Clinical significance and correlation of the level change of plasma lysophosphatidic acid in patients before and during radiotherapy

Objective: To investigate the effects of radiotherapy on the level of lysophosphatidic acid (LPA) in different patients. Methods: Three groups of patients (metastatic brain tumor group, non-brain tumor group and primary brain tumor group) were given external irradiation (by linear accelerator). LPA level, white blood cell count and platelet count in the blood plasma were evaluated pre-irradiation and after irradiation with 40 Gy and 60 Gy respectively. Results: The LPA level decreased gradually as irradiation doses increase in metastatic brain tumor group non-brain tumor group (after irradiation with 60 Gy 0.05), and neoplasm volume changed little. White blood cell count and platelet count gradually decreased with the increasing irradiation doses in metastatic brain tumor group and primary brain tumor group, but there was no significant correlation to LPA level. However, there was a negative correlation to LPA level in non-brain tumor group (r=-0.285 and r=-0.237, both P<0.05 ). Conclusions: There is a negative correlation between radiotherapy dose and LPA level in metastatic brain tumor patients and non-brain tumor patients. LPA level could be used as a predictor of the effect of the radiotherapy in tumor treatment. (authors)