Iron deficiency anaemia and delayed diagnosis of colorectal cancer: a retrospective cohort study

Real-world colorectal cancer diagnostic pathways in Ontario, Canada: A population-based study

OBJECTIVE

This study aimed to identify colorectal cancer (CRC) diagnostic pathways and describe patients in those pathway groups.

METHODS

This was a cross-sectional study of CRC patients in Ontario, Canada, diagnosed 2009-2012 that used linked administrative data at ICES. We used cluster analysis on 11 pathway variables characterising patient presentation, symptoms, procedures and referrals. We assessed associations between patient- and disease-related characteristics and diagnostic pathway group. We further characterised the pathways by diagnostic interval and number of related physician visits.

RESULTS

Six diagnostic pathways were identified, with three adhering to provincial diagnostic guidelines: screening (N = 4494), colonoscopy (N = 10,066) and imaging plus colonoscopy (N = 3427). Non-adherent pathways were imaging alone (N = 2238), imaging and emergency presentation (N = 2849) and no pre-diagnostic workup (N = 887). Patients in adherent pathways were younger, had fewer comorbidities, lived in less deprived areas and had earlier stage disease. The median diagnostic interval length varied across pathways from 12 to 126 days, correlating with the number of CRC-related visits.

CONCLUSIONS

This study demonstrated substantial variations in real-world CRC diagnostic pathways and 25% were diagnosed through non-adherent pathways. Those patients were older, had more comorbid disease and had higher stage cancer. Further research needs to identify and describe the reasons for divergent diagnostic processes.

The Prevalence of Anaemia in a District General Hospital in the United Kingdom

Aim Investigating the prevalence of hospital-acquired anaemia in a United Kingdom (UK) secondary care setting to describe the level of appropriate management prior to discharge back to primary care. Design and settings An observational study of 13 medical and surgical wards in a UK district general hospital. Method Single-day examination of notes, blood results and drug charts, with a 30-day follow up, using pre-set definitions of anaemia and exclusion criteria. Results Two hundred and sixty-seven patients were included. Of them, 52% were anaemic on admission, 62.2% were anaemic on the study day, 16% had hospital-acquired anaemia and 49%-82% had no biochemical indices checked during the admission or in the last 12 months. Also, 53% of anaemic patients are being discharged without appropriate treatment, with over a third being under-investigated. Conclusion The prevalence of anaemia in a UK district general hospital is high. Causes of anaemia are complex, posing a potentially modifiable risk factor for falls, readmission and mortality.

A population-based study on time trends of hemoglobin in primary care comparing prediagnostic colorectal cancer patients vs age- and sex-matched controls

BACKGROUND

Some 40% of colorectal cancer (CRC) patients present with anemia. Temporal trends of gradually decreasing Hb are suggested as a supplementary diagnostic tool for CRC. We set out to explore this concept in a strictly defined population.

METHODS

A laboratory database identified patients ≥40 years that had ≥1 Hb test reported from primary care, Örebro county in 2000-17. Linkage to the Swedish Colorectal Cancer Registry identified patients diagnosed with CRC. Other primary care patients served as controls (1:10), matched by age and sex. Prediagnostic Hb in cases and controls were compared and temporal trajectories of Hb modelled using a nonlinear three-parameter logistic function.

RESULTS

1,534 CRC patients and 15,333 controls were identified. The average number of reported Hb tests in primary care per year increased successively, and diagnostic delay from detection of anemia to diagnosis of CRC decreased; in 2015-17 it was median 4 (IQR 2-6) months. No association was found between last Hb and stage of right-/left-sided colon, or rectal cancer.A statistically significantly lower Hb in CRC patients was discernable 609 days (20 months) prior to diagnosis for men and 905 days (30 months) for women, both in the range of normal Hb. The frequency of Hb testing in the general population via primary care was surprisingly low, and was ≥50% annually only in octogenarians.

CONCLUSION

The findings indicate a potential for Hb trends to inform the diagnostic process of CRC but whether it will translate into any clinical advantage is yet uncertain.

Factors contributing to time to diagnosis in symptomatic colorectal cancer: A scoping review

INTRODUCTION

Colorectal cancer (CRC) is the third most common cancer worldwide (Ferlay et al., 2015, International Journal of Cancer, 136, E359), and delayed diagnosis is associated with mortality (Tørring et al., 2011, British Journal of Cancer, 104, 934; Tørring et al., 2012, Journal of Clinical Epidemiology, 65, 669). The purpose of this review was to determine the factors associated with time to diagnosis in symptomatic CRC using scoping review methods.

