NOS2 Polymorphism in Aspect of Left and Right-Sided Colorectal Cancer

Background: The NOS2 gene polymorphism rs2297518 is associated with an increased level of NO, which could contribute to colorectal cancer (CRC) development. We hypothesized that the potential influence of the NOS2 gene polymorphism on cancer development may vary between right-sided and left-sided colon cancers, and rectal cancers. The aim of this study was to determine the rs2297518 polymorphism influence on colorectal cancer development with regard to tumor localization. Methods: This case-control study included 199 patients with CRC and 120 controls. The qPCR endpoint genotyping was conducted using the TaqMan® genotyping assay. Results: This study revealed significant differences in tumor characteristic and in the minor alelle A frequency in the NOS2 genotype between colorectal cancers with different localizations. The mucinous adenocarcinoma was diagnosed significantly more often in right-sided cancers than in left-sided (30.6% vs. 10.9%, p = 0.009) and rectal cancers (30.6% vs. 7.1%, p = 0.0003). The minor allele A of the NOS2 genotype was observed more frequently in right-sided cancers than in left-sided cancers (44.9% vs. 23.1%, p = 0.0137) and more frequently in rectal cancers than in left-sided cancers (40.0% vs. 23.1%, p = 0.0285). Conclusions: In conclusion, the results support the hypothesis that the SNP rs2297518 of the NOS2 gene influences colorectal cancer development with regard to tumor localization.

Faecal haemoglobin: Measurement, applications, and future potential

Faecal hemoglobin concentrations (f-Hb) can be quantitated using faecal immunochemical test for haemoglobin (FIT) analytical systems. FIT are of proven value and widely used in colorectal cancer (CRC) screening. Several factors affect f-Hb including sex, age, deprivation, geographical region, and FIT system. Thus, FIT data may not be transferable. Women are disadvantaged in programmes using a single f-Hb threshold for all participants, but risk scoring or sex stratified thresholds could be used to minimise this problem. In addition, low but detectable f-Hb, below the threshold, implies future risk of CRC. In several countries, where colonoscopy resources are constrained, FIT are now accepted as of added value in assessment of patients presenting in primary or secondary care with symptoms, although some serious colorectal disease is missed. Elevated f-Hb in the absence of any discernible colorectal lesions is common and has been found in several diseases with a systemic inflammatory component, including circulatory, respiratory, digestive, neuropsychological, blood and endocrine diseases, and others. There is growing evidence for the value of f-Hb in post-polypectomy surveillance, potentially saving costs and colonoscopy. There may be a role for FIT systems which have lower limits of detection than currently available methods. The faecal material remaining in FIT specimen collection devices could be used for further studies, including assessment of the microbiome. The estimation of f-Hb is now a mature investigative tool but further research will undoubtedly expand applications of value.

ADT-OH synergistically enhanced the antitumor activity of celecoxib in human colorectal cancer cells

BACKGROUND

Colorectal cancer is one of the most prevalent cancers in the world, but the research on its prevention, early diagnosis and treatment is still a major challenge in clinical oncology. Thus, there is a pressing requirement to find effective strategies to improve the survival of colon cancer patients.

METHODS

Celecoxib has been accounted to be an effective antitumor drug, but may exhibit significant side effects. In recent studies, 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADT-OH), one of the most commonly used reagents for the synthesis of sustained-release H2 S donors, has also been reported to inhibit cancer progression by affecting processes such as cell cycle, angiogenesis, and apoptosis. Therefore, we evaluated the therapeutic effect of the combination of ADT-OH and celecoxib on colorectal cancer through in vitro and in vivo, hoping to achieve better therapeutic effect and reduce the effect of celecoxib on gastric injury through exogenous administration of H2 S.

RESULTS

Our results demonstrated that ADT-OH combined with celecoxib synergistically inhibited the proliferation and migration ability of human colorectal cancer HCT116 cells, altered cell cycle and cytoskeleton, increased intracellular reactive oxygen species (ROS), and promoted cell apoptosis. Noteworthy, in vivo studies also indicated the excellent antitumor therapeutic effect of the combination therapy without apparent toxicity.

CONCLUSIONS

In general, our results provide a reasonable combination strategy of low-dose ADT-OH and celecoxib in the preclinical application of colorectal cancer.

Screening for colorectal cancer: awareness and adherence among Italian women

OBJECTIVE

To evaluate women's awareness about and attendance to colorectal cancer (CRC) screening programs in an area of Southern Italy, and to investigate related potential determinants.

METHODS

The survey was conducted among women through a self-administered questionnaire.

