• Title/Summary/Keyword: False-negative results

Search Result 307, Processing Time 0.029 seconds

Accuracy of Combined Visual Inspection with Acetic Acid and Cervical Cytology Testing as a Primary Screening Tool for Cervical Cancer: a Systematic Review and Meta-Analysis

  • Chanthavilay, Phetsavanh;Mayxay, Mayfong;Phongsavan, Keokedthong;Marsden, Donald E;White, Lisa J;Moore, Lynne;Reinharz, Daniel
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.14
    • /
    • pp.5889-5897
    • /
    • 2015
  • Background: The performance of combined testing visual inspection with acetic acid (VIA) and cervical cytology tests might differ from one setting to another. The average estimate of the testing accuracy across studies is informative, but no meta-analysis has been carried out to assess this combined method. Objective: The objective of this study was to estimate the average sensitivity and specificity of the combined VIA and cervical cytology tests for the detection of cervical precancerous lesions. Materials and Methods: We conducted a systematic review and a meta-analysis, according to the Cochrane Handbook for Systematic Review of Diagnostic Test Accuracy. We considered two cases. In the either-positive result case, a positive result implies positivity in at least one of the tests. A negative result implies negativity in both tests. In the both-positive case, a positive result implies having both tests positive. Eligible studies were identified using Pubmed, Embase, Website of Science, CINHAL and COCRANE databases. True positive, false positive, false negative and true negative values were extracted. Estimates of sensitivity and specificity, positive and negative likelihood (LR) and diagnostic odds ratios (DOR) were pooled using a hierarchical random effect model. Hierarchical summary receiver operating characteristics (HSROC) were generated and heterogeneity was verified through covariates potentially influencing the diagnostic odds ratio. Findings: Nine studies fulfilled inclusion criteria and were included in the analysis. Pooled estimates of the sensitivities of the combined tests in either-positive and both-positive cases were 0.87 (95% CI: 0.83-0.90) and 0.38 (95% CI: 0.29-0.48), respectively. Corresponding specificities were 0.79 (95% CI: 0.63-0.89) and 0.98 (95% CI: 0.96-0.99) respectively. The DORs of the combined tests in either-positive or both-positive result cases were 27.7 (95% CI: 12.5-61.5) and 52 (95% CI: 22.1-122.2), respectively. When including only articles without partial verification bias and also a high-grade cervical intraepithelial neoplasia as a threshold of the disease, DOR of combined test in both-positive result cases remained the highest. However, DORs decreased to 12.1 (95% CI: 6.05-24.1) and 13.8 (95% CI: 7.92-23.9) in studies without partial verification bias for the combined tests in the either-positive and both-positive result cases, respectively. The screener, the place of study and the size of the population significantly influenced the DOR of combined tests in the both-positive result case in restriction analyses that considered only articles with CIN2+ as disease threshold. Conclusions: The combined test in the either-positive result case has a high sensitivity, but a low specificity. These results suggest that the combined test should be considered in developing countries as a primary screening test if facilities exist to confirm, through colposcopy and biopsy, a positive result.

Comparison of Histopathology, Serology and PCR for the Diagnosis of Malignant Catarrhal Fever (Malignant Catarrhal Fever의 병리조직학적 진단과 혈청학적 진단 및 PCR 진단법의 비교)

  • Kim, Ok-jin;Crawford, Timothy B.
    • Korean Journal of Veterinary Research
    • /
    • v.43 no.3
    • /
    • pp.471-476
    • /
    • 2003
  • Malignant catarrhal fever (MCF) is a systemic disease of ruminants caused by ovine herpesvirus 2 (OvHV-2). OvHV-2 is a gamma herpesvirus, which induces frequent latent infection and often difficult to detect its antigens and even specific nucleic acids because of its low viral copies in the infected tissues. Histopathology, serology and polymerase chain reaction (PCR) were compared for the diagnosis of MCF using 10 bison infected with OvHV-2. Histopathological diagnosis was performed using the criteria which was based upon the pathognomic lesions. Serological diagnosis was conducted using its serum with competitive ELISA for the detection of antibodies of OvHV-2. Also, the nest PCR was performed with peripheral blood leukocytes for the detection of OvHV-2-specific DNAs. Primers 556 and 775 were used for the primary amplification, and primers 556 and 555 were used for the secondary amplification. As the results, positive cases were 6 by histopahology, 9 by serology and 10 by PCR. As comparing with other diagnostic methods, PCR was found to be more sensitive than histopathology and serology. The recent development of molecular diagnostic assays has provided powerful tools for investigating how viruses survive in nature. Development of PCR specific for viruses has dramatically improved the accuracy of diagnosis of viruses in clinically infected animals. Furthermore, amplification of viral genomic material by nest PCR represents the most sensitive method for the detection of viruses and might be detected successfully even though very low viral DNA copies. So, it could be used as the first choice for the detection of viral DNAs with low copies such as the status of latent infection. However, it has also some limitation of application like as false negative results by PCR inhibitors and false positive results by contamination. The results of this study suggest that the use of molecular biological methods like PCR may increase the accuracy for the diagnosis of infectious diseases. However, in diagnostic laboratory, it is recommended that PCR assay must be conducted with other diagnostic methods for more reliable diagnosis.

