110 patients observed over a three-year period suffering from cancer of the breast, digestive apparatus, lung and urogenital apparatus, and submitted simultaneouly to the DNCB skin test and to radioimmunological measurement of CEA have been studied. Confirming what has already been reported, the epicutaneous findings and laboratory results show there is an almost constant correlation between marked reactivity to DNCB and normal CEA titre and that, on the contrary, ml response to immune stimulation is often matched by a pathological CEA value. It is maintained that this type of cross investigation may be important for prognosis as the basis for initial assessment of the probable clinical course of the disease and the response of the patient to immunochemotherapeutic treatment.