Proper Cut-off Value Research Articles

Optimal cutoff values of allergen-specific immunoglobulin E to house dust mites and animal dander based on skin-prick test results: Analysis in 16,209 patients with allergic rhinitis.

The most common tests for allergen sensitization in patients with allergic rhinitis are the skin-prick test (SPT) and an in vitro test to detect serum specific immunoglobulin E (sIgE). However, in vitro allergen test results were interpreted dichotomically as positive or negative at a threshold of 0.35 kU/L of sIgE, regardless of the patient characteristics or antigen types. The purpose of this study was to determine the cutoff value for sIgE in house-dust mites and animal dander, and to analyze differences in cutoff value according to age and gender. A total of 16,209 patients with more than one allergic rhinitis symptom who underwent both SPT and serum sIgE testing were retrospectively evaluated between March 2008 and May 2012. There were 9374 male (57.8%) and 6835 female (42.2%) patients. The mean age was 31.8 years (range, 2-89 years). The criterion standard for allergen sensitization was defined as a wheal of >3 mm or an allergen-to-histamine ratio of ≥1 in SPT results. The Youden index was used to calculate the cutoff value of sIgE. Cutoff values of sIgE for Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, and dog were 0.69, 1.16, 0.13, and 0.45 kU/L, respectively. The cutoff value of sIgE changed according to age for D. pteronyssinus and D. farinae but not for cat and dog allergens. When categorizing according to age group, the cutoff values of sIgE for D. pteronyssinus and D. farinae had a tendency to decrease with age. There was no significant difference in cutoff value according to gender. The cutoff value for sIgE differed for each antigen and changed with age. Physicians should select the proper cutoff value for sIgE for appropriate criteria according to antigen and patient age rather than using a uniform cutoff value.

Prognosis of locally advanced rectal cancer can be predicted more accurately using pre- and post-chemoradiotherapy neutrophil-lymphocyte ratios in patients who received preoperative chemoradiotherapy.

PurposeThe neutrophil-lymphocyte ratio (NLR) has been suggested as an inflammation-related factor, but also as an indicator of systemic anti-tumor immunity. We aimed to evaluate the prognostic value of the NLR and to propose a proper cut-off value in patients with locally advanced rectal cancer who received preoperative chemoradiation (CRT) followed by curative total mesorectal excision (TME).MethodsA total of 110 rectal cancer patients with clinical T3-4 or node-positive disease were retrospectively analyzed. The NLR value before preoperative CRT (pre-CRT NLR) and the NLR value between preoperative CRT and surgery (post-CRT NLR) were obtained. Using a maximally selected log-rank test, cut-off values were determined as 1.75 for the pre-CRT NLR and 5.14 for the post-CRT NLR.ResultsPatients were grouped as follows: group A, pre-CRT NLR ≤ 1.75 and post-CRT NLR ≤ 5.14 (n = 29); group B, pre-CRT NLR > 1.75 and post-CRT NLR ≤ 5.14, or pre-CRT NLR ≤ 1.75 and post-CRT NLR > 5.14 (n = 61); group C, pre-CRT NLR > 1.75 and post-CRT NLR > 5.14 (n = 20). The median follow-up time was 31.1 months. The 3-year disease-free survival (DFS) and overall survival (OS) rates showed significant differences between the NLR groups (3-year DFS rate: 92.7% vs. 73.0% vs. 47.3%, for group A, B, and C, respectively, p = 0.018; 3-year OS rate: 96.0% vs. 85.5% vs. 59.8%, p = 0.034). Multivariate analysis revealed that the NLR was an independent prognostic factor for DFS (p = 0.028).ConclusionBoth the pre-CRT NLR and the post-CRT NLR have a predictive value for the prognosis of patients with locally advanced rectal cancer treated with preoperative CRT followed by curative TME and adjuvant chemotherapy. A persistently elevated post-CRT NLR may be an indicator of an increased risk of distant metastasis.

Evaluation of a proper cutoff value on quantitative dual-energy perfusion CT for the assessment of acute pulmonary thromboembolism.

