'Low' faecal immunochemical test (FIT) colorectal cancer: a 4-year comparison of the Nottingham '4F' protocol with FIT10 in symptomatic patients.

AIM: The aim of this work was to evaluate colorectal cancer (CRC) outcomes after 'low' (sub-threshold) faecal immunochemical test (FIT) results in symptomatic patients tested in primary care. METHOD: This work comprised a retrospective audit of 35 289 patients with FIT results who had consulted their general practitioner with lower gastrointestinal symptoms and had subsequent CRC diagnoses. The Rapid Colorectal Cancer Diagnosis pathway was introduced in November 2017 to allow incorporation of FIT into clinical practice. The local '4F' protocol combined FIT results with blood tests and digital rectal examination (DRE): FIT, full blood count, ferritin and finger [DRE]. The outcome used was detection rates of CRC, missed CRC and time to diagnosis in local 4F protocols for patients with a subthreshold faecal haemoglobin (fHb) result compared with thresholds of 10 and 20 µg Hb/g faeces. RESULTS: A single threshold of 10 µg Hb/g faeces identifies a population in whom the risk of CRC is 0.2%, but this would have missed 63 (10.5%) of 599 CRCs in this population. The Nottingham 4F protocol would have missed fewer CRCs [42 of 599 (7%)] despite using a threshold of 20 µg Hb/g faeces for patients with normal blood tests. Subthreshold FIT results in patients subsequently diagnosed with a palpable rectal tumour yielded the longest delays in diagnosis. CONCLUSION: A combination of FIT with blood results and DRE (the 4F protocol) reduced the risk of missed or delayed diagnosis. Further studies on the impact of such protocols on the diagnostic accuracy of FIT are expected. The value of adding blood tests to FIT may be restricted to specific parts of the fHb results spectrum.

A Poisson scaling approach to backward wave propagation in a tube.

A mathematical analysis of wave propagation along an elastic cylindrical tube is presented, with the aim of determining the range of Poisson's ratio for which backward wave propagation (i.e. at negative group velocity) can occur near the ring frequency. This range includes zero Poisson's ratio and a surrounding interval of positive and negative values, whose width depends on the thickness of the tube. The whole range of Poisson's ratio is considered, so that the work applies to modern materials, e.g. composites. All results are presented in simple analytic form by means of a dominant balance in parameter space. The identification of this balance, which is unique, is a main new result in the paper, which makes possible a new type of shell theory based on 'Poisson scaling'. The mathematical approach is deductive from the equations of motion, rather than being based on kinematic hypotheses. A key finding, accessible via the Poisson scaling, is that the regime of negative group velocities extends to high wavenumbers, while being confined to a narrow band of frequencies. Thus responses localized in space are possible for near-monochromatic forcing, an important fact for nonlinear theories of tube dynamics near the ring frequency. This article is part of the theme issue 'Wave generation and transmission in multi-scale complex media and structured metamaterials (part 1)'.

Quantitative FIT stratification is superior to NICE referral criteria NG12 in a high-risk colorectal cancer population.

BACKGROUND: Guidelines for urgent investigation of colorectal cancer (CRC) are based on age and symptom-based criteria. This study aims to compare the diagnostic value of clinical features and faecal immunochemical test (FIT) results to identify those at a higher risk of CRC, thereby facilitating effective triage of patients. METHODS: We undertook a review of all patients referred for investigation of CRC at our centre between September 2016 and June 2018. Patients were identified using a prospectively recorded local database. We performed a logistic regression analysis of factors associated with a diagnosis of CRC. RESULTS: One-thousand-and-seven-hundred-eighty-four patients with FIT results were included in the study. Change in bowel habit (CIBH) was the most common referring clinical feature (38.3%). Patients diagnosed with CRC were significantly older than those without malignancy (74.0 years vs 68.9 years, p = 0.0007). Male patients were more likely to be diagnosed with CRC than females (6.5% vs 2.5%, Chi-squared 16.93, p < 0.0001). CRC was diagnosed in 3.5% (24/684) with CIBH compared to 8.1% (6/74) with both CIBH and iron deficiency anaemia. No individual or combination of referring clinical features was associated with an increased diagnosis of CRC (Chi-squared, 8.03, p = 0.155). Three patients with negative FIT results (< 4 µg Hb/g faeces) were diagnosed with CRC (3/1027, 0.3%). The highest proportion of cancers detected was in the ≥ 100 µg Hb/g faeces group (55/181, 30.4%). CONCLUSION: In a multivariate model, FIT outperforms age, sex and all symptoms prompting referral. FIT has greater stratification value than any referral symptoms. FIT does have value in patients with iron deficiency anaemia.

