Analysis of Under-Diagnosed Malignancy during Fine Needle Aspiration Cytology of Lymphadenopathies.

Fine needle aspiration cytology (FNAC) is a useful tool in the evaluation of lymphadenopathy. It is a safe and minimally invasive procedure that provides preoperative details for subsequent treatment. It can also diagnose the majority of malignant tumors. However, there are some instances where the diagnosis of tumors remains obscure. To address this, we re-analyzed the misinterpreted patients' samples using mRNA sequencing technology and then identified the characteristics of non-Hodgkin's lymphoma that tend to be under-diagnosed. To decipher the involved genes and pathways, we used bioinformatic and biological analysis approaches, identifying the response to oxygen species, inositol phosphate metabolic processes, and peroxisome and PPAR pathways as possibly being involved with this type of tumor. Notably, these analyses identified FOS, ENDOG, and PRKAR2B as hub genes. cBioPortal, a multidimensional cancer genomics database, also confirmed that these genes were associated with lymphoma patients. These results thus point to candidate genes that could be used as biomarkers to minimize the false-negative rate of FNAC diagnosis. We are currently pursuing the development of a gene chip to improve the diagnosis of lymphadenopathy patients with the ultimate goal of improving their prognosis.

Major Clues and Pitfalls in the Differential Diagnosis of Parathyroid and Thyroid Lesions Using Fine Needle Aspiration Cytology.

BACKGROUND: It is difficult to distinguish parathyroid lesions (PLs) from thyroid lesions using fine needle aspiration cytology (FNAC) because of their proximity and their similar cytomorphological features. METHODS: FNAC smears of 46 patients with pathologically proven PLs that were histologically diagnosed as parathyroid adenoma (PA, n = 35), parathyroid hyperplasia (PH, n = 3), atypical parathyroid adenoma (APA, n = 1), and parathyroid carcinoma (PC, n = 7) were retrospectively reviewed and analyzed. RESULTS: Our initial cytological diagnoses indicated correct diagnoses in 31 of 46 PL patients (67%). The 15 erroneous diagnoses were 5 patients with non-specific benign disease (11%), 4 with nodular hyperplasia of the thyroid (9%), 5 with atypical cells (11%), and 1 with a metastatic papillary thyroid carcinoma (2%). Follicular pattern, papillary structures, colloid-like material, and macrophages, which often suggest thyroid lesions, were also present in some PLs. We found that branching capillaries along the papillary structures, stippled nuclear chromatin, and frequent occurrence of naked nuclei were useful for determining a parathyroid origin. CONCLUSIONS: It is important to be aware that PLs are frequently mistaken for thyroid lesions based on FNAC. The specific and unique characteristics of PLs identified here may be helpful in diagnosis.

Expression of activated Notch1 and Hey1 in papillary thyroid carcinoma.

AIMS: The Notch signalling pathway is involved in normal development as well as tumorigenesis. However, it is unclear whether Notch activation is related to diverse clinicopathological factors in papillary thyroid carcinoma (PTC). METHODS AND RESULTS: We examined the relationship between clinicopathological factors and the expression of activated Notch1 and Hey1, which are indicators of Notch signalling pathway activation, in 109 PTC cases. Activated Notch1 showed strong, moderate and weak expression in 23, 48 and 36 cases, respectively. Its expression was related significantly to histopathological variants (P = 0.007), lymph node metastasis (P = 0.016), BRAF mutation (P = 0.036) and extent of surgery (P = 0.014). Hey1 immunostaining could be divided into two groups: positive and negative, with 26 and 83 cases, respectively. Its expression was related significantly to histopathological variants (P = 0.026), extrathyroidal extension (P = 0.005), BRAF mutation (P = 0.048) and recurrence or soft tissue metastasis (P = 0.000). Multivariate analysis revealed that tumour size (>1 cm), Hey1 immunoreactivity and the presence of lymph node metastasis were associated significantly with recurrence or soft tissue metastasis (odds ratio = 7.38, 4.28 and 12.00, respectively). CONCLUSIONS: Thus, we found that activation of Notch signalling was correlated significantly with clinicopathological parameters. Therefore, Notch signalling could be a useful prognostic marker in patients with PTC.

