Pemetrexed is the preferred chemotherapy in the management of non-squamous non-small cell lung cancer (non-sq-NSCLC), yet in lack of biomarkers for predicting efficacy. Dexamethasone which is one of premedication of pemetrexated, may downregulate p53 through the glucocorticoid receptor (GR). The purpose of our study was to explore the effect of GR in peripheral blood mononuclear cell (PBMC) on pemetrexed efficacy.
One hundred and twenty-two patients with stage IV non-sq-NSCLC who received first-line pemetrexed-containing chemotherapy were retrospectively reviewed. The expression of GR in PBMC were measured before treatment with pemetrexed using flow cytometry, and Real-Time PCR was used to detect the level of GRα and GRß.
The response rate for all patients was 38.5%, with a median PFS of 5.9 months and OS of 14.3 months. In univariate analyses, patients with low level of GRα/GRß ratio in PBMC had higher RR, better PFS, and better OS than those with high level of GRα/GRß ratio (RR: 48.2% vs. 30.3%, p = 0.043; mPFS: 6.9 months vs. 4.0 months, p = 0.000; mOS: 18.7 months vs. 12.2 months, p = 0.005). The baseline GRα/GRß ratio was an independent factor for RR (odds ratio [OR] = 0.451, 95%CI: 0.208-0.978, p = 0.044), PFS (HR = 1.584, 95%CI: 1.094-2.295, p = 0.015), and OS (HR = 1.761, 95%CI: 1.195-2.595, p = 0.004).
Demographic and clinical characteristics of patients
|Characteristics||No. of patients|
|Aage (years)||< 60||60|
|current or ever||44|
|T stage||1 or 2||63|
|3 or 4||59|
|GRα/GRß ratio||< 450||56|
|regimen||PEM + DDP||86|
|PEM + CBP||36|
Baseline GRα/GRß ratio in PBMC may play a role in predicting the efficacy of first-line pemetrexed-containing chemotherapy in stage IV non-sqNSCLC patients.
Clinical trial identification
All authors have declared no conflicts of interest.