Lower gastrointestinal symptoms are prevalent among individuals colonoscoped within the Bowel Cancer Screening Programme

AIM

The National Health Service Bowel Cancer Screening Programme (BCSP) aims to detect earlier stage cancer in asymptomatic individuals. Early experience suggested that many participants had lower gastrointestinal symptoms before screening. The study evaluated the prevalence of lower gastrointestinal symptoms and consultation behaviour among individuals undergoing colonoscopy at the South of Tyne BCSP Centre.

METHOD

Data were collected on all undergoing clinic assessment and colonoscopy. Symptoms were categorized as altered bowel habit (ABH), rectal bleeding (RB), abdominal pain (AP) and unexplained weight loss (UWL).

RESULTS

Symptoms were present in 65.1% (492/756) of subjects, 64.4% (431/669) of those with a non-cancer diagnosis and 70.1% (61/87) of those with cancer. Among those with a non-cancer diagnosis, symptoms were ABH in 52% (224/431), RB in 81.4% (351/431), AP in 15.3% (66/431) and UWL in 3.0% (13/431). In those with cancer symptoms they were ABH in 33.3% (29/87), RB in 55.2% (48/87) and AP in 11.5% (10/87). There was no significant difference in the prevalence of symptoms in those with a cancer or non-cancer diagnosis. A total of 34.2% (157/459) of individuals with symptoms had consulted their general practitioner, 28.1% (16/57) of those with cancer and 35.1% (141/402) without.

CONCLUSION

A large proportion of individuals colonoscoped in the BCSP reported symptoms predating screening. Their prevalence did not differ significantly between cancer and non-cancer diagnoses. The majority had not consulted their general practitioner. Health promotion regarding the importance of lower gastrointestinal symptoms and a risk assessment tool to help select those needing urgent specialist assessment are required.

Bowel cancer screening is safe, detects earlier stage cancer and adenomas in 50% of cases: experience of the prevalent round of screening from two first wave centres in the North East of England

OBJECTIVE

The NHS Bowel Cancer Screening Programme (BCSP) began roll-out in 2006 aiming to reduce cancer mortality through detection at an earlier stage. We report results from the prevalent round of screening at two first wave centres and compare with the UK pilot study.

DESIGN

This is a service evaluation study. Data were collected prospectively for all individuals undergoing faecal occult blood testing (FOBt) and colonoscopy including: uptake and outcomes of FOBt, colonoscopic performance, findings, histological data and complications. Continuous data were compared using a two-tailed test of two proportions.

SETTING

The South of Tyne and Tees Bowel Cancer Screening centres.

PATIENTS

Participants of the BCSP.

MAIN OUTCOME MEASURES

1) Colonoscopy Quality Assurance and 2) Cancer stage shift.

RESULTS

195,772 individuals were invited to participate. Uptake was 54% and FOBt positivity 1.7%. 1524 underwent colonoscopy with caecal intubation in 1485 (97%). 180 (12%) cancers were detected. Dukes stages were: 76 (42%) A; 47 (26%) B; 47 (26%) C; 8 (4%) D and 2 (1%) unknown. This demonstrates a significantly earlier stage at diagnosis compared with data from 2867 non-screening detected cancers (p<0.001). Adenomas were detected in 758 (50%). One perforation occurred (0.07%) and two intermediate bleeds requiring transfusion only (0.12%). Both caecal intubation and adenoma detection were significantly higher than in the UK pilot study (p<0.001).

CONCLUSIONS

The prevalent round of screening demonstrates a high adenoma and cancer detection rate and significantly earlier stage at diagnosis. Complications were few providing reassurance regarding safety. Efforts are required to improve uptake.

Silencing and activation of embryonic globin gene expression

An understanding of the mechanisms that control developmental stage-specific transcription of globin genes offers the promise of successful therapeutic activation of fetal or embryonic beta-type genes in beta-thalassemia syndromes. A large body of evidence supports the notion of conservation of such mechanisms across vertebrate species and validates the use of pre-clinical studies of silencing and activation of fetal or embryonic globin genes in animals. Using globin gene transfections into primary avian erythroid cells and cultured murine erythroleukemia cells, we have studied mechanisms involved in stage-specific embryonic beta-type globin gene silencing and activation. These studies show that 1) methylation of the exact CpG nucleotides that are methylated in normal adult erythroid cells in vivo is capable of blocking transcription of a transfected embryonic globin gene promoter via binding of a methyl DNA binding protein in primary erythroid cells. 2) Activation of embryonic beta-type globin gene transcription in adult erythroid cells by short chain fatty acids is mediated through specific DNA sequences both in the promoter and downstream of the promoter.