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.

The use of trastuzumab in Japanese patients with HER2-positive advanced or metastatic gastric cancer

102

Background: The Trastuzumab for Gastric Cancer (ToGA) study showed the efficacy of trastuzumab for HER2-positive gastric cancer (HGA). The aim of this study is to evaluate the benefit of trastuzumab for Japanese HGA patients.

Methods: ToGA was an open-label, international, phase III, randomized controlled trial undertaken in 122 centers in 24 countries. Median overall survival (OS) was 13.8 months in those assigned to trastuzumab plus chemotherapy (C+T) compared with 11.1 months in those assigned to chemotherapy alone (C) with hazard (HR) ratio of 0.74. Subgroup analyses of patients enrolled from Japan were undertaken to estimate the hazard ratio (HR) for OS in the Japanese population. Based upon the prescribed protocol for Japan, we calculated HR using multiple Cox regression model with prespecified covariates in the ToGA study in order to make up for the small number of Japanese patients and reduce the bias in the baseline characteristics between two groups.

Results: Sixteen institutes participated and 102 patients were enrolled, of which 101 patients were evaluable for this research. The median OS was 15.9 months in C+T arm versus 17.7 months in C arm. The HR for OS was 1.00 [95% CI: 0.59-1.69]. However, the HR for OS adjusted for the above covariates was estimated to be 0.68 [95% CI: 0.36-1.27]. There were differences between C+T arm and C arm in some baseline characteristics. Higher frequencies were seen in C arm as follow: intestinal type, prior gastrectomy, and smaller number of metastatic sites. For HER2 status, the percentage of patients with IHC0/FISH+ was lower in C+T arm (5.9%) than in C arm (18.0%), while that of patients with HER2 status IHC2+/FISH+ was higher in C+T arm (35.3%) than in C arm (26.0%).

Conclusions: Although ToGA's overall OS HR = 0.74 (p = 0.0046), in the Japan patient subgroup, the unadjusted hazard ratio was 1.00. However, there was an imbalance of the baseline characteristics between the treatment arms in Japanese population. When adjusted for these characteristics, the HR was 0.68 which is similar to those in the ToGA study. Adding trastuzumab to chemotherapy in Japanese population appears to confer a similar magnitude of benefit compared to the whole population enrolled in the ToGA study.

[Table: see text]

Development of pancreatic cancers during long-term follow-up of side-branch intraductal papillary mucinous neoplasms

BACKGROUND AND STUDY AIMS

Side-branch intraductal papillary mucinous neoplasms (SB-IPMNs), and associated synchronous and metachronous pancreatic cancers are increasingly detected as imaging modalities become more sensitive. We investigated the natural history of SB-IPMN, and the incidence and characteristics of pancreatic cancers among patients undergoing long-term follow-up.

PATIENTS AND METHODS

We reviewed the clinical, imaging, and pathological features in 103 patients, diagnosed at the Aichi Cancer Center between September 1988 and September 2006 as having SB-IPMN, and conservatively followed up for ≥ 2 years (median 59 months) based on an endoscopic ultrasonography (EUS) database.

RESULTS

74 (71.8 %) patients had nonprogressive lesions. Overall, six patients (5.8 %) developed pancreatic cancers during follow-up, with intraductal papillary mucinous (IPM) carcinoma in four, and ductal carcinoma of pancreas that was not IPMN in two patients. Of the six pancreatic cancers, five were diagnosed at a resectable stage. The 5-year and 10-year actuarial rates of development of pancreatic cancer were 2.4 % and 20.0 %, respectively. Although, at the last follow-up, cyst size, main pancreatic duct (MPD) diameter, mural nodule size, and frequency of metachronous and/or synchronous cancers of other organs were significantly higher in patients who developed IPM carcinoma, resected SB-IPMNs without mural nodules and dilated MPDs had no IPM carcinomas.

CONCLUSIONS

The frequency of pancreatic cancers is high on long-term follow-up of SB-IPMN. Although conservative management is appropriate for selected patients, regular and long-term imaging, especially by EUS is essential, even if SB-IPMN remains unchanged for 2 years. Presence of mural nodule and dilated MPD seem to be more appropriate indicators for resection than cyst size alone for SB-IPMNs.

AVAGAST: A randomized, double-blind, placebo-controlled, phase III study of first-line capecitabine and cisplatin plus bevacizumab or placebo in patients with advanced gastric cancer (AGC)

LBA4007

Background: The median survival for patients (pts) with AGC in most phase III studies is less than 1 year. The addition of bevacizumab (bev) to chemotherapy (chemo) is supported by a strong preclinical rationale and by phase II evaluation. AVAGAST is the first randomized study to compare the efficacy and safety of bev + chemo vs placebo + chemo.

Methods: Pts with inoperable, locally advanced or metastatic stomach/gastroesophageal junction adenocarcinoma with no prior therapy were randomized 1:1 to capecitabine (cape, or 5-FU) + cisplatin (cis) and either bev (7.5 mg/kg iv) or placebo q3w. Stratification variables: geographical region, fluoropyrimidine treatment, disease status. Cis was given for 6 cycles; bev/placebo + cape/5-FU were given until disease progression or unmanageable toxicity. Primary objective: compare overall survival (OS); secondary objectives: compare progression-free survival (PFS), overall response rate (ORR), and safety (as overseen by an independent DSMB).

