Distributions of FcγRIIa-131 and FcγRIIIa-158 polymorphisms and clinical response to cetuximab in Japanese patients with metastatic colorectal cancer (mCRC)

565

Background: Polymorphisms in fragment C receptor (FcγR) are expected as a predictive biomarker of cetuximab (Cmab). Previous studies have convincingly confirmed the distributions (dists) of FcγR polymorphisms in Western population and shown the existence of linkage disequilibrium (LD) between FcγRIIa and FcγRIIIa polymorphisms. Meanwhile, the dists in Asian population have been unknown but a few studies for non-cancer patients have suggested the difference in dists between Asian and Western populations. We investigated the dists of FcγR polymorphisms and their association with clinical response to Cmab in Japanese mCRC patients.

Methods: Ninety-three patients with irinotecan/oxaliplatin/5-FU-refractory mCRC and treated by Cmab plus irinotecan or Cmab monotherapy were retrospectively registered from 8 centers in Japan. FcγR polymorphisms were determined from genomic DNA extracted from peripheral blood samples based on the Multiplex allele-specific PCR method. Comparisons according to FcγR polymorphisms were evaluated using Fisher's exact test for response rate (RR) and log-rank test for progression-free survival curves (PFS).

Results: The dists of FcγRIIa HH/HR/RR and FcγRIIIa VV/VF/FF were 68/30/2% and 4/40/56%, respectively (Table). The absence of LD between FcγRIIa and FcγRIIIa polymorphisms was confirmed (GENEPOP, p=0.526; Linkdis, p=0.146). Of 74 patients with KRAS wild-type and treated by Cmab plus irinotecan, no difference according to FcγR polymorphisms was observed in either RR (IIa: HH 37% vs. HR/RR 36%, p=1.00; IIIa: VV/VF 39% vs. FF 35%, p= 0.81) or PFS curves (IIa: HH vs. HR/RR, p=0.84; IIIa: VV/VF vs. FF, p=0.09). Similar results were seen in patients treated by cetuximab monotherapy.

Conclusions: This study clarified an ethnic difference in the frequencies of FcγR polymorphisms. Associations between the polymorphisms and clinical response to Cmab did not reach a statistical significance.

[Table: see text]

No significant financial relationships to disclose.

Clinical outcome in patients with metastatic colorectal cancer harboring KRAS p.G13D mutation treated with cetuximab

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Background: Metastatic colorectal cancer patients with KRAS codon 12 or 13 mutated tumors are presently excluded from treatment with cetuximab (Cmab). On the other hand, a few patients who have mutated KRAS status occasionally respond to Cmab. The tumors of those patients predominantly had codon 13 mutation, and all codon 13 responder have mutation of p.G13D. We now compared the efficacy of Cmab among patients with p.G13D- mutant, other KRAS mutant and KRAS wild-type colorectal cancer.

Methods: The patients from 9 Japanese institutions were retrospectively collected and analyzed. All patients were refractory to fluoropyrimidine, oxaliplatin and irinotecan, and were treated with Cmab and irinotecan combination regimen. Response rate (RR), progression-free survival (PFS) and overall survival (OS) were calculated respectively according to KRAS status.

Results: Ninety four patients were treated with combination therapy. Among 94 cases, 7 cases were p.G13D-mutant KRAS, 23 cases were other mutant KRAS and 63 cases were wild-type KRAS. Baseline characteristics by each subset were well-balanced. While one partial response (PR) and 4 stable diseases (SD) cases were found in 7 p.G13D-mutated cases, no PR was found in other KRAS mutated cases. Median PFS of the patients with p.G13D-mutant, other KRAS mutant and KRAS wild-type were 4.5 months (95%CI 1.7-), 2.3 months (95%CI 1.9-4.3), 4.6 months (95%CI 3.5-6.5) respectively. And median OS of the patients with p.G13D- mutant, other KRAS mutant and KRAS wild-type were 9.3months (95%CI 8.5- 11.8), 7.4 months (95%CI 4.5-9.4), 12.2 months (95%CI 8.7-19.8) respectively. Although statistical significance was not found between the two mutated groups, there are trends that the patients with p.G13D-mutant may have received better clinical benefits from Cmab than the patients with other KRAS mutant.

Conclusions: Cmab may have therapeutic benefit in the patients with KRAS p.G13D-mutant colorectal cancer although further evaluation is warranted.

