Screening and surveillance of colorectal cancer

Evaluation of Fecal M2PK as a Diagnostic Marker in Colorectal Cancer

BACKGROUND

Invasive colonoscopy is the gold standard for patients at risk for colorectal cancer. However, the need for non-invasive and specific markers is required.

OBJECTIVE

To evaluate the sensitivity of the glycolytic pyruvate kinase isoenzyme type M2 dimer (M2PK) as a diagnostic biomarker for colorectal cancer (CRC) and adenomatous colorectal polyps (CRP) screening.

DESIGN

Case-control.

PATIENTS

Twenty patients with CRC, 20 patients with CRP (lack criteria for colonic cancer by biopsy), and 20 normal subjects.

OUTCOME

Complete blood count (CBC), erythrocyte sedimentation rate (ESR), tumor markers: carcino embryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), fecal occult blood test (FOBT), and fecal M2PK. Pelvic and abdominal ultrasound (US), colonoscopy, and a histopathological examination.

RESULTS

Only weight loss and cachexia were significantly associated with CRC than CRP or control groups. M2PK was the most sensitive and specific test in differentiating CRC from CRP and the control subjects (sensitivity = 75%, specificity = 100%).

LIMITATIONS

(1) The selection of cases for three well-matched groups, as to perform colonoscopy in well-prepared cases and conditions. (2) Replicates in more than 20 cases for confirmation at the expense of enrolling new patients. (3) The cost associated with tumor markers analysis.

CONCLUSION

Fecal M2PK can be used as a precolonoscopy screening test for CRC patients, and is superior to other tumor markers, and in indicating the progress of colorectal adenomas > 1 cm. Thus being cost-effective and easy-to-perform test, it is a feasible tool to preselect patients who require colonoscopy.

The safety and effectiveness of 2-liter polyethylene glycol plus ascorbic acid in patients with liver cirrhosis: A retrospective observational study

The safety of bowel-cleansing agents is an important issue in clinical practice, especially in patients with chronic diseases. Although the safety and efficacy of polyethylene glycol (PEG) has been investigated in many studies, few studies on PEG plus ascorbic acid exist. In this study, we compared the safety of 2 bowel-cleansing agents for patients with liver cirrhosis: 2-liter PEG (2 L PEG) plus ascorbic acid versus 4-liter PEG (4 L PEG). We performed a retrospective study on colonoscopy in patients with liver cirrhosis. Patients referred for colonoscopy were divided into 2 groups: 2 L PEG plus ascorbic acid (n = 105) and 4 L PEG (n = 61). Safety was assessed by comparing the clinical factors and laboratory findings as follows: blood biochemistry, electrolytes, weight change, and bowel-cleansing quality. Serum electrolytes, laboratory findings, and body weight showed no significant change between the 2 groups. There was no significant change in clinical factors before and after bowel preparation in the PEG group or the PEG plus ascorbic acid group. The acceptability and compliance of patients was better in the 2 L PEG plus ascorbic acid than the 4 L PEG group. In subgroup analysis, patients with compensated or decompensated cirrhosis showed no increased risk of electrolyte imbalances after bowel preparation. Child-Pugh scores did not influence the outcome after bowel cleansing. Successful cleansing was mostly achieved in both groups. Our analysis showed that of the use of 2 L PEG plus ascorbic acid could be a safe choice for colonoscopy in patients with liver cirrhosis.

Factors influencing quality of bowel preparation for colonoscopy

Recent technological advances in colonoscopy have led to improvements in both image enhancement and procedural performance. However, the utility of these technological advancements remain dependent on the quality of bowel preparation during colonoscopy. Poor bowel preparation has been shown to be associated with lower quality indicators of colonoscopy performance, such as reduced cecal intubation rates, increased patient discomfort and lower adenoma detection. The most popular bowel preparation regimes currently used are based on either Polyethylene glycol-electrolyte, a non-absorbable solution, or aqueous sodium phosphate, a low-volume hyperosmotic solution. Statements from various international societies and several reviews have suggested that the efficacy of bowel preparation regimes based on both purgatives are similar, although patients’ compliance with these regimes may differ somewhat. Many studies have now shown that factors other than the type of bowel preparation regime used, can influence the quality of bowel preparation among adult patients undergoing colonoscopy. These factors can be broadly categorized as either patient-related or procedure-related. Studies from both Asia and the West have identified patient-related factors such as an increased age, male gender, presence of co-morbidity and socio-economic status of patients to be associated with poor bowel preparation among adults undergoing routine out-patient colonoscopy. Additionally, procedure-related factors such as adherence to bowel preparation instructions, timing of bowel purgative administration and appointment waiting times for colonoscopy are recognized to influence the quality of colon cleansing. Knowledge of these factors should aid clinicians in modifying bowel preparation regimes accordingly, such that the quality of colonoscopy performance and delivery of service to patients can be optimised.

