Serum levels of hepatocyte growth factor and epiregulin are associated with the prognosis on anti-EGFR antibody treatment in KRAS wild-type metastatic colorectal cancer

Background:

Ligands of transmembrane receptor tyrosine kinases have important roles in cell proliferation, survival, migration and differentiation in solid tumours. We conducted this study to evaluate the relationship between concentration of serum ligands and prognosis of patients with metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) antibodies.

Methods:

Between August 2008 and August 2011, serum samples were obtained from KRAS wild-type patients who met the inclusion criteria and received an anti-EGFR antibody treatment. Serum concentration of ligands was measured by an enzyme-linked immunosorbent assay, and somatic mutations of KRAS, BRAF, PIK3CA and BRAF were analysed by direct sequencing.

Results:

A total of 103 patients were enrolled in the present study. At the pretreatment serum levels, patients with high levels of hepatocyte growth factor (HGF) had shorter progression-free survival (PFS) and overall survival (OS) compared with those with low levels of HGF (median PFS: 6.4 months vs 4.4 months; P<0.001, median OS: 15.3 months vs 8.0 months; P<0.001, respectively). Patients with high levels of epiregulin (EREG) also had shorter PFS and OS compared with those with low levels of EREG (median PFS: 6.6 months vs 4.9 months; P=0.016, median OS: 13.8 months vs 7.4 months; P=0.048, respectively). In addition, patients whose serum levels of ligands were elevated at progressive disease had shorter PFS and OS compared with other patients.

Conclusions:

Our study indicated that high levels of HGF and EREG were associated with resistance to treatment with anti-EGFR antibodies in KRAS wild-type patients with mCRC. Our findings will contribute to the newly combination therapy on the treatment of anti-EGFR antibodies.

RET-rearranged non-small-cell lung carcinoma: a clinicopathological and molecular analysis

BACKGROUND

To elucidate clinicopathological characteristics of non-small-cell lung carcinoma (NSCLC) cases carrying RET rearrangements causing oncogenic fusions to identify responders to therapy with RET tyrosine kinase inhibitors.

METHODS

We investigated 1874 patients with carcinomas, including 1620 adenocarcinomas (ADCs), 203 squamous cell carcinomas (SCCs), 8 large cell carcinomas, and 43 sarcomatoid carcinomas (SACs). Fluorescence in situ hybridisation (FISH) and/or reverse transcription-PCR (RT-PCR) were performed to detect RET gene rearrangement.

RESULTS

In all, 22 cases (1.2%) showed RET rearrangements; all cases were of ADC histology. Of the 22 patients, 19 possessed KIF5B-RET fusion genes, whereas 3 possessed CCDC6-RET fusion genes. The RET-rearranged tumours were significantly more common in younger patients (P=0.038) and tended to occur in patients with no history of smoking (P=0.051). In addition, RET rearrangements were not associated with gender, occupational history (particularly radioactive exposure), tumour size, lymph node status, tumour stage, or patient survival. The predominant growth pattern in RET-rearranged ADCs was lepidic in 6 cases, papillary in 9 cases, acinar in 2 cases, micropapillary in 1 case, and solid in 4 cases. Cells with cytoplasmic mucin production were at least focally present in 12 of the 22 (54.5%) RET-rearranged ADC cases. Among the 21 analysed RET-rearranged tumours, RET immunopositivity was observed in 15 cases (71.4%), and was significantly associated with RET rearrangement (P<0.001).

CONCLUSIONS

The RET rearrangements were observed in 1.2% of NSCLCs. All cases of RET rearrangement were ADCs. The RET rearrangements were more likely to be observed in younger patients. Although cytoplasmic mucin production was at least focally present in 54.5% of RET-rearranged ADCs, specific histological features were not detected.

