Differences in femoral neck geometry associated with age and ethnicity

SUMMARY

We studied femoral geometry in relation to age and ethnicity in a cross-sectional study. Age-associated cortical thinning showed the most pronounced effect, and Koreans studied here had thicker cortices and lower buckling ratios than those reported for other races. Cortical thickness may thus be a major determinant of hip fracture risk.

INTRODUCTION

The rate of hip fracture varies by age and ethnicity. The geometric properties of the femur influence femoral strength and fragility, but differences in femoral geometry according to age and ethnicity are poorly understood. To explain the high prevalence of hip fractures in the elderly and the relatively low hip fracture rate in Asian populations, we studied age-related changes and ethnic differences in femoral geometry.

METHODS

We recruited 214 peri- or postmenopausal women aged 46 to 85 years (mean age, 60.6 years). Their proximal femoral bone mineral densities (BMD) were measured by quantitative computed tomography and further analyzed geometric properties.

RESULTS

We observed large declines in trabecular volumetric bone mineral density associated with aging (33.03% less than the reference value in the oldest group, respectively). Cortical thickness decreased remarkably with age as well, and only 53.94% of the baseline value remained in the oldest group. As a result, the cortical buckling ratio increased geometrically and reached 239.14% of the reference value in the oldest group. In comparisons with other ethnic groups, Korean subjects had thicker cortices than their American, European, and African counterparts.

CONCLUSIONS

In this cross-sectional study, cortical thickness showed a pronounced age-associated decrease, and the cortical buckling ratio showed a strong age-associated increase. This may in part explain the higher rates of hip fractures in the elderly. When compared with other races, Asians had thicker cortical bone and lower buckling ratios, which may partially explain the lower prevalence of hip fractures in Asians.

Comparison of open and laparoscopic live donor left lateral sectionectomy

BACKGROUND

The present study was undertaken to determine whether laparoscopic live donor left lateral sectionectomy (LLS) in paediatric liver transplantation is a feasible, safe and reproducible procedure, compared with open live donor left lateral sectionectomy (OLS).

METHODS

A retrospective review was conducted of all consecutive live donor procedures for paediatric liver transplantation performed between May 2008 and October 2009. All live donor hepatectomies were carried out by a single surgeon.

RESULTS

A total of 26 live donor procedures for paediatric liver transplantation were performed, of which 11 were LLS and 11 OLS; four left hepatectomies were excluded. The LLS group had a significantly shorter hospital stay (mean(s.d.) 6·9(0·3) versus 9·8(0·9) days; P = 0·001) and time to oral diet (2·1(0·3) versus 2·7(0·4) days; P = 0·012). Duration of operation, blood loss, warm ischaemia time and out-of-pocket medical costs were comparable between groups. There was no death in either donor group and only one complication, a wound seroma, in the OLS group.

CONCLUSION

LLS seemed to be a safe, feasible and reproducible procedure, and was associated with reduced hospital stay.

Pathology of epstein-barr virus-associated gastric carcinoma and its relationship to prognosis

Among Epstein-Barr virus (EBV)-associated neoplasms, EBV-associated gastric carcinoma (EBVaGC) is the most common tumor worldwide. In contrast to the predominant site of occurrence of EBV-negative gastric carcinoma in the antrum, EBVaGC occurs most frequently in the proximal stomach, including the cardia, fundus and body. Microscopically, EBVaGC can be subclassified into three histological subtypes according to the host cellular immune responses: lymphoepithelioma-like carcinoma, carcinoma with Crohn's disease-like lymphoid reaction, and conventional-type adenocarcinoma. Recent studies have shown that patients with the lymphoepithelioma-like carcinoma subtype of EBVaGC have the best overall and disease-free survival, followed by Crohn's disease-like reactions, which in turn have better survival than patients with conventional-type adenocarcinoma. Histologic subclassifications of EBVaGCs are based on the differing degree and pattern of infl ammatory response and the extent of desmoplasia. Because these subclassifications appear to be a powerful prognostic parameter, further research into the underlying mechanisms of the cellular immune reaction in these pathologic subtypes of EBVaGCs may play a key role in understanding the innate immune response of patients with this highly aggressive carcinoma.