Background The cutoff value for assessing the severity of acute pulmonary thromboembolism (PTE) using relative volumetric evaluations of dual-energy perfusion computed tomography (DEpCT) is unclear. Purpose To determine the proper cutoff value for determining the severity of PTE using DEpCT volumetry. Material and Methods A total of 185 patients with venous thromboembolism were included in this study, of whom 61 were diagnosed with acute PTE. DEpCT images were three-dimensionally reconstructed at the following attenuation ranges: 1-2 HU (V2), 1-10 HU (V10), and 1-120 HU (V120). The ratios of low perfusion areas associated with each threshold range per V120 were also calculated, and the relative ratios were expressed as %V2 to %V10. These values were compared with factors indicating the severity of PTE, including the pulmonary arterial pressure, heart rate, CT angiographic obstruction index (CTOI), and right/left ventricular diameter ratio (RV/LV). Results The area under the curve (AUC) of %V2 was highest (0.783) among these values (95% confidence interval, 0.710-0.856) based on the presence of IPCs. The %V2 showed moderate correlations with CTOI (r = 0.36, P = 0.005) and RV/LV (r = 0.36, P = 0.004) in the patients with acute PTE. Conclusion Volumetric evaluations of DEpCT images using the lowest attenuation threshold range (1-2 HU) exhibit the best correlation with factors suggesting the severity of acute PTE.

Age-Specific Cutoff Value for the Application of Percent Free Prostate-Specific Antigen (PSA) in Chinese Men with Serum PSA Levels of 4.0-10.0 ng/ml.

ObjectiveThe influence of age on the performance of percent free prostate-specific antigen (%fPSA) in diagnosing prostate cancer (PCa) in East Asians is controversial. We tested the diagnostic performance of %fPSA in a multi-center biopsy cohort in China and identified the proper age-specific cutoff values to avoid unnecessary biopsies.MethodsConsecutive patients with a prostate-specific antigen (PSA) level of 4.0–10.0 ng/ml or 10.1–20.0 ng/ml who underwent transrectal ultrasound-guided or transperineal prostate biopsy were enrolled from 22 Chinese medical centers from Jan 1, 2010 to Dec 31, 2013. The diagnostic accuracy of PSA and %fPSA was determined using the area under the receiver operating characteristic (ROC) curve (AUC). Age-specific cutoff values were calculated using ROC curve analysis.ResultsThe median %fPSA was much lower in younger patients compared with older patients with a PSA level of 4.0–10.0 ng/ml or 10.1–20.0 ng/ml. The AUC of %fPSA was higher than PSA only in older patients. In patients aged 50 to 59 years, %fPSA failed to improve the diagnosis compared with PSA in these two PSA ranges. Age-specific cutoff values were 24%, 27% and 32% for patients aged 60–69, 70–79 and ≥80 years, respectively, to reduce unnecessary biopsies in men with PSA levels of 4.0–10.0 ng/ml to detect 90% of all PCa.ConclusionsThe effectiveness of %fPSA is correlated with age in the Chinese population. Age-specific cutoff values would help avoid unnecessary biopsies in the Chinese population.

Predicting Factors for Conversion from Fluoroscopy Guided Percutaneous Transthoracic Needle Biopsy to Cone-Beam CT Guided Percutaneous Transthoracic Needle Biopsy