RET-rearranged non-small-cell lung carcinoma: a clinicopathological and molecular analysis

Background:

To elucidate clinicopathological characteristics of non-small-cell lung carcinoma (NSCLC) cases carrying RET rearrangements causing oncogenic fusions to identify responders to therapy with RET tyrosine kinase inhibitors.

Methods:

We investigated 1874 patients with carcinomas, including 1620 adenocarcinomas (ADCs), 203 squamous cell carcinomas (SCCs), 8 large cell carcinomas, and 43 sarcomatoid carcinomas (SACs). Fluorescence in situ hybridisation (FISH) and/or reverse transcription–PCR (RT–PCR) were performed to detect RET gene rearrangement.

Results:

In all, 22 cases (1.2%) showed RET rearrangements; all cases were of ADC histology. Of the 22 patients, 19 possessed KIF5B–RET fusion genes, whereas 3 possessed CCDC6–RET fusion genes. The RET-rearranged tumours were significantly more common in younger patients (P=0.038) and tended to occur in patients with no history of smoking (P=0.051). In addition, RET rearrangements were not associated with gender, occupational history (particularly radioactive exposure), tumour size, lymph node status, tumour stage, or patient survival. The predominant growth pattern in RET-rearranged ADCs was lepidic in 6 cases, papillary in 9 cases, acinar in 2 cases, micropapillary in 1 case, and solid in 4 cases. Cells with cytoplasmic mucin production were at least focally present in 12 of the 22 (54.5%) RET-rearranged ADC cases. Among the 21 analysed RET-rearranged tumours, RET immunopositivity was observed in 15 cases (71.4%), and was significantly associated with RET rearrangement (P<0.001).

Conclusions:

The RET rearrangements were observed in 1.2% of NSCLCs. All cases of RET rearrangement were ADCs. The RET rearrangements were more likely to be observed in younger patients. Although cytoplasmic mucin production was at least focally present in 54.5% of RET-rearranged ADCs, specific histological features were not detected.

Visceral fat accumulation is associated with cerebral small vessel disease

BACKGROUND AND PURPOSE

Obesity is associated with the risk of coronary artery disease and stroke. Visceral fat plays a significant role in the atherogenic effects of obesity. Whether visceral fat accumulation, as measured by computed tomography (CT), is an independent risk factor for the presence of cerebral small vessel disease (SVD) was investigated.

METHODS

This study comprised 506 Japanese subjects 35-74 years of age (mean 55.3 years) without a history of symptomatic cerebrovascular disease who underwent health screening tests, including brain magnetic resonance imaging, carotid echography and measurements of the visceral fat area (VFA) and subcutaneous fat area (SFA) on abdominal CT. Visceral fat accumulation was defined as VFA ≥ 100 cm(2) . Logistic regression analysis was performed to examine the associations between visceral fat accumulation and cerebral SVD such as white matter lesions (WMLs) and silent lacunar infarction (SLI).

RESULTS

The prevalence of WMLs and SLI but not carotid plaque were significantly higher in subjects with VFA ≥ 100 cm(2) than those with VFA < 100 cm(2) . A VFA ≥ 100 cm(2) was associated with WMLs and SLI independent of age, cardiovascular risk factors and other measurements of obesity, such as waist circumference and body mass index. A large waist circumference was independently associated with SLI. SFA, the combination of VFA and SFA, and body mass index were not associated with WMLs or SLI.

CONCLUSIONS

Visceral fat accumulation was independently associated with the presence of cerebral SVD in subjects without a history of symptomatic cerebrovascular disease.