RESULTS

Overall, only 20.3% of respondents knew the three cancer screening tests offered to women and this knowledge, at the multivariate logistic regression analysis, resulted to be significantly higher in women who knew the two most common cancers in females, in those who were graduated, had a personal or family history of cancer, and had been informed about cancer prevention by physicians. Only 29.2% of women had ever undergone FOBT, 25% for screening purposes and, of these, 76.4% in the previous 2 years. Among those who had never undergone FOBT, 28.9% reported they had not been invited to attend, 34.5% that the test had not been prescribed by anyone, and 19.1% had no time to undergo. The results of the multivariate logistic regression model revealed that significant determinants of having undergone FOBT for screening purposes were having undergone mammography, having at least one chronic disease, not reporting alcohol consumption and having been informed about cancer screening by physicians.

CONCLUSION

Our findings have revealed a concerning low awareness about and adherence to CRC screening in women and have highlighted the fundamental role of healthcare workers and of enabling factors in the decision process. Interventions should be directed to increasing awareness, and to promote cancer prevention screening pathways more centered on women's health needs and convenience.

Benefit of Biennial Fecal Occult Blood Screening on Colorectal Cancer in England: A Population-Based Case-Control Study

BACKGROUND

The English national bowel cancer screening program offering a guaiac fecal occult blood test began in July 2006. In randomized controlled trials of guaiac fecal occult blood test screening, reductions in mortality were accompanied by reductions in advanced stage colorectal cancer (CRC). We aimed to evaluate the effect of participation in the national bowel cancer screening program on stage-specific CRC incidence as a likely precursor of a mortality effect.

METHODS

In this population-based case-control study, cases were individuals diagnosed with CRC aged 60-79 years between January 1, 2012, and December 31, 2013. Two controls per case were matched on geographic region, gender, date of birth, and year of first screening invitation. Screening histories were extracted from the screening database. Conditional logistic regression with correction for self-selection bias was used to estimate odds ratios (odds ratios corrected for self-selection bias [cOR]) and 95% confidence intervals (CIs) by Duke stage, sex, and age.

RESULTS

14 636 individuals with CRC and 29 036 without were eligible for analysis. The odds of CRC (any stage) were increased within 30 days of a screening test and decreased thereafter. No reduction in CRC (any stage) among screened individuals compared with those not screened was observed (cOR = 1.00, 95% CI = 0.89 to 1.15). However, screened individuals had lower odds of Duke stage D CRC (cOR = 0.68, 95% CI = 0.50 to 0.93). We estimate 435 fewer Duke D CRC by age 80 years in 100 000 people screened biennially between ages 60 and 74 years compared with an unscreened cohort.

CONCLUSION

The impact of colorectal screening on advanced CRC incidence suggests that the program will meet its aim of reducing mortality.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

Medication use and risk of proximal colon cancer: a systematic review of prospective studies with narrative synthesis and meta-analysis

PURPOSE

Evidence of differences in the etiology of, and poorer survival from, proximal colon compared to the distal colorectum, necessitates research into its risk factors. This systematic review summarizes the evidence on medication use and proximal colon cancer risk.

METHODS

MEDLINE and EMBASE were searched for prospective studies investigating nine medication groups, namely non-steroidal anti-inflammatory drugs (NSAIDs), exogenous hormones, i.e., hormone replacement therapy (HRT) or oral contraceptives (OCs), statins, proton pump inhibitors, anti-hypertensives, metformin (an antidiabetic), antidiarrheals or laxatives, and the risk of proximal colon cancer. Narrative synthesis and meta-analyses, using random effects models to estimate risk ratios (RRs) and 95% confidence intervals (CIs), were conducted.

RESULTS

Twenty nine publications investigating NSAIDs (n = 13), exogenous hormones [HRT (n = 9) or OCs (n = 4)] statins (n = 5), anti-hypertensives (n = 1), and metformin (n = 1) were included. Summary RRs reported a protective effect of aspirin use (RR 0.80, 95% CI 0.73-0.89) but no associations between HRT (RR 0.92, 95% CI 0.83-1.02), OC (RR 1.06, 95% CI 0.98-1.14) or statin use (RR 0.94, 95% CI 0.67-1.31), and proximal colon cancer incidence compared to never/non-use. One study on metformin and one on anti-hypertensives reported no association. Sources of between-study heterogeneity included study design, period of exposure ascertainment, exposure source, and exposure comparison, but this exploration was hindered by the small numbers of studies.

CONCLUSION

Despite some studies on NSAID or HRT use, evidence on the impact of a range of medications on proximal colon cancer risk is limited. This highlights the need for more research to inform chemoprevention strategies.

