What is the value of computered tomography colonography in patients screening positive for fecal occult blood? A systematic review and economic evaluation

Screening of colorectal cancer: present and future

Colorectal cancer (CRC) is the third most common cancer in males and second in females, and the fourth most common cause of cancer death worldwide. Currently, about 60-70% of diagnosed cases in symptomatic patients are detected at an advanced stage of disease. Earlier stage detection through the use of screening strategies would allow for better outcomes in terms of reducing the disease burden. Areas covered: The aim of this paper is to review the current published evidence from literature which assesses the performance and effectiveness of different screening tests for the early detection of CRC. Expert commentary: Adequate screening strategies can reduce CRC incidence and mortality. In the last few decades, several tests have been proposed for CRC screening. To date, there is still insufficient evidence to identify which approach is definitively superior, and no screening strategy for CRC can therefore be defined as universally ideal. The best strategy would be the one that can be economically viable and to which the patient can adhere best to over time. The latest guidelines suggest colonoscopy every 10 years or annual fecal immuno-chemical test (FIT) for people with normal risk, while for individuals with high risk or hereditary syndromes specific recommendations are provided.

Methods and novel technology for microRNA quantification in colorectal cancer screening

The screening and diagnosis of colorectal cancer (CRC) currently relies heavily on invasive endoscopic techniques as well as imaging and antigen detection tools. More accessible and reliable biomarkers are necessary for early detection in order to expedite treatment and improve patient outcomes. Recent studies have indicated that levels of specific microRNA (miRNA) are altered in CRC; however, measuring miRNA in biological samples has proven difficult, given the complicated and lengthy PCR-based procedures used by most laboratories. In this manuscript, we examine the potential of miRNA as CRC biomarkers, summarize the methods that have commonly been employed to quantify miRNA, and focus on novel strategies that can improve or replace existing technology for feasible implementation in a clinical setting. These include isothermal amplification techniques that can potentially eliminate the need for specialized thermocycling equipment. Additionally, we propose the use of near-infrared (NIR) probes which can minimize autofluorescence and photobleaching and streamline quantification without tedious sample processing. We suggest that novel miRNA quantification tools will be necessary to encourage new discoveries and facilitate their translation to clinical practice.

Review of economic evidence in the prevention and early detection of colorectal cancer

This paper aims to systematically review the cost-effectiveness evidence, and to provide a critical appraisal of the methods used in the model-based economic evaluation of CRC screening and subsequent surveillance. A search strategy was developed to capture relevant evidence published 1999-November 2012. Databases searched were MEDLINE, EMBASE, National Health Service Economic Evaluation (NHS EED), EconLit, and HTA. Full economic evaluations that considered costs and health outcomes of relevant intervention were included. Sixty-eight studies which used either cohort simulation or individual-level simulation were included. Follow-up strategies were mostly embedded in the screening model. Approximately 195 comparisons were made across different modalities; however, strategies modelled were often simplified due to insufficient evidence and comparators chosen insufficiently reflected current practice/recommendations. Studies used up-to-date evidence on the diagnostic test performance combined with outdated information on CRC treatments. Quality of life relating to follow-up surveillance is rare. Quality of life relating to CRC disease states was largely taken from a single study. Some studies omitted to say how identified adenomas or CRC were managed. Besides deterministic sensitivity analysis, probabilistic sensitivity analysis (PSA) was undertaken in some studies, but the distributions used for PSA were rarely reported or justified. The cost-effectiveness of follow-up strategies among people with confirmed adenomas are warranted in aiding evidence-informed decision making in response to the rapidly evolving technologies and rising expectations.

Preferences for CT colonography and colonoscopy as diagnostic tests for colorectal cancer: a discrete choice experiment

OBJECTIVE

Computed tomography colonography (CTC) is an alternative diagnostic test to colonoscopy for colorectal cancer and polyps. The aim of this study was to determine test characteristics important to patients and to examine trade-offs in attributes that patients are willing to accept in the context of the diagnosis of colorectal cancer.

METHODS

A discrete choice study was used to assess preferences of patients with clinical indications suspicious of colorectal cancer who experienced both CTC and colonoscopy as part of a diagnostic accuracy study in South Australia. Results were analyzed by using a mixed logit model and presented as odds ratios (ORs) for preferring CTC over colonoscopy.

RESULTS

Colonoscopy was preferred over CTC as the need for a second procedure after CTC increased (OR of preferring CTC to colonoscopy = 0.013), as the likelihood of missing cancers or polyps increased (OR of preferring CTC to colonoscopy = 0.62), and as CTC test cost increased (OR of preferring CTC to colonoscopy = 0.65-0.80). CTC would be preferred to colonoscopy if a minimal bowel preparation was available (OR = 1.7). Some patients were prepared to trade off the diagnostic and therapeutic advantage of colonoscopy for a CTC study with a less intensive bowel preparation. Preferences also varied significantly with sociodemographic characteristics.

