Expression of Estrogen Receptor Beta 1, but Not Estrogen Receptor Beta 2 or Alpha Is Linked to Worse Prognosis in Stage I Adenocarcinoma, in Women, in a Large Epidemiological Cohort but Not in a Smaller, Single-Hospital-Based Series
S Sethi, M Cote, F Lonardo. Karmanos Cancer Center, Wayne State University and The Detroit Medical Center, Detroit, MI; Karmanos Cancer Center and Wayne State University, Detroit, MI
Background: Data support the existence of gender differences in the incidence and mortality of lung cancer. However, the extent of such differences and its biological basis remain incompletely characterized. Particularly, the role that sex hormone receptors have on survival and their relation to the clinical and pathological variables of Non Small Cell Lung Cancer (NSCLC) remain poorly defined.
Design: We studied estrogen receptor alpha, beta 1 (EstRB-1) and beta 2 by immunohistochemistry in a series of 504 NSCLC, accrued through a local cancer registry, as a part of an ongoing epidemiological study of lung cancer (series 1). These included 397 women, 107 men; 349 adenocarcinoma, 75 squamous cell carcinoma, 50 poorly differentiated NSCLC, 30 of other histology, with a mean follow-up of 64.7 months. We also studied (series 2) 72 adenocarcinoma consecutively resected at our institution, composed of 28 women, and 44 men, with a mean follow-up of 130 months. All markers were scored separately for intensity (1 lowest, to 3 highest) and extent of positivity (1≤10%;2=11-50%;3≥50%). The two scores were multiplied to generate a final score (1-9): cases where this was ≥ 3 were considered expressors.
Results: Among the hormone receptors studied in series 1, only a positive EstRB-1 constitutes a predictor of reduced prognosis and this is seen only in women with stage I adenocarcinoma (mean follow-up 63.9 months, p value=0.02); a positive EstRb-1 has no relation to age, gender or race. In series 2, EstRB1 does not constitute a significant predictor of survival, in either local or advanced disease, men or women.
Conclusions: 1) Expression of Estrogen Receptor Beta-1, but not estrogen receptor beta 2 or alpha, affects survival in adenocarcinoma but not other histiotypes of NSCLC. 2) EstRB-1 only affects survival in women and stage I disease.3) The effect of EstRB-1 on prognosis is revealed by analysis of a large cohort, while goes unnoticed in a small single-hospital based series.4) EstRB-1 levels may contribute, in conjunction with other factors, to the reported gender differences existing in the biology of lung cancer.
Tuesday, March 23, 2010 1:30 PM
Platform Session: Section F, Tuesday Afternoon