DOG1 and PKC-θ are useful in the diagnosis of KIT-negative gastrointestinal stromal tumors

Pathological diagnosis of gastrointestinal stromal tumors (GISTs) is based on histological findings and immunohistochemical demonstration of the KIT protein. KIT-negative GISTs account for ∼5% of cases and cause diagnostic difficulties. In the era of imatinib therapy, a correct diagnosis of GISTs is important for therapeutic reasons regardless of KIT expression. Recently, DOG1 has been introduced as an important diagnostic marker with high sensitivity and specificity. In this study, immunohistochemical staining for DOG1 and protein kinase C-θ (PKC-θ) in whole tissue sections, and mutation analyses for KIT and PDGFRA were performed in 26 KIT-negative GISTs. Tissue microarrays of 112 KIT-positive GISTs were used as controls. Overall, 25 KIT-negative GISTs were located in the stomach, and 1 in the rectum. The histological subtype was spindle in 12, epithelioid in 11, and mixed in 3 cases. The expression of DOG1 and PKC-θ was positive in 24 (92%) and in 25 cases (96%), respectively. All 26 KIT-negative GISTs expressed either DOG1 or PKC-θ, and 23 cases (89%) were positive for both makers. PKC-θ was positive in two cases (8%), which lacked both KIT and DOG1 expressions. Mutation analysis showed PDGFRA exon 18 mutation in 15 cases (58%) and KIT exon 11 mutation in 1 case (4%), whereas the remaining 10 cases (39%) were wild type for both KIT and PDGFRA. The expression of DOG1 and PKC-θ showed no significant difference in KIT-negative and KIT-positive GISTs (P=1.000 and P=0.167, respectively). Our findings suggest that both DOG1 and PKC-θ can be used in the diagnosis of KIT-negative GISTs and they show positive staining even in KIT-negative tumors, which are wild type for KIT and PDGFRA on mutation analysis.

Phase I trial of capecitabine plus everolimus (RAD001) in patients with previously treated metastatic gastric cancer

Purpose

Everolimus is a novel inhibitor of the mammalian target of rapamycin pathway, which is aberrantly activated in cancer cell. We conducted a phase I study of capecitabine plus everolimus (RAD001) in refractory gastric cancer patients.

Methods

Patients with metastatic gastric cancer and progression after prior chemotherapy were eligible. Four dose levels were planned as follows: Level 1, 5 mg bid/day of everolimus (D1-D21) and 500 mg/m² bid/day of capecitabine (D1-14); Level 2, 5 mg bid/day of everolimus (D1-D21) and 750 mg/m² bid/day of capecitabine (D1-14); Level 3, 5 mg bid/day of everolimus (D1-D21) and 1000 mg/m² bid/day of capecitabine (D1-14); and Level 4, 10 mg bid/day of everolimus (D1-D21) and 1000 mg/m² bid/day of capecitabine (D1-14). Treatment was repeated every 3 weeks until disease progression, patient refusal, or any serious adverse event.

Results

Fifteen patients were enrolled in this study between November 2009 and April 2010. Fifteen patients were enrolled (median age, 50 years; men, 9). Six patients had received two previous chemotherapy regimens; six patients had three previous chemotherapy regimens before the study treatment. Thus, the majority of patients were heavily pretreated. The dose-limiting toxicities were grade 3 infection, grade 3 mucositis, and grade 3 hyperglycemia and hyponatremia. After a median follow-up duration of 5.6 months (range, 2.3–8.1 months), median PFS was 1.8 months (95% CI, 0.8–2.8 months). The maximum best change observed was a 28.7% decrease in sum of longest diameters when compared with baseline.

Conclusions

The combination of capecitabine and everolimus showed satisfactory toxicity profile and modest clinical benefit in patients with refractory gastric cancer. The recommended dose of capecitabine and everolimus was 650 mg/m² twice daily and 5 mg twice daily, respectively.

