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Biomedical subjects

R W Giard

Publications and source records attributed to R W Giard.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Cervical smears unsuitable for exclusion of cervical carcinoma].

In women with contact bleeding or vaginal discharge, cervical smears are often made to exclude the possibility of cervical carcinoma. During the past ten years, several women sued pathologists for failure to diagnose cervical cancer because of false-negative results entailing a diagnostic delay of years. This, however, is unjustifiable: clinicians have to consider the aim of performing a test and always have to interpret the outcome within the clinical context. If the indication for testing is to exclude cervical cancer with enough certainty, a false-negative rate possibly as high as 45% makes the smear definitely unsuitable for this aim.

Diagnosis, Differential↗
PubMed1999

[Truth after death].

Diagnosis is central to medicine. In spite of tremendous diagnostic technological advances, no infallible test exists and in the complex diagnostic process the physician may well get lost. The ultimate feedback on the accuracy of diagnosis is the autopsy. Five patients illustrate that the autopsy may disclose unexpected results. The first patient was a 9-year-old girl who suffered from daily abdominal spasmodic pain but each time recovered. She died suddenly; autopsy revealed intestinal intussusception. A 46-year-old man who was treated for hypertension developed pain in the chest and the lower back, but there were no other signs of myocardial infarction. He died suddenly; autopsy revealed a dissecting aortic aneurysm with rupture in the left pleural cavity. A 21-year-old woman, an excellent swimmer, drowned during a swim in the sea. Autopsy revealed severe widespread coronary disease with multiple myocardial infarction. A 32-year-old Surinam woman developed acute coma and died from cardiorespiratory arrest. At autopsy she had massive pulmonary embolism and generalized lymphadenopathy due to sarcoidosis. The last patient, a 32-year-old woman suffered from fatigue after her fourth child was born. She was admitted with severe dyspnoea and her chest X-ray showed interstitial fibrosis. She died presently and autopsy revealed metastatic colon carcinoma with pulmonary lymphangitis carcinomatosa. Systematic reviews of the results of autopsies show no decline in the percentage of false diagnoses and/or unexpected findings in spite of the enormous growth of the diagnostic armamentarium. Although we may radiologically 'slice' the body in incredible detail or investigate human cells at the molecular level, the autopsy has by no means become obsolete and is an invaluable tool for quality control and teaching.

Adenocarcinoma↗
PubMed1999

[Increasingly sophisticated detection of lymph node metastases: the problem of stage migration].

The standard technique for the detection of lymph node metastases (LNM) underdiagnosis a large proportion of the cases. The more intensive the search for LNM, the larger the number of LNM detected. Most of these newly detected LNM are of microscopic size ('micrometastases'). As a result of a more accurate lymph node staging, more patients have a higher stage of disease (stage migration). In addition to direct methods for revealing LNM microscopically, indirect molecular methods such as the polymerase chain reaction have become available. These methods are extremely sensitive but possibly have an unacceptable low specificity. Caution is needed when introducing techniques for molecular ultrastaging. The clinical significance of newly detected LNM is yet ill understood. Owing to the recent introduction of the sentinel node procedure lymph nodes are much more intensively examined. This may lead to stage migration for a substantial number of women and it is yet unclear whether this is to their benefit. The results of observational research to determine the clinical significance of (micro) metastases should not lag behind the ever increasing sensitivity of detection techniques.

Diagnostic Techniques and Procedures↗
PubMed1998

[The drawbacks of diagnostic diligence].

More, earlier and better diagnostic work is being done nowadays, leasing to detection of abnormalities and preliminary stages that used to remain undetected; a large reservoir of subclinical disorders is found to exist. More intensive and sensitive diagnostic methods as a rule lead to higher disease prevalence figures, with the consequences of a seeming increase of disease risk, unnecessary further examinations, treatment and follow-up of individuals and overestimation of the effects of treatment. This may even start a vicious circle. More attention should be given to using diagnostic methods in such a way that the earlier and more frequent detection of disease actually profits the patient. The proof of this should be found in scientific (population) studies of the magnitude and severity of the burden of disease, the determinants of progression, the severity of abnormalities and diseases and the favourable effect of (early) treatment.