Expression of Lamin A/C in early-stage breast cancer and its prognostic value.

PURPOSE: Lamins A/C, a major component of the nuclear lamina, play key roles in maintaining nuclear integrity, regulation of gene expression, cell proliferation and apoptosis. Reduced lamin A/C expression in cancer has been reported to be a sign of poor prognosis. However, its clinical significance in breast cancer remains to be defined. This study aimed to evaluate expression and prognostic significance of lamin A/C in early-stage breast cancer. METHODS: Using immunohistochemical staining of tissue microarrays, expression of lamin A/C was evaluated in a large well-characterised series of early-stage operable breast cancer (n = 938) obtained from Nottingham Primary Breast Carcinoma Series. Association of lamin A/C expression with clinicopathological parameters and outcome was evaluated. RESULTS: Positive expression rate of lamin A/C in breast cancer was 42.2% (n = 398). Reduced/loss of expression of lamin A/C was significantly associated with high histological grade (p < 0.001), larger tumour size (p = 0.004), poor Nottingham Prognostic Index score (p < 0.001), lymphovascular invasion (p = 0.014) and development of distant metastasis (p = 0.027). Survival analysis showed that reduced/loss of expression of lamin A/C was significantly associated with shorter breast cancer-specific survival (p = 0.008). CONCLUSION: This study suggests lamin A/C plays a role in breast cancer and loss of its expression is associated with variables of poor prognosis and shorter outcome.

Clinical validation of an autoantibody test for lung cancer.

BACKGROUND: Autoantibodies may be present in a variety of underlying cancers several years before tumours can be detected and testing for their presence may allow earlier diagnosis. We report the clinical validation of an autoantibody panel in newly diagnosed patients with lung cancer (LC). PATIENTS AND METHODS: Three cohorts of patients with newly diagnosed LC were identified: group 1 (n = 145), group 2 (n = 241) and group 3 (n = 269). Patients were individually matched by gender, age and smoking history to a control individual with no history of malignant disease. Serum samples were obtained after diagnosis but before any anticancer treatment. Autoantibody levels were measured against a panel of six tumour-related antigens (p53, NY-ESO-1, CAGE, GBU4-5, Annexin 1 and SOX2). Assay sensitivity was tested in relation to demographic variables and cancer type/stage. RESULTS: The autoantibody panel demonstrated a sensitivity/specificity of 36%/91%, 39%/89% and 37%/90% in groups 1, 2 and 3, respectively, with good reproducibility. There was no significant difference between different LC stages, indicating that the antigens included covered the different types of LC well. CONCLUSION: This assay confirms the value of an autoantibody panel as a diagnostic tool and offers a potential system for monitoring patients at high risk of LC.

Faecal immunochemical testing and blood tests for prioritization of urgent colorectal cancer referrals in symptomatic patients: a 2-year evaluation.

BACKGROUND: A novel pathway incorporating faecal immunochemical testing (FIT) for rapid colorectal cancer diagnosis (RCCD) was introduced in 2017. This paper reports on the service evaluation after 2 years of pathway implementation. METHODS: The RCCD protocol was based on FIT, blood results and symptoms to stratify adult patients in primary care. Two-week-wait (2WW) investigation was indicated for patients with rectal bleeding, rectal mass and faecal haemoglobin (fHb) level of 10 µg Hb/g faeces or above or 4 µg Hb/g faeces or more in the presence of anaemia, low ferritin or thrombocytosis, in all other symptom groups. Patients with 100 µg Hb/g faeces or above had expedited investigation . A retrospective audit of colorectal cancer detected between 2017 and 2019 was conducted, fHb thresholds were reviewed and critically assessed for cancer diagnoses. RESULTS: In 2 years, 14788 FIT tests were dispatched with 13361 (90.4 per cent) completed returns. Overall, fHb was less than 4 µg Hb/g faeces in 9208 results (68.9 per cent), 4-9.9 µg Hb/g in 1583 (11.8 per cent), 10-99.9 µg Hb/g in 1850 (13.8 per cent) and 100 µg Hb/g faeces or above in 720 (5.4 per cent). During follow-up (median 10.4 months), 227 colorectal cancers were diagnosed. The cancer detection rate was 0.1 per cent in patients with fHb below 4 µg Hb/g faeces, 0.6 per cent in those with fHb 4-9.9 µg Hb/g faeces, 3.3 per cent for fHb 10-99.9 µg Hb/g faeces and 20.7 per cent for fHb 100 µg Hb/g faeces or above. The detection rate in the cohort with 10-19.9 µg Hb/g faeces was 1.4 per cent, below the National Institute for Health and Care Excellence threshold for urgent referral. The colorectal cancer rate in patients with fHb below 20 µg Hb/g faeces was less than 0.3 per cent. CONCLUSION: Use of FIT to "rule out" urgent referral from primary care misses a small number of cases. The threshold for referral may be adjusted with blood results to improve stratification .

