Factors predicting pituitary adenoma invasiveness in acromegalic patients

Robotic Radiosurgery for Persistent Postoperative Acromegaly in Patients with Cavernous Sinus-Invading Pituitary Adenomas-A Multicenter Experience

Simple Summary

Growth hormone-secreting tumors of the pituitary gland which infiltrate surrounding tissue structures may not be fully resectable. This causes many patients to suffer from acromegaly after an unsuccessful surgery. To limit the considerable morbidity and mortality of such patients, effective and safe treatment options are needed. Fractionated radiotherapy and growth hormone-lowering medication are possible treatment options. Robotic radiosurgery (RRS) may be a suitable treatment modality as well. However, only sparse and heterogeneous data are available. This first retrospective multicenter study investigated the efficacy and safety of RRS for this patient group. Outcomes provide evidence that RRS may achieve biochemical disease control or remission in most of the patients. The hormone levels are decreasing after treatment, whereas favorable risk and safety profiles of RRS were shown. No new tumor growth was observed throughout the available follow-up. These findings may guide future care for this challenging patient population.

Abstract

Background: The rates of incomplete surgical resection for pituitary macroadenomas with cavernous sinus invasion are high. In growth hormone-producing adenomas, there is a considerable risk for persistent acromegaly. Thus, effective treatment options are needed to limit patient morbidity and mortality. This multicenter study assesses the efficacy and safety of robotic radiosurgery (RRS) for patients with cavernous sinus-invading adenomas with persistent acromegaly. Methods: Patients who underwent RRS with CyberKnife for postoperative acromegaly were eligible. Results: Fifty patients were included. At a median follow-up of 57 months, the local control was 100%. The pretreatment insulin-like growth factor 1 (IGF-1) levels and indexes were 381 ng/mL and 1.49, respectively. The median dose and prescription isodose were 18 Gy and 70%, respectively. Six months after RRS, and at the last follow-up, the IGF-1 levels and indexes were 277 ng/mL and 1.14, as well as 196 ng/mL and 0.83, respectively (p = 0.0001 and p = 0.0002). The IGF-1 index was a predictor for biochemical remission (p = 0.04). Nine patients achieved biochemical remission and 24 patients showed biochemical disease control. Three patients developed a new hypopituitarism. Conclusions: RRS is an effective treatment for this challenging patient population. IGF-1 levels are decreasing after treatment and most patients experience biochemical disease control or remission.

A single-center observational study assessing the predictive factors associated with the prognosis of acromegaly

AIM

The aim of this study was to clarify the prognostic values of various preoperative factors, including the surgeon's ability as well as the patient's age, gender, tumor size, cavernous sinus invasion, compression of the optic chiasm, hypopituitarism, immunohistochemical (IHC) staining pattern of the adenoma, and insulin-like growth factor-1 (IGF-1) level, in acromegalic patients who had undergone pituitary surgery.

STUDY DESIGN

This single-center, retrospective study assessed the medical records of 108 patients who had undergone pituitary surgery with the same neurosurgical team.

RESULTS

The mean total follow-up period after surgery was 44.8 (min: 24, max: 59) months. Remission was reported in 67 (62.0%) patients, and 57 (52.8%) patients did not experience recurrence. Initial tumor volume, IGF-1 level, and optic chiasm compression, but not patients' age, gender, cavernous sinus invasion, and IHC staining patterns of the adenoma, were prognostic of either remission or recurrence. An IGF-1 level of 860 ng/mLwas found to be a convenient cut-off point for determining remission.

CONCLUSIONS

The experience of the surgical team suggests that the initial tumor volume, IGF-1 level, and optic chiasm compression have high prognostic values in relation to pituitary surgery for patients with acromegaly.

Pretreatment serum GH levels and cardio-metabolic comorbidities in acromegaly; analysis of data from Iran Pituitary Tumor Registry

Background

Acromegaly is a rare chronic disabling disorder, in which growth hormone (GH) excess is associated with a range of clinical features and systemic complications. The present study aims to evaluate the association between pretreatment basal GH levels as well as GH levels after oral glucose tolerance test (OGTT) and cardio-metabolic comorbidities, including diabetes mellitus (DM), left ventricular hypertrophy (LVH) and hypertension (HTN) in patients with active acromegaly.

Methods

A retrospective study of the medical records regarding 113 patients with acromegaly registered at two main centers of Iran Pituitary Tumor Registry during 2011-2018.

Results

The mean age of the patients was 42.76 ± 11.6 (range: 21-72) years. Mean GH level at baseline was 21 ng/ml while nadir GH levels at 60 and 120 min after glucose were 6.95 and 9.05 ng/ml, respectively. There was a negative correlation between age and basal serum GH level (r= -0.196, p = 0.038). Hypertension and diabetes mellitus were detected in 26.8% and 19.7% of the patients. A positive correlation was detected between serum GH values and systolic blood pressure. There was not any significant difference in basal GH and GH post OGTT regarding DM, Diastolic blood pressure and LVH.

Conclusions

Our findings suggest that pretreatment basal GH levels are higher in younger patients with acromegaly. Furthermore, higher GH values (0, 60 and 120 min) during OGTT are associated with higher systolic blood pressure. A comprehensive evaluation of this population regarding comorbidities should be performed.

