Abstract B22: Is there a role of estrogen and progesterone receptors in differentiating primary neuroendocrinal lung tumors from metastatic adenocarcinoma?

Abstract

Abstract Background: The distinction between primary lung carcinoma and metastatic tumors is essential for patient management and treatment. However for metastatic tumors, a wedge resection is often the procedure of choice, whereas for primary pulmonary neoplasms the standard treatment is to perform at least a lobectomy with mediastinal lymph node sampling. Computed tomography scans, histology and immunohistochemical stains still have some limitations in differentiating primary neuroendocrinal lung tumors and metastatic adenocarcinoma. Estrogen and progesterone receptors, although more frequently immunoreactive in breast carcinomas and gynecologic tumors than in primary lung tumors, can be positive in metastatic pulmonary adenocarcinoma. Objective: To assess estrogen and progesterone receptor expression in primary pulmonary neuroendocrine tumors. Design: Fifty seven neuroendocrine lung neoplasms including small cell carcinomas (25), carcinoids (19), large cell neuroendocrine carcinomas (6), and combined small cell carcinomas (7) were evaluated in this cross-sectional study for estrogen and progesterone receptors. Lung metastasis from gynecologic tumors (27) and non-small cell lung carcinomas (30) were also stained for comparison. Settings: Chest and gynecology departments of Assuit and Woman's Health University hospitals. Results: Neuroendocrine primary lung neoplasm demonstrated focal to diffuse estrogen and progesterone expression. There was no correlation with the size of the tumor, the sex or the age of the patients. In comparison with neuroendocrine lung carcinomas, lung metastasis from gynecologic adenocarcinomas (20 endocervical cancer, 7 endometrial cancer) expressed estrogen and progesterone receptors more frequently (p<0.7). Non-small cell carcinomas had less immunoreactivity for estrogen and progesterone than primary neuroendocrinal lung tumors and gynelogic lung metastasis (p<0.4). Conclusions: Although estrogen and progesterone receptor staining is frequently associated with gynecologic tumors, it can also be observed in “nontarget” organs. Therefore, presence of estrogen and progesterone expression in lung metastasis from gynecologic adenocarcinomas should not exclude a primary pulmonary neoplasm. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B22.