A Study of Diagnostic Value on Fine Needle Aspiration Cytology of the Breast Masses (유방종괴의 세침흡인세포학의 진단적 가치에 관한 연구)

  • Kim, Dong-Won;Lee, Dong-Wha
    • The Korean Journal of Cytopathology
    • /
    • v.4 no.1
    • /
    • pp.1-8
    • /
    • 1993
  • This study was performed in order to evaluate the accuracy and the usefulness of the fine needle aspiration cytology (FNAC) on the breast lesions, to compare the FNAC findings between fibroadenoma and fibrocystic disease, and to determine the accuracy of cytologic Black's nuclear grading. The subjects in this study were 110 cases of FNAC, later confirmed by biopsy, between January 1988 and December 1991. The results are as follows ; 1 Comparison between the results of the FNAC and the histologic findings revealed that FNAC had a sensitivity of 96.6%, a specificity of 100%, a false negative rate of 3.4% a false positive rate of 0.0%, and an overall diagnostic accuracy of 98.2%. 2 Semi-quantitative evaluation of epithelial celluarity, stroma, and naked nuclei in the smears of aspirate showed high celluarity in 56.7% of the aspirates from fibroadenoma and in 0% of those from fibrocystic disease. Abundant stroma was found in 46.7% of the fibroadenoma and none of fibrocystic disease. Numerous naked nuclei were found in 60% of the fibroadenoma and 4.5% of the fibrocystic disease. The overall diagnostic accuracy was 98% 3. In order to determine the accuracy of Black's nuclear grading of FNAC on breast carcinoma, we retrospectively studied 38 cases of ductal carcinomas diagnosed by FNAC with subsequent histologic confirmation. The concordance rate with histology was 94.7%. These results suggest that FNAC of breast is a diagnostically accurate method, and provide for the preoperative differential diagnosis between fibroadenoma and fibrocystic disease. Our results also suggest that the evaluation of nuclear grading of FNAC can predict clinical outcome and decide the way of management of breast cancer.

  • PDF

Comparison Between Two Detection Methods for HPV16, HPV18 and P16Ink4a Biomarkers in Diagnosis of Abnormal Cervical Cytology

  • Khazaei, Sedigheh;Izadi, Babak;Mirbahari, Seyed Ghasem;Madani, Seyed Hamid;Khosravi, Shohre Malek;Alagha, Mohsen Emami;Sajadimajd, Soraya
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.12
    • /
    • pp.5223-5227
    • /
    • 2016
  • Background: Cervical cancer is the second most common cancer among women in many populations. While the Pap smear is a well established screening test it suffers from both false-positive and false-negative results in diagnosis of cancers and precancerous states. In this study, immunocytochemistry of the P16 biomarker and HPV-PCR were compared for their diagnostic potential. Materials and methods: In the study, we obtained pairs of specimens from 45 women with cervical dysplasia. One sample was placed in a liquid-based solution, and processed for staining of sections with antibodies to P16. HPV-PCR was performed on the other and the results obtained were analyzed by T-test using SPSS v. 15. Results: Using HPV-PCR 71% of the samples were found to be infected with either HPV 16 or HPV 18, and the rate of infection did not have a statistically significant relationship with higher grades of dysplasia (p= 0.253). In contrast, with immunocytochemistry evaluation of P16, 64% of the specimens were positive, but the percentage of positive results significantly increased with higher grades of dysplasia (p= 0.0001). Conclusion: Employment of the P16 marker as an optional test might be preferable over HPV-PCR for cervical dysplasia in our geographical region.

