ABSTRACT
The prognostic role of estrogen receptors in lung cancer is not validated. Results from patients with early stage non-small lung cancer patients indicate a prognostic role of estrogen receptor 1 (ESR1) mRNA expression in these patients. Automated RNA extraction from paraffin and RT-quantitative PCR was used for evaluation of tumoral ESR1 and progesterone receptor (PGR) mRNA expression. The test cohort consisted of 31 patients with advanced or metastatic non-small cell lung cancer (NSCLC) patients, treated in a first-line registry trial. For validation, 53 patients from a randomized multicentre first-line study with eligible tumor samples were evaluated. There was no significant correlation of ESR1 expression with clinical characteristics. ESR1 high expression was of significant positive prognostic value in the training set with a median overall survival (OS) of 15.9 versus 6.2 months for high versus low ESR1 expression patients (p = 0.0498, HR 0.39). This could be confirmed in the validation cohort with a median OS of 10.9 versus 5.0 months in ESR1 high versus low patients, respectively (p = 0.0321, HR 0.51). In the multivariate analysis adjusted for histological subtype, gender, age and performance status, ESR1 expression remained an independent prognostic parameter for survival in both cohorts. In contrast to ESR1, PGR expression was not able to separate prognostic groups or to predict outcome significantly (for OS; p = 0.94). Our study shows that ESR1 mRNA as assessed by qPCR represents a reliable method for detecting ESR1 expression in NSCLC and that ESR1 expression is an independent prognostic factor in metastatic NSCLC.
Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Estrogen Receptor alpha/genetics , Gene Expression Regulation, Neoplastic , Lung Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Multivariate Analysis , Neoplasm Metastasis , Paraffin Embedding/methods , Predictive Value of Tests , Prognosis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Progesterone/genetics , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction/methods , Time FactorsABSTRACT
Adjuvant chemotherapy (ACT) leads to a modest improvement in survival among patients with completely resected non-small cell lung cancer (NSCLC) but molecular predictors are still rare. Publicly available gene microarray, clinical and follow-up data from two different studies on early-stage NSCLC were used to determine the expression of estrogen receptor 1 (ESR1). Expression values were calculated against clinical and survival data in a training set (n = 138) and a test set (subpopulation from the adjuvant JBR.10 study) allowing the determination of the prognostic effect of ESR1 in the observational arm as well as the predictive effect of ESR1 regarding ACT. Data were well balanced in terms of ESR1 expression. ESR1 high expression was of significant positive prognostic value in the training set and this could be confirmed in the test set cohort (hazard ratio for overall survival 0.248, 95% confidence interval: 0.088-0.701; p = 0.008). Additionally, ESR1 low tumors showed a benefit from ACT in terms of 5-year survival (33.3% observation arm and 77.8% ACT arm; p = 0.003), whereas patients with ESR1 high tumors did not have any benefit from ACT (test of interaction p = 0.024). ESR1 is an independent positive prognostic factor for survival in early-stage NSCLC patients. Patients with ESR1 high tumors did not benefit from ACT.