Results: From Sep 2007 to Dec 2008, 774 pts were enrolled. Treatment arms were balanced. Approx 95% of pts were metastatic. Two-thirds of pts were male, 49% of pts were from Asia/Pacific, 32% from Europe and 19% from the Americas. Median OS was 10.1 months with chemo + placebo and 12.1 months with chemo + bev in the intent-to-treat population (HR 0.87; p=0.1002). Median OS according to geographical region was 6.8 vs. 11.5 months (HR 0.63) in the Americas, 8.6 vs. 11.1 months (HR 0.85) in Europe and 12.1 vs. 13.9 months in Asia-Pacific (HR 0.97). Secondary endpoints and AEs of special interest for Bev are summarized below ( Table ).

Conclusions: While the primary endpoint was not met (median OS HR 0.87; p=0.1002), there was a significant improvement in PFS and ORR and an acceptable safety profile for bev + chemo in patients with AGC.

[Table: see text]

[Table: see text]

Neutropenia as a prognostic factor in advanced gastric cancer patients undergoing second-line chemotherapy with weekly paclitaxel

BACKGROUND

Neutropenia during chemotherapy has been reported to be a predictor of better survival in patients with several types of cancers, although there are no reports in pretreated patients.

METHODS

We retrospectively analyzed 242 patients with advanced gastric cancer (AGC) who received weekly paclitaxel (Taxol) as second-line chemotherapy. Background characteristics and neutropenia as time-varying covariates (TVCs) were analyzed as prognostic factors.

RESULTS

Of the 242 patients, mild neutropenia (grades 1-2) occurred in 101 patients (41.7%) and severe neutropenia (grades 3-4) occurred in 63 patients (26.0%). The other 78 patients (32.2%) did not experience neutropenia. According to a multivariate Cox model with neutropenia as a TVC, hazard ratios of death were 0.61 [95% confidence interval (CI) 0.43-0.85; P = 0.004] for patients with mild neutropenia and 0.61 (95% CI 0.41-0.88; P = 0.009) for those with severe neutropenia. Among the patients in landmark analysis (landmark of 2.5 months; median time to treatment failure of paclitaxel), mild and severe neutropenia remained significant prognostic factors.

CONCLUSIONS

Our results indicate that neutropenia during chemotherapy is associated with improved survival in patients with AGC who received weekly paclitaxel as second-line chemotherapy. Prospective trials are required to assess whether dosing adjustments based on neutropenia may improve chemotherapy efficacy.

Phase II study of S-1 plus leucovorin in patients with metastatic colorectal cancer

BACKGROUND

S-1, a novel oral fluoropyrimidine, is well tolerated in patients with metastatic colorectal cancer (mCRC). The response rate of S-1 for colorectal cancer is high, ranging from 35% to 40%. This study aimed to evaluate the safety and efficacy of S-1 combined with oral leucovorin (LV) to enhance antitumor activity in chemotherapy-naive patients with mCRC.

PATIENTS AND METHODS

S-1 was given orally twice daily for two consecutive weeks at a daily dose of 80-120 mg, followed by a 2-week rest period, within a 4-week cycle. LV was given orally twice a day at a daily dose of 50 mg, simultaneously with S-1.

RESULTS

Of the 56 patients with previously untreated mCRC, 32 (57%) had partial responses. The median follow-up period was 27.2 months. The median time to progression was 6.7 months (95% confidence interval 5.4-7.9). The median survival time was 24.3 months. There was no treatment-related death or grade 4 toxicity. The most common grade 3 toxic effects were diarrhea (32%), anorexia (21%), stomatitis (20%), and neutropenia (14%).

CONCLUSION

S-1 combined with LV therapy demonstrated promising efficacy and acceptable safety in chemotherapy-naive patients with mCRC without the concurrent use of irinotecan, oxaliplatin, or molecular-targeted drugs.

Efficacy results from the ToGA trial: A phase III study of trastuzumab added to standard chemotherapy (CT) in first-line human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (GC)

LBA4509

Background: Advanced GC is an incurable disease; new and less toxic treatments are needed. HER2 overexpression has been reported in 6–35% of stomach and gastroesophageal tumors. Trastuzumab (H; Herceptin), a monoclonal antibody against HER2, has shown survival benefits when given with CT in patients (pts) with HER2-positive early and metastatic breast cancer. The ToGA study is the first randomized, prospective, multicenter, phase III trial to study the efficacy and safety of H in HER2- positive GC. Methods: Pts with HER2-positive gastroesophageal and gastric adenocarcinoma (locally advanced, recurrent, or metastatic) were randomized to receive H+CT (5-fluorouracil or capecitabine and cisplatin) q3w for 6 cycles or CT alone. H was given until disease progression. The primary end point was overall survival (OS); secondary end points included overall response rate (ORR), progression-free survival, time to progression, duration of response, and safety. An interim analysis was planned at 75% of deaths and the Independent Data Monitoring Committee recommended releasing the data as the pre-specified boundary was exceeded and median follow-up of pts was 17.1 months. Results: Tumors from 3,807 pts were centrally tested for HER2 status: 22.1% were HER2 positive (abstract #4556). 594 pts were randomized 1:1 at sites in Europe, Latin America, and Asia. Baseline characteristics were well balanced across arms. Median OS was significantly improved with H+CT compared to CT alone: 13.5 vs. 11.1 months, respectively (p=0.0048; HR 0.74; 95% CI 0.60, 0.91). ORR was 47.3% in the H+CT arm and 34.5% in the CT arm (p=0.0017). Safety profiles were similar with no unexpected adverse events in the H+CT arm. There was no difference in symptomatic congestive heart failure between arms. Asymptomatic left ventricular ejection fraction decreases were reported in 4.6% of pts in the H+CT arm and 1.1% in the CT arm. Conclusions: This first randomized trial investigating anti-HER2 therapy in advanced GC showed that H+CT is superior to CT alone. The OS benefit indicates that H is a new, effective, and well-tolerated treatment for HER2-positive GC.

