treatment outcome according to tumor HER2 status (a pre-defined subgroup) and EGFR expression in EXPAND study pts. Methods: Tumor HER2 status was determined primarily by immunohistochemistry (IHC), HER2 +ve tumors were IHC 3+ or IHC 2+ and fluorescence in situ hybridization (FISH) +ve. EGFR expression was assessed by IHC. A continuous scoring system (scale of 0–300) was used to determine the level of EGFR expression. Biomarker status was correlated with clinical outcome. Results: In both treatment arms, pts with HER2 +ve tumors (n=144) vs HER2 -ve tumors (n=535) had a longer median overall survival (OS): 13.3 (95% CI 10.9–15.5) vs 9.2 (95% CI 8.1–10.5) months in the CT + cetuximab arm and 14.0 (95% CI 11.3–17.1) vs 9.7 (95% CI 8.6–11.0) months in the CT arm, and a better overall response rate, 51.4 (95% CI 39.3–63.3) vs 27.0 (95% CI 21.9–32.6) % and 37.5 (95% CI 26.4–49.7) vs 26.4 (95% CI 21.1–32.3) % respectively. In stepwise multivariable models, pts with HER2 -ve vs HER2 +ve tumors showed an increased risk of death (adjusted hazards ratio 1.552, 95% CI 1.244–1.936) and reduced odds of response (adjusted odds ratio 0.477, 95% CI 0.316–0.720). EGFR tumor expression was evaluable in 774 pts from the intent to treat population (n=904). The EGFR IHC score was low (median 0, range 0–300). No discriminating threshold for the IHC score was identified. However in pt subgroups defined by a series of cut-off points from an IHC score of 10 upwards (rising incrementally by 10), there was a tendency for improved OS, progression-free survival, and tumor response when adding cetuximab to CT in pts with high tumor EGFR IHC scores. Conclusions: In this analysis of EXPAND study pts, those with HER2 +ve tumors were associated with better outcome irrespective of the treatment arm compared with pts with HER2 -ve tumors. Tumor EGFR expression was generally low. Adding cetuximab to CT failed to improve outcome overall, but may benefit a small proportion of pts with high EGFR tumor expression. Clinical trial information: 2007-004219-75.

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.

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.

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 of docetaxel in patients with paclitaxel-resistant advanced gastric cancer

BACKGROUND

Although there appears to be incomplete cross-resistance between docetaxel and paclitaxel in several types of malignancies, to our best knowledge there have been no available data on this for advanced gastric cancer.

METHODS

We retrospectively evaluated the efficacy and safety of docetaxel in patients with paclitaxel-resistant advanced gastric cancer. Docetaxel was administered at 50-60 mg/m2 every 3 weeks.

RESULTS

Twenty-one patients were evaluated. All patients had received 2 or more previous chemotherapy regimens. Among the 12 patients with measurable lesions, apparent tumor shrinkage was seen in 1 patient for an overall response rate of 8. 3% and a disease control rate of 33. 3%. Median progression free survival and overall survival of all patients were 2. 6 months and 6. 7 months, respectively. There were no correlations between the progression free survival of docetaxel and the progression free survival of previous paclitaxel and between the progression free survival of docetaxel and taxane-free interval(Spearman's correlation coefficients of ρ=-0. 14 and ρ=-0. 02, respectively). Grade 3/4 neutropenia developed in 8 patients(38%)and Grade 3 febrile neutropenia in 1 patient(4. 8%).

CONCLUSIONS

Docetaxel showed modest activity in paclitaxel-resistant advanced gastric cancer patients, and no correlations between previous efficacy of paclitaxel or taxane-free interval were seen.

Efficacy of mosapride citrate with polyethylene glycol solution for colonoscopy preparation

AIM: To evaluate the efficacy and safety of adjunctive mosapride citrate for bowel preparation before colonoscopy.

METHODS: We conducted a randomized, double-blind, placebo-controlled study with mosapride in addition to polyethylene glycol (PEG)-electrolyte solution. Of 250 patients undergoing colonoscopy, 124 were randomized to receive 2 L PEG plus 15 mg of mosapride citrate (mosapride group), and 126 received 2 L PEG plus placebo (placebo group). Patients completed a questionnaire reporting the acceptability and tolerability of the bowel preparation process. The efficacy of bowel preparation was assessed by colonoscopists using a 5-point scale based on Aronchick’s criteria. The primary end point was optimal bowel preparation rates (scores of excellent/good/fair vs poor/inadequate).