KIT amplification and gene mutations in acral/mucosal melanoma in Korea

Mucosal and acral melanomas have demonstrated different genetic alterations and biological behavior compared with more common cutaneous melanomas. It was recently reported that gain-of-function KIT mutations and/or copy number increases are more common in mucosal and acral melanomas. Thus, we studied the frequency and pattern of KIT aberrations in mucosal and acral melanomas in Korea. We analyzed 97 patients who were pathologically confirmed with mucosal or acral melanoma between 1997 and 2010 at Samsung Medical Center. Of the 97 melanoma patients, 92 were screened for mutations in KIT exons 11, 13, 17, and 18, BRAF and NRAS genes. KIT copy number was assessed by quantitative, real-time PCR. Of the 97 patients, 55 (56.7%) were mucosal, 40 (41.2%) were acral melanoma, and two were of unknown primary origin. Among seven cases with KIT mutation, five (60.0%) occurred in exon 11, one (20.0%) in exon 17, and one (20.0%) in exon 13. Point mutations were the most common, resulting in substitutions in exon 11 (K558R, T574A, L576P, and V559A), exon 13 (N655K), and exon 17 (N822K). A novel Thr574Ala (c.1720A>G) KIT mutation, which has not been reported in melanoma or other tumor types, was identified in one genital melanoma case. Of the 97 mucosal or acral melanoma specimens, 49 were tested for KIT gene copy number changes using quantitative PCR. Increased KIT copy number was identified in 15 patients: seven (40%) of 20 acral melanomas and eight (31%) of 26 mucosal melanomas. Our study implicates that a significant proportion of acral and mucosal melanomas have KIT mutations in Asian population.

Impact of MET amplification on gastric cancer: possible roles as a novel prognostic marker and a potential therapeutic target

Identification of critical genes which play pivotal roles in controlling tumor growth and survival will establish the basis for developing therapeutic targets. With the aim of establishing personalized medicine for treatment of solid tumors, we focused on MET amplification in gastric cancer patients, given the extreme sensitivity to c-Met inhibitor in MET amplified gastric cancer cell lines. We tested MET amplification and activation of c-Met in various gastric cancer cell lines and tissue samples from 482 gastric cancer patients who underwent curative surgery. Gastric cancer cell lines with MET amplification by quantitative real-time PCR (qPCR) and FISH predicted sensitivity to PHA-665,752, a selective c-Met kinase inhibitor. Of the 472 patients who had DNA sample available for qPCR analysis, 100 patients (21.2%) had a MET copy number greater than 4.0 copies and demonstrated poorer survival following curative surgery with statistical significance (5-year OS; 50.0 vs. 59.1%; MET amplification (+) vs. MET amplification (-); P = 0.0134). These results suggest that the increased MET copy number measured by qPCR plays an important role in determining prognosis in gastric cancer patients. However, the predictive role of MET amplification for treatment response should be further explored in upcoming clinical trials.

Hyperuricemia in kidney transplant recipients with intact graft function

OBJECTIVES

The aim of this study was to investigate the prevalence of hyperuricemia and factors predicting its occurrence, and to establish the relationship over time between serial changes in estimated glomerular filtration rate (eGFR) and uric acid (UR) concentration in kidney transplant (KT) recipients with eGFR >60 mL/min/1.73 m(2).

METHODS

Adult patients who underwent KT at the Asan Medical Center between 1990 and 2008 and maintained eGFR >60 mL/min/1.73 m(2) were retrospectively assessed. Clinical and laboratory data were obtained from inpatient and outpatient charts and from the hospital electronic database.

RESULTS

Of 356 patients, 301 (84.55%) had normal UR levels and 55 (15.45%) had hyperuricemia. After multivariate adjustment, transplant duration, male gender, eGFR, diabetes mellitus (DM), and calcium level were associated with higher mean UR levels. Mean UR level increased significantly and mean eGFR decreased significantly during the first year after transplantation, but there were no significant differences over the next 4 years. Serial UR and eGFR levels changed almost simultaneously.

CONCLUSIONS

Transplantation duration, male gender, eGFR level, DM, and serum calcium level were risk factors for hyperuricemia in kidney recipients with intact graft function. Increased uric acid after KT did not significantly affect graft function.

Significance of smoking history and FDG uptake for pathological N2 staging in clinical N2-negative non-small-cell lung cancer

BACKGROUND

This study was conducted to evaluate whether smoking history and the standardized uptake value (SUV) of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) uptake are associated with unexpected pathological N2 status (pN2) in non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

We analyzed the data of 220 patients who underwent surgical resection with clinical N2-negative status on computed tomography (CT) and positron emission tomography (PET)-CT. The maximum SUV of primary tumor was chosen for logistic analysis.

