Faecal immunochemical test (FIT)-directed pathways based on a single test have been implemented for symptomatic patients. However, with a single test, the sensitivity is 87 per cent at 10 µg haemoglobin (Hb) per g faeces. This aims of this study were to define the diagnostic performance of a single FIT, compared with double FIT in symptomatic populations. Two sequential prospective patient cohorts referred with symptoms from primary care were studied. Patients in cohort 1 were sent a single FIT, and those in cohort 2 received two tests in succession before investigation. All patients were investigated, regardless of having a positive or negative test (threshold 10 µg Hb per g). In cohort 1, 2260 patients completed one FIT and investigation. The sensitivity of single FIT was 84.1 (95 per cent c.i. 73.3 to 91.8) per cent for colorectal cancer and 67.4 (61.0 to 73.4) per cent for significant bowel pathology. In cohort 2, 3426 patients completed at least one FIT, and 2637 completed both FITs and investigation. The sensitivity of double FIT was 96.6 (90.4 to 99.3) per cent for colorectal cancer and 83.0 (77.4 to 87.8) per cent for significant bowel pathology. The second FIT resulted in a 50.0 per cent reduction in cancers missed by the first FIT, and 30.0 per cent for significant bowel pathology. Correlation between faecal Hb level was only modest (r_s = 0.58), and 16.8 per cent of double tests were discordant, 11.4 per cent in patients with colorectal cancer and 18.3 per cent in those with significant bowel pathology. FIT in patients with high-risk symptoms twice in succession reduces missed significant colorectal pathology and has an acceptable workload impact.

Lymph nodes (LNs) are believed to be the first organs targeted by colorectal cancer cells detached from a primary solid tumor because of their role in draining interstitial fluids. Better detection and assessment of these organs have the potential to help clinicians in stratification and designing optimal design of oncological treatments for each patient. Whilst highly valuable for the detection of primary tumors, CT and MRI remain limited for the characterization of LNs. B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) can improve the detection of LNs and could provide critical complementary information to MRI and CT scans; however, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines advise that further evidence is required before US or CEUS can be recommended for clinical use. Moreover, knowledge of the lymphatic system and LNs is relatively limited, especially in preclinical models. In this pilot study, we have created a mouse model of metastatic cancer and utilized 3D high-frequency ultrasound to assess the volume, shape, and absence of hilum, along with CEUS to assess the flow dynamics of tumor-free and tumor-bearing LNs in vivo. The aforementioned parameters were used to create a scoring system to predict the likelihood of a disease-involved LN before establishing post-mortem diagnosis with histopathology. Preliminary results suggest that a sum score of parameters may provide a more accurate diagnosis than the LN size, the single parameter currently used to predict the involvement of an LN in disease.

Background: Faecal immunochemical testing (FIT) is widely used in bowel screening programmes and assessing symptomatic patients for suspected colorectal cancer (CRC). The evidence for single test performance of FIT in both settings is considerable; however, the use of a repeat test to increase sensitivity remains uncertain. We aimed to review what increase in test positivity would be generated by additional FITs, whether a repeated FIT detects previously missed CRC and advanced colorectal neoplasia (ACRN), and to estimate the sensitivity of double-FIT strategies to diagnose CRC and ACRN. Methods: A systematic search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) was performed using key search terms. Studies reporting the use of more than one FIT in the same screening round or planned assessment of a single symptomatic patient episode were included. Studies were categorised by the reported study population into asymptomatic, mixed (cohorts of combined asymptomatic, symptomatic, or high-risk surveillance), or symptomatic cohorts. Results: A total of 68 studies were included for analysis (39 asymptomatic, 21 mixed, 7 symptomatic, and 1 study with discrete asymptomatic and symptomatic data). At a threshold of 10 µg Hb/g, the two-test positivity ranged between 8.1 and 34.5%, with an increase from the second test of 3–9.2 percentage points. Four out of five studies comparing one versus two tests for diagnosing CRC at 10 µg Hb/g identified additional cases with the second test, with a minimum of 50% reduction in missed CRC. At a threshold of 20 µg Hb/g, the second test increased the positivity by 1.3–6.7 percentage points, with a two-test positivity of between 5.1 and 25.0%. Using a threshold of 20 µg Hb/g, five out of seven studies had a 25% reduction in missed CRC. A meta-analysis estimated the double-FIT sensitivity at 10 µg Hb/g for CRC in mixed-risk and symptomatic cohorts to be 94% and 98%, respectively. Conclusions: Repeated use of FIT helps to diagnose more cases of CRC with a moderate increase in positivity. A double-FIT strategy at 10 µg Hb/g in mixed and symptomatic cohorts has a very high sensitivity for CRC.

