Clinicopathological characteristics associated with the prognosis of recurrent gonadotroph tumors.

Although gonadotroph tumor regrowth is frequent after pituitary surgery, the systematic use of adjuvant radiotherapy is limited by its long-term complications. In this context, it is important to predict which tumors are most likely to regrow after surgery, and especially, which tumors are most likely to regrow rapidly. Clinicopathological characteristics associated with the prognosis of radiotherapy-naïve, recurrent pituitary tumors are currently unknown. In this longitudinal, observational, retrospective, monocentric cohort study, we analyzed the clinicopathological characteristics associated with the prognosis of recurrent, radiotherapy-naïve gonadotroph tumors, specifically with the progression-free survival after a second pituitary surgery. We found that the Ki67 index of radiotherapy-naïve, recurrent gonadotroph tumors was the only parameter statistically associated with the progression-free survival after a second pituitary surgery, P = 0.02. Specifically, radiotherapy-naïve gonadotroph tumors with a positive Ki67 index had shorter progression-free survival after the second surgery (median 31 months) compared to radiotherapy-naïve gonadotroph tumors with a negative Ki67 index (median 75 months). Thus, our study pinpoints that the Ki67 index could be used to guide the management strategy for recurrent gonadotroph tumors that are still radiotherapy-naïve by the time of the second pituitary surgery.