Progress and priorities in reducing the time to cancer diagnosis

Key developments in early diagnosis research and policy since the publication of the highly cited BJC review "Is increased time to diagnosis and treatment associated with poorer outcomes?" by Neal et al. in 2015 are summarised. Progress achieved since 2015 is described and priorities for further research identified.

Faecal immunochemical testing (FIT): sources of result variation based on three years of routine testing of symptomatic patients in English primary care

Introduction: We aimed to determine the analytical capabilities of a commonly used faecal immunochemical test (FIT) to detect faecal haemoglobin (Hb) in symptomatic people attending primary care in the context of the English NICE DG30 guidance.Materials and Methods: Data obtained from independent verification studies and clinical testing of the HM-JACKarc FIT method in routine primary care practice were analysed to derive performance characteristics.Results: Detection capabilities for the FIT method were 0.5 µg/g (limit of blank), 1.3 µg/g (limit of detection) and 3.0 µg/g (limit of quantitation). Of 33 non-homogenized specimens, 31 (93.9%) analysed in triplicate were consistently categorized relative to 10 µg/g, compared to all 33 (100%) homogenized specimens. Imprecision was higher (median 27.8%, (range 20.5% to 48.6%)) in non-homogenized specimens than in homogenized specimens (10.2%, (7.0 to 13.5%)). Considerable variation was observed in sequential clinical specimens from individual patients but no positive or negative trend in specimen degradation was observed over time (p = 0.26).Discussion: The FIT immunoassay evaluated is capable of detecting faecal Hb at concentrations well below the DG30 threshold of 10 µg/g and is suitable for application in this context. The greatest practical challenge to FIT performance is reproducible sampling, the pre-analytical step associated with most variability. Further research should focus on reducing sampling variability, particularly as post-COVID-19 guidance recommends greater FIT utilization.

Determinants and extent of weight recording in UK primary care: an analysis of 5 million adults' electronic health records from 2000 to 2017

BACKGROUND

Excess weight and unexpected weight loss are associated with multiple disease states and increased morbidity and mortality, but weight measurement is not routine in many primary care settings. The aim of this study was to characterise who has had their weight recorded in UK primary care, how frequently, by whom and in relation to which clinical events, symptoms and diagnoses.

METHODS

A longitudinal analysis of UK primary care electronic health records (EHR) data from 2000 to 2017. Descriptive statistics were used to summarise weight recording in terms of patient sociodemographic characteristics, health professional encounters, clinical events, symptoms and diagnoses. Negative binomial regression was used to model the likelihood of having a weight record each year, and Cox regression to the likelihood of repeated weight recording.

RESULTS

A total of 14,049,871 weight records were identified in the EHR of 4,918,746 patients during the study period, representing 26,998,591 person-years of observation. Around a third of patients had a weight record each year. Forty-nine percent of weight records were repeated within a year with an average time to a repeat weight record of 1.92 years. Weight records were most often taken by nursing staff (38-42%) and GPs (37-39%) as part of a routine clinical care, such as chronic disease reviews (16%), medication reviews (6-8%) and health checks (6-7%), or were associated with consultations for contraception (5-8%), respiratory disease (5%) and obesity (1%). Patient characteristics independently associated with an increased likelihood of weight recording were as follows: female sex, younger and older adults, non-drinkers, ex-smokers, low or high BMI, being more deprived, diagnosed with a greater number of comorbidities and consulting more frequently. The effect of policy-level incentives to record weight did not appear to be sustained after they were removed.

CONCLUSION

Weight recording is not a routine activity in UK primary care. It is recorded for around a third of patients each year and is repeated on average every 2 years for these patients. It is more common in females with higher BMI and in those with comorbidity. Incentive payments and their removal appear to be associated with increases and decreases in weight recording.

Serum carcinoembryonic antigen trends for diagnosing colorectal cancer recurrence in the FACS randomized clinical trial

BACKGROUND

Most guidelines recommend that patients who have undergone curative resection for primary colorectal cancer are followed up for 5 years with regular blood carcinoembryonic antigen (CEA) tests to trigger further investigation for recurrence. However, CEA may miss recurrences, or patients may have false alarms and undergo unnecessary investigation.

METHODS

The diagnostic accuracy of trends in CEA measurements for recurrent colorectal cancer, taken as part of the FACS (Follow-up After Colorectal Surgery) trial (2003-2014), were analysed. Investigation to detect recurrence was triggered by clinical symptoms, scheduled CT or colonoscopy, or a CEA level of at least 7 μg/l above baseline. Time-dependent receiver operating characteristic (ROC) curve analysis was used to compare the diagnostic accuracy of CEA trends with single measurements. CEA trends were estimated using linear regression.

RESULTS

The area under the ROC curve (AUC) for CEA trend was at least 0·820 across all 5 years of follow-up. In comparison, the AUCs for single measurements ranged from 0·623 to 0·749. Improvement was most marked at the end of the first year of follow-up, with the AUC increasing from 0·623 (95 per cent c.i. 0·509 to 0·736) to 0·880 (0·814 to 0·947). However, no individual trend threshold achieved a sensitivity above 70 per cent (30 per cent missed recurrences).

CONCLUSION

Interpreting trends in CEA measurements instead of single CEA test results improves diagnostic accuracy for recurrence, but not sufficiently to warrant it being used as a single surveillance strategy to trigger further investigation. In the absence of a more accurate biomarker, monitoring trends in CEA should be combined with clinical, endoscopic and imaging surveillance for improved accuracy.

Weight loss as a predictor of cancer and serious disease in primary care: an ISAC-approved CPRD protocol for a retrospective cohort study using routinely collected primary care data from the UK

BACKGROUND

Unexpected weight loss is a symptom of serious disease in primary care, for example between 1 in 200 and 1 in 30 patients with unexpected weight loss go on to develop cancer. However, it remains unclear how and when general practitioners (GPs) should investigate unexpected weight loss. Without clarification, GPs may wait too long before referring (choosing to watch and wait and potentially missing a diagnosis) or not long enough (overburdening hospital services and exposing patients to the risks of investigation). The overall aim of this study is to provide the evidence necessary to allow GPs to more effectively manage patients with unexpected weight loss.

METHODS

A retrospective cohort analysis of UK Clinical Practice Research Datalink (CPRD) data to: (1) describe how often in UK primary care the symptom of reported weight loss is coded, when weight is measured, and how GPs respond to a patient attending with unexpected weight loss; (2) identify the predictive value of recorded weight loss for cancer and serious disease in primary care, using cumulative incidence plots to compare outcomes between subgroups and Cox regression to explore and adjust for covariates. Preliminary work in CPRD estimates that weight loss as a symptom is recorded for approximately 148,000 eligible patients > 18 years and is distributed evenly across decades of age, providing adequate statistical power and precision in relation to cancer overall and common cancers individually. Further stratification by cancer stage will be attempted but may not be possible as not all practices within CPRD are eligible for cancer registry linkage, and staging information is often incomplete. The feasibility of using multiple imputation to address missing covariate values will be explored.

DISCUSSION

This will be the largest reported retrospective cohort of primary care patients with weight measurements and unexpected weight loss codes used to understand the association between weight measurement, unexpected weight loss, and serious disease including cancer. Our findings will directly inform international guidelines for the management of unexpected weight loss in primary care populations.