Population-based organized screening by faecal immunochemical testing and colorectal cancer mortality: a natural experiment

BACKGROUND

Population-based organized screening programmes for colorectal cancer (CRC) are underway worldwide, with many based on the faecal immunochemical test (FIT). No clinical trials assessing FIT compared with no screening are planned, and few studies have assessed the population impact of such programmes.

METHODS

Before 2010, 11 out of 50 Spanish provinces initiated population-based organized screening programmes with FIT for an average-risk population aged 50-69 years. We used a quasi-experimental design across Spanish provinces between 1999 and 2016 to evaluate their impact on population age-standardized mortality and incidence rates due to CRC. Difference-in-differences and synthetic control analyses were performed to test for validation of statistical assumptions and to assess the dynamics of screening-associated changes in outcomes over time.

RESULTS

No differences in outcome trends between exposed (n = 11) and control (n = 36) provinces were observed for up to 7 years preceding the implementation of screening. Relative to controls, exposed provinces experienced a mean increase in age-standardized incidence of 10.08% [95% confidence interval (CI) (5.09, 15.07)] 2 years after implementation, followed by a reduction in age-standardized mortality rates due to CRC of 8.82% [95% CI (3.77, 13.86)] after 7 years. Results were similar for both women and men. No associated changes were observed in adjacent age bands not targeted by screening, nor for 10 other major causes of death in the exposed provinces.

CONCLUSIONS

FIT-based organized screening in Spain was associated with reductions in population colorectal cancer mortality. Further research is warranted in order to assess the replicability and external validity of our findings, and on gender-specific use of FIT in organized screening.

Piloting gender-oriented colorectal cancer screening with a faecal immunochemical test: population-based registry study from Finland

OBJECTIVE

To assess the feasibility and evaluate the performance of a relaunched colorectal cancer (CRC) screening programme with different cut-offs for men and women.

DESIGN

Population-based registry study.

SETTING

Nine municipalities in Finland which started CRC screening with faecal immunochemical test (FIT) in April 2019 with cut-off levels 70 µg Hg/g faeces for men and 25 µg Hg/g faeces for women.

PARTICIPANTS

Men (n=13 059) and women (n=14 669) aged 60-66 years invited to screening during the first programme year.

OUTCOME MEASURES

Participation rates, positivity rates, detection rates of CRC and advanced adenoma (AA), and positive predictive values (PPV) of FIT for CRC and AA.

RESULTS

Altogether 21 993 invitees returned stool samples. The participation rate of women (83.4%; 95% CI 82.8 to 84.0) was significantly higher than that of men (74.7%; 95% CI 73.9 to 75.4). The positivity rates were 2.4% (2.2 to 2.7) and 2.8% (2.5 to 3.1), respectively. In total, 37 CRCs and 116 AAs were detected. The detection rates of CRC and AA per 1000 participants were 1.8 (1.1 to 2.9) and 7.2 (5.6 to 9.1) for men and 1.6 (0.9 to 2.4) and 3.8 (2.8 to 5.0) for women. The PPVs per 100 positive tests were 6.6 (4.0 to 10.3) and 25.7 (20.6 to 31.4) for men and 6.4 (3.9 to 9.8) and 15.5 (11.6 to 20.2) for women.

CONCLUSIONS

The chosen FIT strategy narrowed the gap in the diagnostic performance between men and women especially in the detection of CRC. The participation rates were excellent. The levels of positivity and detection rates were moderate and need further action. The results indicate that gender-specific protocols can be introduced to organised CRC screening. It is yet to be seen whether they are more effective than a uniform screening protocol.

Metformin mitigates gastrointestinal radiotoxicity and radiosensitises P53 mutation colorectal tumours via optimising autophagy

BACKGROUND AND PURPOSE

There is an urgent but unmet need for mitigating radiation-induced intestinal toxicity while radio sensitising tumours for abdominal radiotherapy. We aimed to investigate the effects of metformin on radiation-induced intestinal toxicity and radiosensitivity of colorectal tumours.

EXPERIMENTAL APPROACH

Acute and chronic histological injuries of the intestine from mice were used to assess radioprotection and IEC-6 cell line was used to investigate the mechanisms in vitro. The fractionated abdominal radiation model of HCT116 and HT29 tumour grafts was used to determine the effects on colorectal cancer.

KEY RESULTS

Metformin alleviated radiation-induced acute and chronic intestinal toxicity by optimising mitophagy which was AMPK-dependent. In addition, our data indicated that metformin increased the radiosensitivity of colorectal tumours with P53 mutation both in vitro and in vivo.

