Perspectives of colorectal cancer screening in Germany 2009

Use of blood-based biomarkers for early diagnosis and surveillance of colorectal cancer

Early screening for colorectal cancer (CRC) holds the key to combat and control the increasing global burden of CRC morbidity and mortality. However, the current available screening modalities are severely inadequate because of their high cost and cumbersome preparatory procedures that ultimately lead to a low participation rate. People simply do not like to have colonoscopies. It would be ideal, therefore, to develop an alternative modality based on blood biomarkers as the first line screening test. This will allow for the differentiation of the general population from high risk individuals. Colonoscopy would then become the secondary test, to further screen the high risk segment of the population. This will encourage participation and therefore help to reach the goal of early detection and thereby reduce the anticipated increasing global CRC incidence rate. A blood-based screening test is an appealing alternative as it is non-invasive and poses minimal risk to patients. It is easy to perform, can be repeated at shorter intervals, and therefore would likely lead to a much higher participation rate. This review surveys various blood-based test strategies currently under investigation, discusses the potency of what is available, and assesses how new technology may contribute to future test design.

Results of National Colorectal Cancer Screening Program in Croatia (2007-2011)

AIM: To study the epidemiologic indicators of uptake and characteristic colonoscopic findings in the Croatian National Colorectal Cancer Screening Program.

METHODS: Colorectal cancer (CRC) was the second leading cause of cancer mortality in men (n = 1063, 49.77/100  000), as well as women (n = 803, 34.89/100  000) in Croatia in 2009. The Croatian National CRC Screening Program was established by the Ministry of Health and Social Welfare, and its implementation started in September, 2007. The coordinators were recruited in each county institute of public health with an obligation to provide fecal occult blood testing (FOBT) to the participants, followed by colonoscopy in all positive cases. The FOBT was performed by hypersensitive guaiac-based Hemognost card test (Biognost, Zagreb). The test and short questionnaire were delivered to the home addresses of all citizens aged 50-74 years consecutively during a 3-year period. Each participant was required to complete the questionnaire and send it together with the stool specimen on three test cards back to the institute for further analysis. About 4% FOBT positive cases are expected in normal risk populations. A descriptive analysis was performed.

RESULTS: A total of 1  056  694 individuals (born between 1933-1945 and 1952-1957) were invited to screening by the end of September 2011. In total, 210  239 (19.9%) persons returned the envelope with a completed questionnaire, and 181 102 of them returned it with a correctly placed stool specimen on FOBT cards. Until now, 12  477 (6.9%), FOBT-positive patients have been found, which is at the upper limit of the expected values in European Guidelines for Quality Assurance in CRC Screening and Diagnosis [European Union (EU) Guidelines]. Colonoscopy was performed in 8541 cases (uptake 66%). Screening has identified CRC in 472 patients (5.5% of colonoscopied, 3.8% of FOBT-positive, and 0.26% of all screened individuals). This is also in the expected range according to EU Guidelines. Polyps were found and removed in 3329 (39% of colonoscopied) patients. The largest number of polyps were found in the left half of the colon: 64% (19%, 37% and 8% in the rectum, sigma, and descendens, respectively). The other 36% were detected in the proximal part (17% in the transverse colon and 19% in ceco-ascending colon). Small polyps in the rectum (5-10 mm in diameter), sigmoid and descending colon were histologically found to be tubular adenomas in 60% of cases, with a low degree of dysplasia, and 40% were classified as hyperplastic. Polyps of this size in the transverse or ceco-ascending colon in almost 20% had a histologically villous component, but still had a low degree of dysplasia. Polyps sized 10-20 mm in diameter were in 43% cases tubulovillous, and among them, 32% had areas with a high degree of dysplasia, especially those polyps in the ceco-ascending or transverse part. The characteristics of the Croatian CRC Screening National Program in the first 3 years were as follows: relatively low percentage of returned FOBT, higher number of FOBT-positive persons but still in the range for population-based programs, and higher number of pathologic findings (polyps and cancers).

CONCLUSION: These results suggest a need for intervention strategies that include organizational changes and educational activities to improve awareness of CRC screening usefulness and increase participation rates.

Use of RNA isolated from feces as a promising tool for the early detection of colorectal cancer

Colorectal cancer is one of the most common forms of cancer worldwide. Early detection would allow patients to be treated surgically and halt the progression of the disease; however, the current methods of early detection are invasive (colonoscopy and sigmoidoscopy) or have low sensitivity (fecal occult blood test). The altered expression of genes in stool samples of patients with colorectal cancer can be determined by RT-PCR. This is a noninvasive and highly sensitive technique for colorectal cancer screening. According to information gathered in this review and our own experience, the use of fecal RNA to determine early alterations in gene expression due to malignancy appears to be a promising alternative to the current detection methods and owing to its low cost could be implemented in public health services.

[The Alliance for the Prevention of Colorectal Cancer in Spain. A civil commitment to society]

Colorectal cancer (CRC) is the most common malignant tumor in Spain, when men and women are considered together, and the second leading cause of cancer death. Every week in Spain over 500 cases of CRC are diagnosed, and nearly 260 people die from the disease. Epidemiologic estimations for the coming years show a significant increase in the number of annual cases. CRC is a perfectly preventable tumor and can be cured in 90% of cases if detected in the early stages. Population-based screening programs have been shown to reduce the incidence of CRC and mortality from the disease. Unless early detection programs are established in Spain, it is estimated that in the coming years, 1 out of 20 men and 1 out of 30 women will develop CRC before the age of 75. The Alliance for the Prevention of Colorectal Cancer in Spain is an independent and non-profit organization created in 2008 that integrates patients' associations, altruistic non-governmental organizations and scientific societies. Its main objective is to raise awareness and disseminate information on the social and healthcare importance of CRC in Spain and to promote screening measures, early detection and prevention programs. Health professionals, scientific societies, healthcare institutions and civil society should be sensitized to this highly important health problem that requires the participation of all sectors of society. The early detection of CRC is an issue that affects the whole of society and therefore it is imperative for all sectors to work together.

Peroxisome proliferator-activated receptor-γ 34C>G polymorphism and colorectal cancer risk: A meta-analysis

AIM: To investigate the association between peroxisome proliferator-activated receptor-γ (PPAR-γ) gene polymorphism 34 C>G and colorectal cancer (CRC), a meta-analysis review was performed in this report.

METHODS: A systematic literature search and selection of eligible relevant studies were carried out. Nine independent studies with a total number of 4533 cases and 6483 controls were included in the meta-analysis on the association between polymorphism 34 C>G and CRC.

RESULTS: There was no evidence for the association between PPAR-γ 34 C>G and CRC if all of the subjects in the nine studies were included. However, CG + GG showed a marginally significant difference from CC (OR = 0.84, 95% CI: 0.69-1.01, P = 0.07) in random-effect model. Stratified meta-analysis indicated that PPAR-γ 34 C>G was associated with colon cancer (OR = 0.8, 95% CI: 0.65-0.99, P = 0.04) in random-effect model, and the G allele decreased colon cancer risk. No significant association was observed between PPAR-γ 34 C>G and rectal cancer.

CONCLUSION: PPAR-γ 34 C>G is associated with colon cancer risk, but not associated with CRC and rectal cancer risk.