Outcomes of transsphenoidal surgery in dopamine agonist-resistant prolactinomas: a retrospective study

Purpose Dopamine agonists (DA) comprise first-line treatment for prolactinomas. However, some patients show no response to DA and are considered resistant. In this study, we retrospectively analyzed the outcomes of DA-resistant prolactinoma patients after transsphenoidal surgery (TSS). Methods A total of 94 consecutive patients with DA-resistant prolactinomas who underwent TSS were retrospectively enrolled in the present study. Early postoperative remission rate, prolactin (PRL) levels, and recurrence rate were analyzed. Results Of 94 DA-resistant patients, 47 (50%) achieved early remission 1 week post-surgery, including 41.18% of macroprolactinoma patients and 73.08% of microprolactinoma patients. PRL levels on the first postoperative day were significantly lower than preoperative PRL levels (p < 0.001). Total resection rate in macro- and microprolactinomas were, respectively, 75 and 96.15%. A recurrence of hyperprolactinemia and tumor was, respectively, found in 31.91 and 19.15% of patients with a follow-up of 39.53 +/- 2.172 months (range 3-86). A higher hyperprolactinemia recurrence was observed in patients with invasive prolactinomas (p = 0.021) or preoperative PRL levels >= 200 ng/ml (p = 0.029). Univariate logistic regression indicated that larger maximum tumor diameter (p = 0.045), invasive prolactinomas (p = 0.002), and absence of early postoperative remission (p = 0.004) were significant predictors of tumor recurrence. However, using multivariate stepwise logistic regression, only invasiveness and early postoperative remission remained significant. Conclusion Tumor invasiveness and preoperative PRL levels were significant predictors of hyperprolactinemia recurrence after TSS. For tumor recurrence, invasiveness and early postoperative remission were independent predictors.