Prediction of response to neoadjuvant chemotherapy in osteosarcoma using dual-phase (18)F-FDG PET/CT.

OBJECTIVES: We evaluated the ability of dual-phase (18)F-FDG PET/CT to predict the histological response after neoadjuvant chemotherapy (NAC) in osteosarcoma. METHODS: Thirty-one patients with osteosarcoma treated with NAC and surgery were prospectively enrolled. After injection of (18)F-FDG, both early (~60 min) and delayed (~150 min) PET were acquired before and after the completion of NAC. SUVmax, early/delayed SUVmax change (RImax), and early/delayed SUVmean change (RImean) of tumour were measured before (SUV1, RImax1, and RImean1) and after NAC (SUV2, RImax2, and RImean2). Then, we calculated the percentage changes between SUV1 and SUV2 (%SUV). RESULTS: Twelve patients (39%) exhibited good histological response after NAC. SUVmax, RImax, and RImean significantly decreased after NAC. Before NAC, only RImean1 predicted good histological response with the optimal criterion of < 10%, sensitivity of 92%, specificity of 57%, and accuracy of 71%. After NAC, %SUV, SUV2, and RImax2 predicted histological response. By using combined criterion of %SUV and RImax2 or SUV2 and RImean1 or SUV2 and RImax2, accuracies were 81%, 77%, and 77%, respectively. CONCLUSIONS: The histological response after NAC could be predicted by using RImean1 before the initiation of NAC in osteosarcoma. The combined use of SUV and RI values may provide a better prediction. KEY POINTS: • Pretreatment dual-phase FDG-PET was useful to predict histological response in osteosarcoma. • A combination of early and delayed PET may increase the predictive value. • Early/delayed SUV change of tumours significantly decreased after neoadjuvant chemotherapy.

Clinical outcome of low-grade central osteosarcoma and role of CDK4 and MDM2 immunohistochemistry as a diagnostic adjunct.

INTRODUCTION: Low-grade osteosarcoma encompasses parosteal osteosarcoma (POS) and low-grade central osteosarcoma (LCOS), with LCOS more rare than POS. LCOS is also more likely to be misdiagnosed and inappropriately treated with an intralesional procedure, due to its misleading radiological features and the overlap of its pathological characteristics with those of benign bone tumors. Therefore, as a diagnostic adjunct for LCOS, immunohistochemical assay with murine double-minute type 2 (MDM2) and cyclin-dependent kinase 4 (CDK4) have been tried with controversial results. We investigated (1) the clinical course and surgical outcome of LCOS, and (2) the diagnostic role of immune-histochemical markers (CDK4, MDM2) and their correlation with clinico-radiologic findings. MATERIALS AND METHODS: We retrospectively reviewed 16 LCOS patients with regard to age, gender, tumor location, plain radiographic pattern, tumor volume, extraosseous extension, initial diagnosis, initial treatment, definitive diagnosis, definitive treatment, surgical margins, histochemical markers, and oncological outcome. RESULTS: Final survival status was continuous disease-free in 14, alive with disease in 1, and remaining 1 patient died of other cancer. Except for 1 patient who had not undergone excision of their primary lesion, no patients developed a local recurrence. Eight tumors (50%) showed diffuse immunostaining for CDK4. Three of 8 tumors labeled for CDK4 were also positive for MDM2. Six (75%) of 8 CDK4-positive tumors displayed lytic lesions on a plain radiograph; in contrast, 2 (33%) of 6 tumors showing a sclerotic pattern on a plain radiograph were positive for CDK4. CONCLUSIONS: The diagnosis of LCOS is challenging; however, if it is properly diagnosed, there is a high chance of a cure with wide excision alone. Positive immunostaining for CDK4 or MDM2 may be used as a diagnostic adjunct, although negative immunostaining cannot rule out this tumor. The clinical, radiological, and typical pathological findings are vital in raising the suspicion of this rare tumor.

Early response monitoring to neoadjuvant chemotherapy in osteosarcoma using sequential ¹8F-FDG PET/CT and MRI.