METHODS

We performed database and citation searches to identify studies which examine the length of any interval from symptom presentation to diagnosis. Study selection was conducted by two independent reviewers. Factors contributing to time to diagnosis were extracted from selected articles and mapped onto a conceptual framework consisting of four levels: patient and disease factors, provider factors, organisation/setting factors and sectors of influence.

RESULTS

From the 31 studies included in this review, we identified 138 unique factors, 17 of which were investigated by at least three studies and 11 of which had consistent results. Patient and disease factors were most commonly studied. Patient perception that their symptoms were benign, a non-urgent referral, female sex and rectal tumour location were each associated with a longer time to diagnosis.

CONCLUSION

Thus far, the literature has focused on patient or disease-related factors, while other levels of influence have been relatively understudied.

Pyrrole derivatives as potential anti-cancer therapeutics: synthesis, mechanisms of action, safety

Pyrrole derivatives (PDs) chloro-1-(4-chlorobenzyl)-4-((3-(trifluoromethyl)phenyl)amino)-1H-pyrrole-2,5-dione (MI-1) and 5-amino-4-(1,3-benzothyazol-2-yn)-1-(3-methoxyphenyl)-1,2-dihydro-3H-pyrrole-3-one (D1) were synthesised as inhibitors of several protein kinases including EGFR and VEGFR. The aim of the study was to reveal the exact mechanisms of PDs' action EGFR and VEGFR are involved in. We observed, that both PDs could bind with EGFR and VEGFR and form stable complexes. PDs entered into electrostatic interactions with polar groups of phospholipid heads in cell membrane, and the power of interaction depended on the nature of PD radical substituents (greater for MI-1 and smaller for D1). Partial intercalation of MI-1 into the membrane hydrophobic zone also occurred. PDs concentrations induced apoptosis in malignant cells but normal ones had different sensitivity to those. MI-1 and D1 acted like antioxidants in inflamed colonic tissue, as evidenced by reduce of lipid and protein peroxidation products (by 43-67%) and increase of superoxide dismutase activity (by 40 and 58%) with restoring these values to control ones. MI-1 restored reduced haemoglobin and normalised elevated platelets and monocytes in settings of colorectal cancer, whereas D1 normalised only platelets. Thus, MI-1 and D1 could be used as competitive inhibitors of EGFR and VEGFR and antioxidants, which might contribute to realisation of their anti-inflammatory, proapoptotic and antitumor activity.

Colonoscopy resource availability and its association with the colorectal cancer diagnostic interval: A population-based cross-sectional study

BACKGROUND

Colonoscopy is a key resource used to diagnose colorectal cancer (CRC). This study evaluated the relationship between colonoscopy availability and the length of the CRC diagnostic interval.

METHODS

This is a cross-sectional study of CRC patients diagnosed in Ontario, Canada, in 2008-2012. We used administrative health data to characterise colonoscopist density, private colonoscopy clinic access, distance to the closest colonoscopist and the diagnostic interval, defined as the time from patients' first cancer-related healthcare encounter to their cancer diagnosis date. We used multivariable quantile regression to evaluate the association between colonoscopy availability and the diagnostic interval, modelling the median and 90th percentile.

RESULTS

The median diagnostic interval was 84 days (90th percentile 323 days). The diagnostic interval was longer in patients residing in areas with lower colonoscopists density or private clinic access (adjusted median difference = 9 and 19 days, respectively), with evidence of effect modification by symptom status. Increased distance to a colonoscopist was associated with a longer diagnostic interval in asymptomatic patients, but a shorter diagnostic interval in symptomatic patients (adjusted median difference = 29 and -25 days, respectively).

CONCLUSIONS

This study demonstrated that reduced colonoscopy resource availability is associated with longer diagnostic intervals for CRC patients.

The value of using the faecal immunochemical test in general practice on patients presenting with non-alarm symptoms of colorectal cancer

Background

Around 50% of individuals with colorectal cancer (CRC) initially present with non-alarm symptoms.

Methods

We investigated the value of using the faecal immunochemical test (FIT) in the diagnostic process of CRC and other serious bowel disease in individuals presenting with non-alarm symptoms in general practice. The study was conducted in the Central Denmark Region from 1 September 2015 to 30 August 2016. The FIT was used as a rule-in test on patients aged ≥30 years with non-alarm symptoms of CRC. The cut-off value was set to 10 µg Hb/g faeces.

