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We are very grateful for the interest in our paper on improving colorectal cancer (CRC) risk prediction in symptomatic patients attending primary care1 expressed by Doctors Zheng and Wang,2 and they highlight some interesting points which we address in the Discussion. To date, the generalisability of Faecal Immunochemical Test (FIT)-based research conducted on a specific FIT analyser has been questioned because the stool collection devices used by analyser manufacturers are not standardised and contain different buffer fluid/antibodies which may influence the faecal haemoglobin concentration measured. Despite this, our findings are similar to the work of Crooks et al whose analyses were performed on the OC Sensor.3 We cannot comment on whether the Faecal Occult Blood (FOB) Gold analyser would perform similarly. They also reaffirm an acknowledged limitation of our study in that the classification of iron deficient anaemia (IDA) status was made using an associated low mean corpuscular volume. In Northern Europe, the prevalence of thalassaemia trait is very low and would not influence our study conclusions. However, in areas of high prevalence (such as some parts of Asia) we agree that other biochemical indices of iron deficiency would be required. We also agree that with the increasing incidence of early onset CRC (EoCRC), it would be helpful if there were broader age-adjusted referral thresholds. Our study contained small numbers of patients with EoCRC; therefore, pooling our data with other centres may enable more objective risk prediction. Finally, in symptomatic patients, FIT testing should be viewed not as a diagnostic test but as an adjunct to clinical acumen. There are no prospective studies to address the optimum mode of safety netting for patients whose FIT result falls below a referral threshold, but some studies have suggested a double FIT test can increase sensitivity for CRC.4 In Scotland, the pragmatic guidance has been to assess the FIT result in conjunction with a full blood count result (to identify IDA and thus prompt a referral), and to repeat the FIT test within 6 weeks if symptoms persist5; retrospective studies in Scotland would suggest this strategy is effective.6 7