Technical validation of an autoantibody test for lung cancer.

BACKGROUND: Publications on autoantibodies to tumour-associated antigens (TAAs) have failed to show either calibration or reproducibility data. The validation of a panel of six TAAs to which autoantibodies have been described is reported here. MATERIALS AND METHODS: Three separate groups of patients with newly diagnosed lung cancer were identified, along with control individuals, and their samples used to validate an enzyme-linked immunosorbant assay. Precision, linearity, assay reproducibility and antigen batch reproducibility were all assessed. RESULTS: For between-replicate error, samples with higher signals gave coefficients of variation (CVs) in the range 7%-15%. CVs for between-plate variation were only 1%-2% higher. For between-run error, CVs were in the range 15%-28%. In linearity studies, the slope was close to 1.0 and correlation coefficient values were generally >0.8. The sensitivity and specificity of individual batches of antigen varied slightly between groups of patients; however, the sensitivity and specificity of the panel of antigens as a whole remained constant. The validity of the calibration system was demonstrated. CONCLUSIONS: A calibrated six-panel assay of TAAs has been validated for identifying nearly 40% of primary lung cancers via a peripheral blood test. Levels of reproducibility, precision and linearity would be acceptable for an assay used in a regulated clinical setting.

Autoantibodies in lung cancer: possibilities for early detection and subsequent cure.

BACKGROUND: People with lung cancer usually present at a late stage in the course of their disease when their chances of long-term survival are low. At present there is little to offer for early diagnosis, even in those at high risk of developing the disease. Autoantibodies have been shown to be present in the circulation of people with various forms of solid tumour before cancer-associated antigens can be detected, and these molecules can be measured up to 5 years before symptomatic disease. OBJECTIVE: To assess the potential of a panel of tumour-associated autoantibody profiles as an aid to other lung cancer screening modalities. METHODS: Plasma from normal controls (n = 50), patients with non-small cell lung cancer (n = 82) and patients with small cell lung cancer (n = 22) were investigated for the presence of autoantibodies to p53, c-myc, HER2, NY-ESO-1, CAGE, MUC1 and GBU4-5 by enzyme-linked immunosorbent assay. RESULTS: Raised levels of autoantibodies were seen to at least 1/7 antigens in 76% of all the patients with lung cancer plasma tested, and 89% of node-negative patients, with a specificity of 92%. There was no significant difference between the detection rates in the lung cancer subgroups, although more patients with squamous cell carcinomas (92%) could be identified. CONCLUSION: Measurement of an autoantibody response to one or more tumour-associated antigens in an optimised panel assay may provide a sensitive and specific blood test to aid the early detection of lung cancer.

Could stool collection devices help increase uptake in bowel cancer screening programmes?

OBJECTIVE: To understand the usage and acceptability of a faecal collection device amongst participants in the National Health Service Bowel Cancer Screening Programme, with the aim of influencing future uptake. SETTING: Participants completing faecal occult blood test retests as part of the routine Bowel Cancer Screening Programme in Eastern England. METHODS: A faecal collection device and questionnaire were sent to all potential retest participants during a one-month period to collect information on prior stool collection methods and ease of use and usefulness of the enclosed faecal collection device. RESULTS: Out of 1087 participants invited, 679 (62.5%) returned their questionnaire. Of these, 429 (63.2%) trialled the faecal collection device at least once, 163 (38.4%) found the device made collecting their sample easier than previously, 189 (44.6%) found it made collection more difficult and 72 (17.0%) said it made no difference. Similar numbers reported finding that the faecal collection device made collecting the sample more pleasant (130, 31.5%), less pleasant (103, 25.0%) and no different (179, 43.4%) compared with previous collection without a faecal collection device. CONCLUSION: Although a small proportion of participants found the faecal collection device helpful, a considerable majority did not or did not use it at all. Offering faecal collection devices is unlikely to produce a substantial increase in bowel cancer screening uptake.

A class of reduced-order models in the theory of waves and stability.