Results

A total of 3462 valid FITs were performed. Of these, 540 (15.6%) were positive. Three months after FIT performance, 51 (PPV: 9.4% (95% CI: 7.0;11.9)) individuals with a positive FIT were diagnosed with CRC and 73 (PPV: 13.5% (95%CI: 10.6;16.4)) with other serious bowel disease. Of CRCs, 66.7% were diagnosed in UICC stage I & II and 19.6% in stage IV. The false negative rate for CRC was <0.1% for the initial 3 months after FIT performance.

Conclusion

The FIT may be used as a supplementary diagnostic test in the diagnostic process of CRC and other serious bowel disease in individuals with non-alarm symptoms of CRC in general practice.

Development and validation of a predictive model for detection of colorectal cancer in primary care by analysis of complete blood counts: a binational retrospective study

OBJECTIVE

The use of risk prediction models grows as electronic medical records become widely available. Here, we develop and validate a model to identify individuals at increased risk for colorectal cancer (CRC) by analyzing blood counts, age, and sex, then determine the model's value when used to supplement conventional screening.

MATERIALS AND METHODS

Primary care data were collected from a cohort of 606 403 Israelis (of whom 3135 were diagnosed with CRC) and a case control UK dataset of 5061 CRC cases and 25 613 controls. The model was developed on 80% of the Israeli dataset and validated using the remaining Israeli and UK datasets. Performance was evaluated according to the area under the curve, specificity, and odds ratio at several working points.

RESULTS

Using blood counts obtained 3-6 months before diagnosis, the area under the curve for detecting CRC was 0.82 ± 0.01 for the Israeli validation set. The specificity was 88 ± 2% in the Israeli validation set and 94 ± 1% in the UK dataset. Detecting 50% of CRC cases, the odds ratio was 26 ± 5 and 40 ± 6, respectively, for a false-positive rate of 0.5%. Specificity for 50% detection was 87 ± 2% a year before diagnosis and 85 ± 2% for localized cancers. When used in addition to the fecal occult blood test, our model enabled more than a 2-fold increase in CRC detection.

DISCUSSION

Comparable results in 2 unrelated populations suggest that the model should generally apply to the detection of CRC in other groups. The model's performance is superior to current iron deficiency anemia management guidelines, and may help physicians to identify individuals requiring additional clinical evaluation.

CONCLUSIONS

Our model may help to detect CRC earlier in clinical practice.

Validity and completeness of colorectal cancer diagnoses in a primary care database in the United Kingdom

Purpose

To validate the recorded diagnoses of colorectal cancer (CRC) and identify false negatives in The Health Improvement Network (THIN) primary care database.

Methods

We conducted a validation study of incident CRC cases in THIN among patients aged 40–89 years from 2000–2011. CRC Read code entries (N = 3805) were verified by manual review of patients' electronic medical records (EMRs) including free‐text comments. Incident CRC cases in THIN ascertained following manual review were validated against two data sources deemed gold standards: (i) questionnaires sent to primary care practitioners (PCPs; for a random sample of 100 potential CRC cases), and (ii) Hospital Episode Statistics (HES) among linked practices. False negatives in THIN were identified by searching for International Classification of Diseases‐10 codes related to CRC in HES.

Results

Of 3805 CRC cases identified in THIN via Read codes, 3033 patients (80.0%) were considered definite cases after manual review of EMRs. The positive predictive value (PPV) of CRC Read codes was 86.0% after removing patients identified from THIN via a Read code for ‘fast track referral for suspected CRC’. The response rate from PCPs was 87.0% (n = 87), and the PPV of CRC in THIN was 100% based on PCP questionnaires. Using HES, the PPV for CRC in THIN was 97.9% (556/568), and false negative rate was 6.1% (36/592).

Conclusions

CRC diagnostic Read codes in THIN have a high PPV, which is increased further following manual review of free‐text comments. The false negative rate of CRC diagnoses in THIN is low. © 2015 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