[Table: see text]

Gastric submucosal tumors: Lessons learned from 10-year follow-up

e15631

Background: Gastric Submucosal tumors (SMTs) were incidentally discovered esophagogastroduodenoscopy (EGD). However, they have not been studied in detail of epidemiology. Furthermore, no treatment strategy for SMTs has been established with few studies looking into long-term outcomes. The aim of this study is to clarify the clinical features and long-term outcomes of gastric SMT at a single institute for 10-year period. Methods: We performed a total of 5307 EGDs and detected 188 gastric SMTs during 1998. All clinical data including incidence, size and location in stomach were analyzed for the medical records. A retrospective review was conducted for 10-year period for 109 patients and 79 patients were excluded because of simultaneous surgery (3), disappear in follow- up EGD (27), lost of follow-up (49). Results: Gastric SMTs were detected 188 (81 males, 107 females) of 5307 patients (3.5%). Majority size of SMTs was less than 1cm (64%) and SMTs<2cm were 91%. 56% of SMTs located middle one third of stomach, and half (22%) of the remaining SMTs were detected at upper and lower one third, respectively. In 10-year follow-up, 83 of 109 patients were alive at December 2008. One patient was dead of SMT and the remaining 25 patients were dead of other disease till December 2008. Enlargement of SMT was observed in 2 of 109 SMTs (1.8%). Both of them underwent surgical resection and diagnosed as gastrointestinal stromal tumors (GIST). One patient was annually monitored by endoscopy, from 0.6cm to 1.5cm during 4 years, without recurrence for 6 years after surgical intervention. Another didn't undergo regular endoscopy, from 1.8cm to 8cm during 2 years, with recurrence, and consequently died of SMT. Conclusions: The incidence of SMTs is 3.5%, majority (91%) is small (<2cm), and frequent location is middle one third of stomach. Most of SMTs might be managed conservatively, but regular endoscopy is required.

No significant financial relationships to disclose.

Efficacy results from the ToGA trial: A phase III study of trastuzumab added to standard chemotherapy (CT) in first-line human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (GC)

LBA4509

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

[Table: see text]

Updated results of randomized phase III study of 5-fluorouracil (5-FU) alone versus combination of irinotecan and cisplatin (CP) versus S-1 alone in advanced gastric cancer (JCOG 9912)

4514

Background: We reported the primary results of JCOG9912 in ASCO 2007. In the planning, this study with 230 patients (pts) per arm had 80% power to demonstrate 10% superiority of CP and non-inferiority with 5% margin (HR=1.16) of S-1 at 6 months in overall survival (OS) and 0.05 study-wise 1-sided alpha. Primary analysis was conducted in Feb 2007, one year after the last patient accrual with 601 deaths (85%) of all randomized 704 pts. S-1 showed statistically significant non-inferiority to 5-FU (p<0.001), but after adjusting for multiplicity either S-1 or CP failed to show statistically significant superiority to 5-FU (CP, hazard ratio (HR)=0.85 (95% CI, 0.70–1.04), p=0.055 and S-1, HR=0.83 (0.68–1.01), p=0.034). Methods: The survival information of all surviving 103 pts at the primary analysis was updated in Apr 2008 when 660 pts (94%) were dead. An updated analysis and multivariate analyses with Cox proportional hazard model were conducted. The multivariate analysis model included arms, sex, age, tumor status (unresectable/recurrent), PS, the number of metastatic sites, target lesion (TL), macroscopic type, histological type and peritoneal dissemination. Results: The updated results are shown in Table . OS curves and HRs remained almost identical to the previous report. Multivariate analyses showed that number of metastatic sites (≥2), PS (≥1), presence of TL were associated with worse survival, and that the adjusted HRs of CP and S-1 were 0.79 (0.65–0.95, p=0.014) and 0.80 (0.66–0.96, p=0.017), respectively. There was no significant interaction among baseline factors and treatment arms. Conclusions: The updated results reconfirmed the primary conclusion that S-1 monotherapy can be a new standard regimen for advanced gastric cancer, and suggest that CP is still worthy for further clinical investigation.