This paper presents a class of approximations to a type of wave field for which the dispersion relation is transcendental. The approximations have two defining characteristics: (i) they give the field shape exactly when the frequency and wavenumber lie on a grid of points in the (frequency, wavenumber) plane and (ii) the approximate dispersion relations are polynomials that pass exactly through points on this grid. Thus, the method is interpolatory in nature, but the interpolation takes place in (frequency, wavenumber) space, rather than in physical space. Full details are presented for a non-trivial example, that of antisymmetric elastic waves in a layer. The method is related to partial fraction expansions and barycentric representations of functions. An asymptotic analysis is presented, involving Stirling's approximation to the psi function, and a logarithmic correction to the polynomial dispersion relation.

Lipid composition and (Na+ + K+)-ATPase activity in rat lens during triparanol-induced cataract formation.

The development of triparanol cataracts in rats is accompanied by the loss of lens (Na+ + K+)-ATPase activity and by alteration in the lens content and composition of phospholipids, sterols and phospholipid acyl groups. The lipid changes occur along the same time course as the loss of (NA+ + K+)-ATPase activity. Triparanol feeding produces a decrease in lens phospholipid content. The percentage contents of phosphatidylcholine and phosphatidyl-serine decrease while the content of sphingomyelin substantially increases. The amounts of oleic acid in lens phospholipids decrease while stearic and palmitic acids increase; however, these changes are relatively small. Sterol content is also decreased while the percentage content of desmosterol increases markedly. Feeding of the cataractogenic agents galactose and diazacholesterol also alters the lens lipid compositions and (Na+ + K+)-ATPase activity. A loss of phosphatidylserine is the only change in lipid properties which always accompanies a loss of the enzyme activity. The possible relationships between the lens content of phosphatidylserine, (Na+ + K+)-ATPase activity and the mechanism of triparanol-induced cataract formation are discussed.

Pattern of usage of the VH4-21 gene by B lymphocytes in a patient with EBV infection indicates ongoing mutation and class switching.

Following infection with EBV, patients have selectively raised serum levels of immunoglobulins encoded by the VH4-21 gene. In order to follow the detailed pattern of usage of the VH4-21 gene by blood B lymphocytes of a typical patient during infection, EBV lines were established, and transformed B cells were hybridized and cloned. In addition, to widen the genetic analysis, cDNA preparations from the EBV transformants using the gene were also analysed by polymerase chain reaction, cloning and sequencing. The majority (12/15) of the clonally distinct sequences derived from IgM utilized the VH4-21 gene in germ line configuration; however, 3/15 showed replacement mutations. For one of these, a heterogeneous pattern of mutation within the clone indicated ongoing mutation, and one sequence contained a stop codon. Three distinct clones which had rearranged to C gamma were obtained, and all were extensively mutated, with some evidence for a role for antigen in selection. Following resolution of the infection, no VH4-21-encoded products were detectable by this approach. It appears therefore that infection with EBV leads to selective activation, mutation and class switching of the VH4-21 gene, with the unusual feature that B cells harbouring deleterious mutations in the functional gene are able to survive in the circulation.

Qualitative research in healthcare: an introduction to grounded theory using thematic analysis.

In today's NHS, qualitative research is increasingly important as a method of assessing and improving quality of care. Grounded theory has developed as an analytical approach to qualitative data over the last 40 years. It is primarily an inductive process whereby theoretical insights are generated from data, in contrast to deductive research where theoretical hypotheses are tested via data collection. Grounded theory has been one of the main contributors to the acceptance of qualitative methods in a wide range of applied social sciences. The influence of grounded theory as an approach is, in part, based on its provision of an explicit framework for analysis and theory generation. Furthermore the stress upon grounding research in the reality of participants has also given it credence in healthcare research. As with all analytical approaches, grounded theory has drawbacks and limitations. It is important to have an understanding of these in order to assess the applicability of this approach to healthcare research. In this review we outline the principles of grounded theory, and focus on thematic analysis as the analytical approach used most frequently in grounded theory studies, with the aim of providing clinicians with the skills to critically review studies using this methodology.

A recombinant HIV provirus is synergistically activated by the HIV Tat protein and the HSV IE1 protein but not by the HSV IE3 protein.

To study the effects of regulatory proteins encoded by herpes viruses on the HIV long terminal repeat (LTR) in the presence or absence of HIV-encoded regulatory products, we prepared a proviral construct containing 5' and 3' HIV LTR, but lacking the coding sequences of any HIV proteins. This construct allowed the effects of herpesvirus regulatory proteins on the HIV LTR to be assessed in a construct similar to the HIV provirus whilst also allowing their interactions with HIV-encoded regulatory proteins to be studied. In this system, the herpes simplex virus (HSV) protein IE1 (ICPO) but not the IE3 (ICP4) protein can activate the HIV LTR, whereas both proteins are active on a single plasmid-borne HIV LTR. Although the activation of the LTR by IE1 is strongly stimulated by the HIV Tat protein, it can also be observed in the absence of Tat, indicating that HSV infection via IE1 has the potential to activate an entirely silent, latent HIV provirus.