CONCLUSIONS

Despite CTC's often being perceived as a preferred test, this may not always be the case. Informed decision making for diagnostic tests for colorectal cancer should include discussion of the benefits, downsides, and uncertainties associated with alternative tests, as patients are willing and able to make trade-offs between what they perceive as the advantages and disadvantages of these diagnostic tests.

Effectiveness of a clinic-based colorectal cancer screening promotion program for underserved Hispanics

BACKGROUND

Hispanics in the United States are less likely than other groups to receive screening services for colorectal cancer.

METHODS

The authors conducted a clinic-based individual randomized trial that enrolled Hispanic patients ages 50 to 79 years who had been seen in the Seattle-based community clinic in the past 5 years. A total of 501 patients met the eligibility criteria and were randomized to 1 of 3 conditions: 1) usual care; 2) mailed fecal occult blood test (FOBT) card and instructions on how to complete the test (mailed FOBT only); and 3) mailed FOBT card and instructions on how to complete the test, telephone reminders, and home visits (mailed FOBT and outreach). The authors assessed postintervention differences in rates of FOBT screening in intervention and usual care groups using computerized medical records reviewed from June 2007 to March 2008.

RESULTS

Data analysis occurred between November 2008 and September 2009. Nine-month postintervention screening rates were 26% among patients who received the mailed packet only intervention (P < .001 compared with usual care) and 31% in the group that received the mailed packet and outreach intervention (P < .001 compared with usual care). This compared with 2% in the group that received usual care. Screening rates in the mailed FOBT only group and in the mailed FOBT and outreach group were not significantly different (P = .28).

CONCLUSIONS

Culturally appropriate clinic-based interventions may increase colorectal cancer screening among underserved Hispanics.

Cost-effectiveness of colorectal cancer screening with computed tomography colonography or fecal blood tests

OBJECTIVE

To assess the cost-effectiveness of colorectal cancer screening using computed tomography colonography (CTC) and immunological fecal occult blood test (iFOBT).

METHODS

CTC and iFOBT strategies were compared with Nn screening or guaiac FOBT (gFOBT) using Markov modeling. CTC was proposed at 50, 60, and 70 years, whereas gFOBT and iFOBT were performed every 2 years beginning at 50 years until 74 years of age with a 30-year time horizon. We calculated incremental cost-effectiveness ratios and efficiency ratios (ERs). Then, we performed univariate and probabilistic sensitivity analyses.

RESULTS

With gFOBT as reference, colorectal cancer prevention rate was 18% for CTC and 11% for iFOBT. The incremental cost-effectiveness ratio of CTC and iFOBT were respectively 3204 and 5458 euro per life years gained (LYG), the ER for CTC was 0.22 and the ER for iFOBT was 2.08 colonoscopies per LYG. Cost-effectiveness results were sensitive to CTC cost. In the probabilistic sensitivity analysis, compared with CTC, iFOBT strategy was cost-effective for 84.6% of simulations when we assumed a willingness to pay (WTP) of 20,000 euro/LYG.

CONCLUSION

CTC requires substantially less colonoscopies than iFOBT and is cost-effective for low values of WTP. However, iFOBT is the preferred screening strategy for a WTP greater than 6207 euro/LYG.

[Anemia in the elderly]

Anemia is a common disorder in the elderly and is associated with increased morbidity and mortality. In elderly subjects, in whom anemia is highly prevalent, there are several aspects, such as a hemoglobin at a level which should concern us limit, or identifying its causes, that are not easy to establish. This review focuses on knowing what is considered to be normal hemoglobin levels in adults and the common causes and potential consequences of anemia in elderly patients. It provides a diagnostic algorithm and an approach to treatment that addresses new treatments such as parenteral iron drugs and erythropoiesis-stimulating agents.

Population-based screening for colorectal cancer: Australian research and implementation

Australia is one of the first countries in the world to implement an organized whole-of-population screening program for colorectal cancer (CRC). Australians have made broad contributions to CRC in general ranging from primary prevention through genetics, secondary prevention and treatment, to palliation. This overview focuses on some of the contributions of direct relevance to population-based screening, stretching from technology development to population-based controlled studies and health services research. In terms of simple screening tests in a two-step screening strategy, the evidence is overwhelming that fecal immunochemical tests for hemoglobin (FITs) improve detection and are more acceptable. FIT-based screening is clearly acceptable to Australians and it has been demonstrated that a national organized screening program is feasible. In terms of benefit for Australians, with full roll out and high uptake by the population we could see the number of cases dying from CRC halved by this strategy. To this will be added the extra-screening benefits of improved diagnosis, improved treatment and improved public awareness, all benefits of other screening programs. CRC screening has progressed from a matter of irrelevance and distaste, to commonwealth government policy in the context of an organized program for all Australians.