RESULTS

Seventy-two patients (33%) had never smoked. The SUV ranged from 1.0 to 29.0 (median 9.1). In univariate analysis, adenocarcinomas (P = 0.019), female gender (P = 0.010), N1 on CT (P = 0.025), and N1 PET-CT (P = 0.001) were associated with a high probability of pN2. The proportion of pN2 in never smokers was higher than in ever smokers (26% versus 10% respectively; P = 0.002). The SUV remained on a multivariate logistic model (odds ratio 1.1; 95% confidence interval 1.0-1.2; P = 0.010) and it had a better predictive value in never smokers than in ever smokers (P = 0.017).

CONCLUSIONS

This study indicates an association between smoking history and pN2 in clinically negative N2 NSCLC. The different roles of FDG uptake were also suggested based on smoking history.

Endoscopic and histopathological characteristics suggesting the presence of gastric mucosal high grade neoplasia foci in cases initially diagnosed as gastric mucosal low grade neoplasia by forceps biopsy in Korea

BACKGROUND

As biopsy sites may miss coexisting gastric mucosal high grade neoplasia (HGN) foci, making a diagnosis of gastric mucosal low grade neoplasia (LGN) based only on forceps biopsy specimens can be inaccurate. Therefore, to achieve an accurate diagnosis, endoscopic mucosal resection (EMR) of the entire lesion is required. However, EMR can cause serious complications such as perforation or bleeding. Considering these points, it is necessary to identify the characteristics suggesting coexisting HGN foci in cases initially diagnosed as LGN by forceps biopsy.

METHODS

Three hundred and five lesions from 282 consecutive patients were initially diagnosed as LGN by forceps biopsy and later resected using EMR. The still photographs from endoscopies and pathology slides of these lesions were reviewed.

RESULTS

After EMR, 272 lesions (89.2%) were finally diagnosed as LGN and 33 lesions (10.8%) were diagnosed as having HGN foci, including 1 intramucosal carcinoma. Univariate analysis showed that lesions >1.0 cm on endoscopy and lesions with tubulovillous or villous histology on forceps biopsy specimens were significantly more frequently found in cases with HGN than in LGN cases. Multivariate analysis demonstrated that lesion size >1.0 cm on endoscopy and findings of tubulovillous or villous histology on forceps biopsy specimens were independent risk factors for coexisting HGN foci in cases initially diagnosed as LGN by forceps biopsy.

CONCLUSIONS

If the lesions diagnosed as LGN by forceps biopsy are >1.0 cm on endoscopy or show tubulovillous or villous histology, EMR might be considered to avoid the risk of missing HGN foci.

Genotypes of NK cell KIR receptors, their ligands, and Fcγ receptors in the response of neuroblastoma patients to Hu14.18-IL2 immunotherapy

Response to immunocytokine (IC) therapy is dependent on natural killer cells in murine neuroblastoma (NBL) models. Furthermore, killer immunoglobulin-like receptor (KIR)/KIR-ligand mismatch is associated with improved outcome to autologous stem cell transplant for NBL. Additionally, clinical antitumor response to monoclonal antibodies has been associated with specific polymorphic-FcγR alleles. Relapsed/refractory NBL patients received the hu14.18-IL2 IC (humanized anti-GD2 monoclonal antibody linked to human IL2) in a Children's Oncology Group phase II trial. In this report, these patients were genotyped for KIR, HLA, and FcR alleles to determine whether KIR receptor-ligand mismatch or specific FcγR alleles were associated with antitumor response. DNA samples were available for 38 of 39 patients enrolled: 24 were found to have autologous KIR/KIR-ligand mismatch; 14 were matched. Of the 24 mismatched patients, 7 experienced either complete response or improvement of their disease after IC therapy. There was no response or comparable improvement of disease in patients who were matched. Thus KIR/KIR-ligand mismatch was associated with response/improvement to IC (P = 0.03). There was a trend toward patients with the FcγR2A 131-H/H genotype showing a higher response rate than other FcγR2A genotypes (P = 0.06). These analyses indicate that response or improvement of relapsed/refractory NBL patients after IC treatment is associated with autologous KIR/KIR-ligand mismatch, consistent with a role for natural killer cells in this clinical response.

