Preliminary Study Of Impacts Of Radiation Therapy On Hematopoietic System In Cancer Patients And Its Relevant Mechanisms

Purpose: To investigate the impacts of radiation therapy on the hematopoietic system,including red blood cells,white blood cells and platelets,and the relevant mechanisms of its development and progression.Methods: To retrospectively analyze the changes of peripheral blood counts in 446 patients with malignant tumors receiving radiation therapy in recent years,including hemoglobin(Hb),white blood cell(WBC),neutrophil(N),lymphocyte(L)and platelet(PLT),and also observe the clinical outcomes of cancer patients after radiation therapy in our hospital.Simultaneously,using the prospective study,changes of the serum levels of Hepcidin and Erythropoietin(EPO)in 93 cancer patients was detected before,during,and after radiation therapy,and their relationships to anemia and the relevant clinical significance would be further analyzed.Results:(1)Levels of WBC,N,L,PLT and Hb in patients before radiation therapy were(6.06±4.29)×109/L,(4.02±2.87)×109/L,(1.43±0.62)×109/L,(203.63±91.89)×109/L and(119.85±19.87)g/L,respectively,which were significantly higher than those levels[(4.60±2.31)×109/L,(3.31±2.10)×109/L,(0.75±0.46)×109/L,(167.93±78.21)×109/L and(116.32±24.25)g/L] after radiation therapy(P<0.05).(2)After radiation therapy,cases with insults of hematopoieticsystem was significantly more than those before radiation therapy(307 cases vs.203 cases,χ2=62.10,P<0.01).In addition,cases of involvement affecting one cell line was significantly more than those affecting two and three cell lines(χ2=9.74,P < 0.01).The degree of involvement was mainly between mild and moderate,the severe cases were rare.(3)Before,during and after radiation therapy,the levels of Hb were(127.8±17.6)g/L,(123.4±16.5)g/L and(119.5±24.9)g/L,respectively,which was gradually decreased induced by radiation therapy(F=8.47,P<0.01).Additionally,the levels of EPO were(5.01±1.59)mg/mL,(5.31±1.97)mg/mL and(5.82±2.32)mg/mL,respectively,which was gradually increased induced by radiation therapy(F=7.58,P<0.01).Moreover,the levels of Hepcidin were(3.36±2.49)mg/mL,(3.08±2.12)mg/mL and(9.36±1.36)mg/mL,respectively,which was gradually decreased induced by radiation therapy(F=3.82,P<0.05).(4)In18 patients with emerging anemia after radiation therapy,10 cases were thoracic and upper abdominal tumors(55.6%),4 cases were urogenital tumors(22.2%),and 2 cases were intestinal cancer and nasopharyngeal carcinoma(11.1%).Other patients receiving radiation therapy for tumors of head and neck,extremity and skin all not got anemia.(5)Using the correlation analysis,results showed that the levels of Hepcidin were both negatively correlated to that of Hb before and during radiation therapy.(r=-0.307 and-0.300,P=0.003 and 0.011).However,levels of EPO were not correlated to either Hepcidin or Hb before,during,and after radiation therapy.Conclusions:(1)The radiation therapy was harmful to the bone marrowhematopoietic function,whose major representation was the varying reduction of Hb,WBC and PLT.Moreover,the insults of radiation therapy were associated with the regions and doses of radiation.(2)The levels of Hepcidin were positively correlated to that of Hb.The levels of EPO were negatively correlated to that of Hb.However,levels of Hepcidin showed no correlation to that of EPO.(3)We proposed that the anemia after radiation therapy should be resulted from the direct damage and inhibition of bone marrow induced by radiation,which may be different to the anemia induced by the systemic inflammation after surgery,chemotherapy and tumor per se.