No significant financial relationships to disclose.

Retrospective analysis of first-line chemotherapy in 132 patients with advanced small-bowel adenocarcinoma

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Background: No standard care has been established for advanced small-bowel adenocarcinoma (SBA). The aim of this study is to explore a most promising chemotherapy regimen for advanced SBA.

Methods: All data were collected from medical records of patients with advanced or recurrent SBA who received chemotherapy between April 1999 and March 2009 at 41 hospitals in Japan. Selection criteria were as follows: 1) histologically proven SBA, excluding ampullary carcinoma, 2) no previous chemotherapy or radiotherapy, 3) ECOG PS 0-2, 4) adequate bone marrow, hepatic and renal functions, 5) no concomitant malignancy. Patients were divided into the five groups by regimens: group A, fluoropyrimidine alone; group B, fluoropyrimidine + cisplatin; group C, fluoropyrimidine + oxaliplatin; group D, fluoropyrimidine + irinotecan; group E, others. Progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan-Meier method.

Results: Demographics of selected 132 patients were: median age (range), 59 (23-78) years; male/female, 87/45; location of primary tumor, duodenum/jejunum/ileum/unknown, 80/32/17/3; advanced/recurrent disease, 91/41. The numbers of the patients in group A, B, C, D and E were 60, 17, 22, 11 and 22, and objective response rates (ORR) in the patients with target lesions were 20% (9/46), 38% (5/13), 42% (8/19), 25% (2/8), 21% (4/19), respectively. Median PFS and OS were 6.0 and 14.0 months for the whole population, and those in each group are shown in the Table.In comparison with fluoropyrimidine alone (A), oxaliplatin-combined regimens (C) associated with better PFS (HR=0.53 [0.31-0.93], p=0.03) and OS (HR=0.64 [0.33-1.25], p=0.19), while cisplatin-combined regimens (B) did not (HR=1.54 [0.88-2.68], p=0.13 for PFS and HR=1.67 [0.94-2.97], p=0.08 for OS) by univariate analysis.

Conclusions: It is suggested that oxaliplatin-combined regimens might be the most promising regimen for advanced SBA.

[Table: see text]

No significant financial relationships to disclose.

Multicenter feasibility study of 5-FU, leucovorin, plus paclitaxel (FLTAX) for peritoneal disseminated gastric cancer with massive ascites or inadequate oral intake

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Background: Oral fluoropyrimidine plus cisplatin is widely used as a standard treatment for advanced gastric cancer, but patients (pts) with severe peritoneal metastasis often cannot tolerate this regimen. The aim of this study was to assess the feasibility of fluorouracil (5-FU), leucovorin (LV), plus paclitaxel (PTX) for peritoneal disseminated gastric cancer with massive ascites or inadequate oral intake.

Methods: Peritoneal disseminated gastric cancer with massive ascites or inadequate oral intake were enrolled in Part I (Level 1 (n=6): 5-FU bolus/l- LV div 2hr/PTX div 1hr = 500/250/60, Level 2 (n=6): 600/250/80 mg/m2 (day1, 8, 15, q4w) to determine dose-limiting toxicity (DLT) and recommended dose (RD). In Part II (n=19), primary endpoint was completion rate of 2 cycles to evaluate the feasibility of this regimen at RD level.

Results: One of Level 1 pts had DLT with grade 4 gastrointestinal perforation. Two of Level 2 pts had DLT (grade 3 febrile neutropenia and grade 3 infection with normal neutrophils) and treatment-related death (TRD) was observed in one patient due to pneumonia with grade 4 neutropenia. The RD was determined to be Level 1. Twenty-five patients were enrolled at RD level: first-line/second-line=18/7, performance status 0/1/2=1/19/5. The completion rate of 2 cycles was 92% and objective response rate of ascites was 45%. Grade 3 or 4 neutropenia was observed in 12% (febrile neutropenia in 8%). Five patients out of 7 second-line patients died within 30 days after last administration of FLTAX (TRD: 1 and disease progression: 4).

Conclusions: RD of FLTAX regimen was 5-FU/l-LV/PTX=500/250/60 mg/m2. This regimen was feasible as the first-line treatment against peritoneal disseminated gastric cancer patients with massive ascites or inadequate oral intake.