Clinical Characteristics of False-Positive Lymph Node on Chest CT or PET-CT Confirmed by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Lung Cancer

  • Lee, Jongmin;Kim, Young Kyoon;Seo, Ye Young;Choi, Eun Kyoung;Lee, Dong Soo;Kim, Yeon Sil;Hong, Sook Hee;Kang, Jin Hyoung;Lee, Kyo Young;Park, Jae Kil;Sung, Sook Whan;Kim, Hyun Bin;Park, Mi Sun;Yim, Hyeon Woo;Kim, Seung Joon
    • Tuberculosis and Respiratory Diseases
    • /
    • v.81 no.4
    • /
    • pp.339-346
    • /
    • 2018
  • Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a standard procedure to evaluate suspicious lymph node involvement of lung cancer because computed tomography (CT) and $^{18}F$-fluorodeoxyglucose positron emission tomography-CT (PET-CT) have limitations in their sensitivity and specificity. There are a number of benign causes of false positive lymph node such as anthracosis or anthracofibrosis, pneumoconiosis, old or active tuberculosis, interstitial lung disease, and other infectious conditions including pneumonia. The purpose of this study was to evaluate possible causes of false positive lymph node detected in chest CT or PET-CT. Methods: Two hundred forty-seven patients who were initially diagnosed with lung cancer between May 2009 and December 2012, and underwent EBUS-TBNA to confirm suspicious lymph node involvement by chest CT or PET-CT were analyzed for the study. Results: Of 247 cases, EBUS-TBNA confirmed malignancy in at least one lymph node in 189. The remaining 58 patients whose EBUS-TBNA results were negative were analyzed. Age ${\geq}65$, squamous cell carcinoma as the histologic type, and pneumoconiosis were related with false-positive lymph node involvement on imaging studies such as chest CT and PET-CT. Conclusion: These findings suggest that lung cancer staging should be done more carefully when a patient has clinically benign lymph node characteristics including older age, squamous cell carcinoma, and benign lung conditions.

Breast Magnetic Resonance Imaging Indications in Current Practice

  • Taif, Sawsan Abdulkareem
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.2
    • /
    • pp.569-575
    • /
    • 2014
  • Although mammography is the primary imaging modality for the breast, it has its limitations especially with dense breast parenchyma. Breast magnetic resonance imaging (MRI) has evolved into an important adjunctive tool as it is currently the most sensitive technique for breast cancer detection. Despite this high sensitivity, overlap in the appearances of some benign and malignant breast lesions results in additional unnecessary intervention with negative results. These false positives, in addition to high cost and limited availability, necessitate establishing proper indications for breast MRI. The literature was here reviewed for recent clinical trials, meta-analyses and review papers which have studied this important subject. PubMed; the US national library of medicine, was utilized to review the literature in the last twenty years. Using the obtained information, current uses of breast MRI are discussed in this paper to determine the indications which are relevant to clinical practice.

Internal Amplification Control for a Cryptosporidium Diagnostic PCR: Construction and Clinical Evaluation

  • Hawash, Yousry;Ghonaim, M.M.;Al-Hazmi, Ayman S.
    • Parasites, Hosts and Diseases
    • /
    • v.53 no.2
    • /
    • pp.147-154
    • /
    • 2015
  • Various constituents in clinical specimens, particularly feces, can inhibit the PCR assay and lead to false-negative results. To ensure that negative results of a diagnostic PCR assay are true, it should be properly monitored by an inhibition control. In this study, a cloning vector harboring a modified target DNA sequence (${\approx}375bp$) was constructed to be used as a competitive internal amplification control (IAC) for a conventional PCR assay that detects ${\approx}550bp$ of the Cryptosporidium oocyst wall protein (COWP) gene sequence in human feces. Modification of the native PCR target was carried out using a new approach comprising inverse PCR and restriction digestion techniques. IAC was included in the assay, with the estimated optimum concentration of 1 fg per reaction, as duplex PCR. When applied on fecal samples spiked with variable oocysts counts, ${\approx}2$ oocysts were theoretically enough for detection. When applied on 25 Cryptosporidium-positive fecal samples of various infection intensities, both targets were clearly detected with minimal competition noticed in 2-3 samples. Importantly, both the analytical and the diagnostic sensitivities of the PCR assay were not altered with integration of IAC into the reactions. When tried on 180 randomly collected fecal samples, 159 were Cryptosporidium-negatives. Although the native target DNA was absent, the IAC amplicon was obviously detected on gel of all the Cryptosporidium-negative samples. These results imply that running of the diagnostic PCR, inspired with the previously developed DNA extraction protocol and the constructed IAC, represents a useful tool for Cryptosporidium detection in human feces.

