Cushings disease: prospective assessment of factors influencing the efficacy of transsphenoidal surgery
P Witek1,3, G Zielinski1, K Szamotulska2 & W Zgliczynski3
Introduction: Assessment of the efficacy of surgical treatment for Cushings disease (CD) is one of the biggest challenges in contemporary endocrinology. The aim of this study was prospective evaluation of factors influencing the result of transsphenoidal surgery for CD.
Methods: The study population consisted of 36 consecutive patients with CD hospitalized in the Department of Endocrinology from 2005 to 2009 and operated on using the same surgical protocol in the Department of Neurosurgery. Preoperative hormonal assessment, results of MRI and histopathological examination were taken into account. Particular attention was paid to the early postoperative cortisol levels measured at 6.00 on the first day after surgery.
Results: Mean serum cortisol level on the 1st postoperative day was 6.0±9.02 μg/dl (median: 1.98 μg/dl). Twenty three patients (63.9%) were regarded as surgically cured from CD using commonly adopted criteria. In all cured cases, the serum cortisol level on the 1st postoperative day was ≤ 2.5 μg/dl. In the cured group, there was a significantly greater number of patients with pituitary microadenoma clearly visualized in the preoperative MRI than in the non-cured group (73.9 vs 38.5%; P=0.036). A difference was also demonstrated with regard to results of immunohistochemical examination. The confirmation of corticotroph adenoma was more frequently observed in the cured group in comparison with the non-cured group (87 vs 53.8%; P=0.028). There was no difference in terms of preoperative ACTH (P=0.88) and cortisol levels (P=0.71).
Conclusion: The optimal cut off value suggesting remission of CD is serum cortisol level ≤ 2.5 μg/dl on the 1st postoperative day. Other factors influencing the remission of CD are: the distinct pituitary microadenoma visualized in the MRI and the histopathologically confirmed presence of corticotroph adenoma. However, any of preoperative hormone measurements affected the efficacy of surgical treatment.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This work was supported, however funding details unavailable.