서는 유용하면서 간편한 시술이다(1). 일반적으로는 투시 조영 Purpose: To evaluate the predicting factors for conversion from fluoroscopy guided percutaneous transthoracic needle biopsy (PTNB) to cone-beam CT guided PTNB. Materials and Methods: From January 2011 to December 2012, we retrospectively identified 38 patients who underwent cone-beam CT guided PTNB with solid pulmonary lesions, and 76 patients who underwent fluoroscopy guided PTNB were matched to the patients who underwent cone-beam CT guided PTNB for age, sex, and lesion location. We evaluated predicting factors such as, long-axis diameter, short-axis diameter, anterior-posterior diameter, and CT attenuation value of the solid pulmonary lesion affecting conversion from fluoroscopy guided PTNB to conebeam CT guided PTNB. Pearson χ test, Fisher exact test, and independent t test were used in statistical analyses; in addition, we also used receiver operating characteristics curve to find the proper cut-off values affecting the conversion to cone-beam CT guided PTNB. Results: Short-axis, long-axis, anterior-posterior diameter and CT attenuation value of the solid pulmonary lesion in patients who underwent fluoroscopy guided PTNB were 2.70 ± 1.57 cm, 3.40 ± 1.92 cm, 3.06 ± 1.81 cm, and 35.67 ± 15.70 Hounsfield unit (HU), respectively. Short-axis, long-axis, anterior-posterior diameter and CT attenuation value of the solid pulmonary lesion in patients who underwent cone-beam CT guided PTNB were 1.60 ± 1.30 cm, 2.20 ± 1.45 cm, 1.91 ± 1.99 cm, and 18.32 ± 23.11 HU, respectively. Short-axis, long-axis, anterior-posterior diameter, and CT attenuation value showed a significantly different mean value between the 2 groups (p = 0.001, p < 0.001, p = 0.003, p < 0.001, respectively). Odd ratios of CT attenuation value and short-axis diameter of the solid pulmonary lesion were 0.952 and 0.618, respectively. Proper cut-off values affecting the conversion to cone-beam CT guided PTNB were 1.65 cm (sensitivity 68.4%, specificity 71.1%) in short-axis diameter and 29.50 HU (sensitivity 65.8%, specificity 65.8%) in CT attenuation value. Conclusion: Low CT attenuation value and small short-axis diameter of the solid pulmonary lesion affect conversion from fluoroscopy guided PTNB to cone-beam CT guided PTNB. Index terms Percutaneous Transthoracic Needle Biopsy Cone-Beam CT Solid Pulmonary Lesion Fluoroscopy Predicting Factors

Batasan Prostate Specific Antigen (PSA) Pada Pasien Kanker Prostat Untuk Memprediksi Metastasis Ke Tulang Di Rumah Sakit Sardjito, YOGYAKARTA

The object of this study to establish a serum PSA cut-off value to predict the presence of bone metastasis in prostate cancer. Methods: Consecutive patients diagnosedwith prostate cancer were retrospectively analyzed. Patients had received bone scintigraphy and had their PSA concentration measured. The proper cut-off value was established based on statistical analysis in order to predict the possibility of bone metastasis among them. Results: eighty-three consecutive patients with prostate cancer were enrolled, and 55 patients (66%) with bone metastasis confirmed by scintigraphic findings. A serum PSA concentration of 17.65 ng/ml gave the best sensitivity (78.33%) and specificity (65.21%). The PPV and NPV were 85.45% and 53.57%, respectively (p<0.05) Conclusion: a cut-off value of 17.65 ng/ml appears to be an appropriate benchmark for stratifying metastatic bone disease in prostate cancer patientssuch that if a patient with newly diagnosed prostate cancer and without any skeletal symptoms has a serum PSA concentration of less than 17.65 ng/ml,we suggest that they would not need to undergo bone scintigraphy.

Blood spot versus plasma chitotriosidase: A systematic clinical comparison

ObjectivesThis study aimed to evaluate the agreement between blood spot and plasma chitotriosidase using the economic substrate 4-methylumbelliferyl-β-D-N,N′,N″-triacetylchitotrioside, and to investigate the utility of the blood spot assay for the wide scale screening for lysosomal storage disorders among the clinically suspected. Design and methodsBlinded blood spot samples were compared with the corresponding plasma levels in 199 children (56 with confirmed diagnoses of ten different lysosomal storage disorders, 73 normal controls and 70 pathological controls). Several performance criteria (limit of detection, linearity, within-run and day-to-day precision and sample stability) were also evaluated. ResultsPlasma assay performed better by most criteria; however, blood spot performance was quite satisfactory. Quantitative values of the two methods can't be used interchangeably based on their 95% limits of agreement. Diagnostic sensitivity and specificity derived from ROC curves were 75.0 and 85.3% for the plasma assay and 71.4 and 79.0% for the blood spot assay, respectively. Cohen's kappa was 0.72 (95% CI: 0.616–0.821) denoting a good categorical agreement between the two methods. ConclusionThe clinical use of blood spot chitotriosidase for the screening of lysosomal storage disorders can be quite practical, provided proper cut-off values are determined for each lab.