Expression of HSP90 in gastrointestinal stromal tumours and mesenchymal tumours

AIMS

Heat shock proteins (HSP) are up-regulated under conditions of increased stress, including cancer. Recently, HSP90 has been shown to be crucial to the expression and activation of the KIT oncoprotein. The aim was to explore the role of HSP90 expression as a prognostic marker and therapeutic target in gastrointestinal stromal tumours (GISTs) and other mesenchymal tumours.

METHODS AND RESULTS

The expression of HSP90 was evaluated by immunohistochemistry in 92 GISTs, 47 mesenteric fibromatoses, six schwannomas, leiomyomas, melanomas, malignant peripheral nerve sheath tumours and leiomyosarcomas. Western blotting was performed in 22 selected cases. HSP90 overexpression was found in 33.7% of GISTs and was correlated with non-gastric location, mixed histological subtype, high mitotic index, high risk grades, and specific mutation genotypes. In mesenchymal tumours, HSP90 overexpression was found in 66.7% of malignant peripheral nerve sheath tumours, 83.3% of leiomyosarcomas, and 100% of melanomas. HSP90 expression by Western blotting correlated with the results of immunohistochemistry. The Cox proportional hazards model showed that HSP90 expression is an independent predictor of recurrence in GISTs (P = 0.003).

CONCLUSIONS

Overexpression of HSP90 is predictive of adverse behaviour in GISTs and may provide a therapeutic solution to the challenge of imatinib-resistant GISTs and other mesenchymal sarcomas.

Clinical practice guideline for accurate diagnosis and effective treatment of gastrointestinal stromal tumor in Korea

Despite the rarity in incidence and prevalence, gastrointestinal stromal tumor (GIST) has emerged as a distinct pathogenetic entity. And the clinical management of GIST has been evolving very rapidly due to the recent recognition of its oncogenic signal transduction pathway and the introduction of new molecular-targeted therapy. Successful management of GIST requires a multidisciplinary approach firmly based on accurate histopathologic diagnosis. However, there was no standardized guideline for the management of Korean GIST patients. In 2007, the Korean GIST study group (KGSG) published the first guideline for optimal diagnosis and treatment of GIST in Korea. As the second version of the guideline, we herein have updated recent clinical recommendations and reflected changes in diagnosis, surgical and medical treatments for more optimal clinical practice for GIST in Korea. We hope the guideline can be of help in enhancing the quality of diagnosis by members of the Korean associate of physicians involving in GIST patients's care and subsequently in achieving optimal efficacy of treatment.

Mucinous gastric cancer presents with more advanced tumor stage and weaker β-catenin expression than nonmucinous cancer

BACKGROUND

Mucinous gastric carcinoma (MGC) is a rare type of gastric cancer; its biological behavior is controversial. In this study, we attempted to clarify the clinical and pathological features as well as the prognostic significance of MGC. We also compared the expression patterns of CDX-2 and β-catenin between MGC and nonmucinous gastric carcinoma (NMGC).

METHODS

We reviewed the records of 9218 patients with gastric cancer who underwent gastric cancer surgery between January 1997 and December 2006. The clinicopathological features and clinical outcome of MGC (n = 197) were compared to NMGC (n = 9021). Immunohistochemical staining using the tissue array method was performed on MGC (n = 194) and NMGC (n = 89) tissues.

RESULTS

MGC had a larger size and a higher frequency of Borrmann type I findings in advanced cases than NMGC. In addition, MGC had deeper invasion, more lymph node and lymphatic involvement, a more advanced tumor stage, and lower 5-year survival rates than NMGC. Age, depth of invasion, lymph node metastasis, lymphatic invasion, and curability were independent prognostic factors; but the mucinous histological type itself was not predictive of outcome. β-Catenin immunoreactivity was statistically significantly weaker in MGC than NMGC; however, there was no difference in CDX-2 expression between the two groups.

CONCLUSIONS

MGC presents at a more advanced stage and was larger than NMGC. The poor prognosis of MGC was related to the more advanced tumor stage at diagnosis; the histological type was not an independent prognostic factor. The result of immunohistochemical staining suggests that MGC has a distinct pathway of carcinogenesis from NMGC.