[Table: see text]

[Table: see text]

Pathological features of advanced gastric cancer (GC): Relationship to human epidermal growth factor receptor 2 (HER2) positivity in the global screening programme of the ToGA trial

4556

Background: HER2 positivity is thought to be a negative prognostic factor in GC, correlating with poor survival rates. Reported HER2-positivity rates in GC have varied widely (6–35%). The ToGA trial is evaluating the addition of trastuzumab (Herceptin) to chemotherapy in HER2-positive advanced GC. It is the first randomised Phase III trial to provide prospective information on HER2-positivity rates in GC. Enrollment is complete, with 3,883 patients screened in 24 countries. The pathological features of GC and the relationship with HER2 positivity will be examined. Methods: Advanced GC tumour samples were centrally screened by immunohistochemistry (IHC; HercepTest) and fluorescence in situ hybridisation (FISH; PharmDx) in parallel. A HER2-scoring system modified from the protocol in breast cancer (BC) was used: a score of IHC 3+ and/or FISH positive was defined as HER2 positive. Results: Final data showed an overall HER2-positivity rate of 22.1% evaluated from 3807 patients. The HER2-positivity rate was similar between Europe (23.6%) and Asia (23.5%). HER2-positivity rates were higher in gastro-oesophageal junction (GEJ) than stomach cancer (33.2% vs 20.9%; p<0.001) and in intestinal than diffuse/mixed cancer (32.2% vs 6.1%/20.4%; p<0.001). This is reflected in above-average HER2-positivity rates in countries with the highest GEJ:stomach cancer ratios (France 0.56 [HER2 positivity 26.9%]; Germany 0.53 [23.7%]; UK 0.33 [25.8%]) and intestinal:diffuse cancer ratios (UK 3.4 [HER2 positivity 25.8%]; Australia 2.6 [32.8%]; Japan 2.8 [27.8%]). The modified HER2-scoring system showed concordance between IHC and FISH results of 87.5%. In BC most IHC 0/1 samples are FISH negative but, in ToGA, the frequency of IHC 0/1 samples testing FISH positive was almost as high as IHC 2/FISH-positive samples (23% vs 26%). Conclusions: The overall HER2-positivity rate in advanced GC in ToGA is 22.1%. Variations in tumour location and type mostly explain the difference in HER2-positivity rates between countries. Efficacy data will enable further evaluation of the clinical significance of HER2 IHC and FISH scoring patterns.

[Table: see text]

Diagnostic yield of nonfunctional pancreatic neuroendocrine tumor using endoscopic ultrasound-guided fine needle aspiration biopsy

e15680

Background: Radiological examinations including computed tomography (CT) and endoscopic ultrasound sonography (EUS) are important for the diagnosis of pancreatic neuroendocrine tumors (PNETs). Pathological diagnosis is not needed with functional PNETs because the diagnosis is made by biochemical testing. Therefore, pathological diagnosis is essential for the non-functional PNETs (nf-PNETs). In this study, we examined the diagnostic yield of radiological examinations and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for nf-PNETs. Methods: From January 1997 to December 2007, consecutive 38 cases were pathologically diagnosed from as nf-PNETs at Aichi Cancer Center Hospital. Of these 33 patients was diagnosed with surgical specimen, 5 patients with EUS-FNA specimen. Of 33 patients, 16 patients underwent EUS-FNA preoperatively, and were examined further: their EUS-FNA specimens were submitted for additional immunohistochemical examination for CD 56, chromogranin A, synaptophysin, somatostatin receptor 2A (SSTR2A) and Ki-67 using cell block method. Staging of PNETs was performed according to WHO classification. Results: 16 patients (10 men and 6 women) who ranged in age from 23 to 81 years. The mean of tumor size was 2.2 cm and ranged from 0.7 to 4.4 cm. Diagnosis by CT and EUS was 12 (75.0%) PNETs, two pancreatic cancer, one solid papillary tumors and one malignant lymphoma. Accurate diagnosis by cytology and immunohistochemistry was 75.0% and 93.8%, respectively. The Ki-67 in specimens of malignancy tended to be higher than those of benign or uncertain behavior. If we assumed that a tumor with Ki-67 of more than 2% was malignancy, the diagnostic accuracy was 75.0%. Positive reaction to SSTR2A was up to 14 out of 16 nf-PNETs. Conclusions: The EUS-FNA is a useful tool for diagnosing nf-PNETs with immunohistochemical staining compared to cytology and radiological examinations. Ki-67 may be also effective to predict the degree of malignancy.

No significant financial relationships to disclose.

Validation of genotyping of gastrointestinal stromal tumor in Japan

e21502

Background: Most gastrointestinal stromal tumors (GIST) have activating mutations in the KIT or PDGFRA gene. Genotyping of GIST is important in Dx and Tx of GIST. Methods of genotyping using genomic DNA extracted from paraffin-embedded specimens are diverse and not standardized. We did validation study of genotyping using special reference to sequencing data obtained from cDNA from fresh GIST samples. Methods: Three DNA extraction methods (QIAamp, DEXPAT, or original) and four PCR methods (Ex Taq, AmpliTaq condition-1, AmpliTaq condition-2, or QIAGEN Tag) were compared using 20 paraffin-embedded specimens with special reference to sequencing data obtained from cDNA from corresponding 20 fresh GIST samples. After DNA extraction, KIT exon 9, 11, 13 and 17, and PDGFRA exon 12 and 18 were amplified by each PCR method using specific primers and directly sequenced. Results: In evaluation of PCR method, the protocol with Ex Taq showed 100% amplication of DNA and sequence agreement, the protocol with QIAGEN Tag 99%, and the protocol with AmpliTaq condition-2 86% agreement, and the protocol with AmpliTaq condition-1 showed much less amplication and higher disagreement. For the DNA extraction, the protocol with QIAamp showed best DNA extraction and its DNA sequence data were consistent with reference sequence in 98%, DNA sequence obtained using DEXPAT showed 33% consistency, and 89% of DNA sequence data obtained from an original method was agreed with reference data. Some modifications improved DNA amplication but inconsistent sequence data also increased probably due to miss-PCR. Conclusions: Each DNA extraction method had different quantity of DNA and four PCR methods showed different quality. Using this validation study, a standard genotyping method in Japan was established.