PURPOSE: We evaluated the potential of sequential fluorine-18 fluorodeoxyglucose ((18) F-FDG) positron emission tomography (PET)/computed tomography (CT) and MRI (PET/MRI) after one cycle of neoadjuvant chemotherapy to predict a poor histologic response in osteosarcoma. METHODS: A prospective study was conducted on 30 patients with osteosarcoma treated with two cycles of neoadjuvant chemotherapy and surgery. All patients underwent PET/MRI before, after one cycle, and after the completion of neoadjuvant chemotherapy, respectively. Imaging parameters [maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and tumor volume based on magnetic resonance (MR) images (MRV)] and their % changes were calculated on each PET/MRI data set, and histological responses were evaluated on the postsurgical specimen. RESULTS: A total of 17 patients (57%) exhibited a poor histologic response after two cycles of chemotherapy. Unlike the little volumetric change in MRI, PET parameters significantly decreased after one and two cycles of chemotherapy, respectively. After one cycle of chemotherapy, SUVmax, MTV, and TLG predicted the poor responders. Among these parameters, either MTV ≥ 47 mL or TLG ≥ 190 g after one cycle of chemotherapy was significantly associated with a poor histologic response on multivariate logistic regression analysis (OR 8.98, p = 0.039). The sensitivity, specificity, and accuracy of these parameters were 71%, 85% and 77%; and 71%, 85% and 77 %, respectively. CONCLUSION: The histologic response to neoadjuvant chemotherapy in osteosarcoma can be predicted accurately by FDG PET after one course of chemotherapy. Among PET parameters, MTV and TLG were independent predictors of the histologic response.

¹8F-FDG PET SUVmax as an indicator of histopathologic response after neoadjuvant chemotherapy in extremity osteosarcoma.

PURPOSE: This study evaluated the usefulness of the maximum standardized uptake value (SUVmax) as a measure of histologic response to neoadjuvant chemotherapy in patients with extremity osteosarcoma. The correlation between [(18) F]FDG PET SUVmax values and histologic response to preoperative chemotherapy was also assessed prospectively using PET/MRI. METHODS: A total of 26 consecutive patients with high-grade osteosarcoma were prospectively enrolled. All patients underwent parallel PET and MRI scans before and after neoadjuvant chemotherapy. Using the PET and MRI images and pathologic mapping, we assessed the percentage necrosis by histology at the highest metabolic activity point in the tumors. This was defined as the minimum histologic response. The predictive values of SUVmax before (SUV1) and after (SUV2) chemotherapy and the SUV change ratio were determined. Correlations were also investigated among SUV2, minimum histologic response and histologic response. RESULTS: Histologically, 13 patients were classified as good responders and 13 as poor responders. Patients with an SUV2 of >5 showed a poor histologic response. A significant correlation was found between SUV2 and histologic response (Spearman's rho -0.642; P < 0.001), and SUV2 and histologic response were both found to be significantly correlated with minimum histologic response (Spearman's rho -0.515 and 0.911; P = 0.007 and P < 0.001, respectively). CONCLUSION: A SUVmax of more than 5 after neoadjuvant chemotherapy identified the majority of histologic nonresponders (sensitivity 61.3 %, PPV 88.9 %). Tumor necrosis at the point of maximum metabolic activity was found to be significantly correlated with the histologic response of entire resected specimen.

S6K1 inhibition enhances tamoxifen-induced cell death in MCF-7 cells through translational inhibition of Mcl-1 and survivin.

S6 kinase 1 (S6K1) was suggested to be a marker for endocrine therapy resistance in breast cancer. We examined whether tamoxifen's effect can be modulated by S6K1 inhibition. S6K1 inhibition by PF4708671, a selective inhibitor of S6K1, acts synergistically with tamoxifen in S6K1-high MCF-7 cells. Similarly, the knockdown of S6K1 with small interfering RNA (siRNA) significantly sensitized MCF-7 cells to tamoxifen. Inhibition of S6K1 by PF4708671 led to a marked decrease in the expression levels of the anti-apoptotic proteins Mcl-1 and survivin, which was not related to mRNA levels. In addition, suppression of Mcl-1 or survivin, using specific siRNA, further enhanced cell sensitivity to tamoxifen. These results showed that inhibition of S6K1 acts synergistically with tamoxifen, via translational modulation of Mcl-1 and survivin. Based on these findings, we propose that targeting S6K1 may be an effective strategy to overcome tamoxifen resistance in breast cancer.