Feasibility of endoscopic mucosal resection as salvage treatment for patients with local failure after definitive chemoradiotherapy for stage IB, II, and III esophageal squamous cell cancer

Local failure after definitive chemoradiotherapy (CRT) for stage IB, II, and III esophageal cancer is one of the causes of poor outcome. Endoscopic mucosal resection (EMR) is an effective treatment for superficial esophageal cancer. However, its feasibility as a salvage treatment for local recurrent or residual tumors after definitive CRT for stage IB, II, and III esophageal cancer remains unclear. Between January 2000 and February 2008, 274 patients with stage IB, II, and III esophageal squamous cell cancer excluding T4 received definitive CRT at the National Cancer Center Hospital, Japan. Of these patients, nine patients with local recurrence after achieving complete response and two patients with residual tumor underwent salvage EMR. The technique of salvage EMR involved a strip biopsy method. We retrospectively reviewed the 11 patients (13 lesions). Characteristics of all 11 patients were as follows: median age of 69 (range: 45-78); male/female: 10/1; baseline clinical stage (Union for International Cancer Control 7th) IB/IIA/IIB/III: 1/3/7/0. The depth of resected tumor was limited to the mucosal layer in seven lesions and submucosal in six lesions. En bloc resection was performed on six lesions (46%). The vertical margin was free of cancer cells in 11 lesions (84.6%). No major complications, such as hemorrhage requiring blood transfusion and perforation, were experienced. At a median follow-up period of 38.9 months (range: 5.3-94 months) after salvage EMR, no recurrence was detected in six patients (54%). Local recurrence was detected in five patients (27%). Of these patients, two had lung metastasis simultaneously, and one was also detected lung metastasis 2 months after the detection of local recurrence. The 5-year survival rate after salvage EMR was 41.6%. Salvage EMR is a feasible treatment option for local recurrent or residual lesions after definitive chemotherapy and/or radiotherapy for stage IB, II, and III esophageal squamous cell cancer.

Downregulation of Max dimerization protein 3 is involved in decreased visceral adipose tissue by inhibiting adipocyte differentiation in zebrafish and mice

BACKGROUND

The diet-induced obesity model of zebrafish (DIO-zebrafish) share a common pathophysiological pathway with mammalian obesity.

OBJECTIVES

We aimed to investigate the role of Max dimerization protein 3 (MXD3) in visceral fat accumulation and adipocyte differentiation, by conducting knockdown experiments using zebrafish and mouse preadipocytes.

METHODS

To identify genes related to visceral adiposity, we conducted transcriptome analyses of human and zebrafish obese populations using the Gene Expression Omnibus and DNA microarray. We then intraperitoneally injected morpholino antisense oligonucleotides (MO-mxd3) to knockdown mxd3 gene expression in DIO-zebrafish and measured several parameters, which reflected human obesity and associated metabolic diseases. Finally, lentiviral Mxd3 shRNA knockdown in mouse 3T3-L1 preadipocytes was conducted. Quantitative PCR analyses of several differentiation markers were conducted during these gene knockdown experiments.

RESULTS

We found that MXD3 expression was increased in the obese population in humans and zebrafish. Intraperitoneal MO-mxd3 administration to DIO-zebrafish suppressed the increase in body weight, visceral fat accumulation and the size of mature adipocytes. Subsequently, dyslipidemia and liver steatosis were also ameliorated by MO-mxd3. In mouse adipocytes, Mxd3 expression was drastically increased in the early differentiation stage. Mxd3 shRNA inhibited preadipocyte proliferation and adipocyte maturation. Quantitative PCR analyses showed that the early differentiation marker, CCAAT/enhancer-binding protein delta (Cebpd) and late differentiation markers (CCAAT/enhancer-binding protein, alpha and peroxisome proliferator-activated receptor gamma) were downregulated by Mxd3 knockdown in 3T3-L1 cells and DIO-zebrafish. Subsequently, mature adipocyte markers (adiponectin and caveolin 1 for zebrafish, and fatty acid binding protein 4 and stearoyl-coenzyme A desaturase 1 for mouse adipocytes) were also decreased.

CONCLUSION

Mxd3 regulates preadipocyte proliferation and early adipocyte differentiation via Cebpd downregulation in vitro and in vivo. Integrated analysis of human and zebrafish transcriptomes allows identification of a novel therapeutic target against human obesity and further associated metabolic disease.

