Apart from the probable risk attributable to vascular compromise, GH-secreting pituitary adenoma as such may confer an increased risk for RON development as previously suggested5,6,13,39. Older age is another possible risk factor for RON65. In 27 of 32 cases, reviewed in Table 2, age was reported. In this series median age was 53 years, which is approximately 10 years older than the age reported at diagnosis of acromegaly42, and than the median age of the presented cohort11. However, in general there is a lack of data in pu-b-lished series with respect to age in those patients who did and who did not develop RON. Therefore, it is not possible to draw definite conclusions about age as a risk factor for RON development.
Remarkably, as shown in Table 2, 20 of 23 patients (87, 95%CI: 66 – 97%), in whom gender was reported, were female, our two cases included (P<0.001 from an equal sex distribution). Since the occurrence of acromegaly is not increased in females42 and it is unlikely that females are treated with radiation therapy more frequently than males, this would suggest that females are at an increased risk for the development of RON. To our knowledge a female predisposition for RON has not been reported earlier.