NECESSITY OF MULTIMODAL TREATMENT OF ACROMEGALY AND OUTCOMES

Prognostic Models in Growth-Hormone- and Prolactin-Secreting Pituitary Neuroendocrine Tumors: A Systematic Review

Growth-hormone (GH)- and prolactin (PRL)-secreting PitNETs (pituitary neuroendocrine tumors) are divided into multiple histological subtypes, which determine their clinical and biological variable behavior. Proliferation markers alone have a questionable degree of prediction, so we try to identify validated prognostic models as accurately as possible. (1) Background: The data available so far show that the use of staging and clinical-pathological classification of PitNETs, along with imaging, are useful in predicting the evolution of these tumors. So far, there is no consensus for certain markers that could predict tumor evolution. The application of the WHO (World Health Organisation) classification in practice needs to be further evaluated and validated. (2) Methods: We performed the CRD42023401959 protocol in Prospero with a systematic literature search in PubMed and Web of Science databases and included original full-text articles (randomized control trials and clinical trials) from the last 10 years, published in English, and the search used the following keywords: (i) pituitary adenoma AND (prognosis OR outcome OR prediction), (ii) growth hormone pituitary adenoma AND (prognosis OR outcome OR prediction), (iii) prolactin pituitary adenoma AND (prognosis OR outcome OR prediction); (iv) mammosomatotroph adenoma AND (prognosis OR outcome OR prediction). (3) Results: Two researchers extracted the articles of interest and if any disagreements occurred in the selection process, these were settled by a third reviewer. The articles were then assessed using the ROBIS bias assessment and 75 articles were included. (4) Conclusions: the clinical-pathological classification along with factors such as GH, IGF-1, prolactin levels both preoperatively and postoperatively offer valuable information.

Efficiency and Safety of CyberKnife Robotic Radiosurgery in the Multimodal Management of Patients with Acromegaly

OBJECTIVE

To analyze, in a cohort of acromegalic patients, the results of the efficiency and safety of radiosurgery (CyberKnife), as well as the prognostic factors associated with disease remission.

MATERIAL AND METHODS

Observational, retrospective, longitudinal, and analytical study that included acromegalic patients with persistent biochemical activity after initial medical-surgical treatment, who received treatment with CyberKnife radiosurgery. GH and IGF-1 levels at baseline after one year and at the end of follow-up were evaluated.

RESULTS

57 patients were included, with a median follow-up of four years (IQR, 2-7.2 years). The biochemical remission rate was 45.6%, 33.33% achieved biochemical control, and 12.28% attained biochemical cure at the end of follow-up. A progressive and statistically significant decrease was observed in the comparison of the concentrations of IGF-1, IFG-1 x ULN, and baseline GH at one year and at the end of follow-up. Both cavernous sinus invasion and elevated baseline IGF-1 x ULN concentrations were associated with an increased risk of biochemical non-remission.

CONCLUSION

Radiosurgery (CyberKnife) is a safe and effective technique in the adjuvant treatment of GH-producing tumors. Elevated levels of IGF x ULN before radiosurgery and invasion of the cavernous sinus by the tumor could be predictors of biochemical non-remission of acromegaly.

Determinants of immediate and long-term remission after initial transsphenoidal surgery for acromegaly and outcome patterns during follow-up: a longitudinal study on 659 patients

OBJECTIVE

Treatment outcomes following initial transsphenoidal surgery (TSS) for acromegaly are erratic. Identifying outcome patterns can assist in informing patients about possible treatment outcomes and planning for individualized adjuvant treatments in advance. In this study, the authors aimed to investigate the immediate and long-term endocrine remission rates following initial TSS for acromegaly, identify clinical determinants of treatment outcomes, and explore outcome patterns during a long-term follow-up and the pattern-specific patient features.

METHODS

This prospective, single-center, longitudinal cohort study enrolled patients with acromegaly who underwent TSS in the period from 2015 to 2018 at the authors' institution. Immediate remission, assessed on the 2nd postoperative morning, and long-term remission, assessed at least 18 months after TSS, were evaluated according to the strict 2010 consensus criteria (random growth hormone [GH] < 1 ng/ml or GH nadir < 0.4 ng/ml after oral glucose tolerance test, and age- and sex-normalized insulin-like growth factor 1). Univariate and bivariate regression analyses were used to identify determinants of remission.