Role of aquaporin-5 in gallbladder carcinoma

BACKGROUND/PURPOSE

Aquaporins (AQPs) are important in controlling bile formation. However, the exact role in human gallbladder carcinogenesis has not yet been defined.

METHODS

AQP-5-expressing gallbladder carcinoma (GBC) cell lines (NOZ) were transfected with anti-AQP-5 small interfering RNA (siRNA). Growth, migration, invasion assay, and drug susceptibility tests were performed. Next, microRNA (miRNA) expression was analyzed by miRNA oligo chip (3D-Gene®). AQP-5 and AQP-5-related miRNA target gene expressions were also analyzed using tissue microarray (TMA) in 44 GBC samples.

RESULTS

Treatment with AQP-5 siRNA decreased cell proliferation, migration, and invasion. On the other hand, those cells increased IC50 of gemcitabine. By performing miRNA assays, miR-29b, -200a, and -21 were shown to be highly overexpressed in cells treated with AQP-5 siRNA NOZ. When focusing on miR-21, phosphatase and tensin homolog (PTEN) was found to be a target of miR-21. In the TMA, AQP-5/PTEN coexpression was significantly associated with the depth of invasion and MIB-1 index (p = 0.003, 0.010). Survival of patients with a high AQP-5/PTEN coexpression was longer than that of patients with a low coexpression (p = 0.003).

CONCLUSIONS

Our result suggested that miR-21 and PTEN may contribute to the role of AQP-5 in GBC. AQP-5 and PTEN cascades are favorable biomarkers of GBC.

Bacterial loads of Ureaplasma urealyticum contribute to development of urethritis in men

Ureaplasma urealyticum could be a pathogen of non-gonococcal urethritis (NGU) in men. However, ureaplasma is often detected in men without NGU, and the proportion of cases possibly attributable to this pathogen is still undefined. We attempted to determine the bacterial loads of U. urealyticum significantly associated with NGU. The 16S rRNA genes of U. urealyticum were quantified by a real-time polymerase chain reaction-based assay in first-void urine (FVU) from 26 asymptomatic and 25 symptomatic men positive for U. urealyticum. The leucocyte counts in first-void urine (FVU) were determined as an objective measure of inflammatory response to ureaplasma in the hosts by automated quantitative urine particle analysis. Positive correlations were observed between copies of the 16S rRNA genes of U. urealyticum per ml and the leucocyte counts per µl in FVU (r = 0.49, p = 0.0003). Loads of ≥10(4) copies of the 16S rRNA gene of U. urealyticum/ml, corresponding to ≥5 × 10(3) cells of U. urealyticum/ml in FVU, were significantly associated with the presence of urethritis symptoms (p < 0.0001) and with higher leukocyte counts in FVU (p < 0.0001). The bacterial load of U. urealyticum, possibly of ≥5 × 10(3) cells of U. urealyticum/ml in FVU, could be significantly associated with the development of symptomatic NGU.

Progesterone stimulates proliferation of a long-lived epithelial cell population in rat mammary gland

BACKGROUND

Long-lived somatic cells such as stem/progenitor cells may progressively accumulate oncogenic mutations and cause cancer. Some evidence suggests that pre-menopausal administration of progesterone confers a long-term increased risk of breast cancer.

AIM

To clarify the effect of progesterone on long-lived mammary epithelial cells in rats.

MATERIALS AND METHODS

Female Sprague- Dawley rats (3 and 7 weeks of age) were implanted sc with 14-day slow-release pellets of 5-bromo-2'-deoxyuridine (BrdU) and were sacrificed every 2 weeks between 0 and 10 weeks after the release period. Some rats at 7 weeks of age were also implanted with progesterone and sacrificed 0 or 10 weeks after the release period. Mammary glands were examined by immunohistochemistry and immunofluorescence for BrdU, proliferative cell nuclear antigen (PCNA) and progesterone receptor (PR).