Agreement between Colposcopic Diagnosis and Cervical Pathology: Siriraj Hospital Experience

  • Tatiyachonwiphut, Molpen;Jaishuen, Atthapon;Sangkarat, Suthi;Laiwejpithaya, Somsak;Wongtiraporn, Weerasak;Inthasorn, Perapong;Viriyapak, Boonlert;Warnnissorn, Malee
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.1
    • /
    • pp.423-426
    • /
    • 2014
  • Aim: To evaluate the agreement between colposcopic diagnosis and cervical pathology a retrospective chart review was performed. Materials and Methods: This study included 437 patients who underwent colposcopy and cervical biopsy or conization at Siriraj Hospital from October 2010 - December 2012. The patient clinical characteristics, cervical cytology results, colposcopic diagnoses, cervical pathology results were recorded and correlations between variables were analyzed. Results: Agreement of colposcopic diagnosis and cervical pathology was matched in 253 patients (57.9%). The strength of agreement with weighted Kappa statistic was 0.494 (p<0.001). Colposcopic diagnoses more often overestimated (31.1%) than underestimated (11%) the cervical pathology. Agreement of colposcopic diagnosis and cervical pathology within 1 grade was found in 411 patients (94.1%). Positive predictive value (PPV) of high grade colposcopy or more was 75.5%, whereas the negative predictive value (NPV) of insignificant and low grade colposcopy was 83.8%. False positives of high grade colposcopy or more were 21%. False negatives of insignificant or low grade colposcopy were 19.1%. Conclusions: Strength of agreement between colposcopic diagnosis and cervical pathology was found to be only moderate. A biopsy at colposcopy should be performed at a gold standard level to detect high grade lesions.

Nonspecific Mouse Hepatitis Virus Positivity of Genetically Engineered Mice Determined by ELISA

  • Han, Dae Jong;Kim, Hyuncheol;Yeom, Su-Cheong
    • Biomedical Science Letters
    • /
    • v.21 no.1
    • /
    • pp.9-14
    • /
    • 2015
  • Mouse hepatitis virus (MHV) is a major pathogen in laboratory mice that usually leads to fatal diseases, such as hepatitis, multiple sclerosis, encephalitis, and respiratory disease. MHV has a high infection rate, and it needs to be detected as soon as possible to prevent its spread to other facilities. However, MHV detection by enzyme-linked immunosorbent assay (ELISA) often gives false positives; thus, it is very important that the results are confirmed as true positives in the early infection stage or distinguished as false positives with more accurate, reliable methods. Under microbiological screening, MHV ELISA-positive mice were found in four GFP-tagging transgenic mice. To verify the detection of the MHV antigen directly, reverse transcription polymerase chain reaction (RT-PCR) was performed, and the mice were determined to be MHV negative. Additional serum antibody-based screening was conducted with three different ELISA kits, and multiplexed fluorometric immunoassay (MFIA) was performed to confirm their accuracy/sensitivity. In brief, the ELISA kit for A59 nucleocapsid protein (MHV-A59N) revealed MHV ELISA positivity, while other ELISA kits (MHV-S lysate and MHV-JHM lysate) demonstrated MHV negativity. In MFIA, only the test for the recombinant A59 nucleocapsid antigen was MHV positive, which was consistent with the ELISA results. These results suggest that the ELISA kit with the recombinant A59 nucleocapsid antigen might induce non-specific MHV ELISA positivity and that confirmation is therefore essential.

A Study on Availability about Positron Emission Mammography of Breast Cancer (유방암 환자의 Positron Emission Mammography에서의 유용성에 관한 연구)

  • Kim, Seung-Jeong;Kim, Jae-Il;Kim, Jin-Eui;Kim, Hyun-Joo
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.14 no.2
    • /
    • pp.60-64
    • /
    • 2010
  • Purpose: Until now the general study for breast cancer patient has been mammography, breast sonography for anatomic diagnostics and $^{18}F$-FDG whole body PET for functional one. But the PEM (Positron Emission Mammography) was developed to increase sensitivity, specificity and accuracy to improve the disadvantage of each study. Therefore this present study aims to describe availability of PEM for improving diagnosis of breast cancer. Materials and Methods: During 3 months from January in 2010, PEM was performed on 100 patients who had history of breast cancer. Using Naviscan's PEM Flex Solo II scanner, PEM images of breast were acquired. And then we evaluated sensitivity, specificity and accuracy of PEM data by comparing results of PEM images with postoperative pathologic finding. Results: On the 100 patients, it could reveal 89 true positive, 9 false positive, 7 false negative and 87 true negative. Thus the results of sensitivity, specificity and accuracy for PEM was evaluated 92.7%, 90.6% and 91.7%. Conclusion: The sensitivity, specificity and accuracy have been reported 83.7%, 68.5% and 77.1% in mammography, and that was 89.1%, 79.1% and 83.4% in breast sonography. However the results of PEM were more increased than others. Therefore the results of this study will be available that PEM used diagnosis with breast cancer, used preoperative operation plan and helps to discovery of a part recurrence.

  • PDF