Editorial: Parents and longevity.
Journal: BMJ (1974)

basis of any mass screening programme for the earlier detec- tion of colon cancer.At that time, too, attention was focused on C.E.A. in bladder cancer, but now it seems that C.E.A. measurements in the urine offer little additional assistance to its management.Have the past two years provided reason to sustain our interest in this test, or is it still too susceptible to the vagaries of individual variation to make it a practical proposition ?A recent conference on colorectal cancer held in Leeds pro- vided a chance to take stock of how the C.E.A. test might help the surgeon assess the prognosis and manage the follow-up of patients with cancer of the large bowel.At present, this whole topic is the subject of a combined Medical Research Council- Department of Health trial, and no doubt the results will not be available for another year or two.There are now a few supraregional centres in Britain providing the C.E.A. test on request, and it seems that the real advance in clinical practice is the use of C.E.A. plasma levels measured repeatedly over one or two years after excision of a colorectal cancer.Sorokin et al.2 followed 102 patients who had undergone potentially curative surgery and found progressively rising C.E.A. titres in six of them who were asymptomatic and in whom extensive clinical examination revealed metastases.The C.E.A. titre remained raised for as long as 29 months before the diagnosis was confirmed in one case.They also described a further six patients with stable elevation of C.E.A., three of whom had evidence of liver disease.Professor A. M. Neville reported to the conference observations of 220 patients with apparent successful resections followed for two years.Progressive rises in the C.E.A. level due to metastases occurred in 26 patients, with a lead time of nine to 18 months ahead of confirmation of the diagnosis.In a further 10 patients rising titres were noted synchronously with clinical detection of tumour.In a further 17 patients the C.E.A. level is raised but they are asymptomatic and so far without clinical evidence of tumour.In the British trial a raised C.E.A. has not been an indication for an intensive investigation, so the data on lead time relates to standard practice in the follow-up clinics.Similar results were given by Dr. P. Dykes from Birmingham, where again the experience is that a persistent postoperative raised C.E.A. or a rising titre indicates recurrence or metastases.The pattern of change in hepatic metastases is becoming clearer.Small metastases discovered at laparotomy may at first produce no change in the C.E.A., while later both the C.E.A. and plasma gamma glutamyl transpeptidase levels begin a progressive rise, sometimes simultaneously, sometimes one before the other; and finally the classical liver function tests become abnormal, often preceded by changes in the C.E.A. and G.G.T. for many weeks.The increase in C.E.A. produced by non-hepatic metastases and local recurrence is less marked, and the tests available so far are not as reliable as an early warning system as they are for hepatic metastases.It is still too early to say what clinical significance should be given to a finding of a moderate pre- operative elevation of C.E.A. in a primary colorectal cancer.A large series of patients and long follow-up will be needed for this question to be answered.It is, however, clear that high preoperative C.E.A. values (150 ng/ml) are almost invariably associated with coincidental metastases or metastases becoming evident within a year.Though C.E.A. is non-specific, repeated measurements and the study of the pattern of change in titre compensate for this lack of specificity.Transient rises are of no diagnostic significance.Patients in whom metastatic colorectal cancer is the cause for a raised C.E.A. eventually