Trends in the full blood count blood test and colorectal cancer detection: a longitudinal, case-control study of UK primary care patient data

Abstract

Background: The full blood count (FBC) is a common blood test performed in general practice. It consists of many individual parameters that may change over time due to colorectal cancer. Such changes are likely missed in practice. We identified trends in these FBC parameters to facilitate early detection of colorectal cancer. Methods: We performed a retrospective, case-control, longitudinal analysis of UK primary care patient data. LOWESS smoothing and mixed effects models were derived to compare trends in each FBC parameter between patients diagnosed and not diagnosed over a prior 10-year period. Results: There were 399,405 males (2.3%, n = 9,255 diagnosed) and 540,544 females (1.5%, n = 8,153 diagnosed) in the study. There was no difference between cases and controls in FBC trends between 10 and four years before diagnosis. Within four years of diagnosis, trends in many FBC levels statistically significantly differed between cases and controls, including red blood cell count, haemoglobin, white blood cell count, and platelets (interaction between time and colorectal cancer presence: p <0.05). FBC trends were similar between Duke’s Stage A and D colorectal tumours, but started around one year earlier in Stage D diagnoses. Conclusions: Trends in FBC parameters are different between patients with and without colorectal cancer for up to four years prior to diagnosis. Such trends could help earlier identification.

Early detection of colorectal cancer using symptoms and the ColonFlag: case-control and cohort studies

“…We identified cases of CRC up until 14/01/2014 using codelists developed for the first project 13 , for practices linked to the National Cancer Registry (NCR) (clinical codes have previously been reported 15 ). An initial inspection of the capture of CRC diagnoses in CPRD indicated that linkage to the NCR would be important for high quality outcome assessment (analysis available on request).…”

“…Age and sex were available for all individuals. FBC indices were extracted using CPRD Medcodes (clinical codes have previously been reported 15 ). We extracted symptom codes after searching the literature to identify symptoms associated with CRC [16][17][18][19] .…”

BLOod Test Trend for cancEr Detection (BLOTTED): protocol for an observational and prediction model development study using English primary care electronic health record data

“…Methods for incorporating repeated measures data into clinical decision rules are well known [ 4 ]. Our group has recently completed analyses investigating trends in multiple components of the full blood count blood test in the 10 years prior to colorectal cancer diagnosis [ 5 ]. We also developed dynamic prediction models (using joint modelling) designed for early detection of colorectal cancer, using only data earlier than 2 years before diagnosis, which incorporated trends to identify a 2-year risk of diagnosis [ 6 ].…”

BLOod Test Trend for cancEr Detection (BLOTTED): protocol for an observational and prediction model development study using English primary care electronic health records data

“…Methods for incorporating repeated measures data into clinical decision rules are well known 4 . Our group has recently completed analyses investigating trends in multiple components of the full blood count blood test in the ten years prior to colorectal cancer diagnosis 5 .…”

“…Methods for incorporating repeated measures data into clinical decision rules are well known 4 . Our group has recently completed analyses investigating trends in multiple components of the full blood count blood test in the ten years prior to colorectal cancer diagnosis 5 . We also developed prediction models (using joint modelling) designed for early detection of colorectal cancer, using only data earlier than two years before diagnosis, which incorporated trends to identify two-year risk of diagnosis 6 .…”