CONCLUSION AND IMPLICATIONS

Metformin may be a radiotherapy adjuvant agent for colorectal cancers especially those carrying P53 mutation. Our findings provide a new strategy for further precise clinical trials for metformin on radiotherapy.

miR-331-3p suppresses cell invasion and migration in colorectal carcinoma by directly targeting NRP2

Colorectal carcinoma (CRC) is a common tumor of the digestive system with poor prognosis. Studies have shown that aberrant microRNA (miRNA) expression can affect CRC progression by regulating target genes. In the present study, we investigated the functional roles and potential mechanisms of miR-331-3p in CRC. The expression of miR-331-3p and neuropilin-2 (NRP2) in CRC was detected by RT-qPCR. Then, Transwell assays were conducted to investigate the influence of miR-331-3p on CRC cell invasion and migration abilities. Luciferase reporter assays were performed to determine the target gene of miR-331-3p. It was found that miR-331-3p expression was notably declined in CRC and inversely correlated with the NRP2 expression. miR-331-3p upregulation significantly inhibited CRC cell invasion and migration. Additionally, western blot analysis demonstrated that miR-331-3p restoration evidently suppressed CRC cell EMT. Moreover, NRP2 was conformed to be a novel target of miR-331-3p and knockdown of NRP2 partially inversed the effects of the miR-331-3p inhibitor on cell invasion and migration. These results suggested that miR-331-3p exerted tumor suppressive roles in CRC by targeting NRP2 and miR-331-3p/NRP2 may serve as a potential therapy for CRC.

Population-based colorectal cancer screening programmes using a faecal immunochemical test: should faecal haemoglobin cut-offs differ by age and sex?

BACKGROUND

The Basque Colorectal Cancer Screening Programme has both high participation rate and high compliance rate of colonoscopy after a positive faecal occult blood test (FIT). Although, colorectal cancer (CRC) screening with biannual (FIT) has shown to reduce CRC mortality, the ultimate effectiveness of the screening programmes depends on the accuracy of FIT and post-FIT colonoscopy, and thus, harms related to false results might not be underestimated. Current CRC screening programmes use a single faecal haemoglobin concentration (f-Hb) cut-off for colonoscopy referral for both sexes and all ages. We aimed to determine optimum f-Hb cut-offs by sex and age without compromising neoplasia detection and interval cancer proportion.

METHODS

Prospective cohort study using a single-sample faecal immunochemical test (FIT) on 444,582 invited average-risk subjects aged 50-69 years. A result was considered positive at ≥20 μg Hb/g faeces. Outcome measures were analysed by sex and age for a wide range of f-Hb cut-offs.

RESULTS

We analysed 17,387 positive participants in the programme who underwent colonoscopy. Participation rate was 66.5%. Men had a positivity rate for f-Hb of 8.3% and women 4.8% (p < 0.0001). The detection rate for advanced neoplasia (cancer plus advanced adenoma) was 44.0‰ for men and 15.9‰ for women (p < 0.0001). The number of colonoscopies required decreased in both sexes and all age groups through increasing the f-Hb cut-off. However, the loss in CRC detection increased by up to 28.1% in men and 22.9% in women. CRC missed were generally at early stages (Stage I-II: from 70.2% in men to 66.3% in women).

CONCLUSIONS

This study provides detailed outcomes in men and women of different ages at a range of f-Hb cut-offs. We found differences in positivity rates, neoplasia detection rate, number needed to screen, and interval cancers in men and women and in younger and older groups. However, there are factors other than sex and age to consider when consideration is given to setting the f-Hb cut-off.

Locating sex- and gender-specific data in health promotion research: evaluating the sensitivity and precision of published filters

Objective

This study explored the effectiveness of search filters in identifying sex- and gender-specific data in health promotion studies that are indexed in MEDLINE.

Methods

Literature searches were conducted to identify studies on patient or consumer attitudes and behaviors toward colorectal cancer screening, nutritional labeling, and influenza vaccination. Publications reporting sex- or gender-specific outcome data constituted the gold standards for this study. The sensitivity and precision of previously published gender-specific filters, as well as individual filter component terms, were calculated and compared with values identified in prior studies.

Results

The sensitivity and precision of published sex or gender filters varied across topics. Sensitivity values ranged from 14.3% to 92.5%, while precision varied from 17.9% to 51.4%. These filters were less sensitive and less precise in their identification of relevant studies than has been reported in previous studies. Further, while the MEDLINE Medical Subject Headings (MeSH) term “Sex Factors” achieved the greatest average precision (59.3%) of any individual filter term, the MEDLINE check tag “Female” returned the highest average sensitivity (90.1%), with an average precision of 25.0% across topics.