AB0725 Quantitative measurement of humero-acromial, humero-coracoid, and coraco-clavicular intervals for the diagnosis of subacromial and subcoracoid impingement of shoulder joint

BackgroundShoulder impingement is an important entity and has to be proved with imaging and pathologically if needed. This research is acquired for the clinical and surgical applications of impingement, based...

Dual-time-point F-18 FDG PET/CT imaging for differentiating the lymph nodes between malignant lymphoma and benign lesions

PurposeThe purpose of the present study is to evaluate the clinical value of dual-time-point F-18 FDG PET/CT imaging to differentiate malignant lymphoma (ML) from benign lymph node (BLN).Materials and methodsThe subjects were 310 lymph nodes in 84 patients (195 ML lesions in 30 patients and 115 BLN in 54 patients associated with various etiologies.). F-18 FDG PET/CT scan was performed at 50 min (early scan) and at 100 min (delayed scan) after the injection. First, the maximum standardized uptake value (SUVmax) of each lesion at early and delayed scans was calculated. Second, we estimated the difference between early and delayed SUVmax (D-SUVmax) and the retention index (RI-SUVmax) to evaluate the change of tracers in the lesions. Furthermore, proper cut-off values of them were evaluated using receiver operating characteristic analysis. The efficacy of each parameter was analyzed with ANOVA.ResultsDelayed SUVmax and D-SUVmax in ML were significantly higher than those in BLN. Proper cut-off value in delayed SUVmax was 4.0 and in D-SUVmax was 1.0. When the proper cut-off value in D-SUVmax was applied, the D-SUVmax yielded the role of diagnosis with sensitivity of 82.6 %, specificity of 65.2 %, positive predictive value of 80.1 % and negative predictive value of 68.8 %, respectively.ConclusionsThe delayed SUVmax and D-SUVmax were useful indices to differentiate ML from BLN, regardless of histologic subtype. Dual-time-point F-18 FDG PET/CT imaging may help to consider whether there is any need to proceed to more invasive tests, such as biopsy, in individual patients.

Triage vital signs predict in-hospital mortality among emergency department patients with acute poisoning: a case control study

BackgroundTo document the relationship between triage vital signs and in-hospital mortality among emergency department (ED) patients with acute poisoning.MethodsPoisoning patients who admitted to our emergency department during the study period were enrolled. Patient’s demographic data were collected and odds ratios (OR) of triage vital signs to in-hospital mortality were assessed. Receiver operating characteristic curve was used to determine the proper cut-off value of vital signs that predict in-hospital mortality. Logistic regression analysis was performed to test the association of in-hospital mortality and vital signs after adjusting for different variables.Results997 acute poisoning patients were enrolled, with 70 fatal cases (6.7%). A J-shaped relationship was found between triage vital signs and in-hospital mortality. ED triage vital signs exceed cut-off values independently predict in-hospital mortality after adjusting for variables were as follow: body temperature <36 or >37°C, p < 0.01, OR = 2.8; systolic blood pressure <100 or >150 mmHg, p < 0.01, OR: 2.5; heart rate <35 or >120 bpm, p < 0.01, OR: 3.1; respiratory rate <16 or >20 per minute, p = 0.38, OR: 1.4.ConclusionsTriage vital signs could predict in-hospital mortality among ED patients with acute poisoning. A J-curve relationship was found between triage vital signs and in-hospital mortality. ED physicians should take note of the extreme initial vital signs in these patients.

The Association of Lumbosacral Sagittal Alignments and the Patterns of Lumbar Disc Degeneration

Results: This study found a moderate correlation between pelvic incidence, sacral slope, lumbar lordosis, and the number of lumbar degenerative disc (r =-0.451, p <0.001; r =-0.433, p <0.001; r =-0.425, p <0.001). We calculated the most proper cut-off value of pelvic incidence associated with more than three segments of multiple lumbar disc degeneration, using a minimum p-value approach. Conclusions: As pelvic incidence, sacral slope, and lumbar lordosis indicating the parameters of lumbosacral sagittal alignments get smaller, the numbers of lumbar disc degenerations and herniated intervertebral discs increase. When pelvic incidence is below 45.6 degrees, it is more likely for degenerative changes of lumbar disc to affect more than three segments.