No significant financial relationships to disclose.

Chemotherapy for patients with advanced gastric cancer with performance status 2

e15627

Background: S-1 plus cisplatin is considered to be the standard chemotherapy for Japanese patients with advanced gastric cancer (AGC) according to the results of three phase III trials (JCOG9912/SPIRITS/TOP-002). However, since few patients with poor performance status (PS2) were included in these phase III trials (27 of 1317; 2%), the standard treatment of patients with PS2 has not been established yet. In also, the characteristics and prognosis of AGC patients with PS2 has not been reported in detail. Methods: We retrospectively analyzed 545 patients with AGC treated by chemotherapy during the period from January 2003 to June 2008. Patients characteristic and treatment results were compared between PS0–1 and PS2. Results: At the beginning of 1st-line chemotherapy, PS0–1/2/3–4 was 454/69/22 cases respectively. Patients with peritoneal/pleural dissemination was more common in PS2 than PS0–1 (75% vs. 43%, p<0.001). Patients with multiple metastatic places was more common in PS2 (62% vs. 43%; p=0.007). Fewer patients in PS2 were registered in clinical trial (1.4% vs. 25%, p<0.001). First-line chemotherapy using oral drug (S- 1/capecitabine) was significantly fewer in PS2 (43% vs. 75%, P<0.001). Median time to treatment failure was significantly shorter in PS2 (2.3 months vs. 4.2 months, p<0.001). Patients who could receive second-line chemotherapy were significantly fewer in PS2 (50% vs. 75%, p<0.001). With the median follow up time of 42 months, median survival time of patients with PS0–1 was 14.8 months (95% CI;13.1–16.5) and that of patients with PS2 was 6.1 months (4.3 to 7.4 months; hazard ratio for death 3.0: 95% CI2.3–4.0; p<0.001). Mortality rate within 30 days was higher in PS2 (3% vs. 0.2%; p<0.001). Conclusions: AGC patients with PS2 had not only had poor prognosis compared with PS0–1 but also had fewer chance of registration in the clinical trial, shorter time to treatment failure, and higher mortality rate within 30 days. Considering these different characteristics and treatment results of PS0–1 and PS2, clinical trial especially targeting AGC patients with PS2 is necessary to evaluate optimal chemotherapeutic regimens for PS2 patients.

No significant financial relationships to disclose.

EUS-guided choledochoduodenostomy for palliative biliary drainage in patients with malignant biliary obstruction: results of long-term follow-up

Five patients with obstructive jaundice caused by malignant periampullary biliary stenosis underwent EUS-guided choledochoduodenostomy (EUS-CDS) from the first portion of the duodenum using a convex echoendoscope and a needle knife. All the steps of the procedure including passage dilatation and the plastic stent placement were performed through the accessory channel of the echoendoscope over the guide wire. Stent insertion was technically successful in all five patients. The procedure was also clinically effective in relieving jaundice in all cases. One patient developed pneumoperitoneum, which resolved with conservative management. Stent exchange was successful in seven of eight attempts in patients with stent occlusion. One failure was due to tumor invasion to the choledochoduodenal fistula. Stent patency was maintained in the remaining patients throughout their survival period. The average stent patency was 211.8 days. EUS-CDS from the first portion of the duodenum appears to be feasible and safe in cases of obstructive jaundice caused by distal bile duct obstruction.

HER2 positivity in advanced gastric cancer is comparable to breast cancer

15057

Background: Accurate HER2 testing is required to identify patients eligible for treatment with trastuzumab (Herceptin®). HER2 positivity is reported as 6–35% in gastric cancer (GC). This range is due to small sample sets and differing methods of evaluation or scoring. A specific HER2-testing process was established for the Phase III ToGA trial, which is evaluating trastuzumab added to chemotherapy in HER2-positive advanced GC. Methods: A validation study was completed to standardise IHC (HercepTest™) and FISH (PharmDx™) protocols, and to establish a scoring system specific for GC (M Hofmann et al. ASCO Gastrointestinal Cancers Symposium 2006. Abstract no. 24). Tumour samples for ToGA were then centrally tested by both IHC and FISH to identify patients eligible for enrolment. Results: To date, 1024 tumour samples have been assessed (243 HER2 positive and 781 HER2 negative) giving an overall HER2-positivity rate of 23.7%. Both IHC and FISH results are available for 960 patients, with 87% concordance. Differences were largely due to FISH-positive cases that were IHC 0/1+. HER2 positivity differed significantly by histological subtype: 36% in intestinal, 7% in diffuse and 23% in mixed. HER2 positivity also varied according to the site of the tumour: 36% (8/22) for gastro-oesophageal junction tumours and 21% (60/291) for gastric tumours. Sample numbers were very small so these results must be treated with caution. The HER2- positivity rate was similar in specimens obtained by biopsy (168/689; 24%) and surgery (71/322; 22%). Conclusions: Using validated methodology and based on the large sample set from the ongoing ToGA trial, the HER2-positivity rate observed in advanced GC is as high as in breast cancer: ∼24%. The first efficacy data from ToGA are expected in 2009.

