• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7381-7384
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• 2015

This study was conducted to 1206 women who had cervical cancer screening at Chonburi Cancer Hospital. The spilt-sample study aimed to compare the efficacy of abnormal cervical cells detection between liquid-based cytology (LBC) and conventional cytology (CC). The collection of cervical cells was performed by broom and directly smeared on a glass slide for CC then the rest of specimen was prepared for LBC. All slides were evaluated and classified by The Bethesda System. The results of the two cytological tests were compared to the gold standard. The LBC smear significantly decreased inflammatory cell and thick smear on slides. These two techniques were not difference in detection rate of abnormal cytology and had high cytological diagnostic agreement of 95.7%. The histologic diagnosis of cervical tissue was used as the gold standard in 103 cases. Sensitivity, specificity, positive predictive value, negative predictive value, false positive, false negative and accuracy of LBC at ASC-US cut off were 81.4, 75.0, 70.0, 84.9, 25.0, 18.6 and 77.7%, respectively. CC had higher false positive and false negative than LBC. LBC had shown higher sensitivity, specificity, PPV, NPV and accuracy than CC but no statistical significance. In conclusion, LBC method can improve specimen quality, more sensitive, specific and accurate at ASC-US cut off and as effective as CC in detecting cervical epithelial cell abnormalities.

• The Korean Journal of Cytopathology
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• v.19 no.2
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• pp.111-118
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• 2008

Background : Cervicovaginal cytology is a screening test of uterine cervical cancer. The sensitivity of cervicovaginal cytology is less than 50%, but studies of cytologic/histologic correlation are limited. We analyzed the diagnostic accuracy of cervicovaginal cytology in the detection of the squamous epithelial lesions of the uterine cervix and investigate the cause of diagnostic discordance. Materials and Methods : We collected a total of 481 sets of cervicovaginal cytology and biopsies over 5 years. The cytologic diagnoses were categorized based on The Bethesda System and the histologic diagnoses were classified as negative, flat condyloma, cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III, or squamous cell carcinoma. Cytohistologic discrepancies were reviewed. Results: The concordance rate between the cytological and the histological diagnosis was 79.0%. The sensitivity and specificity of cervicovaginal cytology were 80.6% and 92.6%, respectively. Its positive predictive value and negative predictive value were 93.7% and 77.7%, respectively. The false negative rate was 19.4%. Among 54 false negative cytology cases, they were confirmed by histology as 50 flat condylomas, 2 CIN I, 1 CIN III, and 1 squamous cell carcinoma. The causes of false negative cytology were sampling errors in 75.6% and interpretation errors in 24.4%. The false positive rate was 7.4%. Among 15 false positive cytology cases, they were confirmed by histology as 12 atypical squamous cells of undetermined significance (ASCUS) and 3 low grade squamous intraepithelial lesions (LSIL). The cause of error was interpretation error in all cases. The overall diagnostic accuracy of cervicovaginal cytology was 85.7%. Conclusions : Cervicovaginal cytology shows high overall diagnostic accuracy and is a useful primary screen of uterine cervical cancer.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.114-119
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• 1987

The author investigated the effect of some variables such as age, sex and the experience of past vaccination on the validity of PHA. The changing pattern of the validity with the change of PHA diagnostic criteria, and the relationship between PHA test result and RIA Ratio Unit were also studied. The results obtained were as follow; 1) No statistically significant difference was found in sensitivity, specificity and negative predictability by sex, but positive predictability was significantly higher in male than that in female. 2) Positive predictability was shown to become higher with the increase of age and nagative predictability was found to be significally different among age groups, but no statistically significant difference was found in sensitivity and specificity by age group. 3) Significantly low specificity and high positive predictability were found in past vaccined group, but no statistically significant difference was found in sensitivity and negative predictability between past vaccined group and non-vaccined group. 4) False negative cases by PHA were found to be the weak positive reactors by RIA and false positive rate of PHA was as high as 46.3 per cent. 5) Sensitivity and specificity of PHA at the diagnostic criteria of HBsAb titer 1:2 were 98.4% and 53.8% respectively, but after increasing the HBsAb titer to 1:64 as the diagnostic criteria the results were 60.0% and 95.6% respectively.

