Straight-to-test faecal tagging CT colonography for exclusion of colon cancer in symptomatic patients under the English 2-week-wait cancer investigation pathway: a service review.

AIM: To present the initial 12 months of data of a straight-to-test (STT) computed tomography colonography (CTC) protocol as the first-line investigation for change in bowel habit (CIBH) and iron deficiency anaemia (IDA) in patients over 60 referred directly from primary care. MATERIALS AND METHODS: In 12 months, 1,792 STT CTC for IDA and CIBH were performed. No colonoscopies were performed as the primary investigation in this cohort. Data from this cohort were gathered prospectively. RESULTS: The colorectal cancer (CRC) detection rate was 4.9% and polyp detection rate was 13.5%. The CRC rate increased related to age (p=0.001), the CRC detection rate was 2.6% in patients aged 60-69 years, compared to 4.9%, 7.4%, and 11.4% in the 70-79, 80-89, and >90 years age groups. The CRC rate was higher in patients with IDA compared to CIBH (6.8% versus 3.9%, p=0.017). There were significantly more left-sided cancers (p=0.0165). Non-colonic cancers were found in 4.3% of patients and 6.8% had incidental findings that required further investigation and 11.9% had a new, potentially significant, incidental finding. CONCLUSION: These results are comparable to colonoscopy in terms of diagnostic accuracy and similar to those of CTC in published multicentre trials. This exciting model of care within radiology enables earlier testing, reduces waiting times, with fewer outpatient appointments, and results in good clinician and patient satisfaction.

Assessment of the inferior mesenteric vein diameter as a surrogate marker to evaluate response to neoadjuvant chemoradiotherapy for locally advanced rectal adenocarcinoma.

AIM: Neoadjuvant chemoradiotherapy for locally advanced rectal cancer aims to downstage prior to definitive management. Repeat imaging assessment of the tumour post-therapy has implications for treatment. Our aim was to assess if the inferior mesenteric vein (IMV) diameter measured on CT can be used as a surrogate marker for evaluation of tumour response to neoadjuvant treatment. METHOD: IMV diameter was assessed in patients with and without locally advanced rectal cancer, pre- and post-radiotherapy, to ascertain if IMV diameter is a surrogate marker of tumour response. RESULTS: IMV diameter was 5.9 mm in patients with rectal cancer vs 4.7 mm in patients without (P = 0.0001). The baseline IMV diameter was significantly higher for cases with local lymphadenopathy [N0 5.2 mm vs N1/2 6 mm (P = 0.0059)] and extramural venous invasion (EMVI) [negative 5.4 mm vs positive 6.4 mm (P = 0.0001)]. Post-radiotherapy there was a significant decrease in the IMV diameter in cases with treatment response compared to non-responders: the percentage change in IMV diameter was a 17.54% decrease vs 1.39% increase (P = 0.0001). These results were reproduced on comparing between magnetic resonance tumour regression grades using ANOVA (P = 0.0001). There was also a significant decrease in IMV diameter when assessing lymph node (LN) and EMVI response vs non-responders (P = 0.0001 and 0.0001 respectively). CONCLUSION: Patients with rectal cancer have a dilated IMV compared with patients without rectal cancer. We confirm that IMV diameter is a potential surrogate marker of LN status and EMVI at baseline. IMV diameter is also a marker of tumour, LN and EMVI response to chemoradiotherapy.

Addressing the Antibiotic Resistance Problem with Probiotics: Reducing the Risk of Its Double-Edged Sword Effect.

Antibiotic resistance is a global public health problem that requires our attention. Indiscriminate antibiotic use is a major contributor in the introduction of selective pressures in our natural environments that have significantly contributed in the rapid emergence of antibiotic-resistant microbial strains. The use of probiotics in lieu of antibiotic therapy to address certain health conditions in both animals and humans may alleviate these antibiotic-mediated selective pressures. Probiotic use is defined as the actual application of live beneficial microbes to obtain a desired outcome by preventing diseased state or improving general health. Multiple studies have confirmed the beneficial effects of probiotic use in the health of both livestock and humans. As such, probiotics consumption is gaining popularity worldwide. However, concerns have been raised in the use of some probiotics strains that carry antibiotic resistance genes themselves, as they have the potential to pass the antibiotic resistance genes to pathogenic bacteria through horizontal gene transfer. Therefore, with the current public health concern on antibiotic resistance globally, in this review, we underscore the need to screen probiotic strains that are used in both livestock and human applications to assure their safety and mitigate their potential in significantly contributing to the spread of antibiotic resistance genes in our natural environments.