Conclusions

Although search filters can facilitate the identification of research evidence to enable decision making, variability in study abstracting and indexing can limit the generalizability and usability of these filters. This potential for variability should be considered when deciding to incorporate a search filter into any literature search. This research highlights the importance of this awareness when developing strategies for searching the published literature and the potential value of supplementing database searching with other methods of study identification.

Predicting the effectiveness of the Finnish population-based colorectal cancer screening programme

Objective

Because colorectal cancer (CRC) has a long natural history, estimating the effectiveness of CRC screening programmes requires long-term follow-up. As an alternative, we here demonstrate the use of a temporal multi-state natural history model to predict the effectiveness of CRC screening.

Methods

In the Finnish population-based biennial CRC screening programme using faecal occult blood tests (FOBT), which was conducted in a randomised health services study, we estimated the pre-clinical incidence, the mean sojourn time (MST), and the sensitivity of FOBT using a Markov model to analyse data from 2004 to 2007. These estimates were applied to predict, through simulation, the effects of five rounds of screening on the relative rate of reducing advanced CRC with 6 years of follow-up, and on the reduction in mortality with 10 years of follow-up, in a cohort of 500,000 subjects aged 60 to 69.

Results

For localised and non-localised CRC, respectively, the MST was 2.06 and 1.36 years and the sensitivity estimates were 65.12% and 73.70%. The predicted relative risk of non-localised CRC and death from CRC in the screened compared with the control population was 0.86 (95% CI: 0.79–0.98) and 0.91 (95% CI: 0.85–1.02), respectively.

Conclusion

Based on the preliminary results of the Finnish CRC screening programme, our model predicted a 9% reduction in CRC mortality and a 14% reduction in advanced CRC.

Development of a Risk Prediction Score for Occult Cancer in Patients With VTE

BACKGROUND

The benefits of a diagnostic workup for occult cancer in patients with VTE are controversial. Our aim was to provide and validate a risk score for occult cancer in patients with VTE.

METHODS

We designed a nested case-control study in a cohort of patients with VTE included in the RIETE (Registro Informatizado Enfermedad TromboEmbólica) registry from 2001 to 2014. Cases included cancer detected beyond the first 30 days and up to 24 months after VTE. Control subjects were defined as patients with VTE with no cancer in the same period.

RESULTS

Of 5,863 eligible patients, 444 (7.6%; 95% CI, 6.8%-8.2%) were diagnosed with occult cancer. On multivariable analysis, variables selected were male sex, age > 70 years, chronic lung disease, anemia, elevated platelet count, prior VTE, and recent surgery. We built a risk score assigning points to each variable. Internal validity was confirmed using bootstrap analysis. The proportion of patients with cancer who scored ≤ 2 points was 5.8% (241 of 4,150) and that proportion in those who scored ≥ 3 points was 12% (203 of 1,713). We also identified scores divided by sex and age subgroups.

CONCLUSIONS

This is the first risk score that has identified patients with VTE who are at increased risk for occult cancer. Our score needs to be externally validated.

Colorectal Cancer Screening in Average Risk Populations: Evidence Summary

Introduction. The objectives of this systematic review were to evaluate the evidence for different CRC screening tests and to determine the most appropriate ages of initiation and cessation for CRC screening and the most appropriate screening intervals for selected CRC screening tests in people at average risk for CRC. Methods. Electronic databases were searched for studies that addressed the research objectives. Meta-analyses were conducted with clinically homogenous trials. A working group reviewed the evidence to develop conclusions. Results. Thirty RCTs and 29 observational studies were included. Flexible sigmoidoscopy (FS) prevented CRC and led to the largest reduction in CRC mortality with a smaller but significant reduction in CRC mortality with the use of guaiac fecal occult blood tests (gFOBTs). There was insufficient or low quality evidence to support the use of other screening tests, including colonoscopy, as well as changing the ages of initiation and cessation for CRC screening with gFOBTs in Ontario. Either annual or biennial screening using gFOBT reduces CRC-related mortality. Conclusion. The evidentiary base supports the use of FS or FOBT (either annual or biennial) to screen patients at average risk for CRC. This work will guide the development of the provincial CRC screening program.

