First but not second postoperative day growth hormone assessments as early predictive tests for long-term acromegaly persistence

Predictors of growth hormone level on postoperative day one in patients with acromegaly

PURPOSE

The growth hormone (GH) level on postoperative day one (POD1), i.e., POD1GH, holds significant value in assessing surgical efficacy and predicting long-term remission in patients with acromegaly. This study aims to explore the factors that influence the GH level of POD1 after microscopic transsphenoidal surgery (mTSS) in patients with acromegaly, providing insights for preoperative clinical decisions.

METHODS

A total of 85 acromegaly patients undergoing mTSS were included in this study. Sex; age; body mass index (BMI); preoperative serum hormone levels and tumor characteristics were assessed for their correlation with POD1GH levels. POD1GH level non-remission, defined as POD1GH > 2.5 ng/mL, was considered an outcome.

RESULTS

The patients with acromegaly were divided into two groups: adult males (43 cases) and adult females (42 cases), with mean ages of 43.33 ± 11.92 years and 47.02 ± 14.18 years, respectively. Correlation and multivariate linear regression analyses revealed positive correlations of preoperative GH and prolactin (PRL) levels in females with POD1GH levels, while preoperative FT3 and TT levels in males were negatively correlated with POD1GH levels. Binary logistic regression and receiver operating characteristic (ROC) analyses identified preoperative GH levels ≥30.25 ng/mL (OR = 2.236, 95%CI = 1.402-3.567, p < 0.001), FT3 levels ≤4.415 pmol/L (OR = 0.329, 95%CI = 0.167-0.648, p < 0.001), and age ≤51 years (OR = 0.566, 95%CI = 0.352-0.911, p = 0.019) as independent risk factors for POD1GH level non-remission.

CONCLUSIONS

Preoperative GH, FT3, TT, and PRL levels are correlated with POD1GH levels, with variations observed between sex. Age, preoperative GH, and FT3 levels can predict POD1GH level non-remission. Therefore, the comprehensive consideration of multiple hormone axes is necessary for predicting postoperative efficacy.

Growth Hormone-Secreting Pituitary Adenoma: Dura Mater Invasion Is Not a Predictor of Acromegaly Persistence After Trans-Sphenoidal Surgery

Objectives: In pituitary adenomas, examinations of surgical specimens have shown that dural invasion occurs in 42-85% of cases. No studies about dura mater invasion have been conducted specifically in acromegaly patients. The aim of the present study was to evaluate the relationship between histologically dural invasion and the main features of GH-secreting adenomas. Methods: This retrospective study included all consecutive acromegaly patients who underwent neurosurgery at our university hospital between 2017 and 2020. The following data were collected: (1) clinical, biochemical and morphological data at diagnosis, at three months, one year after neurosurgery, and at last follow-up; (2) pathological features (dura mater invasion, immunohistochemical analyses, proliferation index Ki-67, p53, and granulation pattern); and (3) radiological features on magnetic resonance images. Results: Of 35 acromegaly patients, 11 had dural invasion (INV+ 31%) and 24 did not (INV- 69%). GH levels at diagnosis were greater in INV+ patients (p = 0.02), and a GH value > 27 ng/mL was able to distinguish INV+ patients (Sensitivity 80%, Specificity 73%, AUC 0.760, p = 0.006). Indeed, patients with GH > 27 ng/mL at diagnosis had a tenfold greater risk of dura mater invasion (OR 10.7; 95% CI 1.74-65.27, p = 0.005). No differences were found in the other clinical, biochemical, morphological, radiological and pathological features. Regarding remission likelihood, IGF-1 levels at diagnosis were lower in cured patients (p = 0.03). Conclusions: The GH level at diagnosis is the only parameter significantly associated with dura mater invasion. Lower IGF-1 levels at diagnosis are significantly associated with remission one year after surgery.

Utility of copeptin in predicting non-pathological postoperative polyuria in patients affected by acromegaly undergoing pituitary neurosurgery

PURPOSE

Copeptin efficiently predicts post-neurosurgical central diabetes insipidus (CDI) in patients with hypothalamic-pituitary lesions, but its role in characterizing changes in diuresis in individuals with acromegaly undergoing neurosurgery remains unexplored. Our study aimed to assess changes in postoperative fluid balance in acromegaly patients and correlate them with both copeptin and growth hormone (GH) levels.

METHODS

This was a secondary analysis of a prospective study involving 15 acromegaly patients undergoing endoscopic endonasal resection at our University Hospital. Fluid balance was assessed daily, and copeptin and GH levels were evaluated preoperatively (T0), and serially on the morning of the first (T2) and second (T3) postoperative day, with an additional measurement of copeptin one hour post-extubation (T1). Patients with pre-existing or post-neurosurgical CDI were excluded from the analysis.

RESULTS

Most patients (11/15) exhibited a negative fluid balance on the second postoperative day, with 4 developing polyuria. Postoperative GH levels did not differ significantly between polyuric and non-polyuric patients, but GH measured at T2 correlated significantly with negative total balance (r = -0.519, p = 0.048). Copeptin levels at T1 were significantly higher in those who developed polyuria (p = 0.013), and a copeptin value > 39.9 pmol/L at T1 showed excellent ability (Sensitivity 100%, Specificity 90.9%, p < 0.001) in predicting postoperative polyuria. Additionally, polyuric patients exhibited a higher T1 / T3 copeptin ratio (p = 0.013) and a negative fluid balance was associated with the remission of acromegaly at 12 months (p = 0.046).

CONCLUSION

The early assessment of copeptin, in addition to facilitating the rapid identification of individuals at increased risk of developing CDI, could also allow the recognition of subjects with a tendency towards non-pathological polyuria in the postoperative setting, at least in individuals affected by acromegaly.

Postoperative GH and Degree of Reduction in IGF-1 Predicts Postoperative Hormonal Remission in Acromegaly

PURPOSE

Determine predictive factors for long-term remission of acromegaly after transsphenoidal resection of growth hormone (GH)-secreting pituitary adenomas.

METHODS

We identified 94 patients who had undergone transsphenoidal resection of GH-secreting pituitary adenomas for treatment of acromegaly at the USC Pituitary Center from 1999-2019 to determine the predictive value of postoperative endocrine lab values.

RESULTS

Patients underwent direct endoscopic endonasal (60%), microscopic transsphenoidal (38%), and extended endoscopic approaches (2%). The cohort was 63% female and 37% male, with average age of 48.9 years. Patients presented with acral enlargement (72, 77%), macroglossia (40, 43%), excessive sweating (39, 42%), prognathism (38, 40%) and frontal bossing (35, 37%). Seventy-five (80%) were macroadenomas and 19 (20%) were microadenomas. Cavernous sinus invasion was present in 45%. Available immunohistochemical data demonstrated GH staining in 88 (94%) and prolactin in 44 (47%). Available postoperative MRI demonstrated gross total resection in 63% of patients and subtotal resection in 37%. Most patients (66%) exhibited hormonal remission at 12 weeks postoperatively. Receiver operating characteristic (ROC) curves demonstrated postoperative day 1 (POD1) GH levels ≥1.55ng/mL predicted failure to remit from surgical resection alone (59% specificity, 75% sensitivity). A second ROC curve showed decrease in corrected insulin-like growth factor-1 (IGF-1) levels of at least 37% prognosticated biochemical control (90% sensitivity, 80% specificity).

CONCLUSION

POD1 GH and short-term postoperative IGF-1 levels can be used to successfully predict immediate and long-term hormonal remission respectively. A POD1 GH cutoff can identify patients likely to require adjuvant therapy to emphasize clinical follow-up.