Does CT colonography have a role for population-based colorectal cancer screening?

Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool tests, with endoscopy used as an adjunct in some countries. Computed tomographic colonography (CTC) is a potential screening test, with an estimated sensitivity of 88?% for advanced neoplasia ≥10?mm. Recent randomised studies have shown that CTC and colonoscopy have similar yields of advanced neoplasia per screened invitee, indicating that CTC is potentially viable as a primary screening test. However, the evidence is not fully elaborated. It is unclear whether CTC screening is cost-effective and the impact of extracolonic findings, both medical and economic, remains unknown. Furthermore, the effect of CTC screening on CRC-related mortality is unknown, as it is also unknown for colonoscopy. It is plausible that both techniques could lead to decreased mortality, as for sigmoidoscopy and gFOBT. Although radiation exposure is a drawback, this disadvantage may be over-emphasised. In conclusion, the detection characteristics and acceptability of CTC suggest it is a viable screening investigation. Implementation will depend on detection of extracolonic disease and health-economic impact. Key Points ? Meta-analysis of CT colonographic screening showed high sensitivity for advanced neoplasia ≥10mm. ? CTC, colonoscopy and sigmoidoscopy screening all have similar yields for advanced neoplasia. ? Good quality information regarding the cost-effectiveness of CTC screening is lacking. ? There is little good quality data regarding the impact of extracolonic findings. ? CTC triage is not clinically effective in first round gFOBT/FIT positives.     

Whole-body MRI as a screening tool?

Screening (early detection of disease in asymptomatic groups of persons) with whole-body MR (wb-MR) has only recently become possible. Technical requirements include extended scanner table range and extended coverage with surface coils. This allows for examining the whole body without repositioning the patient. wb-MR angiography can be combined with cerebral and cardiac MR to form a comprehensive screening protocol for atherosclerosis; and many malignancies can technically be screened for, such as colonic, bronchial, or renal carcinoma. The prerequisites for suited target diseases include enhanced therapeutic options if the disease is detected in an early stage, they should be harmful if detected late, and they should be sufficiently prevalent.The first studies on wb-MR screening reported low prevalences of a variety of assessable pathologies in non-selected groups; prevalences, however, increase with the presence of risk factors. More recent results are suggestive of a potential prognostic impact of MR screening, but studies on the outcome have not yet been published.This article also discusses potential problems and limitations of wb-MR. Some tumour entities cannot sufficiently be assessed, although the structures are included in the field of view. Incidental findings have to be anticipated; they might have an unforeseeable impact on the subject's well being.wb-MR seems technically ‘ready’ for screening. The cost–benefit relation of wb-MR screening, however, especially the impact on the health of the screened subjects, still remains to be investigated.     

Is B-mode ultrasound alone a sufficient screening tool for carotid stenosis? A pilot study

Background

Carotid ultrasound is performed solely in hospital ultrasound departments or outpatient labs, using both B- and Doppler modes. We hypothesize that B-mode without Doppler can be used to classify patients as having carotid stenosis (CS) above or below 50%. Our objective is to determine the frequency with which a CS >50% is found using Doppler when no such stenosis was visible using B-mode.

Methods

This was a retrospective study of 100 patients referred to the stroke clinic and 100 patients referred for carotid endarterectomy (CEA). All patients had an elective carotid ultrasound done at Health Sciences North. The ultrasound reports were mixed together and blinded. Investigators determined if there was a CS of greater or less than 50% based on the carotid diagram. These results were compared to the degree of CS found on Doppler.

Results

In the CEA group, there were 198 ultrasounds, with 153 showing a CS of >50%. Only one case of CS >50% was missed by B-mode. In the clinic group, 32 of 192 ultrasounds showed a CS of >50%. None were missed by B-mode. B-mode had a sensitivity and negative predictive value of 100% and a specificity of 65%.

Conclusion

This study supports the theory that it may be possible to use B-mode ultrasound without Doppler to reliably determine if there is CS above or below 50%. Further research is required before carotid ultrasound using B-mode alone can be recommended.     

Sudden cardiac death in young athletes: time for a Nordic approach in screening?

In 2005, the European Society of Cardiology published recommendations for cardiovascular screening in athletes. Discussion on whether screening is beneficial is ongoing. Recently, the first prospective results on effectiveness of screening in preventing sudden deaths were published from Italy. The results were supportive of screening, but did not provide conclusive evidence. Our suggestion for a Nordic approach on this issue is a directed cardiovascular examination initially involving elite athletes, because this is feasible with respect to the Nordic health care systems and the organization and logistics of elite competitive sports, but also because of the negative aspects of screening large populations. This directed cardiovascular examination would include personal and family history, clinical examination, and electrocardiography (ECG). Further examinations should thereafter be carried out in athletes with suggestive findings in the initial evaluation. The directed cardiovascular examination should be voluntary. It should be conducted at least once, with information on alarming symptoms (syncope, chest pain or dizziness during exercise) and heredity (sudden cardiac death or hereditary heart disease in near relatives) stressed to the athlete as indications for necessary check-ups in the future. The examination would also provide the athlete with an ECG recording, which is valuable as a reference at a later time.     

Simple screening procedure for 72 synthetic cannabinoids in whole blood by liquid chromatography–tandem mass spectrometry

Purpose

In recent years, many synthetic cannabinoids (SCs) have appeared on the drug market. Despite the increasing number of SCs, there are few comprehensive screening methods for their detection in biological specimens. In this context, the purpose of this study was to develop a fast and simple liquid chromatography–tandem mass spectrometry screening procedure for detection and identification of SCs in whole blood.

