OBJECTIVE:To probe into the clinical efficacy of bevacizumah combined with pemetrexed in the treatment of advanced lung adencocarcinoma in the elderly and its effects on immune function.METHODS:Prospective cohort study design was adopted.Patients with advanced lung adenocarcinoma who met the inclusion criteria and admitted into Daxing Teaching Hospital

Capital Medical University from Aug.2015 to Dec.2018 were divided into the control group and the study group according to different treatment regimens.Forty patients in the control group were given pemetrexed 500 mg/m

2

intravenously

and the drug was administered only on the first day

with 21 d for one cycle.Forty-two patients in the study group received pemetrexed 500 mg/m

2

intravenously

and the drug was administered only on the first day

with 21 d for one cycle;hevacizumah 7.5 mg/kg intravenously

and the drug was administered only on the first day

with 14 d for one cycle.Both groups received at least 4 cycles of chemotherapy

and after 4 cycles

the clinical efficacy

adverse drug reactions

and peripheral blood immune indicators were compared between two groups

and the disease progression-free survival（PFS） was followed up.RESULTS:The objective effective rates in the study group and the control group were 52.4%（22/42） and 37.5%（15/40）

respectively

with no statistically significant difference（P=0.176）;the disease control rates were respectively 83.3%（35/42） and 62.5%（25/40）

with statistically significant differences（P=0.033）.The median PFS of the study group was 6.5 months（95%CI:from 5.82 to 7.29 months）

while that of the control group was 5.2 months（95%CI:from 4.45 to 5.97 months）

the difference was statistically significant（P=0.04）.The main grade 3/4 adverse drug reactions in two groups were neutropenia

thrombocytopenia

anemia

nausea and vomiting

fatigue

hypertension and proteinuria

and the difference was not statistically significant（P

>

0.05）.T cell subsets

NK cell activity

IgA and IgM levels in the control group decreased significantly after treatment

and the differences were statistically significant compared with those before treatment（P

<

0.05）.T cell subsets

NK cell activity

IgA and IgM levels in the study group did not decrease significantly after treatment

and the difference was statistically significant compared with those in the control group after treatment（P

<

0.05）.Before and after treatment

there was no statistically significant difference in IgG levels between two groups（P

>

0.05）.CONCLUSIONS:The efficacy of bevacizumab combined with pemetrexed in the treatment of advanced lung adenocarcinoma in the elderly is significant

the disease control rate was superior to pemetrexacin monotherapy

with tolerable adverse drug reactions

and the effects on the level of peripheral immune indicators are small.