Host inflammatory response predicts survival of patients with Epstein-Barr virus-associated gastric carcinoma

BACKGROUND & AIMS

Lymphoepithelioma-like carcinoma (LELC) is a rare subtype of gastric carcinoma (GC) with a better survival rate than other GCs; most cases of LELC are associated with Epstein-Barr virus (EBV) infection. We investigated whether the survival advantage of LELC is related to the EBV infection itself or to associated inflammatory immune responses.

METHODS

From 1994 to 2008, 123 EBV-associated GCs were identified and compared with 405 EBV-negative GCs. EBV-associated GCs were subclassified, based on the pattern of host inflammatory immune responses, into 3 histologic subtypes: typical LELC (n = 53, 43.1%), Crohn's disease-like lymphocytic reaction (CLR) (n = 52, 42.3%), and conventional adenocarcinoma (n = 18, 14.6%). Patients with curatively resected EBV-negative GC were controls. Univariate and multivariate analyses were used, with Bonferroni correction.

RESULTS

Patients with EBV-associated GC had tumors of proximal location, lower N stage (P < .0001), and lower T stage (P = .02) and were older than controls (P = .0003). Upon univariate analysis, patients with EBV-associated GC had longer survival times than controls (P < .004); this difference was not significant in a multivariate analysis with Cox proportional hazards. Stratification of EBV-associated GCs by host cellular immune responses showed that patients with LELC and LELC+CLR have significantly longer overall survival time (hazard ratio, 0.09 and 0.42, respectively) and disease-free survival (hazard ratio, 0.05 and 0.46, respectively; P < .02).

CONCLUSIONS

Prognosis of EBV-associated GCs depends on the patient's inflammatory response. The definition of LELC should be expanded to include EBV-associated GCs with CLR because these have a prognosis similar to LELC.

Predictive value of the ERCC1 expression for treatment response and survival in advanced gastric cancer patients receiving cisplatin-based first-line chemotherapy

PURPOSE

The aim of this study was to determine whether the ERCC1 expression is effective to predict the clinical outcomes of patients with advanced gastric cancer (AGC) and who were treated with cisplatin-based first-line chemotherapy.

MATERIALS AND METHODS

A total of 89 measurable AGC patients received cisplatin and capecitabine, with or without epirubicin, as a part of a randomized phase II study. Patients were included for the current molecular analysis if they had received two or more cycles of chemotherapy, their objective tumor responses were measured and if their paraffin-embedded tumor samples were available. The ERCC1 expression was examined by performing immunohistochemical (IHC) staining, and the patients were divided into two groups (positive or negative) according to the presence of IHC staining of the tumor cell nuclei.

RESULTS

Of the 32 eligible patients, 21 patients (66%) had tumor with a positive expression of ERCC1 and the remaining 11 patients had tumor with a negative ERCC1-expression. The ERCC1-negative patients achieved a higher response rate than that of the ERCC1-positive patients (44% vs. 28%, respectively), although the difference was not statistically significant (p=0.42). The median survival time for the all patients was 14.6 months (95% CI: 13.6 to 15.6 months). The one-year survival rate was similar for the ERCC1-negative patients (61%) and the ERCC1-positive patients (70%).

CONCLUSION

In the current study, the tumor ERCC1 expression by IHC staining could not predict the clinical response or survival of AGC patients who were treated with cisplatin-based first-line chemotherapy. The ERCC1 protein expression does not appear to be a useful tool for the selection of tailored chemotherapy for these patients.

Current trends in the epidemiological and pathological characteristics of gastrointestinal stromal tumors in Korea, 2003-2004

Despite remarkable progress in understanding and treating gastrointestinal stromal tumors (GISTs) during the past two decades, the pathological characteristics of GISTs have not been made clear yet. Furthermore, concrete diagnostic criteria of malignant GISTs are still uncertain. We collected pathology reports of 1,227 GISTs from 38 hospitals in Korea between 2003 and 2004 and evaluated the efficacy of the NIH and AFIP classification schemes as well as the prognostic factors among pathologic findings. The incidence of GISTs in Korea is about 1.6 to 2.2 patients per 100,000. Extra-gastrointestinal GISTs (10.1%) are more common in Korea than in Western countries. In univariate analysis, gender, age, tumor location, size, mitosis, tumor necrosis, vascular and mucosal invasions, histologic type, CD34 and s-100 protein expression, and classifications by the NIH and AFIP criteria were found to be significantly correlated with patient's survival. However, the primary tumor location, stage and classification of the AFIP criteria were prognostically significant in predicting patient's survival in multivariate analysis. The GIST classification based on original tumor location, size, and mitosis is more efficient than the NIH criteria in predicting patient's survival, but the mechanism still needs to be clarified through future studies.