RESULTS

A total of 659 patients with acromegaly (average age 42 years, 44% males) underwent TSS for pituitary adenomas (macroadenomas, 85%; invasive tumors, 35%) and were followed up during a median of 51 months. Immediate and long-term remission rates after initial TSS were 37% and 69%, respectively. Older age at diagnosis (OR 1.7), male sex (OR 1.6), smaller tumors (OR 2.0), noninvasive tumors (OR 4.8), and tumors positive for follicle-stimulating hormone/luteinizing hormone (OR 1.5) were predictors of immediate surgical remission. In addition to the above predictors, lower preoperative GH (OR 2.4), absence of preoperative central hypothyroidism (OR 2.6), and endoscopic TSS (OR 10.6) were predictors of long-term remission. Regression analyses revealed that endoscopic TSS (OR 2.8, 95% CI 1.524-5.291, p = 0.001), absence of cavernous sinus invasion (OR 4.1, 95% CI 2.522-6.613, p < 0.001), older age (OR 1.03, 95% CI 1.006-1.048, p = 0.013), and male sex (OR 2.0, 95% CI 1.224-3.247, p = 0.006) were independent determinants of long-term remission. Five outcome patterns were identified based on the changes in hormonal results during follow-up, including continuous remission (34%), refractory acromegaly (28%), delayed remission (21%), remission after adjuvant therapy (14%), and recurrence after initial remission (3%). The clinical characteristics of each subgroup were identified.

CONCLUSIONS

Cavernous sinus invasion, age at diagnosis, and sex are the best determinants of immediate and long-term remission after initial TSS for acromegaly. Endoscopic TSS predicts a higher long-term remission rate than that with microscopic TSS. The authors identified five outcome patterns in acromegaly and group-specific patient characteristics for clinical decision-making.

Insulin-Like Growth Factor 1 in the Early Postoperative Assessment of Acromegaly

OBJECTIVES

Assessment of surgical outcome in acromegaly is typically recommended at 3 to 6 months following surgery. The purpose of this study was to determine if insulin-like growth factor 1 (IGF-1) concentrations at 6 weeks were equally predictive of surgical outcomes compared with IGF-1 concentrations at 3 to 6 months postoperatively applying newer IGF-1 assays.

METHODS

Retrospective review of patients with newly diagnosed acromegaly who had surgery between 2013 and 2020 and had postoperative IGF-1 measured by 6 weeks and 3 to 6 months.

RESULTS

At 6 weeks, 20 (35%) of the total 57 had normal IGF-1 and became abnormal in 1 at 3 to 6 months, whereas 37 (65%) of 57 had abnormal IGF-1 concentrations at 6 weeks, which normalized in 1 patient by 3 to 6 months. In patients who changed clinical status, IGF-1 at 6 weeks was within ±0.1-fold of normal. Although a difference was seen between median IGF-1 concentrations (286 vs 267 ng/mL, P = .009) at 6 weeks and 3 to 6 months, the mean reduction was small (-19.9 ng/mL).

CONCLUSIONS

Compared with 3 to 6 months, use of IGF-1 at 6 weeks was associated with a change in clinical status in 3.5% of patients. Therefore, in most patients, IGF-1 at 6 weeks can be used to assess clinical outcome via newer assays.

Novel Classification of Acromegaly in Accordance with Immunohistochemical Subtypes: Is There Really a Clinical Relevance?

According to the recent studies, immunohistochemical subtypes of growth hormone (GH) secreting adenomas have been considered as a predictive factor in determining the clinical outcomes including biochemical, radiologic, and endocrine remission. In a 20 year-of time period, acromegaly patients who were treated and followed at the Endocrinology Department of our University Hospital were screened for the study. Of total 98 patients, 65 patients who had been operated by transsphenoidal surgery and having postoperative specimens were included. Postoperative specimens of the surgery of the patients were classified into 3 groups based on the histochemical characteristics (densely, sparsely, and mixed). Parasellar extensions of pituitary tumors were classified into the five grades according to Knosp classification. The patients were investigated and evaluated for postoperative clinical progress, remission rates, comorbidities regarding with the histopathological patterns. Of total 65 patients, 31 were classified as densely granulated (group 1), 32 were classified as sparsely granulated (group 2), and 2 patients were assessed as mixed granulated (group 3). There was no difference between groups for age and gender. Pre-treatment of adenoma size in all groups was correlated with each other and the frequency of macroadenoma (1 vs. 2, 77.4 vs. 84.3%) was higher in two groups. Although mean initial GH levels in group 1 was higher than the other groups (p=0.03), IGF1 levels (age and gender matched) were similar in each group. Adenomas in all groups demonstrated noninvasive radiological characteristics (Knosp grade 0-1-2). Ki-67 proliferation index of both groups (64.5 vs. 50%) was predominantly 1%. With a similar follow-up period, the endocrine remission rates (GH<1 μg/l) in groups were 64 vs. 69%, respectively. In conclusion, classification according to immunohistochemical subtypes of growth hormone secreting adenomas may not be a qualified parameter to evaluate patients with patterns of aggressiveness, clinical outcomes, or treatment response.

Predictors for Remission after Transsphenoidal Surgery in Acromegaly: A Dutch Multicenter Study

CONTEXT

Transsphenoidal surgery (TSS) is the primary treatment of choice in acromegaly. It is important to identify patients in whom surgical cure is not attainable at an early stage, both to inform patients on expected treatment outcome and to select those who are more likely to need additional therapy.