No significant financial relationships to disclose.

Serum REG4 protein in pancreatic cancer as a tumor marker: A prospective study

15063

Background: Pancreatic cancer (PC) shows the worst mortality rate in common malignancies, with 5-year survival rate of 4%. The only way to cure the disease is surgical resection of early stage PC. Establishment of a screening strategy to detect early stage PC is eagerly expected. REG4, a member of the regenerating islet-derived (REG) family, are secreted proteins that play a role in tissue regeneration and inflammation in digestive organs. We reported overexpression of REG4 in PC cells and serum, and preliminary data of the serum REG4 level of pancreatic disease patients including PC patients. We conducted a prospective study to evaluate the role of serum REG4 in PC. Methods: The series included 57 patients diagnosed pathologically as PC between November 2004 and December 2005. Serum REG4 was quantified by standard sandwich ELISA (Enzyme Linked Immunosorbent Assay) using original kit (MBL116: provided by Medical and Biological Laboratories Co., LTD, Japan) before treatment. The upper limit of the test was set at 3.52ng/ml and was based on studies of serum from 48 healthy control subjects. Results: With a specificity of 100%, the diagnostic sensitivity and accuracy were 63.2% and 80.0%, respectively. The ROC (receiver operating characteristic) analysis showed that area under the curve was 0.91. REG4 levels were a significant differences between PC and control (p<0.001), between each T stage and control (T1,T2, T3 or T4 v control), and between each TMN stage and control (stage 1, stage 2, stage 3 or stage 4 v control), but were not a statistical significance with T stage (T1 v T2 v T3 v T4), M stage (M0 v M1) or TNM stage (stage 1 v stage 2 v stage 3 v stage 4) in PC patients. The diagnostic sensitivity of carcinoembryonic antigen (CEA>5.0ng/ml) and carbohydrate antigen19–9 (CA19–9>50U/ml) was 56.5% and 68.4%, respectively. No significant correlation was demonstrated between REG4 and CA19–9 (coefficient of correlation [rs]=0.45). Conclusions: This study shows the potential of serum REG4 as a screening test for PC, especially for early PC. REG4 is considered to be a more useful marker in combination with CA19- 9.

No significant financial relationships to disclose.

Randomized phase III study of 5-fluorouracil (5-FU) alone versus combination of irinotecan and cisplatin (CP) versus S-1 alone in advanced gastric cancer (JCOG9912)

LBA4513

Backgrounds: We conducted a 3-arm phase III study to investigate superiority of CP and non-inferiority of S-1 to 5-FU for advanced gastric cancer in the primary endpoint of overall survival (OS) and secondary endpoints of response rate (RR), time to treatment failure (TTF), non-hospitalized survival (NHS) and toxicities. Methods: Treatments with 5-FU (800mg/m2/d, ci, d1–5, q4w), CP (irinotecan, 70mg/m2, div, d1&15 and cisplatin, 80mg/m2, div, d1, q4w) and S-1 (40mg/m2, b.i.d., d1- 28, q6w) were continued until disease progression or unacceptable toxicities. Tumors were evaluated every two months. With 230 patients (pts) per arm, this study had 80% power to demonstrate 10% superiority of CP and non-inferiority with 5% margin (hazard ratio, HR=1.16) of S-1 and 0.05 study-wise 1-sided alpha. Results: 704 pts having unresectable or recurrent gastric adenocarcinoma with/without target lesions (TL) were randomized between Nov 2000 and Jan 2006. Final analysis was performed in Feb 2007 when 601 pts (85%) were dead. The results of OS are shown in Table . Median TTF/NHS were 2.3M/7.2M for 5-FU, 3.7M/9.5M for CP, and 4.0M/9.2M for S-1. Incidences (%) of grade 4 neutropenia, grade ≥3 febrile neutropenia, infection with neutropenia, anorexia, diarrhea within 6M, and treatment related death (5- FU/CP/S-1) were 0/37/0, 0/9/0, 0/8/0, 13/33/12, 0/9/8, and 0/1.3/0.4. In the subset having TL, RRs of 5-FU/CP/S-1 (n=175/181/175) were 9%/38%/28%, and their median survival times (MST) were 9.0M/12.1M/10.5M and HRs to 5-FU were 0.78 (95%CI, 0.63–0.98) for CP and 0.85 (0.68–1.06) for S-1. In the subset not having TL, the MSTs of 5-FU/CP/S-1 (n=59/55/59) were 13.5M/14.4M/18.1M and HRs were 1.02 (0.68–1.55) for CP and 0.82 (0.55–1.24) for S-1. Conclusions: S-1 showed a significant non-inferiority to 5-FU. Although CP did not show statistically significant superiority to 5-FU in all pts, it may have a benefit for some subgroups such as pts with measurable metastatic diseases.