Comparison of (18)F-FDG PET/CT and (99 m)Tc-MDP bone scintigraphy for detection of bone metastasis in osteosarcoma.

OBJECTIVE: We compared the diagnostic performance of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and (99 m)Tc-methylene diphosphonate bone scintigraphy (BS) for the detection of bone metastasis in osteosarcoma. MATERIALS AND METHODS: We retrospectively reviewed 206 patients with stage II-IV osteosarcoma treated with surgery and chemotherapy as well as at least one paired PET/CT and BS scan (defined as an examination). PET/CT and BS images were interpreted separately. When analyzing the diagnostic yield of a combination of PET/CT and BS (PET/CT+BS), an examination was considered positive if either PET/CT or BS scored positive. The final diagnosis was obtained from histological findings or clinical follow-up with imaging studies for at least 6 months. Diagnostic performances of PET/CT, BS, and their combinations were calculated. RESULTS: Out of 833 examinations in 206 patients, 55 with 101 lesions in 38 patients were confirmed as bone metastases. The sensitivity, specificity, and diagnostic accuracy were 95, 98, and 98%, respectively, for PET/CT; 76, 97, and 96%, respectively, for BS; and 100, 96, and 97%, respectively, for PET/CT+BS in an examination-based analysis. Lesion-based analysis demonstrated that the sensitivity of PET/CT+BS (100%) was significantly higher than that of PET/CT (92%) or BS (74%) alone. BS detected significantly less bone metastases in the growth plate region than outside the growth plate region (22 vs. 77%). CONCLUSIONS: PET/CT is more sensitive and accurate than BS for diagnosing bone metastases in osteosarcoma. The combined use of PET/CT and BS improves sensitivity.

Utility and Limitations of Fine-Needle Aspiration Cytology in the Diagnosis of Lymphadenopathy.

BACKGROUND: Fine needle aspiration cytology (FNAC) is a valuable tool for evaluating lymphadenopathy. The purpose of this study was to assess the reliability and effectiveness of FNAC in the diagnosis of lymphadenopathy. METHODS: Cytological characteristics were evaluated in 432 patients who underwent lymph node FNAC and follow-up biopsy at the Korea Cancer Center Hospital from January 2015 to December 2019. RESULTS: Fifteen (3.5%) of the four hundred and thirty-two patients were diagnosed as inadequate by FNAC, with five (33.3%) of these diagnosed as metastatic carcinoma on histological examination. Of the 432 patients, 155 (35.9%) were diagnosed as benign by FNAC, with seven (4.5%) of these diagnosed histologically as metastatic carcinoma. A review of the FNAC slides, however, showed no evidence of cancer cells, suggesting that the negative results may have been due to FNAC sampling errors. An additional five samples regarded as benign on FNAC were diagnosed as non-Hodgkin lymphoma (NHL) by histological examination. Of the 432 patients, 223 (51.6%) were cytologically diagnosed as malignant, with 20 (9.0%) of these diagnosed as tissue insufficient for diagnosis (TIFD) or benign on histological examination. A review of the FNAC slides of these 20 patients, however, showed that 17 (85.0%) were positive for malignant cells. The sensitivity, specificity, positive predictive value (PPV), negative predictive values (NPV), and accuracy of FNAC were 97.8%, 97.5%, 98.7%, 96.0%, and 97.7%, respectively. CONCLUSIONS: Preoperative FNAC was safe, practical, and effective in the early diagnosis of lymphadenopathy. This method, however, had limitations in some diagnoses, suggesting that additional attempts may be required according to the clinical situation.

Classification of thymoma by fine needle aspiration biopsy according to WHO classification: a cytological algorithm for stepwise analysis in the classification of thymoma.