Abdominal compartment syndrome in childhood: the role of near infrared spectroscopy for the early detection of the organ dysfunction

We found very interesting the manuscript written by Dr. Steinau et al. [1] recently published in your journal. The author proposed their approach for the management of abdominal compartment syndrome (ACS) in childhood presenting a wide case mix of pathology ranging from neonates to school children. We agree that the gold standard for the indirect intrabdominal preassure (IAP) measurement both in adults and children is the intra-bladder pressure monitoring with an intermittent saline bolus. In accordance with the adult guidelines, intrabdominal hypertension (IAH) in children is firstly managed with a conservative therapy, while in the presence of ACS (low abdominal perfusion pressure associated to a new onset of organ dysfunction) early abdominal decompression remains a mandatory approach in order to reduce the high mortality rate associated with this condition [2, 3]. Unfortunately, the ‘‘numbers’’ used in the adult population to perform an abdominal decompression are not applicable in children since the variable abdomen compliance especially in neonates and infants [2]. Many authors [1, 2, 4] suggested proper cut-off values for IAH, to establish the ‘‘critical pressure number’’ at which regularly a switch from IAH to ACS in pediatric patients can be observed. In his work, Dr. Steinau et al. used the criteria proposed by Dr. Eijke [4] to define the pediatric ACS [3]. He considered the pediatric ACS as a lasting IAH higher than 12 mmHg combined with at least one organ dysfunction. We believe that a fixed ‘‘critical’’ number is not suitable for all pediatric patients and that the values proposed by Dr. Stainau are just indicative of an evolving process that could lead or not to a multiple organ dysfunction. Both in adults and children, clinical examination and laboratory testing (base deficit, lactate, unpaired dieresis) are sensitive in detecting abnormalities of tissue perfusion during ACS only after sustained periods of inadequate perfusion, furthermore the early changes in organ metabolism are not easily identified with the traditional monitoring systems. We believe that the outcome of ACS would improve if an earlier detection of regional tissue hypoperfusion would be provided to these patients. Differently from adults, in both neonates and infants, abdominal organs perfusion (kidney) can be monitored using the near infrared spectroscopy (NIRS). This device enables the detection of the states of organ hypoperfusion, allowing a rapid intervention to limit the cascade of multiple organs dysfunction and the development of shock [5–7]. NIRS uses nonpulsatile oximetry to determine venous-weighted oxy-hemoglobin saturation of the underlying regional tissue (rSO2) studied. In pediatrics generally two-site NIRS (brain–kidney) is used for the non invasive assessment of the cardiac output and of its autoregulation in the case of shock [6]. Normally tissue beds with high oxygen consumption (brain) have lower baseline rSO2, where tissue with little metabolic demand (kidney) have a higher baseline rSO2. Figure 1 shows a case of primary ACS for a Clostridium difficilis enterocolitis in a 6-month-old child (7 kg body weight) in which two-site NIRS (brain–kidney) was continuously used to manage the relation between cardiac output and IAP. This patient presented a pathologic change in brain and kidney saturation (dotted arrow) when IAP was *10 mmHg and diuresis was still 1.5 ml/kg/h. This state was not controlled with the medical therapy (deep sedation, neuromuscular M. Di Nardo (&) C. Cecchetti F. Stoppa N. Pirozzi S. Picardo Pediatric Intensive Care Unit, Children’s Hospital Bambino Gesu, Rome, Italy e-mail: matteo.dinardo@tin.it

Sonographic and electrophysiological detection in patients with carpal tunnel syndrome

Objectives: To assess prospectively the significance of sonographic measurements of the median nerve in the diagnosis of carpal tunnel syndrome (CTS), to look for proper parameters and cutoff values for the sonographic diagnosis, and to correlate with the electrophysiological findings.Materials and methods: This study involved 30 patients, who were clinically diagnosed as CTS merely based on their symptoms and signs; and 30 healthy volunteers were served as controls. Eligible subjects underwent sonographic and electromyographic detection.Results: In the CTS patient group, the cross-sectional area (CSA) at the pisiform bone level (CSA2) and the diameter (D) of the median nerve increased. When the cutoff values of CSA2 and D were 0·105 cm2 and 0·195 cm, the sensitivity, specificity and accuracy of the diagnosis were 91·5, 94·5, 94·1%, and 90·7, 80·4, 86·5%, respectively. Both CSA and D were negatively related to sensory conduction velocity, while CSA was positively related to distal motor latency.Conclusion: There is a good association of sonographic with electrophysiologic detection for the diagnosis of CTS.