[Table: see text]

Impact of apex-sparing partial left ventriculectomy on left ventricular geometry, function, and long-term survival of patients with end-stage dilated cardiomyopathy

BACKGROUND AND AIM

Currently, partial left ventriculectomy (PLV) has not been widely accepted as a treatment option for dilated cardiomyopathy (DCM) because its results thus far have been inconsistent. In an animal study, apex-sparing PLV (AS-PLV) was shown to produce greater improvement in left ventricle (LV) function than conventional PLV in which the apex was removed. The aim of this study is to investigate the effectiveness of AS-PLV in a clinical setting.

PATIENTS AND METHODS

From September 1999 to December 2007, 13 patients with DCM underwent AS-PLV. Left ventriculotomy was made in the thinnest portion of the lateral wall without injuring the apex, the papillary muscles, and the circumflex coronary artery, which supplies the neighboring myocardium.

RESULTS

All patients were discharged from the hospital, except for one patient who developed refractory ventricular fibrillation on postoperative day 35. After AS-PLV, the LV diastolic dimension decreased from 71 +/- 10 mm to 55 +/- 9 mm; LV ejection fraction (EF) from 28%+/- 8% to 39%+/- 11%; and New York Heart Association (NYHA) class from 3 +/- 1.7 to 1.5 +/- 0.6; the differences were significant (p < 0.01). LV function and geometry remained unchanged 2 years after AS-PLV with LVDD of 60 +/- 7 mm, LVEF of 34%+/- 8%, and NYHA class of 1.7 +/- 0.6, respectively (N.S vs. at discharge).

CONCLUSIONS

Regardless of the etiology of LV dilatation, AS-PLV restored the ellipsoidal shape of the LV and improved LV function. AS-PLV is a feasible option for treating diseased LVs with lateral wall lesions.

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.

Carvedilol may alleviate late cardiac remodelling following surgical ventricular restoration

OBJECTIVE

Surgical ventricular restoration (SVR) can be effective to treat ischaemic cardiomyopathy or left ventricular (LV) aneurysm. However, the initial improvement in LV function does not always last long because of LV remodelling. Beta-blockers prevent LV remodelling of failing hearts; however, their effects following SVR have not been elucidated. Thus, we sought to investigate the effects of a potent beta-blocker, carvedilol, on LV remodelling and function following SVR in rats with myocardial infarction.

METHODS

Rats, which developed LV aneurysm 4 weeks after coronary artery ligation, underwent SVR. They were orally administered a vehicle (vehicle group), and low or high dose of carvedilol (20 or 50 mg kg(-1)day(-1) for C20 or C50 group) for 4 weeks following SVR (n=7 in each group).

RESULTS

Four weeks following SVR, late cardiac remodelling was alleviated only in the C50 group (LV end-diastolic area: 65+/-4 mm(2) vs 74+/-11 mm(2) and 76+/-11 mm(2) for C50, C20 and vehicle groups; p=0.039 and p=0.013, respectively). There was no difference in LV systolic function (end-systolic elastance) among the three groups; however, LV diastolic functions (LV end-diastolic pressure and the time constant of isovolumic relaxation) were significantly better in the C20 and C50 groups. Histologically, the percentage of myocardial fibrosis in the C50 group (4.1+/-0.2%) was lower than those in the C20 (6.7+/-0.4%, p<0.0001) and vehicle (7.5+/-0.6%, p<0.0001) groups. The mRNA expression of transforming growth factor-beta1 and brain natriuretic peptide in the C50 group were lower than those in the C20 and the vehicle groups.

CONCLUSIONS

High-dose carvedilol alleviated LV remodelling and diastolic dysfunction following SVR accompanying with reduction in myocardial fibrosis. Blockade of beta-adrenergic receptor may be a promising adjuvant therapy in patients following SVR.

Down-regulation of endothelin-1 and alteration of apoptosis signaling following left ventricular volume reduction surgery in heart failure of adult rats