Cost of Illness↗
PubMed1998

[A marked increase in the rate of diagnosed prostate cancer in the Netherlands during 1990-1996].

OBJECTIVE: To study the variation of the number of histologically detected adenocarcinomas of the prostate in the Netherlands during the period 1990-1996. DESIGN: Retrospective. SETTING: National study. METHOD: Use was made of data from the National Automated Morbid-Anatomical Record Department (PALGA), Utrecht. The following data were established for each year of the study period: the total number of histological examinations of the prostate, the number of men involved (often several histological examinations of the prostate of the same man in the same year), how often adenocarcinoma was diagnosed by these examinations and how many men were involved, as well as the age of all carcinoma patients. These data were compared with those concerning variation and incidence of cancer of the prostate obtained from the Netherlands. Cancer Registration and the Central Statistics Office. RESULTS: In 7 years a total of 205,525 histological examinations of the prostate were performed in 179,298 men; the diagnosis 'adenocarcinoma of the prostate' was made 52,964 times in 44,182 men. The number of tissue examinations with the diagnosis 'carcinoma of the prostate' increased by 63% (from 5,596 to 9,146), the number of men in whom this diagnosis was made increased by 62% (from 4,710 to 7,614). The relative frequency of prostate carcinoma in relation to all examinations of the prostate increased in 6 years (1991-1996) from 22% to 28%. In that period, the (uncorrected) incidence increased by 50%, while mortality corrected for age remained the same. CONCLUSION: Of the marked increase of the number of detected cases of carcinoma of the prostate in the study period, only a small part could be attributed to demographic changes. Since autopsies have shown that there exists a large 'stock' of subclinical carcinomas, most of the growth can probably be explained by the more intensive diagnostics with prostate-specific antigen and transrectal ultrasonography.

Adenocarcinoma↗
PubMed1997

[What to do with surgically removed tissues: send it to the pathologist or put it in the medical waste container?].

Clinicians are sometimes in doubt whether or not to send routinely removed tissue to the pathologist, as not every pathological investigation produces relevant findings. It is not easy, however, to select specimens to be investigated. The cost effectiveness of pathological examination should be investigated prospectively in relation to other clinical diagnostic procedures, e.g. if it is decided that it is not cost effective to take biopsies during endoscopy, it may be questioned whether the endoscopy itself is cost effective.

Cost-Benefit Analysis↗
PubMed1997

[Disappointing effectiveness of population screening for cervical cancer].

Systematical screening by cytological cervix examination has not reduced the mortality from cervical carcinoma as much as was expected. One important cause of this is the varying sensitivity of the screening owing to the large number of smears, most of which are normal. Some improvement of the effect of screening might be achieved by combination with computer-assisted microscopical evaluation and with testing for human papilloma virus (PV).

Adult↗
PubMed1996

The diagnostic information of tests for the detection of cancer: the usefulness of the likelihood ratio concept.

No single test is perfect and without false-negative and/or false-positive results. Consequently, the clinician is perpetually confronted with incertitude about the true disease state of the patient. In oncology, these diagnostic errors may have harmful consequences for the patient. It is, therefore, imperative that the clinician knows how often these errors occur, which implies a quantitative evaluation of a test. With this knowledge, the test result must subsequently be interpretated within the clinical framework. Bayes' theorem provides a simple and useful mathematical model for the integration of measures of test performance and clinical data. Traditionally, sensitivity and specificity are used to describe test performance. However, this approach requires that the conclusion of the test is dichotomised into 'normal' and 'abnormal'. Few tests have a natural binary outcome. A test parameter that is applicable to all types of test outcome scales and, at the same time, provides the opportunity to determine the gain in diagnostic information by applying Bayes' theorem, is therefore mandatory. The likelihood ratio meets these conditions. The application of this concept for both the evaluation and the interpretation of various types of tests used in cancer patients is demonstrated.