• The Korean Journal of Cytopathology
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• v.9 no.1
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• pp.37-44
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• 1998

OBJECTIVE: False negatives of cervical smears due to screening errors pose a significant and persistent problem. AutoPap 300 QC System, an automated screening device, is designed to rescreen conventionally prepared Pap smears initially screened by cytotechnologists as normal. Clinical experience and sensitivity of the AutoPap 300 QC System were assessed and compared with current 10% random qualify control technique. MATERIALS AND METHODS: In clinical practice, a total of 18,592 "within normal limits" or "benign cellular changes" cases classified by The Bethesda System were rescreened by the Autopap System. In study for sensitivity of The AutoPap System to detect false negatives, a total of 1,680 "within normal limits" or "benign cellular changes" cases were rescreened both manually and by the AutoPap System. The sensitivity of the AutoPap System to these false negatives was assessed at 10% review rate to compare 10% random manual rescreen. RESULTS: In clinical practice, 38 false negatives were identified by the AutoPap System and we had achieved 0.2% reduction in the false negative rate of screening error. In study for sensitivity, 37 false negatives were identified by manual rescreening, and 23 cases(62.2%) of the abnormal squamous cytology were detected by the AutoPap System at 10% review rate. CONCLUSONS: The AutoPap 300 QC System is a sensitive automated rescreening device that can detect potential false negatives prior to reporting and can reduce false negative rates in the laboratory. The device is confirmed to be about eight times superior to the 10% random rescreen in detecting false negatives.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.511-519
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• 2019

Objectives: The standard method for the enumeration of environmental Legionella is culturing, which has several disadvantages, including long incubation and poor sensitivity. The purpose of this study is to demonstrate the usefulness of real-time PCR and to improve the standard method. Methods: In 200 environmental water samples, a real-time PCR and culture were conducted to detect and quantify Legionella. Using with the results of the survey, we compared the real-time PCR with the culture. Results: Each real-time PCR assay had 100% specificity and excellent sensitivity (5 GU/reaction). In the culture, 36 samples were positive and 164 samples were negative. Based on the results of the culture, real-time PCR showed a high negative predictive value of 99%, 35 samples were true positive, 105 samples were true negative, 59 samples were false positive and one sample was a false negative. Quantitative analysis of the two methods indicated a weak linear correlation ($r^2=0.29$, $r^2=0.61$, respectively). Conclusions: Although it is difficult to directly apply quantitative analysis results of real-time PCR in the enumeration of environmental Legionella, it can be used as a complementary means of culturing to rapidly screen negative samples and to improve the accuracy of diagnosis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5385-5389
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• 2012

Introduction: Sentinel lymph node biopsy (SLNB) is a precise procedure for lymphatic staging in early breast cancer. In a valid SLNB procedure, axillary lymph node dissection (ALND) can be omitted in nodenegative cases without compromising patient safety. In this study, detection rate, accuracy and false negative rate of SLNB for breast cancer was evaluated in a setting with simple modified conventional pathology facilities without any serial sectioning or immunohistochemistry. Material and Medthod: Patients with confirmed breast cancer were enrolled in the study. SLNB and ALND were performed in all cases. Lymph node metastasis was evaluated in SLN and in nodes removed by ALND to determine the false negative rate. Pathologic assessment was carried out only by modified conventional technique with only 3 sections. Detection rate was determined either by lymphoscintigraphy or during surgery. Results: 78 patients with 79 breast units were evaluated. SLN was detected in 75 of 79 cases (95%) in lymphoscintigraphy and 76 of 79 cases (96%) during surgery. SLN metastases was detected in 30 of 75 (40%) cases either in SLNB and ALND groups. Accuracy of SLNB method for detecting LN metastases was 92%. False negative rate was 3 of 30 of positive cases: 10%. In 7 of 10 cases with axillary lymphadenopathy, LN metastastates was detected. Conclusion: SLNB is recommended for patients with various tumor sizes without palpable lymph nodes. In modified conventional pathologic examination of SLNs, at least macrometastases and some micrometastases could be detected similar to ALND. Consequently, ALND could be omitted in node-negative cases with removal of all palpable LNs. We conclude that SLNB, as one of the most important developments in breast cancer surgery, could be expanded even in areas without sophisticated pathology facilities.