While left ventricular (LV) reduction surgery (LVR) is a novel treatment for severe heart failure, alteration of signal transduction pathways by this surgery is unknown. LV endothelin-1 plays a critical role in LV remodeling following myocardial infarction (MI). Another possible mechanism of remodeling is myocardial cell loss due to apoptosis. The purpose of the present study was to determine whether the LV endothelin-1 level and apoptosis signaling change after LVR. Adult rats were divided into two groups: non-MI group and MI group, and the MI group was subjected to permanent ligation of the left anterior descending artery. Four weeks later, rats in the MI group were subjected to LVR (LVR group) or a sham operation (OMI group). Two weeks after the second operation, echocardiography revealed that LVR improved LV systolic function and remodeling. Upregulation of LV endothein-1 was detected only in the OMI group but not in the non-MI group nor in the LVR group. The percentage of terminal deoxynucleotidyl transfer-mediated end-labeling of fragmented nuclei (TUNEL)-positive cardiac myocytes was significantly higher in the OMI group than in the LVR group or the non-MI group. Western blotting of extracts from the left ventricle showed that bcl-2 and bcl-xL levels were restored and caspase-3 activation was repressed after LVR. Thus, LVR modulates the expression of endothelin-1 and apoptosis signaling in failing hearts. These alterations of signal transduction pathways might contribute to the beneficial effects of LVR on systolic function in heart failure.

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

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

Quantitative FDG-uptake by positron emission tomography in progressive hypertrophy of rat hearts in vivo

BACKGROUND

Quantitative myocardial fluorodeoxyglucose positron emission tomography (FDG-PET) for assessing glucose uptake in vivo is reliable in normal rat heart.

OBJECTIVE

To assess the applicability of myocardial FDG-PET on multiple occasions in the longitudinal disease process of progressive hypertrophy of rat heart.

METHODS

Six salt-sensitive Dahl rats (Dahl-S) developing progressive hypertrophy with subsequent dilated cardiomyopathy were compared with salt-resistant Dahl rats (controls). FDG-PET was applied twice at early stage (ES: 14-18 weeks) and at late stage (LS: 22-26 weeks) of hypertrophy. Standardized uptake value (SUV) was calculated for comparing between different animal weights and different injection dosages of FDG. For validating the quantitative study, radioactivity of a total of 36 tissue samples was compared with the corresponding PET values.

RESULTS

The left ventricular mass in Dahl-S increased by 17% at ES and by 25% at LS. The SUV in Dahl-S was 95% of controls at ES and reduced to 62% at LS (P=0.023). The heart function started to deteriorate after LS. Linear regression analysis showed a good correlation between the radioactivity of tissue samples and PET values (Y=1.20X, P<0.0001, R2=0.979).

CONCLUSIONS

Small animal PET studies on longitudinal multiple occasions in vivo were feasible and useful for the repeating assessment of glucose uptake. The reduction of glucose uptake in progressive hypertrophy of heart over time may precede its progression to heart failure.

Chronic chymase inhibition preserves cardiac function after left ventricular repair in rats

OBJECTIVE

Although left ventricular repair (LVR) has been widely performed, the initial improvement of LV function does not last because of LV remodeling. Recent studies have demonstrated that chymase, a local enzyme in the heart, promotes angiotensin II formation as well as activation of transforming growth factor (TGF)-beta, both of which facilitate myocardial fibrosis. Therefore, chymase blockade may play an important role in the prevention of cardiac remodeling after LVR. In this study, the effects of chronic chymase inhibition (Chy-I) after LVR were evaluated in a rat LV aneurysm model.

METHODS

Rats that developed LV aneurysms 4 weeks after coronary artery ligation underwent LVR by plicating the LV aneurysm, and were randomized into two groups, the LVR group and the LVR + Chy-I group that received an oral chymase inhibitor (10 mg/kg/day) for 4 weeks.

RESULTS

Echocardiography revealed better LV function in the LVR + Chy-I group than in the LVR group at 4 weeks. Four weeks after LVR, LV end-diastolic pressure and the time constant of LV isovolumic pressure decay, were significantly lower in the LVR+Chy-I group. The end-systolic pressure-volume relationship was higher in the LVR+Chy-I group. In the LVR+Chy-I group, mRNA expressions of TGF-beta1 and BNP significantly decreased in the LV myocardium. Histology showed reduced interstitial fibrosis in the LVR+Chy-I group.

CONCLUSIONS

Chronic chymase inhibition prevented myocardial fibrosis and preserved cardiac function after LVR. A chymase inhibition could be an important strategy for management after LV repair surgery.