RESULTS: A total of 249 patients were included in the analysis. In the mosapride group, optimal bowel preparation rates were significantly higher in the left colon compared with the placebo group (78.2% vs 65.6%, P < 0.05), but not in the right colon (76.5% vs 66.4%, P = 0.08). After excluding patients with severe constipation, there was a significant difference in bowel preparation in both the left and right colon (82.4% vs 66.7%, 80.8% vs 67.5%, P < 0.05, P < 0.01). The incidence of adverse events was similar in both groups. Among the subgroup who had previous colonoscopy experience, a significantly higher number of patients in the mosapride group felt that the current preparation was easier compared with patients in the placebo group (34/72 patients vs 24/74 patients, P < 0.05).

CONCLUSION: Mosapride citrate may be an effective and safe adjunct to PEG-electrolyte solution that leads to improved quality of bowel preparation, especially in patients without severe constipation.

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.

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.

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.

Regional differences in patient (pt) characteristics of AVAGAST: An exploratory comparison in chemotherapy plus placebo (PL) arm between Japanese (JPN) and the rest of the world (ROW) pts

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Background: AVAGAST study showed regional differences in efficacy, including notable differences in progression free survival (PFS) and overall survival in the PL arm. In Japan, there is a certain number of pts with minimal peritoneal metastasis (PM) diagnosed only by laparoscopy or open surgery, which seems unusual in Western as well as in other Asian countries, and it might have led the differences. Therefore, an exploratory analysis was conducted among the PL arm to examine pt characteristics including PM associated with differences in outcome between JPN and ROW.

Methods: We compared PFS of PL arm between pts enrolled from JPN and those from ROW. Hazard ratio (HR) and its 95% confidence interval (95%CI) between JPN and ROW were calculated using Cox’s proportional hazard model for each major covariates (disease status, performance status, prior gastrectomy, prior (neo)adjuvant chemotherapy, age, sex, primary site, liver metastasis (mets), number of metastatic sites, disease measurability, histologic type, maximum of tumor size, sum of tumor size, bone mets, PM and only PM)

Results: 188 pts from 14 sites were enrolled from JPN, of which 94 pts were randomized to PL arm. Compared with 293 pts from ROW in PL arm, PFS tend to be favorable in JPN. Subgroups of JPN without liver mets, with diffuse or mixed type gastric cancer (GC), with PM and with only PM were clearly favorable than that of ROW. The difference in subgroup with PM was especially large with lower confidence limit of 1.21. When the pts with only PM were excluded, the difference of PFS in PL arm between JPN and ROW became smaller ( Table ).

Conclusions: In this exploratory analysis, pts with PM in JPN had a better prognosis than ROW pts. Understanding this unique pt population may provide insight to the regional differences in outcome noted on this study.

[Table: see text]

Phase II study of sunitinib (SU) in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor (NET)

381

Background: SU is an oral, multitargeted, antiangiogenic, tyrosine kinase inhibitor effective in patients (pts) with unresectable, well-differentiated pancreatic NET. This open-label, phase II study examined whether SU is also effective in Japanese pts with this disease.

Methods: Japanese pts received SU 37.5 mg/day on a continuous daily dosing (CDD) schedule (28-day cycle). The primary endpoint was clinical benefit rate (CBR; complete response [CR] + partial response [PR] + stable disease [SD] ≥24 weeks). Secondary endpoints included: objective response rate (ORR; CR + PR), 6-mos progression-free survival (PFS) probability, safety and pharmacokinetics. Tumor assessments were performed at baseline and 8-wk intervals by CT or MRI (RECIST).

Results: Twelve patients were enrolled and received treatment (tx; median age 54 yrs, range 34–79); 9 were ongoing at data cut-off (July 1, 2011). CBR was 75.0% (95% CI 42.8, 94.5), comprising 5 PRs and 4 pts with SD ≥24 weeks. ORR was 41.7% (95% CI 15.2, 72.3). 6-mos PFS probability was 91.7% (95% CI 53.9, 98.8). One PR occurred in a pt with gastrinoma, in whom gastrin levels decreased by 93% and tumor bulk decreased by 45%. All-causality, any-grade (G) AEs included diarrhea (n=9, 75%), HFS and hypertension (both n=8, 67%). Neutropenia was the most common G3 AE (n=5, 42%, all tx-related). Three pts (25%) experienced G4 AEs (herpes encephalitis, convulsion, loss of consciousness [n=1] and lipase increased [n=2], all tx-related).Two pts (17%) experienced serious AEs: convulsion and loss of consciousness (n=1, tx-related), and acute cholecystitis (n=1, unrelated to tx). There were no deaths on study; one death due to disease progression occurred 3 mos after study withdrawal. On day 15 (cycle 1), mean trough plasma concentrations (n=10) for SU, its metabolite, and SU + metabolite were 53.9, 23.7 and 77.5 ng/mL, respectively. SU on a CDD schedule resulted in sustained drug concentrations without accumulation across cycles.