Likely effect of adding flexible sigmoidoscopy to the English NHS Bowel Cancer Screening Programme: impact on colorectal cancer cases and deaths

Background:

From 2013, once-only flexible sigmoidoscopy (FS) at age 55 is being phased into the England National Health Service Bowel Cancer Screening Programme (NHSBCSP), augmenting biennial guaiac faecal occult blood testing (gFOBT) at ages 60–74. Here, we project the impact of this change on colorectal cancer (CRC) cases and deaths prevented in England by mid-2030.

Methods:

We simulated the life-course of English residents reaching age 55 from 2013 onwards. Model inputs included population numbers, invitation rates and CRC incidence and mortality rates. The impact of gFOBT and FS alone on CRC incidence and mortality were derived from published trials, assuming an uptake of 50% for FS and 57% for gFOBT. For FS plus gFOBT, we assumed the gFOBT effect to be 75% of the gFOBT alone impact.

Results:

By mid-2030, 8.5 million individuals will have been invited for once-only FS screening. Adding FS to gFOBT screening is estimated to prevent an extra 9627 (−10%) cases and 2207 (−12%) deaths by mid-2030. If FS uptake is 38% or 71%, respectively, an extra 7379 (−8%) or 13 689 (−15%) cases and 1691 (−9%) or 3154 (−17%) deaths will be prevented by mid-2030.

Conclusions:

Adding once-only FS at age 55 to the NHSBCSP will prevent ∼10 000 CRC cases and ∼2000 CRC deaths by mid-2030 if FS uptake is 50%. In 2030, one cancer was estimated to be prevented per 150 FS screening episodes, and one death prevented per 900 FS screening episodes. The actual reductions will depend on the FS invitation schedule and uptake rates.

Effectiveness of screening for colorectal cancer with a faecal occult-blood test, in Finland

Background

Screening for colorectal cancer (CRC) with guaiac-based faecal occult-blood test (FOBT) has been reported to reduce CRC mortality in randomised trials in the 1990s, but not in routine screening, so far. In Finland, a large randomised study on biennial FOB screening for CRC was gradually nested as part of the routine health services from 2004. We evaluate the effectiveness of screening as a public health policy in the largest population so far reported.

Methods

We randomly allocated (1:1) men and women aged 60–69 years to those invited for screening and those not invited (controls), between 2004 and 2012. This resulted in 180 210 subjects in the screening arm and 180 282 in the control arm. In 2012, the programme covered 43% of the target age population in Finland.

Results

The median follow-up time was 4.5 years (maximum 8.3 years), with a total of 1.6 million person-years. The CRC incidence rate ratio between the screening and control arm was 1.11 (95% CI 1.01 to 1.23). The mortality rate ratio from CRC between the screening and control arm was 1.04 (0.84 to 1.28), respectively. The CRC mortality risk ratio was 0.88 (0.66 to 1.16) and 1.33 (0.94 to 1.87) in males and females, respectively.

Conclusions

We did not find any effect in a randomised health services study of FOBT screening on CRC mortality. The substantial effect difference between males and females is inconsistent with the evidence from randomised clinical trials and with the recommendations of several international organisations. Even if our findings are still inconclusive, they highlight the importance of randomised evaluation when new health policies are implemented.

Trial registration

002_2010_august.

Faecal haemoglobin concentrations vary with sex and age, but data are not transferable across geography for colorectal cancer screening

BACKGROUND

Faecal immunochemical tests (FIT) are becoming widely used in colorectal cancer (CRC) screening. Availability of data on faecal haemoglobin concentrations (f-Hb) in three countries prompted an observational study on sex and age and the transferability of data across geography.

METHODS

Single estimates of f-Hb in large groups were made in Scotland, Taiwan and Italy using quantitative automated immunoturbidimetry on the Eiken OC-Sensor. Distributions were examined for men and women overall and in four different age groups.

RESULTS

The distributions of f-Hb were not Gaussian and had kurtosis and positive skewness. The distributions were different in the three countries: f-Hb varies with sex and age in all countries, being higher in men and the elderly, but the degree of variation is inconsistent across countries, f-Hb being higher in Scotland than in Taiwan than in Italy, possibly due to different lifestyles. At any cut-off concentration, more men are declared positive than women and more older people are declared positive than younger individuals.

CONCLUSIONS

Our analysis supports the view that setting and using a single f-Hb cut-off in any CRC screening programme is far from ideal. We suggest that individualisation is the optimum approach with f-Hb, alone or with other important factors such as sex and age, used to determine important personal issues such as need for colonoscopy, screening interval between tests and risk of future CRC. Whether there is merit in monitoring f-Hb in individuals over time remains an interesting research question for the future.