Methods

The elaborated qualitative screening method allows the simultaneous detection and identification of 72 compounds from different chemical groups: naphthoylindoles, naphthoylindazoles, benzoylindoles, phenylacetylindoles, tetramethylcyclopropylindoles, indole-3-carboxylic acid esters, indole-3-carboxylic acid amides, indazole-3-carboxylic acid amides, and others. Whole-blood samples (0.2 mL) were precipitated with acetonitrile (0.6 mL). The separation was achieved with the gradient of the mobile phase composition (0.1% formic acid in acetonitrile and 0.1% formic acid in water) and the gradient of the flow rate (0.5–0.8 mL/min) in 16 min. Detection of all compounds was based on dynamic multiple reaction monitoring.

Results

Mass spectrometer parameters for all compounds were presented. All of the compounds were well-separated by their retention times and/or transitions. The limits of detection (LODs) for 50 compounds were in the range 0.01–0.48 ng/mL.

Conclusions

Estimated LODs make this assay suitable for the analysis of biological material. The procedure can be easily expanded for more substances, which is an indispensable advantage in the dynamically developing drug market. It can have wide application in various analytical forensic and clinical laboratories.

     

Low-dose CT: new tool for screening lung cancer?

Lung cancer is the leading cause of death from malignant tumours as it is very common and has a poor prognosis at advanced tumour stages. Prognosis could be improved by treatment at early stages. As these stages are usually asymptomatic, a diagnostic test that would allow detection of early tumour stages in a population at risk could potentially reduce mortality from lung cancer. Previous approaches using chest radiography and sputum cytology in smokers have been disappointing. Fluorescent bronchoscopy and molecular markers are not yet applicable in clinical routine. Because of its high sensitivity for small pulmonary nodules, which are the most common manifestation of early lung cancer, CT appears suitable as a screening test. Low-dose examination parameters can and should be used for this purpose. From clinical practice it is well known that chest CT often demonstrates small pulmonary nodules, which do not represent lung cancer. Therefore, non-invasive diagnostic algorithms are required to avoid unnecessary biopsies in benign lesions. In preliminary studies of low-dose CT using algorithms based on size and density of detected nodules a large proportion of asymptomatic lung cancers and a large proportion of early, resectable tumour stages were found with a small proportion of invasive procedures for benign nodules. Before this technology can be recommended for broad application, however, further information is required regarding appropriate inclusion criteria (smoking habits, age groups) and screening intervals. Most importantly, further data are required to clarify whether lung cancer screening using low-dose CT can actually reduce mortality from lung cancer.     

One-day or two-day procedure for sentinel node biopsy in melanoma?

Purpose  We compared the outcome of a 1-day and a 2-day sentinel node (SN) biopsy procedure, evaluated in terms of lymphoscintigraphic, surgical and pathological findings. Methods  We studied 476 patients with melanoma from two melanoma centres using static scintigraphy and blue dye. A proportional odds model was used for statistical analysis. Results  The number of SNs visualized at scintigraphy increased significantly with time from injection to scintigraphy and activity left in the patient at scintigraphy, and depended on the melanoma location. The number of SNs removed at surgery increased with the number of SNs visualized at scintigraphy and time from injection to surgery. The frequency of nodal metastasis increased with increasing thickness and Clark level of the melanoma, and was highest for two SNs visualized at scintigraphy. Conclusion  This study showed that early vs. late imaging and surgery do make a difference on the outcome of the SN procedure and confirmed the importance of the scintigraphic visualization of all true SNs.     

Should we be screening for myocardial hibernation in heart failure?

Conclusion  To summarize, myocardium can exist in a functionally dormant but still viable state. The CHRISTMAS trial showed that the quantity of viable myocardium is likely to govern response to medical therapy (β-blockers). Many other trials have suggested that myocardial viability is likely to be an important determinant of response to surgical revascularization. Furthermore, an important meta-analysis by Allman et al9 suggests that revascularization is preferable to medical therapy when there is significant myocardial viability. However, the majority of these studies predate the landmark trials of β-blocker and spironolactone therapy, leaving some uncertainty about the superiority of revascularization over best medical therapy. The emergence of techniques able to not only reliably identify but also quantify myocardial viability is likely to become increasingly important, as this appears to be the most promising means of allowing revascularization to be targeted to those most likely to benefit, without risking those with little to gain. The UK HEART and US STICH trials, when complete, will be invaluable in this respect.     

Is breast MRI ever useful in a mammographic screening programme?

OBJECTIVE: To establish the diagnostic impact of breast magnetic resonance imaging (MRI), on the management of cases in our mammographic screening programme. METHODS AND MATERIALS: We analysed the cases examined from July 1997 to December 2000 during which time 44,000 population screening mammograms and 85 MRI studies were undertaken on women identified by computer overlap. The studies were reviewed to find the reason for the MRI study and its diagnostic impact. RESULTS: Of 83 studies analysed, 31 were for recurrence of tumour, 33 in newly diagnosed cancer, 22 to assess extent, 11 to monitor primary chemotherapy. In a small diagnostic subset of 19 cases MRI was used to find or characterize a lesion. The 11 cases in which MRI results caused a measurable beneficial change in management were from the query recurrence and diagnostic groups. In 52 cases from all groups, MR increased diagnostic confidence. In 11 cases MRI results were indeterminate, and in six of these stimulated more studies. CONCLUSION: MRI is an expensive investigation and its use must be justified. There is a limited, but valuable role for breast MRI in selected cases from screening assessment. Misinterpretation of enhancing lesions may generate additional procedures. Diagnostic impact was greatest for the detection of tumour recurrence.