INTERRELATIONSHIPS BETWEEN SINGLE CARBON UNITS METABOLISM AND RESTINGENERGY-EXPENDITURE IN WEIGHT-LOSING PATIENTS WITH SMALL-CELL LUNG-CANCER - EFFECTS OF METHIONINE SUPPLY AND CHEMOTHERAPY

The one-carbon unit metabolism was investigated in 8 weight-losing pat ients with small cell carcinoma of the lung (SCLC). At diagnosis, 6 of the 8 patients had elevated formiminoglutamic acid (FIGLU) excretion after a histidine load, suggesting a lack of one-carbon units. In acco rdance, a significant decrease of FIGLU excretion was observed in the patients after oral administration of DL-methionine for 4 days. The el evated FIGLU excretion was positively correlated to weight loss prior to diagnosis and negatively correlated to serum albumin at time of dia gnosis. After 3 months of combination chemotherapy, FIGLU excretion wa s reduced in all patients except 1, who had progressive disease. Despi te the elevated FIGLU excretions, all patients had normal blood folate levels. The resting energy expenditure (REE) was recorded in 7 patien ts, and a significant, postive correlation was observed between pretre atment FIGLU excretion and REE, although the REE measured in this grou p of patients was within the normal range. These data demonstrate an i ncreased demand of ''active'' one-carbon units in energy consumption i n a group of weight-losing cancer patients. The one-carbon unit defici t was reconditioned by oral administration of the one-carbon unit dono r DL-methionine.