• Journal of Preventive Medicine and Public Health
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• v.33 no.2
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• pp.226-230
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• 2000

Objectives : The purpose of this study was to suggest a proper method for the detection of heaptitis B surface antibody(anti-HBs) in a screening program for hepatitis B vaccination. Methods : Sensivitity, specificity and predictive values were compared between Immunochromatographic assay (ICA) and passive hemagglutination(PHA) in 978 subjects(565 males, 413 females, 19-78 years ranging in age, mean 46.5 years old). EIA was used as a standard method for the detection of HBsAb. Results : Sensitivity in the detection of anti-HBs of PHA and ICA was 88.7%, and 94.9%, specificity was 94.3% and 96.6%, negative predictive value was 96.5%, and 98.0%, and positive predictive value was 82.3%, and 91.3%,, respectively. False negative rate(11.3%) of PHA was higher than that(5.1%) of ICA. The higher the titer of anti-HBs in EIA was, the lower the false negative rate was. There was no false negative result in the cases with $101mIU/{\beta}c$ or more in EIA Conclusion : We suggest that ICA should be the choice of screening method in the detection of anti-HBs in Hepatitis B vaccination program.

• The Korean Journal of Cytopathology
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• v.2 no.1
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• pp.8-19
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• 1991

A statistical analysis of the diagnostic value for 244 aspiration biopsy cytology(ABC) among a total 1,043 cases from various sites was performed. ABC, using diagnostic terminology similar to that of a surgical pathology reports, was compared to the final tissue diagnosis. For the entire series, a sensitivity of 91.8%, a specificity of 99.3%, a positive predictive value of 98.9%, a negative predictive value of 94,8%, and an efficacy of the test of 96.3% were shown. There were 8 false negative and 1 false positive diagnosis. The diagnostic accuracy was 89.8%. Those results indicate that the ABC is a considerably highly accurate procedure that should be routinely employed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.4
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• pp.222-226
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• 2011

This study was conducted to identify the characteristics of analytical errors shown in the Korean quality control program on bulk asbestos analyses using polarized light microscopy (PLM). 179 participating laboratories were required to analyze 4 samples respectively and asked to classify each test sample as asbestos-containing (positive) or non-asbestos-containing (negative). For positive samples, participants were also asked to identify the type and semiquantitate the contents of asbestos present. The test results showed 21 (4%) false negative errors among 562 samples, 9 (6%) false positive errors among 154 samples and 53 (9%) asbestos identification errors among 562 samples. Most of false negative and positive errors were observed in a few types of samples. Higher frequencies of asbestos identification errors were shown in samples containing two or more types of asbestos and samples containing anthophyllite, tremolite or actinolite asbestos. For semiquantitative analyses, the ratios of mean to nominal weight contents were 2.1 for chrysotile and 2.9 for amphiboles. A tendency of over-estimation was observed in semiquantitative analyses using the visual estimation technique and higher in case of analyzing samples containing amphiboles than chrysotile. Coefficients of variation (CVs) of semiquantitative analytical results were 0.44~0.83 and 0.5~1.14 for samples containing chrysotile and amphibole asbestos, respectively.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.50-59
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• 2017

To evaluate the capability of integrated PET-MRI, which has recently been utilized in the clinical practices, on the diagnosis of liver cancer, its utility was assessed by $2{\times}2$ decision matrix. The numbers of abnormal and normal decisions on the liver cancer were 98 and 51 cases, respectively, upon PET-MRI scan results of the subjects, and the numbers of positive and negative decisions were 103 and 62, respectively, upon cytopathologic results. Out of the two tests, 95 cases were shown as true-positive and 3 were false positive, while 62 were true negative and 5 were false negative. Upon the results of PET-MRI test, its sensitivity, specificity, false negative rate, and false positive rate were 95.00%, 95.38%, 0.05%, and 95.15%, respectively. Therefore, it is considered to have the high potential to use the determination of the stage before the surgery, detections of recurrence and remote metastasis, assessment of uncertain remote lymph node metastasis, and so on in the diagnosis of the liver cancer, and also for the clinical utility of PET-MRI to be sufficient by integrated diagnosis and follow up scan with pathological studies.