OBJECTIVE: To evaluate the cytological characteristics of each type of thymoma and introduce an algorithm to classify thymoma using fine needle aspiration biopsy (FNAB). STUDY DESIGN: We retrospectively reviewed the cytological characteristics of 15 cases of thymoma with three thymic carcinoma (1 type A thymoma, 6 type AB thymomas and 8 type B thymomas), which were confirmed by histology. Three major and one minor cytomorphologic parameter were adopted for classification: (1) number of lymphocytes in the smear background; (2) nuclear characteristics of thymic cells; (3) lymphocytes and crush artifacts in thymic cell clusters, and (4) nuclear arrangement of thymic cells. RESULTS: An abundant lymphocytic smear background indicated type B thymomas in 87.5% of cases, contrary to the few lymphocytes in the remaining thymic tumors excluding type B thymomas (90%). Thymic cells contained no vesicular nuclei and inconspicuous nucleoli in 85.7% of type A thymoma and type AB thymoma cases. Type AB thymomas and type B thymomas showed more prominent crush artifacts in cell clusters than type A thymoma and thymic carcinoma. Thymic cells of type B thymomas and thymic carcinoma were arranged without whirling architecture in clusters. The proposed algorithm demonstrated a predictive rate of 88.8% for thymoma classification. CONCLUSIONS: The stepwise classification of thymoma with FNAB may be useful in patients for whom an invasive diagnosis approach is not feasible.

Phosphorylated S6K1 is a possible marker for endocrine therapy resistance in hormone receptor-positive breast cancer.

Cross-talk between the estrogen receptor and the mammalian target of rapamycin (mTOR) pathway is one of the mechanisms of endocrine therapy resistance, and the phosphorylated S6 kinase 1(p-S6K1) is known to be a marker of the mTOR pathway activation. The authors assessed the prognostic significance of p-S6K1 according to the hormone receptor (HR) status. The expression of p-S6K1 was evaluated in 304 breast cancer tissues, and the association between its expression and patient outcomes was investigated. Among 197 cases with the HR (+) tumor, 70 (35.5%) were positive for p-S6K1. Most of the patients (97.5%) with the HR (+) tumor received adjuvant endocrine therapy. The expression of p-S6K1 was found to be an independent worse prognosticator affecting overall survival (OS) and breast cancer-specific survival (BCSS) in the HR (+) group (hazard ratio, 2.62; 95% confidence interval [CI], 1.19-5.76; P = 0.017 and hazard ratio, 3.25; 95% CI, 1.20-8.82; P = 0.020, respectively). In the HR (-) group, however, the p-S6K1 expression was not associated with patients' survival. The expression of p-S6K1 is a worse prognostic factor in patients with HR (+) tumors. These results suggest that the p-S6K1 expression might be a marker for endocrine therapy resistance in patients with HR (+) tumors.

Human papillomavirus infection in lung and esophageal cancers: analysis of 485 Asian cases.

The role of human papillomavirus (HPV) in the development of lung and esophageal cancer remains inconclusive, which is in contrast to the established role HPV plays in the development of uterine cervical cancer. One of the reasons for this is the difference among reported HPV infection rates in these cancers. An analysis of 485 lung and esophageal cancers (176 lung squamous cell carcinoma, 128 lung adenocarcinoma, 181 esophageal carcinoma) in eight institutions in Asia (Tokyo, Kochi, Kagoshima, and Okinawa, Japan; Seoul and Daegu, Korea; Changhua, Republic of China (Taiwan); Singapore, Singapore) was carried out in order to clarify infection rates with HPV. Samples were examined in one laboratory of the Department of Pathology, the University of Tokyo, Japan in order to avoid inter-laboratory variation using a combination of polymerase chain reaction and in situ hybridization (ISH). HPV was found in 6.3%, 7%, and 9.4% of patients with lung squamous cell carcinoma, lung adenocarcinoma, and esophageal cancer, respectively. Among the geographic areas surveyed, Kagoshima exhibited a significantly higher prevalence of HPV infection in cases of esophageal carcinoma (24.1%). There was no geographical difference in the infection rates of HPV in lung carcinomas. Subtype-specific ISH was also performed, which identified the high-risk HPV types 16/18 in the majority (75.7%) of the patients with lung and esophageal cancer positive for HPV.

Oncologic impact of the curettage of grade 2 central chondrosarcoma of the extremity.

