The increasing burden of the 2-week wait colorectal cancer pathway in a single centre: the impact of faecal immunochemical tests

INTRODUCTION

Two-week wait (TWW) volume and colorectal cancer (CRC) detection pose an increasing challenge for NHS cancer services. Primary aims were to assess the introduction of faecal immunochemical tests (FIT) into clinical practice at our centre, the impact on TWW referral volume and CRC diagnoses, and to provide an update to previously published work. A secondary aim was to correlate FIT value and investigation.

METHODS

TWW CRC data following incorporation of FIT into clinical practice were analysed (1 June 2019-31 July 2021). Parameters assessed were monthly referral volume, CRC detection, primary care FIT volume and secondary care investigations. Referrals and CRC detection rates were compared with previously published data (2009-2019). Data relating to primary care FIT were collated from Berkshire and Surrey Pathology Services.

RESULTS

TWW referrals increased 360% (2009-2020). CRC incidence decreased from 8.87% to 3.24%. Following incorporation into clinical practice, primary care FIT requests have increased to >450/month and accompanied 1,722/4,796 referrals. CRC incidence is static (3-4%). Patients with FIT <10µg Hb/g faeces undergo radiological imaging more commonly, whereas FIT-positive patients are more likely to undergo endoscopy, although the difference is not statistically significant.

CONCLUSIONS

No significant change in CRC diagnosis was observed, despite increasing TWW referrals. Increasing utilisation of FIT in both primary and secondary care has helped maintain CRC detection while avoiding diagnostic delay. This study supports growing evidence highlighting the value of FIT in triage, referral and TWW investigation. FIT appears increasingly important for allocating secondary care resources (endoscopy), while guiding primary care referral. Additional low-cost strategies to determine prioritisation or reassurance (e.g. repeat FIT) require further evaluation.

Patient-reported outcome measures show FIT as an acceptable investigation to rule out colorectal cancer in the two-week wait cohort

INTRODUCTION

Use of faecal immunochemical testing (FIT) for symptomatic patients is increasing. FIT is recommended as a triage tool from primary care to the two-week wait (TWW) suspected cancer pathway, but there is still little known about patient attitudes.

AIM

The aim of this study was to explore patient opinions of FIT and how it might be applied in the TWW pathway.

METHODS

A telephone survey was conducted for patients from the TWW pathway who had undergone both conventional colonic investigation and FIT. Five questions explored expectations, attitudes towards results and experience of the investigations using a Likert scale 1-5. Differences in opinion were compared using median and mode scores and visualised using bar charts.

RESULTS

One hundred and nine TWW patients agreed to answer the five questions. All had taken a stool sample for FIT, 50 underwent colonoscopy, 51 had a CT colonography and 8 underwent flexible sigmoidoscopy. Most patients (85%) scored 5 (completely satisfied) with these conventional colonic investigation methods they underwent for ruling out colorectal cancer (median 5). However, 30% of patients scored 5 (completely satisfied) if using a negative FIT to not require additional colonic investigation. The median score to perform FIT was 5 (very easy) compared with a median of 4 (easy) to undergo the other colonic investigations.

CONCLUSIONS

Symptomatic patients can perform FIT with little difficulty, and often would have been happy to avoid conventional colonic investigations with a negative result. However, shared decision-making should be employed to identify those who would be dissatisfied with relying on FIT for further investigation decisions.

O013 The increasing burden of the two-week wait colorectal cancer pathway within a single centre

Introduction

Increasing demand has placed colorectal cancer (CRC) two-week wait (TWW) pathways under pressure. The primary aims of this paper are to review TWW referral numbers and CRC diagnoses within our centre over the past 3 years (before, during and in recovery from the COVID-19 pandemic) and compare outcomes to our previously published data (2009–18). This incorporates the introduction of FIT into our clinical practice.

Methods

TWW CRC referral data from 1st July 2018–31st July 2021 was analysed. Parameters assessed; monthly TWW referrals, CRC detection, % of TWW referrals seen <14 days and investigations utilised. Data from January 2009 to 31 June 2018 was combined. Unpaired t-test was used to compare group means.