Carcinoembryonic antigen level of draining venous blood as a predictor of recurrence in colorectal cancer patient

PurposeWe designed this study to evaluate the efficacy of carcinoembryonic antigen in draining venous blood (vCEA) as a predictor of recurrence.MethodsDraining venous and supplying arterial bloods were collected separately during the operation of 82 colorectal cancer patients without distant metastasis from September 2004 to December 2006. Carcinoembryonic antigen was measured and assessed for the efficacy as a prognostic factor of recurrence using receiver operating characteristic (ROC) and Kaplan-Meier curves.ResultsvCEA is a statistically significant factor that predicts recurrence (P = 0.032) and the optimal cut-off value for vCEA from ROC curve is 8.0 ng/mL. The recurrence-free survival between patients with vCEA levels >8 ng/mL and ≤8 ng/mL significantly differed (P < 0.001). The significance of vCEA as a predictor of recurrence gets higher when limited to patients without lymph node metastasis. The proper cut-off value for vCEA is 4.0 ng/mL if confined to patients without lymph node metastasis. The recurrence-free survival between the patients of vCEA levels >4 ng/mL and ≤4 ng/mL significantly differed (P < 0.001). Multivariate analysis revealed vCEA is an independent prognostic factor in patients without lymph node metastasis.ConclusionvCEA is an independent prognostic factor of recurrence in colorectal cancer patients especially in patients without lymph node metastases.

Abstract P2-06-01: Ki67 Proliferative Index as an Invaluable Biomarker in Hormone Receptor (HR)-Positive Breast Cancer: Ki67 Labelling Index Can Reflect the Differences between Luminal A and B Subtypes Better Than HER2 Expression

Abstract Background: Differentiation by multigene signatures with excellent performance of hormone receptor (HR)-positive BC largely related to their proliferation genes. Despite questions about its usefulness, there is increasing evidence that Ki67 is a valuable prognostic marker. Standardization of Ki67 pathological assessment is the main problem to interpret reported trials. The aims of the study are to evaluate the role Ki67 as prognostic marker to predict relapse in HR-positive BC patients (luminal A and B) in adjuvant setting using prospective patients’ cohort. In addition, cut-off value and significant level of Ki67 were investigated comparing with other biomarkers including HER2 in luminal BCs. Method: We retrospectively analyzed the clinicopathologic characteristics of 1,070 postoperative breast cancer patients including Ki67 and clinical outcomes in terms of relapse free survival (RFS) between 2004 and 2007 at the Samsung Medical Center. Ki67 labelling index was measured in quantitative and semiquantitative method, independently. The percentage of positive nuclei stained for Ki67 was calculated each section based on the approximately 1,000 carcinoma cell nuclei. In addition, Ki67 was graded on a scale from 0 to 4, where 0 = staining of 0-4% of tumor cells, 1 = staining of 5-25% of tumor cells, 2 = 26-50% of tumor cells, 3 = staining of 51-75% of tumor cells, and 4 = staining of more than 76% of tumor cells. ROC curve was drawn to evaluate the usefulness of Ki67 index to get AUC then, find out the proper cut-off value of Ki67 to predict relapse. Multivariate analyses with Cox-regression model were performed. Results: Among 1,564 patients who received curative surgery for invasive breast cancer from January 2004 to June 2007, 1,070 patients with HR-positive were included in this analysis excluding 494 with HER2-enriched or triple negative breast cancer patients. Median follow-up duration was 56.9 months (range 36-77 months). Median age was 46 years (range 22-83 years). Ki67 threshold &amp;gt;19.5%, corresponding to a sensitivity 78.3%, a specificity 51.6% was chosen as cut-off value for relapse in adjuvant patients’ cohort. The AUC was 0.689 (P&amp;lt;0.0001 by Mann-Whitney U test). Overall relapse rate was 5.6%. In univariate analysis by log-rank test for relapse, ER negativity (p=0.010), HER2 positivity (p=0.017), histologic (p=0.001), and nuclear grade (p=0.012), lymphovascular invasion (P&amp;lt;0.0001), TNM stage (0.001), and Ki67 (P&amp;lt;0.0001) were identified risk factors to predict relapse. However, ER negativity, Ki67, and stage were identified as independent risk factors for relapse (Hazard Ratio (HR) 2.7, p=0.031 for ER negativity, HR 3.4, p &amp;lt;0.0001 for Ki67, HR 1.6, p=0.017 for stage) in Cox-regression multivariate analysis. Conclusion: Ki67 could strongly predict clinical outcomes for patients with luminal. 19.5% may be useful cut-off value of Ki67 labelling index. Ki67 may be a better biomarker to predict clinical outcomes than HER2 expression in luminal BCs. ER-/PR+ subset probably has different biology with other luminal BCs. Prospective clinical trials to choose therapeutic option using Ki67 are warranted. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-01.