The structure, organization, and expression of the Leishmania donovani gene encoding trypanothione reductase.

Trypanothione reductase (TR) is an NADPH-dependent flavoprotein oxidoreductase central to thiol metabolism in the trypanosomatids. We report here the cloning by expression of the Leishmania donovani gene. It is single copy, expresses a 2.6-kb transcript and a 52-kDa protein and is located on a 1.1-Mbp chromosome. The 491 amino acid sequence has 76% similarity to Crithidia fasciculata and 67% similarity to Trypanosoma cruzi, Trypanosoma congolense and Trypanosoma brucei TR. Residues recognising the adenosine pyrophosphate moiety of NADPH and FAD, and residues in the catalytic site segment (A47-A67) involving electron transfer from TR to trypanothione disulphide (T(S)2) were completely conserved. Thus inhibitors of TR are likely to be active against the enzyme from all the parasitic trypanosomatids. Two peptide inserts (39-47, 131-140) seen in other TR genes and a C-terminal extension of 19 residues were also present. When the gene was introduced back into L. donovani at high copy number using the pTEX expression vector, we detected elevated expression of TR RNA and a 14-fold increase in TR activity. Transfection and overexpression of the TR gene will facilitate studies of gene function and of the dependence of trypanosomatids on TR for protection against oxidative stress.

Evidence of genetic recombination in Leishmania.

In the genus Leishmania there has been no convincing demonstration of genetic exchange, and it has been proposed that reproduction is clonal. However, preliminary characterization of two strains of Leishmania isolated from wild animals in a zoonotic focus of cutaneous leishmaniasis in the Eastern Province of Saudi Arabia, has suggested that they may represent hybrids of Leishmania major and Leishmania arabica. Evidence presented here strongly supports this hypothesis. Isoenzyme analysis and molecular karyotyping of cloned organisms indicated that the putative hybrids are distinct from other species of Leishmania, and possess characteristics of both L. major and L. arabica. Experiments using highly specific probes demonstrated that kinetoplast minicircle DNA from the putative hybrid contained L. major-specific, but not L. arabica-specific sequences. DNA fingerprinting data obtained using 6 genomic DNA probes were consistent in all cases with a L. major/L. arabica recombinant genotype, and implied both diploidy and allelic segregation. These observations suggest that sexual reproduction may generate genetic diversity within natural Leishmania populations.

A visual interface to computer programs for linkage analysis.

This paper describes a visual approach to the input of information about human families into computer data bases, making use of the GEM graphic interface on the Atari ST. Similar approaches could be used on the Apple Macintosh or on the IBM PC AT (to which it has been transferred). For occasional users of pedigree analysis programs, this approach has considerable advantages in ease of use and accessibility. An example of such use might be the analysis of risk in families with Huntington disease using linked RFLPs. However, graphic interfaces do make much greater demands on the programmers of these systems.

Vesicoureteric reflux: segregation analysis.

Complex segregation analysis was applied to data from 88 families containing at least one person with vesicoureteric reflux. Analysis showed that a single major locus was the most important causal factor in this condition, with the mutant allele being dominant to the normal allele and having a gene frequency of about 0.16%. Forty-five percent of gene carriers will have vesicoureteric reflux and/or reflux nephropathy as adults and 15% will develop renal failure, compared to 0.05% and 0.001%, respectively, for those not carrying the gene. This analysis confirms the importance of screening close relatives of persons with proven vesicoureteric reflux or reflux nephropathy.

Familial paracentric inversion of 1p.

We report a paracentric inversion of 1p in a boy with mild mental retardation. The chromosome aberration was identified by high resolution chromosome banding, and was also present in his phenotypically normal mother and other relatives. The boy's karyotype was considered to be 46,XY,inv(1) (p31,2p36.22) ISCN (1981).

Direct intrachromosomal duplication of 16q and heritable fragile site fra (10) (q25) in the same patient.

We describe a woman with profound mental retardation and a direct duplication of 16q and fragile site fra(10)(q25). The identification and possible origin of the duplicated 16q is discussed along with the clinical manifestations. To our knowledge this is the first direct duplication of 16q to be reported. The karyotype is shown to be 46,XX, dir dup (16) (q11.2----q13).