Abstract
Purpose: :
The predominance of meningioma in adult females, the association with breast cancer and its major growth during pregnancy and luteal phase of menstruation suggest that is a hormone-dependent tumor. It is well documented that sexual hormone receptors expression has significance in growth, tumor grade and prognosis of intracranial benign meningiomas. Due to the lack of studies about orbital meningiomas and sex hormone receptors, the authors conducted this study to determine progesterone and estrogen receptor (PR and ER, respectively) expression of primary orbital meningiomas and evaluate its relation to age, sex, and histological subtype.
Methods: :
Tissue samples from 79 confirmed primary orbital meningioma patients who underwent surgical resection at our institution from 1957 to 2009 were evaluated. Paraffin-embedded tumor tissue specimens from 65 patients were immunostained using monoclonal antibodies for estrogen and progesterone receptors. Positive expression of PR and ER was classified based on percentage of nuclei stained in low, moderate and intense (51% respectively). Correlations of PR and ER expression and intensity, age, sex, and histological subtype were assessed.
Results: :
Sixty-five samples were evaluated; forty-eight (73.84%) were female, with a male-to-female ratio of 1:2.8, and a mean age of 42.69 years (range: 6-78 years). Twenty-eight (43.07%) meningiomas originated from the optic nerve sheath while thirty-seven involved the sphenoid wing (56.93%). Meningothelial meningioma was the most common histological subtype (41.54%) followed by transitional type (58.46%). Sixty-two specimens (95.23%) expressed PR (intense: 81.53%; moderate: 12.31; low: 6.16%). Only one patient expressed ER (1.54%), and also showed PR, both intensely. Sex, age or histological subtype groups showed no difference in expression of PR or ER.
Conclusions: :
This is the largest and first study that confirms the high levels of progesterone receptors and a lack of estrogen receptors expression in primary orbital meningiomas. Our findings suggest these tumors maybe successfully treated with progesterone receptor antagonists or modulators currently under development.
Keywords: receptors • orbit • tumors