Predicting Bone Metastasis in Prostate Cancer Patients: Value of Prostate Specific Antigen

Objective Serum prostate specific antigen (PSA) concentration has been widely applied as a biomarker to diagnose and monitor prostate cancer. Technetium-99m methylene diphosphate (Tc-99m MDP) whole body bone scintigraphy is currently a well-accepted diagnostic procedure for bone metastasis in malignancy. The aim of this study was to establish a useful serum PSA cut-off value to predict the presence of bone metastasis in men with prostate cancer. Materials and Methods Consecutive male patients diagnosed with prostate cancer were retrospectively analyzed. All of the subjects had received both Tc-99m MDP whole body bone scintigraphy and had their serum PSA concentration measured within 1 month. The proper cut-off value was established based on statistical analysis in order to predict the possibility of bone metastasis among prostate cancer patients. Results In total, 101 consecutive male patients (age, 71.92 ± 0.76 years) with prostate cancer were enrolled, and 57 patients (56%) were confirmed by scintigraphic findings to have bone metastases. A serum PSA concentration of 13 ng/mL gave the best sensitivity (96.43%) and specificity (84.09%). The area under the receiver operating characteristics curve revealed excellent discriminatory power (0.93 ± 0.02; p = 0.001). The positive predictive value, negative predictive value and likelihood ratios for positive and negative test were 88.52%, 94.87%, 6.06 and 0.04, respectively. The resulting diagnostic accuracy and odds ratio were 73.87% and 142.76. Conclusion A cut-off value of 13 ng/mL appears to be an appropriate benchmark for stratifying metastatic bone disease in prostate cancer patients such that if a patient with newly diagnosed prostate cancer and without any skeletal symptoms has a serum PSA concentration of less than 13 ng/mL, we suggest that they would not need to undergo bone scintigraphy.

Model consisting of ultrasonographic and simple blood indexes accurately identify compensated hepatitis B cirrhosis

Several models for significant fibrosis or cirrhosis have been introduced for hepatitis C, but are seldom for hepatitis B. The present study retrospectively evaluates the relationship between ultrasonography, blood tests, and fibrosis stage, and constructs a model for predicting compensated cirrhosis. A total of 653 patients with chronic hepatitis B who underwent liver biopsies, ultrasonographic scanning, and routine blood tests were retrospectively analyzed. The patients were divided into the model set and validation set. Blood tests and ultrasonographic indexes were analyzed statistically. An ultrasonographic scoring system consisting of liver parenchyma, gallbladder, hepatic vessel, and splenomegaly was introduced. There were significant differences between cirrhosis and other fibrosis stages in ultrasonographic indexes of liver parenchyma, gallbladder, hepatic vessel, and splenomegaly. Ultrasonographic scores were significantly different between F4 and other fibrosis, and significantly correlated with fibrosis stage. Apart from alanine aminotransferase and alkaline phosphatase, blood tests and patients' age were correlated with fibrosis, and were significantly different between patients with and without cirrhosis. The model for cirrhosis indexes consisting of ultrasonographic score, patient's age, and variables, including platelet, albumin, and bilirubin predicted cirrhosis with area under receiver-operator curve of 0.907 in the model set and 0.849 in the validation set. Using proper cut-off values, nearly 81% patients could be accurately assessed for the absence or presence of cirrhosis. The model consisting of ultrasonographic score, patients' age, blood variables of platelet, albumin, and bilirubin can identify hepatitis B cirrhosis with a high degree of accuracy. The application of this model would greatly reduce the number of biopsies.

