RESUMEN
Plasma noradrenaline (NA), adrenaline (A), dopamine (DA), platelet serotonin (pS), free serotonin (fS), cortisol (CRT), growth hormone (GH), peripheral blood lymphocytes (lymph), lymphocyte subpopulations (LSS) and CD4/CD8 ratio were serially assessed in 50 non-medicated, advanced cancer patients (spontaneous evolution) and in age- and sex-paired controls. Clonidine tests and psychiatric evaluations were also serially performed. Patients showing long symptomless periods had all normal values except for raised pS, whereas those who remained free of symptoms for only a short time had raised NA, A and CRT, plus lowered pS values. Further increases in NA, A and CRT, plus additional increases in DA and fS, occurred during exacerbation periods, during which times reductions in lymph, LSS and NK also were observed. Patients in terminal stages showed maximal decreases of all neurotransmitters and immunological parameters; only DA and fS remained raised. Psychiatric interviews performed simultaneously with the clonidine tests revealed a low incidence of moderate depression during symptomless periods and no depression during exacerbation periods. Several significant positive and negative correlations between neurotransmitters and immunological parameters were found during exacerbation periods. Pain, although not intense, and other symptoms required occasional administration of low doses of non-opiate analgesics.