KRAS mutations in traditional serrated adenomas from Korea herald an aggressive phenotype

The pathogenesis and risk of malignancy of traditional serrated adenomas (TSAs) are unclear. In North America, TSAs are relatively uncommon, occur mainly in the left colon, and in some studies, have not been shown to have a strong association with hyperplastic polyp (HPP) or sessile polyp adenoma (SSA) precursor lesions. In the Far East, and particularly in Korea, TSAs are more common and occur both in the left and right colon. However, the pathogenesis of TSAs in Korean patients, and the similarity to those that occur in North America, have never been evaluated. The purpose of this study was to determine the frequency and type of precursor lesion in TSAs, and to determine the molecular profile according to the grade of histologic dysplasia and/or cancer and anatomic location of the colon in a cohort of Korean patients. One hundred and twelve TSAs were evaluated pathologically and categorized according to the grade of dysplasia (either low or high grade) and the presence or absence of adenocarcinoma. TSAs were also separated into those with serrated versus conventional adenomatous dysplasia. As controls 35 conventional adenomas were evaluated, 14 of which had adenocarcinoma. All lesions were evaluated for the presence and type of precursor lesions and for KRAS and BRAF mutations and methylation of MGMT, hMLH1, and APC. A nondysplastic precursor lesion (HPP or SSA) was identified in 35 TSAs (31.3%). TSAs with a precursor lesion were more commonly found in the right colon compared with the left colon (P=0.03). Mutations of KRAS and BRAF and methylation of MGMT, hMLH1, and APC were present in 29%, 55%, 63%, 56%, and 37% of TSAs, respectively. TSAs with high-grade dysplasia and intramucosal adenocarcinoma showed a significantly higher frequency of KRAS mutation and MGMT methylation, and a significantly lower frequency of BRAF mutations, compared with TSAs with low-grade dysplasia (P<0.05). KRAS mutations were more prevalent in TSAs from the left colon and correlated significantly with higher grades of dysplasia. In a subgroup of TSAs in which both the precursor and neoplastic components were evaluated, a similar molecular profile was shown in both types of epithelium. Our results suggest that up to one-third of TSAs show a histologically identifiable nondysplastic HPP or SSA precursor lesion, particularly in lesions from the right colon. The development of KRAS mutations and methylation of MGMT may herald the onset of an aggressive phenotype in the neoplastic progression of TSAs and also suggests that a fusion between the serrated pathway of carcinogenesis and the chromosomal instability pathway may occur in some TSAs. Further studies are needed to determine the natural history and risk of malignancy of TSAs, specifically related to the anatomic site of development.

Oral bisphosphonate-related osteonecrosis of the jaw: the first report in Asia

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious side effect of bisphosphonate therapy. The incidence of BRONJ is known to be low among patients treated with oral bisphosphonates. We investigated the prevalence, demographics, clinical manifestations, and treatment outcome of 24 patients with oral BRONJ in Asian populations.

INTRODUCTION

The long-term safety of oral bisphosphonates is clinically important considering the rare but potentially serious complications such as bisphosphonate-related osteonecrosis of the jaw (BRONJ) versus the effect of reducing and preventing osteoporotic fracture. The incidence of BRONJ is known to be low among patients treated with oral bisphosphonates around the world. However, the prevalence in those taking oral bisphosphonates for osteoporosis in Asian populations is unknown. Moreover, a recent article, showing that the majority of reported patients who received alendronate were Asian American, raised concern about the prevalence of oral BRONJ in Asian populations. The objective of this study was to investigate the estimated prevalence, clinical characteristics, and treatment outcome of oral BRONJ in Asian populations.

METHODS

From October 2005 to December 2008, a retrospective review of medical charts identified 24 patients receiving oral bisphosphonates diagnosed as BRONJ at the Department of Oral and Maxillofacial Surgery, Yonsei University Dental Hospital, Seoul, South Korea.