Results

TWW referrals have increased 360% from 2009 to 2020. The proportion of TWW referrals with CRC has decreased from 8.87% to 3.24% over this period, whilst the incidence of CRC remained static (mean 58.7 per annum). From 2009–18, TWW referrals=8921, CRC diagnoses=533, mean monthly CRC detection rate=4.7, ratio of referrals to CRC=16.7:1. From 2018–21, TWW referrals= 6523, CRC diagnoses=232, mean monthly CRC detection rate=6.3, ratio of referrals to CRC=28.4:1. There was a statistically significant difference in mean monthly referrals (p-value<0.00001) between the two periods.

Conclusion

Despite ever-increasing TWW referral numbers, no significant change in CRC diagnoses has occurred. We find our service under ever-increasing strain. Additional strategies and guidance are required to help address this. Further studies evaluating FIT and repeat FIT in the symptomatic TWW cohort may have a role in generating such a consensus.

Take-home message

Two week wait colorectal cancer referrals have increased 360% in 12 years. Colorectal cancer detection rate remains static over this timeframe.

The two-week rule colorectal cancer pathway: an update on recent practice, the unsustainable burden on diagnostics and the role of faecal immunochemical testing

INTRODUCTION

Survival for colorectal cancer is improved by earlier detection. Rapid assessment and diagnostic demand have created a surge in two-week rule referrals and have subsequently placed a greater burden on endoscopy services. Between 2009 and 2014, a mean of 709 patients annually were referred to Royal Surrey County Hospital with a detection rate of 53 cancers per year giving a positive predictive value for these patients of 7.5%. We aimed to assess what impact the 2015 changes in National Institute for Health and Care Excellence referral criteria had on local cancer detection rate and endoscopy services.

METHODS

A prospectively maintained database of patients referred under the two-week rule pathway for April 2017-2018 was sub-analysed and the data cross-referenced with all diagnostic reports.

FINDINGS

There were 1,414 referrals, which is double the number of previous years; 80.6% underwent endoscopy as primary investigation and 62 cancers were identified, 51 being of colorectal and anal origin (positive predictive value 3.6%). A total of 88 patients were diagnosed, with other significant colorectal disease defined as high-risk adenomas, colitis and benign ulcers. Overall, a total of 10.6% of our two-week rule patients had a significant finding.Since the 2015 referral criteria, despite a dramatic rise in two-week rule referrals, there has been no increase in cancer detection. It has placed significant pressure on diagnostic services. This highlights the need for a less invasive, cheaper yet sensitive test to rule out cancer such as faecal immunochemical testing that can enable clinicians to triage and reduce referral to endoscopy in symptomatic patients.

Positive peak identification in liquid chromatography using absorbance ratioing with a variable-wavelength spectrophotometric detector

It is frequently necessary to confirm the identification of component peaks isolated in high-performance liquid chromatograms. The UV spectrum of the pure compound is usually a very powerful signature for most compounds. For liquid chromatographic instruments that permit stop-flow operation, a simple approximation is obtained with a variable wavelength UV detector by determining the absorbance ratios at several specific wavelengths to characterize the compound. If the wavelengths are well chosen, these absorbance ratios provide a very specific and a very reliable technique for peak identification. The absorbance ratios are independent of the concentration of the compounds in the detector flow cell. Identity or purity of individual peaks can be confirmed when absorbance ratios are taken from the peaks of individually injected pure standards. Flow can be stopped several times on the leading and trailing edges of broad peaks, and ratios calculated. If the ratios are identical, the peak can be considered to be pure; if ratios differ, the presence of unresolved components can be suspected. Stop-flow ratioing can be performed during gradient elution: standards are injected under rapid elution conditions and the resulting ratios are compared with those of the peaks from the gradient run. Ratios are found to be identical for similar components, regardless of the differences in retention time, thus providing rapid identification of the compounds in the gradient chromatogram. Factors that influence the overall precision of the method are: ability to stop and re-start eluent flow without loss of chromagraphic efficiency, ability to obtain numerical absorbance data from the detector, the wavelength repeatability of the detector, and the requirement that the detector cell design allow slow interruptions without baseline upset.