Urinary excretion of cyclic guanosine 3'.5'-monophosphate in children with malignant tumours.

The present study shows an increased urinary cyclic guanosine 3'.5'-monophosphate (cyclic GMP) excretion rate in children of all age groups bearing malignant tumours or lymphomas. The incidence of increased cyclic GMP excretion was highly significant (79%). Follow-up studies of up to three years have revealed that during periods of remission of malignant disease the urinary cyclic GMP excretion drops to near normal values, whereas recurrences are accompanied by a new increase of cyclic GMP excretion.