RESULTS

After BrdU labeling of 3- and 7-week-old rats, the BrdU index decreased gradually over 10 weeks and resulted in small fractions (1-3%) of label-retaining epithelial cells (LREC) 10 weeks after BrdU labeling in both mammary lobules and ducts. Treatment with progesterone during labeling significantly increased the fraction of long-lived LREC in lobules and ducts by 9- and 4-fold, respectively. The long-lived LREC population in the ducts was enriched for PCNA- and PR-positive cells, but the percentage of positive cells was not affected by progesterone in either lobules or ducts.

CONCLUSIONS

Progesterone stimulates proliferation of a long-lived epithelial cell population in the mammary lobules and ducts of rats. Such cells in the duct are characterized by a high proliferation rate and PR expression.

Association of spinal curve deformity and back extensor strength in elderly women with osteoporosis in Japan and the United States

The difference in the shape of sagittal spinal curvature and distribution of vertebral fractures in women of comparable age with osteoporosis from Japan and the United States with different cultures and lifestyles was identified. Back extensor strength was significantly associated with lumbar lordosis in Akita group, indicating the potential importance of strengthening the back extensor.

INTRODUCTION

The purpose of the study was to assess the association of osteoporotic spinal deformities with back strength in elderly women in Japan and the United States.

METHODS

Subjects diagnosed with osteoporosis were selected to participate prospectively. In both groups, we measured the angles of thoracic kyphosis and lumbar lordosis with plain lateral radiographs and back extensor strength. The number of vertebral fractures and the ratio of lumbar fractures to thoracic fractures are also evaluated. The level of participants' daily activities was assessed with use of comparable tests in Akita (quality-of-life score) and Minnesota (physical activity score).

RESULTS

A total of 102 Japanese women residing in Akita, Japan (Akita group), and 104 white women evaluated in Rochester, MN, USA (Minnesota group), participated in this study. The angle of thoracic kyphosis and lumbar lordosis was higher in the Minnesota group than in the Akita group. The ratio of lumbar fractures to thoracic fractures was higher in the Akita group than in the Minnesota group. In the Akita group, multiple regression analysis revealed that the angle of lumbar lordosis correlated significantly with back extensor strength.

CONCLUSIONS

We identified the difference in the shape of sagittal spinal curvature and distribution of vertebral fractures in women of comparable age with osteoporosis from two geographic areas of the world with different cultures and lifestyles. Back extensor strength was significantly associated with lumbar lordosis in Akita group, indicating the potential importance of strengthening the back extensor for improving or maintaining lumbar lordosis.

Comparison of chemotherapeutic treatment outcomes of advanced extrapulmonary neuroendocrine carcinomas and advanced small-cell lung carcinoma

BACKGROUND

The chemotherapy for small-cell lung carcinoma (SCLC) has been adopted for advanced extrapulmonary neuroendocrine carcinomas (EP-NECs). The aim of this study was to clarify the efficacy of standard SCLC regimens when used to treat EP-NECs and to compare the outcome with that for SCLC.

METHODS

We reviewed the medical records of 136 patients (41 with EP-NEC and 95 with SCLC) who were treated using a platinum-containing regimen for advanced disease between January 2000 and October 2008 at our hospital.

RESULTS

The primary site of the EP-NEC was the gastrointestinal tract in 18 patients (GI tract group); the liver, biliary tract or pancreas in 16 patients (HBP group), and other sites in 7 patients ('others' group). The response rate in the SCLC patients was 77.8%, and the response rate in the EP-NEC patients was 30.8% (37.5% in the GI tract group, 12.5% in the HBP group, and 57.1% in the 'others' group). The median survival time for the SCLC patients was 13.6 months, while that for the EP-NEC patients was 9.2 months (14.9 months in the GI tract group, 7.8 months in the HBP group, and 8.9 months in the 'others' group). A multivariate analysis demonstrated that a poor performance status, liver involvement, and the treatment regimen were independent unfavorable prognostic factors.