An ongoing case-control study to evaluate the NHS Bowel Cancer Screening Programme

BACKGROUND

Colorectal cancer is the third most common cause of cancer death in both males and females in England. A national bowel cancer screening programme was rolled out in England between 2006 and 2010. In the post-randomised controlled trials epoch, assessment of the impact of the programme using observational studies is needed. This study protocol was set up at the request of the UK Policy Research Unit in Cancer Awareness, Screening and Early Diagnosis to evaluate the effect of the current bowel cancer screening programme on incidence of advanced primary colorectal cancer.

METHODS/DESIGN

All incident cases of primary colorectal cancer in England will be included. Cases will be matched to controls with respect to sex, age, area of registration and year of first invitation to screening. Each evaluation round will cover a 2-year period, starting from January 2012, and ongoing thereafter. In the first instance, a pilot will be carried out in a single region. Variables related to colorectal tumour pathology will be obtained to enable selection and matching of cases and controls, and to allow analyses stratification by anatomical subsite within the bowel. Cases at Duke's stage B or worse will be considered as "advanced stage". The influence of sex will also be investigated. The incidence ratio observed in randomised controlled trials between controls (not invited) and non-attender invitees will be used to correct for self-selection bias overall. Screening participation at other national screening programmes (cervical, breast) will also be collected to derive a more contemporaneous adjustment factor for self-selection bias and assess consistency in self-selection correction in female patients.Full ethical approval was obtained from the Health Research Authority.

DISCUSSION

The case-control design is potentially prone to a number of biases. The size of the planned study, the design specifications and the development of analytical strategies to cope with bias should enable us to obtain accurate estimates of reduction in incidence of advanced stage disease. The results of analyses by sex and anatomical subsite may highlight the potential need for sex-specific recommendations in the programme.

Colorectal cancer screening: tests, strategies, and perspectives

Screening has a central role in colorectal cancer (CRC) control. Different screening tests are effective in reducing CRC-specific mortality. Influence on cancer incidence depends on test sensitivity for pre-malignant lesions, ranging from almost no influence for guaiac-based fecal occult blood testing (gFOBT) to an estimated reduction of 66–90% for colonoscopy. Screening tests detect lesions indirectly in the stool [gFOBT, fecal immunochemical testing (FIT), and fecal DNA] or directly by colonic inspection [flexible sigmoidoscopy, colonoscopy, CT colonography (CTC), and capsule endoscopy]. CRC screening is cost-effective compared to no screening but no screening strategy is clearly better than the others. Stool tests are the most widely used in worldwide screening interventions. FIT will soon replace gFOBT. The use of colonoscopy as a screening test is increasing and this strategy has superseded all alternatives in the US and Germany. Despite its undisputed importance, CRC screening is under-used and participation rarely reaches 70% of target population. Strategies to increase participation include ensuring recommendation by physicians, introducing organized screening and developing new, more acceptable tests. Available evidence for DNA fecal testing, CTC, and capsule endoscopy is reviewed.

Optimising faecal occult blood screening:retrospective analysis of NHS Bowel Cancer Screening data to improve the screening algorithm

BACKGROUND

Colorectal neoplasia causes bleeding, enabling detection using Faecal Occult Blood tests (FOBt). The National Health Service (NHS) Bowel Cancer Screening Programme (BCSP) guaiac-based FOBt (gFOBt) kits contain six sample windows (or 'spots') and each kit returns either a positive, unclear or negative result. Test kits with five or six positive windows are termed 'abnormal' and the subject is referred for further investigation, usually colonoscopy. If 1-4 windows are positive, the result is initially 'unclear' and up to two further kits are submitted, further positivity leads to colonoscopy ('weak positive'). If no further blood is detected, the test is deemed 'normal' and subjects are tested again in 2 years' time. We studied the association between spot positivity % (SP%) and neoplasia.

METHODS

Subjects in the Southern Hub completing the first of two consecutive episodes between April 2009 and March 2011 were studied. Each episode included up to three kits and a maximum of 18 windows (spots). For each positivity combination, the percentage of positive spots out of the total number of spots completed by an individual in a single-screening episode was derived and named 'SP%'. Fifty-five combinations of SP can occur if the position of positive/negative spots on the same test card is ignored.The proportion of individuals for whom neoplasia was identified in Episode 2 was derived for each of the 55 spot combinations. In addition, the Episode 1 spot pattern was analysed for subjects with cancer detected in Episode 2.