Bayes Theorem↗
PubMed1994

[National results of cervix cytology diagnosis in 1992; efficacy of screening could be improved].

OBJECTIVE: To analyse all cervical smears performed in 1992 to determine the number of tests per age category and to evaluate the efficacy of the test. DESIGN: Descriptive, retrospective. SETTING: The Netherlands. METHOD: Of every cervix smear registered in the Pathological Anatomical National Automised Archives (PALGA) the quality, signs of inflammation, squamous or columnar epithelial abnormalities and other abnormalities were determined (KOPAC code). RESULTS: In 1992, 784,046 cervix smears were registered, of which 755,844 were KOPAC-coded. Half of the smears came from women younger than 40 years. There was a high frequency of squamous cell abnormalities (II% Pap 2, 2.5% Pap 3a, 0.5% Pap 3b or worse). An accelerated second smear (after 3 months or 1 year) was performed in 14% of the women; 9% underwent > or = 2 cervical smears within 1 year. CONCLUSION: Related to the frequency of newly diagnosed cervix cancer (700 per year), the efficacy of cytology could be improved by limiting the number of smears and strictly applying the assessment criteria to diminish the number of accelerated second smears. Furthermore, second smears should be subject to strict management, determined by evaluation studies.

Adolescent↗
PubMed1993

The evaluation and interpretation of cervical cytology: application of the likelihood ratio concept.

The Papanicolaou smear (Pap test), used for the detection and prevention of neoplastic lesions of the cervix, is known to have both false negative and false positive results. Proper handling of the diagnostic uncertainty resulting from these errors demands quantification of flaws. Traditionally, sensitivity, specificity and predictive values are used for that aim. In this study another approach is advocated, namely the use of the likelihood ratio. For cervical cytology this ratio is the quotient of the probability of a Pap class within the diseased population to the probability of that same Pap class within the non-diseased group. This approach enables the characterization of each Pap class separately, and is therefore much better for clinical interpretation of the result. It is also a superior approach for quality assessment.

Female↗
PubMed1993

Lipoid pneumonitis complicating treatment of Hodgkin's disease.

The development of lipoid pneumonitis (LP) is associated with exposure to mineral, animal or vegetable oils through inhalation or local application. We report here on a 34-year-old patient with lipoid pneumonitis complicating the treatment of Hodgkin's disease. A review of the relevant literature on the pathophysiology and diagnosis of LP is provided with emphasis on possible mechanisms of development of LP in Hodgkin's disease.

Adult↗
PubMed1992

The value of aspiration cytologic examination of the breast. A statistical review of the medical literature.

The decision to perform surgery in patients with a breast mass usually is made on the basis of combined diagnostic information, with fine-needle aspiration cytologic examination (FNAC) playing a central role. To determine and compare the quality of FNAC of the breast, a search was performed of the English literature for articles with quantitative information about their results. Twenty-nine such articles, containing 31,340 aspirations, were identified and summarized. Required data were extracted from these articles. These numbers were analyzed with the use of a two-by-four contingency table to relate the FNAC result (definitely malignant, suspect, benign, or unsatisfactory cytologic material) with the final diagnosis (malignant or benign breast disease). Test characteristics such as sensitivity, specificity, and the likelihood ratios for the four different FNAC results were derived for each study and compared. There was a striking difference between studies with regard to the probability of a particular FNAC upshot (e.g., in patients with breast cancer, the chance of obtaining definitely malignant cytologic material ranged from 0.35 to 0.92), the sensitivity (range, 0.65 to 0.98), the specificity (range, 0.34 to 1.0), and likelihood ratios. In the opinion of the authors, it is virtually impossible to infer general test characteristics of FNAC of the breast from the medical literature because of differences in methods and different biases. At best, the maximum attainable performance of this test can be described. For the development of a policy for breast mass management, the local test characteristics of this highly operator-dependent test should be established.

Biopsy, Needle↗