Conclusions: SU 37.5 mg/day on a CDD schedule demonstrated antitumor activity in Japanese pts with unresectable, well-differentiated pancreatic NET. Common AEs were consistent with the known safety profile of SU.

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.

Bevacizumab in Combination With Chemotherapy As First-Line Therapy in Advanced Gastric Cancer: A Randomized, Double-Blind, Placebo-Controlled Phase III Study

Purpose

The Avastin in Gastric Cancer (AVAGAST) trial was a multinational, randomized, placebo-controlled trial designed to evaluate the efficacy of adding bevacizumab to capecitabine-cisplatin in the first-line treatment of advanced gastric cancer.

Patients and Methods

Patients received bevacizumab 7.5 mg/kg or placebo followed by cisplatin 80 mg/m2 on day 1 plus capecitabine 1,000 mg/m2 twice daily for 14 days every 3 weeks. Fluorouracil was permitted in patients unable to take oral medications. Cisplatin was given for six cycles; capecitabine and bevacizumab were administered until disease progression or unacceptable toxicity. The primary end point was overall survival (OS). Log-rank test was used to test the OS difference.

Results

In all, 774 patients were enrolled; 387 were assigned to each treatment group (intention-to-treat population), and 517 deaths were observed. Median OS was 12.1 months with bevacizumab plus fluoropyrimidine-cisplatin and 10.1 months with placebo plus fluoropyrimidine-cisplatin (hazard ratio 0.87; 95% CI, 0.73 to 1.03; P = .1002). Both median progression-free survival (6.7 v 5.3 months; hazard ratio, 0.80; 95% CI, 0.68 to 0.93; P = .0037) and overall response rate (46.0% v 37.4%; P = .0315) were significantly improved with bevacizumab versus placebo. Preplanned subgroup analyses revealed regional differences in efficacy outcomes. The most common grade 3 to 5 adverse events were neutropenia (35%, bevacizumab plus fluoropyrimidine-cisplatin; 37%, placebo plus fluoropyrimidine-cisplatin), anemia (10% v 14%), and decreased appetite (8% v 11%). No new bevacizumab-related safety signals were identified.

Conclusion

Although AVAGAST did not reach its primary objective, adding bevacizumab to chemotherapy was associated with significant increases in progression-free survival and overall response rate in the first-line treatment of advanced gastric cancer.

[Recurrent autoimmune hemolytic anemia induced by XELOX chemotherapy for colon cancer]

We describe a 54-year old woman with oxaliplatin-induced autoimmune hemolytic anemia and review the clinical features of similar published cases. The present patient had metastatic colon cancer and was admitted to our hospital with a floating sensation and general malaise on day 4 after undergoing the last of 4 cycles of a 7th round of chemotherapy with XELOX. Laboratory data revealed 4.6g/dl hemoglobin and 8.77 mg/dl creatinine. Direct and indirect Coombs tests of a blood sample for blood transfusion were both positive. We diagnosed immune hemolysis with acute renal failure based on the clinical course and blood samples showing haptoglobin <10mg/dl. We treated her with hemodialysis, plasmapheresis and immune suppression with prednisolone, which improved the anemia and renal failure.

Association between insulin-like growth factor-1 polymorphisms and stomach cancer risk in a Japanese population

The insulin-like growth factor (IGF) signaling system plays a central role in cellular growth, differentiation and proliferation. Although the association between IGF1 gene polymorphisms and cancer risk has been evaluated for several carcinomas, this association has not yet been examined for stomach cancer. We investigated the association between IGF1 polymorphisms and the risk of stomach cancer in a Japanese population. A total of 703 patients with stomach cancer and 1462 non-cancer control subjects were enrolled in this case-control study. Associations between polymorphisms of 10 IGF1 loci and the risk of stomach cancer were evaluated using odds ratios (OR) and 95% confidence intervals (CI) in multiple logistic regression models. We observed that the C allele in rs1520220 and the G allele in rs4764887 were significantly associated with stomach cancer risk in the per-allele model after adjusting for other risk factors (OR: 1.14 [95% CI: 1.00-1.30] and OR: 1.18 [95% CI: 1.02-1.36], respectively). We also observed a positive and dose-dependent association between the number of risk alleles and stomach cancer risk (P-trend: 0.019) when examining the two loci in the same model. These associations were still seen after adjusting for potential confounders, including sex, age, smoking status, history of diabetes and family history of stomach cancer. We did not find any significant interaction between these factors and the number of risk alleles. In conclusion, we observed a significant association between IGF1 polymorphisms and stomach cancer risk among a Japanese population. Examination of the biological significance of IGF1 is warranted.