Correlation of meningioma hormone receptor status with hormone sensitivity in a tumor stem-cell assay

Several investigators have detected progesterone receptors in a high percentage of meningioma specimens and have noted progesterone receptors to be more common than estrogen receptors in these specimens. However, a functional significance of such hormone receptor positivity in control of meningioma growth has not been described. This paper describes a paired test of the estrogen and progesterone receptor assay as the biochemical assay and of the human tumor stem-cell clonogenic assay (HTSCCA) as the functional assay in 17 meningioma specimens. Only one (6%) of the 17 specimens was estrogen receptor-positive, while 11 (69%) of 16 specimens were progesterone receptor-positive. The HTSCCA revealed that only two (15%) of 13 specimens were sensitive to estradiol while five (31%) of 16 specimens were sensitive to progesterone. Comparison of progesterone results for the 15 specimens on which both hormone receptor assay and HTSCCA were performed revealed correlation in a majority of cases; four specimens were positive for both assays and five specimens were negative for both assays. No specimen that was negative for progesterone receptors was sensitive to progesterone by HTSCCA. These results suggest that the hormone receptor and sensitivity pattern of meningiomas may differ from that of breast cancer, and that progesterone addition or ablation may be a reasonable therapeutic approach for meningiomas.