[Table: see text] [Table: see text]

Phase I/II study of oral fluoropyrimidine S-1 plus oral Leucovorin as first-line treatment for metastatic colorectal cancer

4093

Background: The results of phase I portion of the treatment with the oral S-1 (a new oral fluoropyrimidine) plus oral leucovorin (LV) in patients (pts) with untreated metastatic colorectal cancer (mCRC) was reported at ESMO 2006. Dose limiting toxicities (DLTs) were grade 3 stomatitis/pharyngitis, nausea, diarrhea, ileus and exanthema. The recommended doses (RDs) for this phase II portion were determined to be S-1 40 mg/m2 and LV 25 mg/body orally given twice daily on days 1 to 14 of a 28-day cycle. The PK profiles of S-1 plus LV were similar to those of S-1 monotherapy and UFT plus LV, respectively. The main purpose of this phase II portion is to evaluate the efficacy and safety of S-1 plus LV at RD level in pts with untreated mCRC. Methods: Pts were eligible as follows; unresectable mCRC with no prior chemotherapy or receiving adjuvant chemotherapy completed at least 6 months before, histologically proven adenocarcinoma, PS(ECOG) 0–2, age 20 to 75, measurable lesions, adequate organ function and written informed consent. The pts received 40 mg/m2 of S-1 plus 25 mg/body of LV twice daily as RD in this phase II portion. The primary endpoint was the objective response rates (RRs), and secondary endpoints were time to progression (TTP) and toxicities. Results: Between Sep 2004 and Jun 2006, 56 pts of 65 enrolled pts received the treatment at RD level. The objective RRs were 55% (36 of 65) for all pts and 55% (31 of 56) for pts at RD. Disease control rates (DCRs) were 86% (56 of 65) for all pts and 86% (48 of 56) for pts at RD. Median TTP was 5.5 months for pts at RD, with a median follow-up of 5.5 months. The median survival time is under observation. During the 6 months from starting the treatment, the most common grade 3/4 toxicities at RD were as follows: diarrhea, 23%; stomatitis, 20%; anorexia, 18%; and neutropenia 13%. Conclusions: A combination of S-1 plus oral LV is an effective, well tolerated, and convenient regimen in pts with untreated mCRC, without the addition of either oxaliplatin or irinotecan. The updated results of the objective RRs, DCRs, TTP reviewed extramurally, and detailed safety profile will be presented at the meeting. This trial was supported by Taiho pharmaceutical co., Ltd., Tokyo, Japan.

No significant financial relationships to disclose.

Systematic review and meta-analysis: importance of CagA status for successful eradication of Helicobacter pylori infection

BACKGROUND

Some, but not all studies have provided evidence that the CagA status of Helicobacter pylori strains is a predictive factor for the outcome of eradication therapy.

AIM

To clarify the association between CagA status and eradication outcome.

METHODS

We included studies reporting the numbers of successful and failed cases in H. pylori-eradication therapy according to the CagA status. Fourteen studies (1529 patients) were included of 325 articles identified in the search. The pooled risk ratio for H. pylori-eradication failure in CagA-negative relative to CagA-positive strains and the pooled risk difference in eradication success between the two groups were used as summary statistics. Meta-regression was used for examining the source of heterogeneity.

RESULTS

The summary risk ratio for eradication failure in CagA-negative relative to CagA-positive was 2.0 (95% CI: 1.6-2.4, P < 0.001), corresponding with the summary risk difference for eradication success between the groups of 11% (95% CI: 3-19%, P = 0.011). Meta-regression analysis demonstrated that usage of polymerase chain reaction examination for CagA status and a high proportion of non-ulcer dyspepsia patients were factors for heterogeneity among studies.

CONCLUSIONS

Our meta-analysis confirmed the importance of the presence of CagA as a predictor for successful eradication of H. pylori.

Recurrence after imatinib treatment for gastrointestinal stromal tumor: Japanese experience in a single institute

19504

Background: Although imatinib is the most effective agent for metastatic gastrointestinal stromal tumors (GISTs), resistance to imatinib develops in most patients. While the effectiveness of an oral multitageted tyrosine kinase inhibitor for intolerant GIST is already reported, many of imatinib resistant patients are not available. We report clinical results of first imatinib and post imatinib treatment in a patient with metastatic or unresectable GIST. Methods: A retrospective review was undertaken in patients with metastatic or unresectable GIST treated with imatinib at Aichi Cancer Center Hospital between June 2001 and December 2005. Treatment schedule was four or six 100-mg capsules of imatinib orally once daily. Patients were evaluated for treatment, recurrence, and survival. Results: Forty-five patients (26 males and 43 metastatic patients) were treated with imatinib at first. The median age was 58 years (range 25–79). Primary tumor sites were as follow; stomach was 13, duodenum 9, small intestine except for duodenum 18, and colorectum 5. Metastatic sites were liver (21 patients), peritoneum (11 patients), both of them (10 patients), and the other (1 patient). The response rate (by RECIST) and PFS was 71.1% (32/45) and 24 months, respectively. Imatinib was well tolerated; only two patients stopped treatment due to nausea and vomiting. Twenty-six patients with disease progression were treated by the combination of many methods, and the following methods underwent as the second therapy; 9 patients underwent surgical resection, 7 patients underwent transarterial chemoembolization (TACE) for liver metastases, 9 patients enrolled in a clinical trial, and 9 patients continued imatininb because of clinical benefit and no other therapeutic options. PFS of surgery and TACE were 6 and 7 months, respectively. Out of 16 patients treated with surgery or TACE, 2 patients were well controlled by TACE more than 1 year. One patient, however, was suffering from intractable liver abscess after TACE. Conclusions: The efficacy and safety of imatinib for GIST is almost the same as in U.S. reports. TACE may be an effective treatment for liver metastases if new agents are not available.