BACKGROUND: Wide excision is considered the standard treatment for high-grade chondrosarcoma, but little is known regarding the effect of curettage on patient outcome in grade 2 chondrosarcoma. METHODS: The records of 32 patients with nonmetastatic grade 2 central chondrosarcoma of the appendicular skeleton were analyzed. The clinical characteristics and outcomes of 15 patients who underwent curettage (the case group) followed by subsequent treatment and 17 patients who underwent standard treatment were compared. The mean follow-up period for all 32 patients was 110 months (range, 31-230 months). RESULTS: Cases had a smaller tumor volume at presentation (P = .02), a lower Enneking's stage IIA (P < .01), a lower rate of biopsy (P < .01), and a lower incidence of chondroid calcification by plain radiography (P < .01) than controls. Of the 32 study subjects, 2 (1 in the each group) developed local recurrence. The 10-year overall and metastasis-free survival rates for all 32 chondrosarcomas were 84.6% ± 14.5% and 70.3% ± 16.5%, respectively. Event-free survivals were similar for cases and controls (P = .16). CONCLUSIONS: Intracompartmental grade 2 chondrosarcoma with nonaggressive radiologic pattern have a chance of curettage. However, proper subsequent management achieves outcomes comparable with those of primary wide excision.

Tumor volume increase during preoperative chemotherapy as a novel predictor of local recurrence in extremity osteosarcoma.

BACKGROUND: Known risk factors (surgical margin, tumor necrosis) of local recurrence (LR) in osteosarcoma are determined by results available after surgery. However, relations between preoperative characteristics and LR have not been clearly defined. METHODS: We compared the clinicopathologic characteristics of 36 osteosarcoma patients with LR and 394 patients without LR after surgery. In addition, prognostic variables were evaluated to establish factors could influence LR. RESULTS: Compared to the non-LR group, the LR group showed an increase in tumor volume ratio (TVR) during preoperative chemotherapy (P < 0.01), inadequate surgical margin (P < 0.01), and poor histologic response (P < 0.01). Univariate analysis of data from 430 patients revealed that an increased TVR (P < 0.01), inadequate surgical margin (P < 0.01), poor histologic response (P < 0.01), and nonosteoblastic pathologic subtype (P = 0.04) were negatively related to LR-free survival. In multivariate analysis, an elevated TVR (P < 0.01, relative risk = 10.26) and inadequate surgical margin (P < 0.01, relative risk = 5.91) emerged as the key prognostic factors for LR. CONCLUSIONS: A TVR increase during preoperative chemotherapy could be used to predict patients at high risk of LR. This finding might be useful when considering surgical options to decrease the risk of LR.

Taurine supplementation restored the changes in pancreatic islet mitochondria in the fetal protein-malnourished rat.

Intra-uterine growth retardation has been linked to the development of type 2 diabetes in later life. Mitochondrial changes have been suggested as a link between fetal malnutrition and adult insulin resistance. Taurine has been implicated in this process. We investigated whether protein malnutrition in early life alters mitochondria of the pancreatic islets in adulthood, and whether taurine supplementation restores these changes. Male offspring of rats fed a control diet, a low-protein diet or a low-protein diet supplemented with taurine during pregnancy and lactation were weaned onto the control diet. In each group, at 20 weeks of age, intravenous glucose tolerance tests, euglycaemic-hyperinsulinaemic clamp studies, morphometric analysis of the pancreatic islets and ultra-structural analysis of the mitochondria of the ß-cells were performed. The expressions of cytochrome c oxidase (COX) I and mitochondrial respiratory chain complex II were also measured. Fetal protein-malnourished rats showed decreased pancreatic islet mass and reduced insulin-secretory responses to a glucose load. These rats also showed reduced mitochondrial DNA-encoded COX I gene expression in the islets. Electron microscopic examination showed abnormal mitochondrial shapes in the ß-cells of fetal protein-malnourished rats. Taurine supplementation to the low-protein diet restored all these changes. Our findings indicate that a maternal protein-restriction diet causes long-lasting mitochondrial changes that may contribute to the development of type 2 diabetes later in life. The lack of taurine may be a key causative factor for these dysfunctional mitochondrial changes.

RANKL expression is related to treatment outcome of patients with localized, high-grade osteosarcoma.

