The appropriate follow-up of primary breast cancer patients is a contr
oversial topic: an intensive surveillance is the rule for many oncolog
ists, but the beneficial effect of this attitude has never been demons
trated. Two consensus conferences focused on this issue, both discoura
ged the routine use of laboratory tests, chest X-ray, radionuclide bon
e scan or liver echography which involve a high financial cost, For th
ese routine investigations the sensitivity to detect recurrence is les
s thant 5%. History and physical examination remain the best methods t
o detect a recurrence, and mammogram is helpful for detecting recurren
t disease in the treated breast or a new primary cancer in the control
ateral breast, which both are curable. The purpose of intensive follow
up is earlier detection of recurrence in order to treat as early as po
ssible, but two randomized studies failed to demonstrate a survival be
nefit in 2600 patients. However with current treatments, only a follow
-up study including a very large number of patients could detect a sur
vival difference. The demonstration of an intensive follow-up benefit
is similar in screening studies where it is recommended to use the mos
t predictive, the less toxic and the less expensive test. Serum C.A. 1
5.3 level which best anticipates diagnosis in follow-up is one of the
best candidates to be used in a randomized study.