title: Early prediction of long-term response to cabergoline in patients with macroprolactinomas.
abstract: BACKGROUND
  Cabergoline is typically effective for treating prolactinomas; however, some patients display cabergoline resistance, and the early characteristics of these patients remain unclear. We analyzed early indicators predicting long-term response to cabergoline.
  
  
  METHODS
  We retrospectively reviewed the cases of 44 patients with macroprolactinomas who received cabergoline as first-line treatment; the patients were followed for a median of 16 months. The influence of various clinical parameters on outcomes was evaluated.
  
  
  RESULTS
  Forty patients (90.9%) were treated medically and displayed tumor volume reduction (TVR) of 74.7%, a prolactin normalization (NP) rate of 81.8%, and a complete response (CR; TVR >50% with NP, without surgery) rate of 70.5%. Most patients (93.1%) with TVR ≥25% and NP at 3 months eventually achieved CR, whereas only 50% of patients with TVR ≥25% without NP and no patients with TVR <25% achieved CR. TVR at 3 months was strongly correlated with final TVR (R=0.785). Patients with large macroadenomas exhibited a low NP rate at 3 months, but eventually achieved TVR and NP rates similar to those of patients with smaller tumors. Surgery independently reduced the final dose of cabergoline (β=-1.181 mg/week), and two of four patients who underwent surgery were able to discontinue cabergoline.
  
  
  CONCLUSIONS
  Determining cabergoline response using TVR and NP 3 months after treatment is useful for predicting later outcomes. However, further cabergoline administration should be considered for patients with TVR >25% at 3 months without NP, particularly those with huge prolactinomas, because a delayed response may be achieved. As surgery can reduce the cabergoline dose necessary for successful disease control, it should be considered for cabergoline-resistant patients.
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Youngki
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Cheol Ryong
authors.initials: CR
authors.lastname: Ku
authors.affiliation: Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Eui-Hyun
authors.initials: EH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Hong
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Eun Jig
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sun Ho
authors.initials: SH
authors.lastname: Kim
keywords: Cabergoline; Dopamine; Hyperprolactinemia; Prolactinoma