RESULTS

During Episode 2, 284,261 subjects completed gFOBT screening and colonoscopies were performed on 3891 (1.4%) subjects. At colonoscopy, cancer was detected in 7.4% (n=286) and a further 39.8% (n=1550) had adenomas. Cancer was detected in 21.3% of subjects with an abnormal first kit (five or six positive spots) and in 5.9% of those with a weak positive test result.The proportion of cancers detected was positively correlated with SP%, with an R(2) correlation (linear) of 0.89. As the SP% increased from 11 to 100%, so the colorectal cancer (CRC) detection rate increased from 4 to 25%. At the lower SP%s, from 11to 25%, the CRC risk was relatively static at ~4%. Above an SP% of 25%, every 10-percentage points increase in the SP%, was associated with an increase in cancer detection of 2.5%.

CONCLUSIONS

This study demonstrated a strong correlation between SP% and cancer detection within the NHS BCSP. At the population level, subjects' cancer risk ranged from 4 to 25% and correlated with the gFOBt spot pattern.Some subjects with an SP% of 11% proceed to colonoscopy, whereas others with an SP% of 22% do not. Colonoscopy on patients with four positive spots in kit 1 (SP% 22%) would, we estimate, detect cancer in ~4% of cases and increase overall colonoscopy volume by 6%. This study also demonstrated how screening programme data could be used to guide its ongoing implementation and inform other programmes.

Which adenomas are detected by fecal occult blood testing? A state-wide analysis from Bavaria, Germany

Guaiac-based fecal occult blood tests (gFOBTs) are the most widely used noninvasive tests for colorectal cancer screening. While it is well known that they detect only a minority of colorectal adenomas, evidence for the characteristics of adenomas associated with detection is sparse. We derived estimates of the positive likelihood ratio (LR+), a summary measure of diagnostic performance, according to adenoma characteristics by comparing findings at colonoscopy among 19,208 and 181,128 participants who underwent colonoscopy to follow-up a positive gFOBT and as a primary screening examination, respectively, in Bavaria, Germany, in 2007-2009. Age and sex-adjusted estimates of LR+ (95% confidence intervals, 95% CI) ranged from 1.09 (1.05-1.13) for adenomas <1 cm to 2.52 (2.30-2.75) for adenomas >2 cm, and were much higher for pedunculated adenomas (1.96, 95% CI 1.85-2.08) than for flat or sessile adenomas (1.11, 95% CI 1.02-1.21 and 1.12, 95% CI 1.08-1.16, respectively). Villous or tubulovillous structure and dysplasia were likewise associated with a higher chance to be detected by gFOBT. Diagnostic performance was worse for proximal than for distal adenomas (age and sex adjusted LR+:1.16, 95% CI 1.09-1.23 and 1.35, 95% CI 1.29-1.41, respectively) which was explained by the lower proportions of large, pedunculated and nontubular adenomas in the proximal colon. Size, pedunculated shape, and nontubular histology are the key determinants of detection which also explain lower detection rates of adenomas located in the proximal colon.

SOCIO-ECONOMIC EFFECTIVENESS OF HEALTH SCREENING ACTIVITY IN 2013 IN RUSSIAN FEDERATION

Aim. To estimate long-term socio-economic effectiveness of broad health screening activity of adults by the results in the year 2013.

Material and methods. The study is performed with the method of mathematic modelling using the results of completed in the year 2013 health screening and with an estimate for adult productive and economically active age (up to 72) for 10-year perspective of potentially prevented deaths from the main chronic non-infectious diseases (CHID), saved years of life and economic expenses by 1 year of saved life.

Results. Through analyzed malignant tumours (MT) maximum deaths are to be prevented from breast cancer. The most significant effect of the performed screening is decrease of cardiovascular (CV) deaths — quantity of potentially saved lifes at productive age during 10 years would be 10 times higher than from MT. Screening for the studied CHID is characteristic for certain economic expediency, because expenses on 1 year of potentially saved life appeared lower than gross domestic product by one inhabitant. The most economic expediency of screening was found at the matter of CV diseases: expenses on 1 year of saved productve life (15,5th RUR) and economically active age (11th RUR), that is significantly lower than domestic gross product by inhabitant. Return of investments into health improvement thank to earlier diagnostics of CHID and further treatment would reach 10 RUR per each invested 1 RUR by 10 years.

Conclusion. The analysis and calculations showed a significant positive effect of health screening in 2013, most of all due to earlier diagnostics and complex action against CV diseases and MT, which are included into screening and observation. Expenses on 1 year of saved life were lower than domestic gross product by inhabitant (in prices of the 2013) and return of investment by maintaining labour potential of economically active population was 10 RUR by 1 invested RUR during 10 years. Economic efficiency of health screening as a strategy to prevent premature death, preventable death and to keep health is clear.