Aortic valve replacement for aortic regurgitation in a patient with antiphospholipid antibody syndrome

Cardiac manifestations of antiphospholipid antibody syndrome (APLS) comprise a major complication. Herein we report our surgical treatment of aortic regurgitation in a patient with APLS. A 61-year-old woman was referred to our hospital with symptoms of congestive heart failure. Systemic lupus erythematosus had been diagnosed at the age of 36, and immunosuppressive therapy has been continuously performed. APLS was also diagnosed at the age of 55, after which cardiomegaly was noted on chest radiographs and aortic regurgitation was evident on echocardiography. Although immunosuppressive therapy had been continued, cardiac symptoms began to develop. With a presumed diagnosis of valvular disease associated with autoimmune disease, the aortic valve was replaced with a bioprosthesis. Noninfective endocarditis was confirmed in the excised specimen and was likely involved in APLS. The patient was discharged on postoperative day 26 without complications.

A novel approach to restore atrial function after the maze procedure in patients with an enlarged left atrium

OBJECTIVE

Left atrial (LA) volume reduction surgery concomitant with the maze procedure has been reported to facilitate sinus rhythm recovery even in patients with refractory atrial fibrillation (AF) with an enlarged LA. However, it is unknown whether the procedures can also restore effective atrial function of the enlarged LA with over-stretched myocardium.

METHODS

The maze procedures in association with mitral valve surgery were performed to 57 AF patients with an enlarged LA (LA diameter >or=60mm). Among them, 32 patients had concomitant LA volume reduction surgery (VR group). Another 25 patients did not have the volume reduction (control group).

RESULTS

Three months postoperatively LA end-diastolic volume (LAEDV, ml) assessed by magnetic resonance (MR) imaging was larger in the VR group than that in the control group (291+/-117 vs 223+/-81 ml, p<0.05). Postoperatively, sinus rhythm recovery rate was better (84 vs 68%, p<0.05) and LAEDV was drastically smaller (118+/-48 vs 203+/-76 ml, p<0.001) in the VR group than those in the control group. Among the patients with sinus rhythm recovery in both groups, LA contraction ejection fraction (%) improved in the VR group but not in the control group (22.3+/-7.8 vs 10.3+/-4.7%, p<0.001).

CONCLUSIONS

The LA volume reduction surgery concomitant with the maze procedure restored contraction of the enlarged LA; however, the maze procedure alone did not restore LA contraction in spite of successful sinus rhythm recovery. LA volume reduction surgery may be desirable to the patients with refractory AF with over-stretched LA.

Clinical significance of dihydropyrimidine dehydrogenase (DPD), epidermal growth factor receptor (EGFR), and excision repair cross-complementing gene 1 (ERCC1) gene expression of tumor tissue in patients with advanced gastric cancer

4629

Background: Many methods for predicting the susceptibility of a gastric cancer(GC) to chemotherapy have been investigated. However, the clinical significance of biomarkers in GC cells remains unclear. There is a need for exploratory evaluations to understand the clinical implications of biomarkers. Methods: This study consisted of 151 patients (pts) who received chemotherapy for advanced GC. cDNA was derived from the laser-captured tumor cells of cancer specimens obtained by surgical resection or endoscopic biopsy and analyzed to determine mRNA expression relative to an internal reference gene (β-actin) using real-time RT-PCR method. Gene expression levels of thymidylate synthase (TS), DPD, orotate phosphoribosyl transferase, dihydrofolate reductase (DHFR), ERCC-1, EGFR and 22 other biomarkers related to anticancer drug sensitivity were measured. Results: DPD, EGFR, and ERCC1 gene expressions were significantly correlated with survival ( Table ). Multivariate analysis revealed that high DPD (p=0.0002, RR=2.67 [95% CI, 1.62–4.25]), low EGFR (p=0.0005, RR=0.29 [0.18–0.50]), and high ERCC1 (p<0.0001, RR=2.27 [1.45–3.47]) gene expressions were independently related to poor survival. As for first-line chemotherapy, an analysis of 60 pts treated with S-1 showed that low DHFR gene expression significantly correlated with a longer time to progression (TTP) (p=0.0017). An analysis of 54 pts who received cisplatin containing regimens ( + irinotecan or + S-1) as first-line therapy showed that low ERCC1 gene expression was slightly related to a better response (p=0.053). Conclusions: These results indicate that expression of DPD, ERCC1, and EGFR gene expressions in cancer specimens have predictive value for the outcome of advanced GC pts treated with chemotherapy. Low DHFR gene expression could be a predictor of a long TTP in patients receiving S-1 therapy.

[Table: see text]

No significant financial relationships to disclose.