CONCLUSION

The response rate and prognosis of the patients with advanced EP-NECs were worse than those of the patients with SCLC in this study. The Eastern Cooperative Oncology Group performance status, liver involvement, and treatment regimen had a larger impact on the prognosis than the primary tumor site, as demonstrated by multivariate analysis.

Combined Treatment of Alendronate and Low-Intensity Pulsed Ultrasound (LIPUS) Increases Bone Mineral Density at the Cancellous Bone Osteotomy Site in Aged Rats: A Preliminary Study

Introduction: During fracture healing, alendronate encourages callus volume by inhibiting bone resorption, whereas low-intensity pulsed ultrasound (LIPUS) enhances bone regeneration by promoting an anabolic response. Methods: In the present study, 9-month-old Sprague-Dawley rats, with a unilateral proximal tibial osteotomy, were treated with alendronate (daily, 1 g/kg) plus sham-LIPUS (n = 14), saline plus LIPUS (20 min/day) (n = 18), alendronate plus LIPUS (n = 16), or saline plus sham- LIPUS as a control (n = 13) for 4 weeks. The rats were then examined for changes in bone mineral density (BMD) during metaphyseal bone repair. Results: The combined therapy signi cantly increased BMD at the osteotomy site at 4 weeks (p < 0.001) compared with the control, without affecting the contralateral, non-osteotomized tibia. Both alendronate and LIPUS alone also exerted a positive, albeit less, effect on BMD in the affected limb (p < 0.001 and p = 0.006, respectively). Conclusions: Alendronate and LIPUS cooperate to enhance BMD during metaphyseal bone healing. Keywords: LIPUS, bisphosphonate, bone mineral density.

Effect of annealing on magnetic properties of Ni80Fe20 permalloy nanoparticles prepared by polyol method

Ni80Fe20 permalloy nanoparticles with narrow size distribution and homogeneous composition have been prepared by the polyol processing at 180 degrees C for 2 h and their particle sizes can be tunable in the size range of 20-440 nm by proper addition of K2PtCI4 agent. X-ray diffraction results show that the NiFe nanoparticles are of face centered cubic structure. The addition of K2PtCl4 does not affect the composition of NiFe NPs but decreases the particle size remarkably. Both saturation magnetization and coercivity of the as-prepared NiFe nanoparticles decrease with decreasing particle size. Annealed at 280 degrees C, however, the saturation magnetization of various sized NiFe nanoparticles increases drastically and approaches to the bulk for the -440 nm NiFe particles, and a maximum coercivity (-270 Oe) happens at a critical size of -50 nm. The magnetic property dependency of these NiFe nanoparticles on annealing has been discussed by considering the surface chemistry.

Combined treatment of alendronate and low-intensity pulsed ultrasound (LIPUS) increases bone mineral density at the cancellous bone osteotomy site in aged rats: a preliminary study

INTRODUCTION

During fracture healing, alendronate encourages callus volume by inhibiting bone resorption, whereas low-intensity pulsed ultrasound (LIPUS) enhances bone regeneration by promoting an anabolic response.

METHODS

In the present study, 9-month-old Sprague-Dawley rats, with a unilateral proximal tibial osteotomy, were treated with alendronate (daily, 1 µg/kg) plus sham-LIPUS (n = 14), saline plus LIPUS (20 min/day) (n = 18), alendronate plus LIPUS (n = 16), or saline plus sham-LIPUS as a control (n = 13) for 4 weeks. The rats were then examined for changes in bone mineral density (BMD) during metaphyseal bone repair.

RESULTS

The combined therapy significantly increased BMD at the osteotomy site at 4 weeks (p < 0.001) compared with the control, without affecting the contralateral, non-osteotomized tibia. Both alendronate and LIPUS alone also exerted a positive, albeit less, effect on BMD in the affected limb (p < 0.001 and p = 0.006, respectively).