OBJECTIVE

To identify predictors for remission after TSS in acromegaly.

METHODS

Large multicenter study with retrospective data collection from 3 tertiary neurosurgical referral centers in The Netherlands. We analyzed clinical data since 2000 from 3 cohorts (Groningen, Nijmegen, and Rotterdam, total n = 282). Multivariate regression models were used to identify predictors of early biochemical remission (12 weeks to 1 year postoperatively) according to the 2010 consensus criteria, long-term remission (age- and sex-normalized insulin-like growth factor 1 [IGF-1] and the absence of postoperative treatment until last follow-up), and relative IGF-1 and growth hormone [GH] reduction.

RESULTS

A larger maximum tumor diameter (odds ratio [OR] 0.91, 95% CI 0.87-0.96, P ≤ .0001) was associated with a lower chance of early biochemical remission. A larger maximum tumor diameter (OR 0.93, 95% CI 0.89-0.97, P = .0022) and a higher random GH concentration at diagnosis (OR 0.98, 95% CI 0.96-0.99, P = .0053) were associated with a lower chance of long-term remission.

CONCLUSION

Maximum tumor diameter and random GH concentration at diagnosis are the best predictors for remission after TSS in acromegaly.

Clinical, biological, radiological, and pathological comparison of sparsely and densely granulated somatotroph adenomas: a single center experience from a cohort of 131 patients with acromegaly

PURPOSE

Growth hormone-producing pituitary adenomas are divided into two clinically relevant histologic subtypes, densely (DG-A) and sparsely (SG-A) granulated. Histologic subtype was evaluated in a large cohort of patients with acromegaly, separating DG-A and SG-A, and correlated with clinicopathological characteristics.

METHODS

Patients with acromegaly undergoing surgery as initial therapy between 1995 and 2015 were identified. Histologic subtype was determined by keratin expression pattern with CAM5.2 and correlated with clinical and imaging parameters, somatostatin receptor subtype 2 (SST2) expression, post-surgical remission rate, and application of a prognostic scoring system incorporating proliferation and invasiveness.

RESULTS

One hundred thirty-one patients were included. Tumors were classified as DG-A (75, 57.3%), SG-A (29, 22.1%), intermediate (I-A) (9, 6.9%), and unclassified (18, 13.7%) when CAM5.2 was negative. DG-A and I-A were combined for analysis (DG/I-A) and compared to SG-A. Age, gender, proliferation, and post-surgical remission did not differ. SG-A were larger [2 vs. 1.5 cm (median), p = 0.03], more frequently invasive [65.5% vs. 32.9%, p = 0.004], associated with higher MRI T2-weighted signal ratio [1.01 vs. 0.82 (median), p = 0.01], showed lower SST2 expression (p < 0.0001), and scored higher in the prognostic classification (p = 0.004). Surgical remission occurred in 41.7% DG/I-A and 41.4% SG-A (p = 1.0). On multivariate analysis, absence of invasion (p = 0.009) and lower pre-operative IGF-1 index (p = 0.0002) were associated with post-surgical remission.

CONCLUSION

CAM5.2 allowed distinction between DG/I-A and SG-A in most but not all cases. Histologic subtype did not predict surgical outcome. Absence of invasion and lower pre-operative IGF-1 index were the only significant predictors of post-surgical remission in this cohort.

Prognostic factors of biochemical remission after transsphenoidal surgery for acromegaly: a structured review

PURPOSE

Biochemical control is the main determinant of survival, clinical manifestations and comorbidities in acromegaly. Transsphenoidal selective adenomectomy (TSA) is the initial treatment of choice with reported biochemical remission rates varying between 32 and 85%. Understanding the limiting factors is essential for identification of patients who require medical treatment.

METHODS

We reviewed the English literature published in Medline/Pubmed until Dec 31, 2019 to identify eligible studies that described outcomes of TSA as primary therapy and performed analyses to determine the main predictors of remission.

RESULTS

Most publications reported single-institution, retrospective studies. The following preoperative parameters were consistently associated with lower remission rates: cavernous sinus invasion by imaging, larger tumor size and higher GH levels. Young age and preoperative IGF-1 levels were predictive in some studies. When controlled for covariates, the best single preoperative predictor was cavernous sinus invasion, followed by preoperative GH levels. Conversely, low GH level in the first few days postoperatively was a robust predictor of durable remission. The influence of tumor histology (sparsely granular pattern, co-expression of prolactin and proliferation markers) on surgical remission remains to be established. Few studies developed predictive models that yielded much higher predictive values than individual parameters.

CONCLUSION

Surgical outcome prognostication systems could be further generated by machine learning algorithms in order to support development and implementation of personalized care in patients with acromegaly.