BACKGROUND: The receptor activator of nuclear factor κB ligand (RANKL/TNFSF11) is expressed in metastatic bone cancer cells and has been suggested to play a key role in cell migration and metastatic behavior. We determined whether RANKL expression is correlated to clinical behavior of localized, high-grade osteosarcoma. PATIENTS AND METHODS: This retrospective, immunohistochemical study was performed using materials obtained from 40 patients treated at Korea Cancer Center Hospital between 1995 and 2007. Prechemotherapy biopsy samples were stained for RANKL and correlations between RANKL expression and clinical characteristics and outcomes were evaluated. Staining was interpreted in a semiquantitative manner using an intensity based scoring system. RESULTS: Thirty cases (75.0%) stained positively for RANKL; 15 (50.0%) had a high RANKL score (≥ 4) and the other 15 a low RANKL score (≤3). RANKL expression and RANKL scores were not related to age, sex, tumor location, tumor volume, or pathologic subtype. However, RANKL expression was related to a poor response to preoperative chemotherapy (P = 0.03) and a high RANKL score was associated with inferior survival. The 5-year event-free survival of patients with RANKL score ≥4 was 17.8 ± 10.5%, which was far worse than those with RANKL scores 1-3 or 0 (50.0 ± 15.8%, 56.0 ± 13.7%, respectively, P = 0.02). CONCLUSIONS: The RANKL-RANK-OPG axis might be a promising target for the treatment of osteosarcoma, but further studies are needed to verify our data in a larger cohort.

Treatment outcome of Korean patients with localized Ewing sarcoma family of tumors: a single institution experience.

OBJECTIVE: Controversy exists about the treatment outcomes of the Ewing sarcoma family of tumors among low-incidence populations. We evaluated whether Korean Ewing sarcoma family of tumors patients have poorer outcomes than Euro-American patients. METHODS: We retrospectively analyzed the clinicopathologic characteristics and outcomes of patients with localized Ewing sarcoma family of tumors treated at Korea Cancer Center Hospital between 1986 and 2008. RESULTS: Seventy-six patients (48 male, 28 female) of median age 20 years (range: 1-69 years) were evaluated. Tumors were located in central-axial parts of the body in 33 cases (43.4%) and extremity in 43 cases (56.6%). Pelvis and femur were the most frequently involved sites. Histologic response to preoperative chemotherapy was analyzed in 48 cases and there were 32 (66.7%) good responders and 16 (33.3%) poor responders. For a median follow-up of 37.9 months (range: 0.9-260.6 months), 5-year overall survival and event-free survival rates were 58.9 ± 6.1 and 52.6 ± 6.1%, respectively. A poor histologic response to preoperative chemotherapy (P= 0.01) and a tumor location in a central-axial body region (P= 0.008) were found to be related to a poorer event-free survival. CONCLUSIONS: Survival of our Ewing sarcoma family of tumors patients was not inferior to those reported for Euro-American cases. Collaborative studies are necessary for further improvements of outcome and we believe that our data provide a basis for future studies targeting Ewing sarcoma family of tumors.

Longitudinal Imaging of Liver Cancer Using MicroCT and Nanoparticle Contrast Agents in CRISPR/Cas9-Induced Liver Cancer Mouse Model.

INTRODUCTION: Micro-computed tomography with nanoparticle contrast agents may be a suitable tool for monitoring the time course of the development and progression of tumors. Here, we suggest a practical and convenient experimental method for generating and longitudinally imaging murine liver cancer models. METHODS: Liver cancer was induced in 6 experimental mice by injecting clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 plasmids causing mutations in genes expressed by hepatocytes. Nanoparticle agents are captured by Kupffer cells and detected by micro-computed tomography, thereby enabling longitudinal imaging. A total of 9 mice were used for the experiment. Six mice were injected with both plasmids and contrast, 2 injected with contrast alone, and one not injected with either agent. Micro-computed tomography images were acquired every 2- up to 14-weeks after cancer induction. RESULTS: Liver cancer was first detected by micro-computed tomography at 8 weeks. The mean value of hepatic parenchymal attenuation remained almost unchanged over time, although the standard deviation of attenuation, reflecting heterogeneous contrast enhancement of the hepatic parenchyma, increased slowly over time in all mice. Histopathologically, heterogeneous distribution and aggregation of Kupffer cells was more prominent in the experimental group than in the control group. Heterogeneous enhancement of hepatic parenchyma, which could cause image quality deterioration and image misinterpretation, was observed and could be due to variation in Kupffer cells distribution. CONCLUSION: Micro-computed tomography with nanoparticle contrast is useful in evaluating the induction and characteristics of liver cancer, determining appropriate size of liver cancer for testing, and confirming therapeutic response.