RESULTS

The estimated prevalence of oral BRONJ was 0.05-0.07%. The average oral bisphosphonate treatment duration was 43.1 months (range, 5-120 months). Treatment with oral antibiotics and/or surgery including sequestrectomy or alveolectomy showed relatively favorable results.

CONCLUSIONS

The prevalence of oral BRONJ in Korea is similar to that reported previously in Western populations. We suggest that recognition of BRONJ and appropriate management pre- and post-dental surgery might reduce the frequency of BRONJ among patients receiving oral bisphosphonates.

Abstract 4019: Functional profiling of signal transduction pathway proteins in gastric cancer patients

Although gastrectomy is the only curative treatment in gastric cancer (GCA) patients, a high recurrence rate ranging from 40 ∼ 60% following curative surgery still accounts for poor overall survival. In order to further improve survival, there is an urgent need to identify reliable molecular prognostic markers for survival or recurrence following adjuvant chemoradiation therapy, which will evolve to the development of patient-tailored treatment strategies. The improvement of gastric cancer therapy will eventually depend on novel therapeutic approaches targeting molecules critical for cancer proliferation. As the transduction pathway proteins function in cell signaling and transmit signals regulating growth, differentiation, adhesion, migration, and apoptosis, they have become targets of various therapeutic agents. Hence, we have developed a multiplexed immunoassay platform for functional profiling of the transduction pathway proteins.

The COllaborative Proximity ImmunoAssay (COPIA) is a multiplexed protein microarray platform that utilizes the formation of a unique immuno-complex requiring co-localization of two detector-antibodies. The detector-antibodies are conjugated with corresponding channeling-enzymes, glucose oxidase (GO) and horseradish peroxidase (HRP). Once target proteins are bound by the capture antibodies, the channeling events between GO and HRP in proximity enables the profiling of the target proteins with extreme sensitivity. COPIA delivers extremely high analytical specificity as it requires multiple entities within target specific proximity for the signal generation/amplification. COPIA can also be configured for each specific target protein to allow differential detection of truncated targets (i.e., p95HER2) from their normal counter parts (i.e., HER2). We applied COPIA to investigate the levels of expression and activation of signaling proteins in frozen tissues collected from GCA patients.

Here we report the prevalence of HER1, HER2, p95HER2, HER3, IGF1-R, c-MET, PI3K, Shc, VEGFR, panCK, and other signal transduction pathway protein expression and their levels of activation in GCA patients. The improvement of gastric cancer therapy will eventually depend on novel therapeutic approaches targeting specific markers identified by functional profiling. As the disease profile often shifts in recurrent cancers and under different therapeutic pressure, clinical information obtained by analyzing samples (often with limited availability) obtained from ‘evolving / heterogeneous disease’ can help clinicians adjust their disease treatment options for each patient according to ‘personal’ cancer profile-shift.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4019.

WT-1 expression in gastrointestinal stromal tumours

AIMS

Wilms' tumour-1 (WT-1) encodes a transcription factor originally identified as a tumour suppressor gene, whose mutations are responsible for tumorigenesis of Wilms' tumour. The overexpression of WT-1 has been demonstrated in variable tumours. In this study, WT-1 immunoreactivity was explored in 97 gastrointestinal stromal tumours (GISTs).

METHODS

The expression of WT-1 was compared with other immunohistochemical markers of GIST and the association with clinicopathological features was also evaluated. For comparison, six melanomas and 71 soft tissue tumours were used.

RESULTS

All 97 GISTs were positive for WT-1 and the staining intensity was strong in 59 (60.8%), moderate in 28 (28.9%) and weak in 10 cases (10.3%). Cytoplasmic staining with moderate to strong intensity was more frequent in GISTs positive for platelet-derived growth factor receptor-alpha (PDGFRA) (p = 0.04). However, WT-1 immunoreactivity was not related to the clinicopathological variables, including tumour location, histological subtype, risk of progression and recurrence status. Leiomyosarcomas, schwannomas, malignant peripheral nerve sheath tumours (MPNSTs) and melanomas showed cytoplasmic staining, whereas leiomyomas and mesenteric fibromatoses were totally negative for WT-1.

CONCLUSIONS

Although the biological roles of WT-1 in GIST are still unknown, our findings might provide a rationale for immunotherapy targeting WT-1 and a therapeutic solution to the challenge of imatinib-resistant GISTs.