Missed Opportunities for the Diagnosis of Colorectal Cancer

Objective. To examine patient and medical characteristics which predict a missed diagnostic opportunity (MDO) for colorectal cancer (CRC). Methods. The sample consisted of 252 patients diagnosed with Stages 1–4 CRC who were diagnosed in the prior six months, had experienced symptoms prior to diagnosis, and were not diagnosed through routine screening. Systematic review of all medical records prior to patients' diagnosis was conducted. An MDO was defined as a clinical encounter where, even in the presence of presumptive CRC symptoms, the CRC diagnostic process is not started. Results. 92 patients (36.5%) experienced an MDO. Almost 80% of alternate diagnoses were other GI-GU diseases, including hemorrhoids and diverticulitis. Stomach pain, anemia, and constipation were the most common symptoms experienced by the MDO group. These symptoms, and weight loss and vomiting, were more likely to be noted in the charts of the MDO patients (P < 0.04). Independent risk factors for MDO included age (<50) [OR = 2.29 (1.14–4.60), P = 0.02] and female sex [OR = 2.19 (1.16–4.16), P = 0.03]. Each additional physician seen, more than doubled the MDO risk [OR = 2.05 (1.53–2.74), P < 0.001]. Conclusions. Females, younger patients, and those consulting more physicians were all more likely to experience an MDO. Continued increased training of physicians to enhance knowledge of who is vulnerable to CRC is needed in addition to an increased focus to adherence to screening recommendations.

The development of a nurse-led iron deficiency anaemia service in a district general hospital

OBJECTIVE

To improve the quality of care provided to patients with iron deficiency anaemia (IDA).

DESIGN

Service development.

SETTING

District General Hospital.

PATIENTS

Adults with IDA.

MAIN OUTCOME MEASURES

Descriptive report of the practicalities and benefits of establishing an IDA clinic.

CONCLUSIONS

The IDA clinic is a novel service development which enhances the management of patients with this common condition, by facilitating prompt confirmation of the diagnosis, replacement therapy and investigation for serious underlying pathology, in particular gastrointestinal malignancy.

The yield of colorectal cancer among fast track patients with normocytic and microcytic anaemia

INTRODUCTION

We receive fast track referrals on the basis of iron deficiency anaemia (IDA) for patients with normocytic anaemia or for patients with no iron studies. This study examined the yield of colorectal cancer (CRC) among fast track patients to ascertain whether awaiting confirmation of IDA is necessary prior to performing bowel investigations.

METHODS

A review was undertaken of 321 and 930 consecutive fast track referrals from Centre A and Centre B respectively. Contingency tables were analysed using Fisher's exact test. Logistic regression analyses were performed to investigate significant predictors of CRC.

RESULTS

Overall, 229 patients were included from Centre A and 689 from Centre B. The odds ratio for microcytic anaemia versus normocytic anaemia in the outcome of CRC was 1.3 (95% confidence interval [CI]: 0.5-3.9) for Centre A and 1.6 (95% CI: 0.8-3.3) for Centre B. In a logistic regression analysis (Centre B only), no significant difference in CRC rates was seen between microcytic and normocytic anaemia (adjusted odds ratio: 1.9, 95% CI: 0.9-3.9). There was no statistically significant difference in the yield of CRC between microcytic and normocytic anaemia (p=0.515, Fisher's exact test) in patients with anaemia only and no colorectal symptoms. Finally, CRC cases were seen in both microcytic and normocytic groups with or without low ferritin.

CONCLUSIONS

There is no significant difference in the yield of CRC between fast track patients with microcytic and normocytic anaemia. This study provides insufficient evidence to support awaiting confirmation of IDA in fast track patients with normocytic anaemia prior to requesting bowel investigations.

The effect of seeking consent on the representativeness of patient cohorts: iron-deficiency anaemia and colorectal cancer

AIM

The study aimed to establish the level of selection bias that may occur should individual patient consent be sought, by comparing characteristics of consenters and nonconsenters to a request for access to medical records within a cohort of patients diagnosed with iron-deficiency anaemia (IDA).

METHOD

A cohort study and cross-sectional survey was carried out of consent preferences that compared the sociodemographic characteristics of patients providing or not providing consent for access to their records, the consent rates by participant subgroup and the predictors of consent/nonconsent.

RESULTS

Of 599 patients mailed requesting consent for access to their medical records, 425 (71.0%) responses were received. Of the valid responses, explicit consent was granted by 371 (62.7%) respondents, with 47 (7.9%) refusals. The characteristics of consenters and nonconsenters differed with regard to age, gender and deprivation quartile. Nonconsent was associated with younger age (40-60 years vs 60 + years; bivariate OR = 2.84; 95% CI = 2.01-4.02), female gender (OR = 1.62; 95% CI = 1.13-2.34) and being socioeconomically deprived (OR = 1.61; 95% CI = 1.15-2.26).

CONCLUSION

The current research governance framework demonstrates a conflict between protecting the rights of the individual and the development of a sound research base to improve the delivery of healthcare services for society as a whole. If epidemiological research includes data only from individuals who have given consent for access to their records, the resulting selection bias may have consequences for the scientific validity and generalizability of research findings, and ultimately the quality of patient care.