Clinical and Pathologic Characteristics Predicted the Postoperative Recurrence and Progression of Pituitary Adenoma: A Retrospective Study with 10 Years Follow-Up

OBJECTIVE: Tumor recurrence or residual regrowth are poor prognoses for pituitary adenoma (PA). However, there is no validated and well-accepted prognostic classification of PAs to predict the clinical outcome and guide clinical practice. We analyzed the relevant data of a large cohort of patients with PA and thereafter proposed a new clinicopathologic classification for prognostic prediction. METHODS: Tumor recurrence or residual regrowth identified by magnetic resonance imaging scans and endocrine studies were analyzed along with associated clinical and pathological characteristics for patients who underwent surgery in 2008-2016 at West China Hospital. A new clinicopathologic classification was proposed and applied. RESULTS: After a median follow-up of 44.0 months, tumor recurrence and residual progression were identified in 48 (25.0%) and 29 (37.2%) patients, respectively. Proliferative potential (hazard ratio [HR], 2.188; P = 0.002), invasiveness (HR, 1.698; P = 0.029), larger tumor size (HR, 1.029; P = 0.004), high-risk PA subtype (HR, 2.151; P = 0.004), and postoperative residual (HR, 1.941; P = 0.007) were risk factors for recurrence/progression in the early stage after surgery. With respect to clinicopathologic classification, compared with grade 1a tumors, grade 1b, 2a, and 2b adenomas had poorer prognosis with an increased probability of tumor recurrence/progression of 5.133-fold, 4.467-fold, and 20.1-fold, respectively. CONCLUSIONS: The proposed clinicopathologic classification of PAs showed significant value in predicting prognosis and succeeded in identifying cases with more clinically aggressive lesions with recurrence or residual regrowth. This prognostic classification may be helpful when identifying aggressive PAs and deciding the appropriate therapeutic strategy for patients with PAs.