title: The postoperative basal cortisol and CRH tests for prediction of long-term remission from Cushing's disease after transsphenoidal surgery.
abstract: BACKGROUND
  Selective adenomectomy via transsphenoidal surgery induces remission of Cushing's disease (CD) in most patients. Although an undetectable postoperative serum cortisol (<2 μg/dl) has been advocated as an index of remission, there is no consensus on predictors of recurrence.
  
  
  OBJECTIVE
  We hypothesized that patients with subnormal cortisol (2-4.9 μg/dl) might achieve long-term remission and that postoperative responses to CRH might predict recurrence.
  
  
  METHODS
  We prospectively studied CD patients with initial remission after adenomectomy or hemihypophysectomy (n = 14). Long-term recurrence (n = 39) or remission (n = 293) was assigned by laboratory results, glucocorticoid dependence, or patient survey at a mean of 10.6 yr after surgery.
  
  
  METHODS
  Postoperatively, morning cortisol was measured on d 3-5, and cortisol and ACTH responses to ovine CRH were assessed around d 10.
  
  
  RESULTS
  Follow-up duration was median 11 yr (range 1-22.8 yr). Fewer patients achieved a cortisol nadir below 2 μg/dl (87%) than below 5 μg/dl (98%), yet recurrence rates were similar (<2 μg/dl, 9.5%; <5 μg/dl, 10.4%; 2-4.9 μg/dl, 20%; not significant). CRH-stimulated cortisol (P < 0.002) and ACTH (P = 0.04) values were higher for the recurrence than the remission group. However, no basal or stimulated ACTH or serum or urine cortisol cutoff value predicted all who later recurred.
  
  
  CONCLUSIONS
  A postoperative cortisol below 2 μg/dl predicts long-term remission after transsphenoidal surgery in CD. Remission in those with intermediate d 3-5 postoperative cortisol values (2-4.9 μg/dl) suggests that these patients do not require immediate reoperation. However, because no single cortisol cutoff value excludes all patients with recurrence, all require long-term clinical follow-up.
authors.affiliation: National Institute of Neurologic Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Lindsay
authors.forename: Edward H
authors.initials: EH
authors.lastname: Oldfield
authors.forename: Constantine A
authors.initials: CA
authors.lastname: Stratakis
authors.forename: Lynnette K
authors.initials: LK
authors.lastname: Nieman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007016:Hypophysectomy / Q000379:methods; D008297:Male; D008875:Middle Aged; D047748:Pituitary ACTH Hypersecretion / Q000097:blood* / Q000601:surgery; D010902:Pituitary Gland / Q000601:surgery*; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012074:Remission Induction; D016896:Treatment Outcome
chemical_list: D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone