[Changes in endocrine status in cancer patients and the effect of chemotherapy on endocrine functions]

Changes in serum growth hormone (GH) concentrations before and after TRH injection, oral glucose tolerance test (OGTT), L-dopa, CB-154 and LHRH administration were investigated in 78 gastric, 32 hepatocellular, 23 colonic, 20 pulmonary, 11 esophageal, 9 pancreatic and 9 other types of cancer patients. In addition, the effect of 5-FU or tegafur on thyroid function was studied in 39 gastric, 12 colonic, 8 hepatocellular, 5 pancreatic and 8 other types of cancer patients. The results obtained were as follows. 1) Paradoxical responses of growth hormones to TRH and OGTT were demonstrated in cancer patients, although normal increases in GH concentrations after L-dopa and CB-154 administration were shown. Incidences of GH response to TRH were significantly higher in female cancer patients than in male cancer patients, although there was no sex difference in the paradoxical responses of serum GH concentrations to OGTT. 2) After curative surgery, paradoxical responses of serum GH levels to TRH and OGTT were gradually diminished. Immunostaining of tumors using GH Ab was negative. Anti-tumor agents showed a stimulatory effect on the paradoxical response to OGTT. 4) More than 3 months after 5-FU or tegafur administration, significant elevations of serum T3, T4 and TBG concentrations were demonstrated in cancer patients, compared to pre-treatment values or those within 2 months after therapy, although there were no significant changes in serum thyroglobulin and TSH levels before and after therapy. In conclusion, tumor-dependent hypothalamic-pituitary changes were recognized in cancer patients. Long-term administration of 5-FU or tegafur caused elevations of serum T3 and T4 through high TBG concentrations.