cea monitoring in colorectal cancer is not a waste of time
TRANSCRIPT
COLORECTAL CANCER: A CAUTIONARY TALE
CEA monitoring in colorectal cancer is not a waste oftimeDavid Mant emeritus professor of general practice 1, John Primrose professor of surgery 2
1University of Oxford, Nuffield Department of Primary Care Health Sciences, Radcliffe Observatory Quarter, Oxford OX2 6GG, UK; 2University ofSouthampton, Southampton, UK
This “cautionary tale” about follow-up of patients after treatmentof colorectal cancer drew attention to newly published data froma trial started in 1982 that showed “no hint of a survivaladvantage associated with knowledge of CEA[carcinoembryonic antigen].1 2 The article said: “The Follow-upAfter Colorectal Surgery (FACS) trial, recently published inJAMA, confirmed the lack of survival benefit, finding a higherdeath rate in patients who were intensively monitored.”3
As lead authors of the JAMA paper, we wish to point out thatthis last statement is grossly misleading. The FACS trial didnot confirm a “lack of survival benefit.” We stated explicitlythat the statistical power of the trial to assess the mortalityadvantage of intensive follow-up was limited. We reported thatthe observed absolute 6% increase in surgery with curative intentpredicts a 2-3% survival advantage; the confidence intervalsaround the total mortality and colorectal cancer specificmortality rates are consistent with this outcome.What the FACS trial shows unequivocally is that blood CEAmonitoring helps advance the detection of treatable recurrentbowel cancer. The question that the trial cannot answer withany precision is: what effect does the consequent earliertreatment of recurrence have on the length and quality ofsurvival? However, it is now clear that resection of livermetastases (the most common site of metastasis from colorectalcancer) can cure selected patients with recurrent disease andmultimodality chemotherapy has a major impact on survival.4Indeed, the nature and effectiveness of both surgical and
oncological treatment of recurrence are evolving so rapidly thatthis question should not be asked of trials that are of historicalinterest only. Assessment of the impact of CEA monitoring onsurvival requires ongoing modelling of the follow-up andtreatment process, with parameter estimates being changed overtime as new trial evidence is generated about the effectivenessof new treatments.We are about to submit an observational analysis of the FACStrial data which shows that monitoring the change in blood CEAlevels over time, rather than focusing on individual test results,would increase the diagnostic lead time gained by CEAmonitoring even more. It is misleading, and potentiallydamaging to the many patients with bowel cancer currentlybeing followed up, for The BMJ to suggest that the evidenceshows that CEA monitoring is a waste of time.
Competing interests: None declared.
1 Godlee F. Colorectal cancer: a cautionary tale [Editor’s Choice]. BMJ 2014;348:g3311.(17 May.)
2 Treasure T, Monson K, Fiorentino F, Russell C. Operating to remove recurrent colorectalcancer: have we got it right? BMJ 2014;348:g2085. (13 May.)
3 Primrose JN, Perera R, Gray A, Rose P, Fuller A, Corkhill A, et al. Effect of 3 to 5 yearsof scheduled CEA and CT follow-up to detect recurrence of colorectal cancer: the FACSrandomized clinical trial. JAMA 2014;311:263-70.
4 Kanas GP, Taylor A, Primrose JN, et al. Survival after liver resection in metastatic colorectalcancer: review and meta-analysis of prognostic factors. Clin Epidemiol 2012;4:283-301.
Cite this as: BMJ 2014;348:g4032© BMJ Publishing Group Ltd 2014
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BMJ 2014;348:g4032 doi: 10.1136/bmj.g4032 (Published 18 June 2014) Page 1 of 1
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