This study aimed to describe the faecal immunochemical test non-return rate of those referred with high-risk symptoms of colorectal cancer from primary care, and the clinical outcomes of the ‘non-returners’. From January 2019 to July 2021, patients referred to secondary care with symptoms suspicious of colorectal cancer and a referral priority of urgent or urgent suspicion of cancer were sent a faecal immunochemical test. All patients were investigated regardless of faecal immunochemical test return or result. Demographics and clinical outcomes such as colorectal cancer prevalence were compared between those who returned a faecal immunochemical test and non-returners. Of 7345 patients included in the study, 874 (11.9%) did not return a faecal immunochemical test. Non-returner characteristics included male sex (P = 0.040), younger age (median age 57 versus 65 years, P < 0.001), per rectal bleeding (P < 0.001) and lower socioeconomic status (median Scottish Index of Multiple Deprivation, 6 versus 7, P < 0.001) compared with those who returned a faecal immunochemical test. Of 6294 patients undergoing colorectal investigation, there was a greater prevalence of colorectal cancer (5.4% versus 3.6% P = 0.032) and significant bowel pathology than in the non-returners (15.3% versus 9.8%, P < 0.001). With a median follow-up of 25 months, the colorectal cancer prevalence for the entire 7345 cohort was equal between those who returned and did not return a faecal immunochemical test (3.2% versus 3.8%, P = 0.108). Of note, the non-returners diagnosed with colorectal cancer were younger (median age 64 versus 73 years, P < 0.001) and from a lower socioeconomic area (median Scottish Index of Multiple Deprivation 4 versus 7, P = 0.015) than faecal immunochemical test returners. Patients referred to secondary care, with symptoms suspicious of colorectal cancer, that did not return a faecal immunochemical test had a similar colorectal cancer prevalence to those that returned the test.

Background: Colorectal cancer (CRC) screening programmes aim to detect early, asymptomatic cancers and improve survival. This study aimed to establish the proportion of interval cancers, and the consequences with regard to stage, clinical outcome, and overall survival. Risk factors associated with interval CRCs were investigated. Methods: The Scottish Bowel Screening Programme uses faecal immunochemical testing at a threshold of 80 µg haemoglobin per g as a positive trigger for investigation. Screening was offered to all eligible individuals in one region, from November 2017 to October 2021. Cancer registries were cross-checked to ensure complete capture of all cancers including interval CRCs. The primary outcome was rate of interval CRCs among participants with follow-up of 24 months, and its relationship to faecal immunochemical testing results, clinical variables, stage, time to diagnosis, and survival. The secondary outcome was identification of risk factors associated with interval CRCs. Results: The Scottish Bowel Screening Programme generated 316 583 tests during the study period. Participation was 71.0% of the eligible population (212 664 patients); it was greater among women (71.9 versus 70.0%; P < 0.001) and in higher socioeconomic areas (76.9 versus 58.6%; P < 0.001). In the screened population, 546 CRCs were diagnosed within 2 years of screening. Some 289 of these patients (52.9%) had positive bowel screening. There were 257 patients with interval CRCs, who waited a median of 13 (interquartile range 7–20) months for diagnosis. Of CRCs diagnosed, 24.9% had screening faecal immunochemical test results of < 10 µg haemoglobin per g. The interval CRC rate was greater in women, older patients, and among the least socioeconomically deprived. Interval CRCs were associated with worse 2-year all-cause mortality than screen-detected CRCs (23.0 versus 10.8%; P < 0.001). Importantly, 121 of the 257 interval CRCs (47.1%) had detectable faecal immunochemical test results at 10–79 µg haemoglobin per g. Conclusion: Patients with interval CRCs and a detectable faecal immunochemical test result below the predetermined threshold appear to be significantly disadvantaged with respect to stage at presentation and survival. Almost half of interval CRCs diagnosed within 2 years had detectable haemoglobin on screening faecal immunochemical test and would be a target for lower positivity thresholds.

We present the case of a 22-year-old man transferred to the regional major trauma centre following a fall of ~15 m. He remained consistently haemodynamically stable for over 10 hours of observation until he deteriorated suddenly with major haemorrhagic shock requiring immediate trauma laparotomy. At laparotomy, 2 L of blood was drained from the abdomen but no source of active bleeding identified. 30 minutes after closure of the abdomen, 500 mL of fresh blood was noted in the drain so he was returned to the theatre where the bleeding source was found to be—after manual compression of a mildly bruised hepatoduodenal ligament—the proper hepatic artery (PHA). This case describes an unusual finding at relaparotomy and shows that even when there is no active bleeding from abdominal organs or classified vessels, it is possible to have isolated injury to PHA.