MR colonography

Combining the advantages of unsurpassed soft tissue contrast and lack of ionizing radiation, MR imaging of the gastrointestinal tract has become increasingly used clinically. Both bowel inflammation and tumor disease of the large bowel can be well visualized by means of MR colonography (MRC). This article describes current techniques of MRC and gives an overview of its clinical outcome. Special focus is directed toward the evaluation of patients' acceptance of MRC.

Natural Death in the Forensic Setting

Although unexpected natural deaths comprise a large proportion of the cases seen in the forensic setting, the investigation of these cases remains a unique challenge. Some cases are straightforward; however, others require special examination and dissections, as well as the use of special dissections and ancillary studies. For the forensic investigator to accurately assign a cause and manner of death, one must be aware of the differential diagnoses, common scenarios, and typical victim. The authors reviewed all forensic cases referred to the Forensic Section of the Medical University of South Carolina over a 15-year period from January 1989-December 2003. The number of natural deaths occurring in adults (age 18 years and older) was 6932, compared with the overall number of 13,227 cases. The natural deaths were then analyzed as to autopsy findings, cause of death, cardiac versus noncardiac, age, race, and gender. Current techniques, special dissections, and ancillary studies that can assist in the classification of these deaths in the forensic setting are reviewed.

Does Radiologist Recommendation for Follow-up with the Same Imaging Modality Contribute Substantially to High-Cost Imaging Volume?

PURPOSE

To retrospectively measure repeat rates for high-cost imaging studies, determining their causes and trends, and the impact of radiologist recommendations for a repeat examination on imaging volume.

MATERIALS AND METHODS

This HIPAA-compliant study had institutional review board approval, with waiver of informed consent. Repeat examination was defined as a same-modality examination performed in the same patient within 0 days to 7 months of a first examination. From a database of all radiology examinations (>2.9 million) at one institution from May 1996 to June 2003, a computerized search identified head, spine, chest, and abdominal computed tomographic (CT), brain and spine magnetic resonance (MR) imaging, pelvic ultrasonography (US), and nuclear cardiology examinations with a prior examination of the same type within 7 months. Examination pairs were subdivided into studies repeated at less than 2 weeks, between 2 weeks and 2 months, or between 2 and 7 months. Automated classification of radiology reports revealed whether a repeat examination from June 2002 to June 2003 had been preceded by a radiologist recommendation on the prior report. Trends over time were analyzed with linear regression, and 95% confidence intervals were calculated.

RESULTS

Between July 2002 and June 2003, 31 111 of 100 335 examinations (31%) were repeat examinations. Body CT (9057 of 20 177 [45%] chest and 8319 of 22 438 [37%] abdomen) and brain imaging (6823 of 18 378 [37%] CT and 3427 of 11 455 [30%] MR imaging) represented the highest repeat categories. Among five high-cost, high-volume imaging examinations, 6426 of 85 014 (8%) followed a report with a radiologist recommendation. Most common indications for examination repetition were neurologic surveillance within 2 weeks and cancer follow-up at 2-7 months. From 1997 to mid-2003, MR imaging and CT repeat rates increased (0.71% per year [P < .01] and 1.87% per year [P < .01], respectively).

CONCLUSION

Repeat examinations account for nearly one-third of high-cost radiology examinations and represent an increasing proportion of such examinations. Most repeat examinations are initiated clinically without a recommendation by a radiologist.

Colorectal cancer screening and surveillance

Screening and surveillance substantially reduce both the incidence and mortality of colorectal cancer. Screening of normal-risk individuals may be accomplished by several methods, including fecal occult blood testing, fiberoptic sigmoidoscopy, double contrast barium enema, and colonoscopy. New technologies for screening are being developed, such as fecal immunochemical testing for blood,fecal DNA testing, and virtual colonoscopy. Patients at increased risk for colorectal cancer, such as those with a positive family history, previous adenomatous polyps or cancer, and inflammatory bowel disease, should be offered more intensive evaluation and surveillance.