Establishment of a prediction method for premature rupture of membranes in term pregnancy using active ceruloplasmin in cervicovaginal secretion as a clinical marker

Term pregnancy complicated by premature rupture of membranes (PROM) is thought to be associated in part with subclinical infection, and places mothers and neonates at an increased risk for several complications. Therefore, perinatal care would be greatly helped if a reliable clinical measure were available for predicting the incidence of PROM. One hundred and ninety-six pregnant women who consented to enter this study were screened using a method developed to assess active ceruloplasmin in cervicovaginal secretion as a clinical marker for predicting the incidence of PROM. Cervicovaginal secretions were obtained from the cervical canal at about 36 weeks of pregnancy. The active ceruloplasmin level in the cervicovaginal secretion was measured using an original enzyme-linked immunoabsorbent assay. Of 196 women, 27 women (13.8%) developed PROM and 169 women (86.2%) did not develop PROM. Active ceruloplasmin in the cervicovaginal secretion was significantly higher in the PROM group than in the non-PROM group (P < 0.001). Analysis using receiver-operating characteristic curves showed that the active ceruloplasmin level (1420.0 ng/mL) proved to be the proper cut-off value to best predict the incidence of PROM. Active ceruloplasmin in the cervicovaginal secretion might be a reliable clinical marker for term PROM.

Performance of some variable selection methods when multicollinearity is present

Variable selection is one of the important practical issues for many scientific engineers. Although the PLS (partial least squares) regression combined with the VIP (variable importance in the projection) scores is often used when the multicollinearity is present among variables, there are few guidelines about its uses as well as its performance. The purpose of this paper is to explore the nature of the VIP method and to compare with other methods through computer simulation experiments. We design 108 experiments where observations are generated from true models considering four factors–the proportion of the number of relevant predictors, the magnitude of correlations between predictors, the structure of regression coefficients, and the magnitude of signal to noise. Confusion matrix is adopted to evaluate the performance of PLS, the Lasso, and stepwise method. We also discuss the proper cutoff value of the VIP method to increase its performance. Some practical hints for the use of the VIP method are given as simulation results.

Proper Cut-off Value of Free to Total PSA Ratio for Detection of Prostate Cancer in Korean Men

To assess whether the free-to-total prostate specific antigen (PSA) ratio (F/T PSA ratio) would enhance prostate cancer detection in Korean men with serum total PSA levels between 4 and 20 ng/ml. A total of 240 consecutive patients whose serum PSA levels were between 4 and 20 ng/ml were enrolled in this two-year study. All patients underwent ultrasound-guided transrectal biopsies of the prostate gland. The F/T PSA ratio was measured using the Roche immunoassay. Of the 240 patients, 202 (84%) had benign histologies, while 38 (16%) had prostate cancer. The two patient groups were well matched for age. The mean F/T PSA ratio showed a statistically significant difference between the two groups: in the benign histology group it was 0.14 (0.04 - 0.37), and 0.10 (0.08 - 0.20) in the prostate cancer group (p < 0.05). Out of the 183 patients with a PSA level between 4-10 ng/ml, the mean F/T PSA ratios were 0.14 and 0.11 in the benign histology (n=158) and prostate cancer groups (n=25), respectively (p < 0.05). From the 57 patients with a PSA level between 10 - 20 ng/ml, the mean F/T PSA ratios were 0.14 and 0.10 in the benign histology (n=44) and prostate cancer groups (n=13), respectively (p < 0.05). Overall, when the cut-off value of the F/T PSA ratio was 0.10, the sensitivity and specificity were 75.0% and 76.5%, while for the cut-off value of 0.15 they were 83.3% and 39.7% respectively. Our data demonstrated the usefulness of the free to total PSA ratio in distinguishing benign prostate disease and cancer disease, hence eliminating unnecessary biopsies. It is recommended that a cut-off value for the F/T PSA ratio of 0.10 be applied to Korean men which this is lower than the value used in Western countries.