No significant financial relationships to disclose.

Indocyanine green is an ideal dye for endoscopic ultrasound-guided fine-needle tattooing of pancreatic tumors

Endoscopic ultrasound-guided fine-needle tattooing (EUS-FNT) is an ideal technique for preoperative marking of lesions detected on preoperative examination. Although India ink has been used for endoscopic tattooing, there have been numerous reports of complications associated with its use. This is the first report of EUS-FNT using indocyanine green (ICG) and describes its use for preoperative marking of a tumor in a 78-year-old man with multiple pancreatic tumors. There were no complications associated with the EUS-FNT procedure and it is suggested that ICG is a more suitable dye for tattooing of pancreatic lesions than India ink, being far less frequently associated with side effects.

Three-dimensional image display without special eyeglasses: observation of magnetic resonance angiography using the stereoscopic liquid crystal display

The authors have developed a new stereoscopic liquid crystal display that provides real-time 3-dimensional image viewing without special eyeglasses. The device consists of 3 major parts: (1) an image display composed of a 10.4-inch color liquid crystal plate with a resolution of 640 x 480, (2) an automatic head tracking system, and (3) a special backlight unit for the right and left eyes. Eight radiologists interpreted 60 cases of magnetic resonance angiography (29 cases of cerebrovascular disease and 31 normal cases) to compare film display and the liquid crystal display (ie, pseudo 3-dimensional display and true 3-dimensional display). Using a continuously distributed scale ranging from 0% to 100%, the observers ranked their confidence levels in determining the presence or absence of steno-occlusive disease, aneurysm, and arteriovenous malformation (AVM) and their locations. For statistical evaluation, receiver operating characteristic (ROC) analysis and Brier score were used. For detecting AVM, film reading showed a significantly higher value in the area under the binormal ROC curve (Az) than did pseudo-3-dimensional display (P < .05). Excluding this, however, no significant difference existed in Az values among the 3 viewing methods. Also, there was no significant difference in Brier score between not only the stereoscopic view and nonstereoscopic view groups, but also the senior and junior groups. Subjective estimation of true 3-dimensional display showed that vessels were more distinguishable with less eye fatigue compared with stereoscopic film reading. The stereoscopic liquid crystal display provided almost equal efficacy to film reading; however, the short optimum distance for observation and the low resolution should be improved.

Role of ultrasonography in the detection of intraductal spread of breast cancer: correlation with pathologic findings, mammography and MR imaging

The purpose of this study was to assess the role of US in the detection of intraductal spread of breast cancer in comparison with mammography (MMG) and MRI. In 46 patients with breast cancer, US features of the intraductal component were classified as ductal type or distorted type. Histopathologically, 29 of 46 (63%) cases had intraductal components, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 89, 76, and 85%, respectively. Each US pattern demonstrated good correspondence to the histologic components, and the distorted type correlated well with comedo-type carcinoma. Mammography was performed in all cases, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 55, 100, and 72%, respectively. In comedo type, MMG could diagnose the extent of intraductal spread more accurately compared with US examination. Magnetic resonance imaging comparison was available in 25 cases. Magnetic resonance imaging depicted intraductal extension as an enhanced area during the early phase of a contrast enhancement study with a sensitivity of 93%. Ultrasound and MRI were closely related in terms of morphologic characteristics: the ductal type of US image correlated well with linear enhancement on MRI, whereas the distorted type correlated with regional or segmental enhancement. Current US examination is useful in depicting the intraductal spread of breast cancer; however, US has a tendency to underestimate intraductal component of comedo type compared with MMG and MRI.

Further reduction of radiation dose in helical CT for lung cancer screening using small tube current and a newly designed filter

A new aluminum filter, 5.8 mm thick at the center, was designed. The effective energy, exposure dose, absorbed dose, and noise were measured by using low-dose technique, very low-dose technique with a conventional filter, and very low-dose technique with a new filter on a chest phantom. Accuracy of very low-dose computed tomography (CT) with a new filter was compared against standard helical CT in 40 patients and against chest radiography in 35 patients. Effective energies were 42.6 keV and 51.6 keV at a conventional filter and the new filter, respectively. Compared against 20mA with a conventional filter, exposure dose was reduced by 17%, and absorbed dose was equivalent, at 30 mA with the new filter. Noise was improved by 9%. Compared with standard helical CT, the sensitivity, specificity, and accuracy of very-low-dose helical CT were 100%, 88%, and 95%, respectively. Very-low-dose helical CT was found to be significantly superior to chest radiography in the detection of lung cancers. Using a smaller tube current and an appropriate filter allows a further reduction in radiation dose in helical CT for lung cancer screening.