CONCLUSION

Alendronate and LIPUS cooperate to enhance BMD during metaphyseal bone healing.

Bioassisted capture and release of nanoparticles on nanolithographed ZnO films

Using an artificial peptide library, we have identified a peptide that has strict selective affinity for ZnO surfaces. The binding affinity of the peptide on the ZnO surface can be controlled simply through changes in phosphate concentration at constant pH and temperature. In this study, we functionalized inorganic nanoparticles by orderly conjugating ZnO-binding peptides (ZnOBPs) on the surface of cadmium selenide (CdSe) nanoparticles and performed spontaneous and reversible nanopatterning of ZnOBP-displayed nanoparticles on lithographed ZnO films. Conjugation of ZnOBPs on CdSe nanoparticles caused spontaneous adsorption of the nanoparticles on a ZnO film, and fluorescence and cathodoluminescence images clearly showed specific adsorption of nanoparticles on the ZnO films lithographed on nano- and micrometer scales. The selectively bound nanoparticles on ZnO films were completely released by changing the phosphate concentration in solution; such release did not require heat or mechanical applications. Repeated capture and release of nanoparticles were achieved on the micrometer scale. Our results show the potential of material-binding peptides for nanopatterning and dynamic microarrays.

Oral administration of recombinant human acid α-glucosidase reduces specific antibody formation against enzyme in mouse

Animal and human studies of enzyme replacement therapy for Pompe disease have indicated that antibodies generated against the infused recombinant human acid α-glucosidase (rhGAA) can negatively impact therapeutic outcome. In this study, we show that oral administration of rhGAA into mice can reduce the titer of anti-rhGAA antibody following immunization with rhGAA. Oral administration of rhGAA is safe and antigen specific, it offers advantages over other immunosuppressive drugs.

Extrapulmonary neuroendocrine tumors: An institutional experience of 337 patients at the National Cancer Center Hospital in Japan

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Background: Extrapulmonary neuroendocrine tumors (EPNET) are a rare and heterogeneous disease entity, and little information regarding these tumors is available. The aim of the present study was to clarify the clinical behavior, treatment strategy, and outcome of EPNET arising from various primary sites.

Methods: We retrospectively reviewed the medical records of 337 patients with pathologically confirmed NET arising from extrapulmonary site between January 2000 and December 2008 at the National Cancer Center Hospital of Japan.

Results: The major primary tumor site was the rectum followed by the pancreas and stomach. Among the gastrointestinal tract tumors, 113 patients had NET from the foregut, 92 patients from the hindgut, and only 4 patients from the midgut. The median patient age was 60 years, and 57% of the patients were male. The histologic grade was as follows: 39% were well-differentiated neuroendocrine tumors (WDNET); 20% were well-differentiated neuroendcrine carcinomas (WDNEC); 33% were poorly differentiated neuroendocrine carcinomas (PDNEC); and 8% were mixed exocrine-endocrine tumors (Mixed). Most NETs from the rectum or duodenum are WDNET, whereas the ratio of PDNEC was high among NET from the genital organs or esophagus. The treatment strategy was associated with the clinical stage or the primary organ; in particular, 94% of the localized rectal NET were resected endoscopically. The 2-year survival rate for all the patients were 70%. A multivariate analysis demonstrated that distant disease of clinical stage and PDNEC of histological grade had a stronger impact on a poor outcome than the primary tumor site. The 2-year survival rate among the patients with WDNET, WDNEC and PDNEC were 97%, 80% and 36%, respectively, and 94%, 72%, and 32% of the patients had localized, regional, and distant disease, respectively.

Conclusions: Japanese patients with EPNET have different clinicopathological features such as the primary organ or treatment procedure compared with previous reports in Western countries. Identifying the precise clinical stage and histological grade of patients with NET is essential because these factors influence the patient outcome.

No significant financial relationships to disclose.