CyberKnife robotic radiosurgery in the multimodal management of acromegaly patients with invasive macroadenoma: a single center's experience

Surgery is the primary treatment for acromegaly. However, surgery may not be curative of some tumors, particularly invasive macroadenomas. Adjuvant radiation, specifically robotic stereotactic radiosurgery (rSRS), may improve the endocrine outcome. We retrospectively reviewed hormonal and radiological data of 22 acromegalic patients with invasive macroadenomas treated with rSRS at Stanford University Medical Center between 2000 and 2016. Prior to treatment, the tumor's median maximal diameter was 19 mm (2.5-50 mm). Cavernous sinus invasion occurred in 19 patients (86.3%) and compression of the optic chiasm in 2 (9.0%). At last follow up, with an average follow up of 43.2 months, all patients had a reduction in their IGF-1 levels (median IGF-1% upper limit of normal (ULN) baseline: 136% vs last follow up: 97%; p = 0.05); 9 patients (40.9%) were cured, and 4 (18.1%) others demonstrated biochemical control of acromegaly. The median time to cure was 50 months and the mean interval to cure or biochemical control was 30.3 months (± 24 months, range 6-84 months). Hypopituitarism was present in 8 patients (36.3%) and new pituitary deficits occurred in 6 patients with a median latency of 31.6 ± 14.5 months. At final radiologic follow-up, 3 tumors (13.6%) were smaller and 19 were stable in size. The mean biologically effective dose (BED) was higher in subjects cured compared to those with persistent disease, 163 Gy3 (± 47) versus 111 Gy3 (± 43), respectively (p = 0.01). No patient suffered visual deterioration. Robotic SRS is a safe and effective treatment for acromegaly: radiation-induced visual complications and hypopituitarism is rare.

Using growth hormone levels to detect macroadenoma in patients with acromegaly

BACKGROUND

The aim of this study was to assess the clinical differences between acromegalic patients with microadenoma and patients with macroadenoma, and to evaluate the predictive value of growth hormone (GH) levels for early detection of macroadenoma.

METHODS

We performed a retrospective analysis of 215 patients diagnosed with a GH-secreting pituitary adenoma. The patients were divided into two groups: the microadenoma group and the macroadenoma group, and the clinical parameters were compared between these two groups. The most sensitive and specific GH values for predicting macroadenoma were selected using receiver operating characteristic (ROC) curves.

RESULTS

Compared with the microadenoma group, the macroadenoma group had a significantly younger age, higher body mass index, higher prevalence of hyperprolactinemia and hypogonadism, and a lower proportion of positive suppression to octreotide. However, there were no significant differences in the gender or in the prevalence of diabetes between the two groups. The tumor diameter was positively correlated with all GH values during the oral glucose tolerance test (OGTT). All GH values were significantly higher in the macroadenoma group than the microadenoma group. Cut-off values for GH levels at 0, 30, 60, 90, and 120 minutes for optimal discrimination between macroadenoma and microadenoma were 5.6, 5.7, 6.3, 6.0, and 5.8 ng/mL, respectively. ROC curve analysis revealed that the GH value at 30 minutes had the highest area under the curve.

CONCLUSION

The GH level of 5.7 ng/mL or higher at 30 minutes during OGTT could provide sufficient information to detect macroadenoma at the time of diagnosis.

Gamma knife radiosurgery for clinically persistent acromegaly

Gamma knife radiosurgery (GKRS) is an important additional strategy for unresected clinically active pituitary adenomas. Radiosurgery for acromegaly aims to achieve tumor growth control and endocrine remission, potentially obviating the need for lifetime medication suppression therapy. Forty patients with clinically active acromegaly underwent GKRS between 1988 and 2009. Thirty-four patients had undergone prior surgical resection. The median follow-up interval was 72 months (range 24-145). Endocrine remission was defined as growth hormones (GH) level <2.5 ng/ml and a normal insulin-like growth factor 1 (IGF-1) level (age and sex adjusted) off growth hormone inhibiting drugs for at least 3 months. Endocrine control was defined as normal GH and IGF-1 levels on suppression medication. Endocrine remission was achieved in 19 (47.5 %) patients and endocrine control in four additional (10.0 %) patients. Patients with lower IGF-1 level and with tumors that were less invasive of the cavernous sinus before GKRS were associated with better GH remission rates. Imaging-defined local tumor control was achieved in 39 (97.5 %) patients (27 had tumor regression). One patient with delayed tumor progression underwent a second GKRS procedure. Three other patients had repeat GKRS because of persistently elevated and clinically symptomatic GH and IGF-1 levels. Sixteen (40.0 %) patients eventually developed a new pituitary axis deficiency at a median onset of 36 months after radiosurgery. No patient developed new visual dysfunction. Gamma knife radiosurgery, which is most often applied in clinically symptomatic acromegaly persistent after initial microsurgery, was most effective when the tumor was less invasive of the cavernous sinus and when patients had lower IGF-1 levels before GKRS. Almost one half of the patients no longer required long term medication suppression.

Efficacy and complications of neurosurgical treatment of acromegaly

The aim of the study was to evaluate the frequency of occurrence of pituitary failure following neurosurgery and the efficacy of transsphenoidal tumour resection in acromegalic patients. We retrospectively evaluated 85 patients (60 female and 25 male), of mean age 43.9 ± 13.2 years, treated by transsphenoidal neurosurgery. Macroadenoma and microadenoma of pituitary were found in 66 (77.6%) and 19 (22.4%) of these patients, respectively. Criteria of cure following neurosurgery were: basal GH<2.5 μg/l, GH at 120 min in OGTT<1.0 μg/l and serum concentration of IGF-1 within normal ranges for age and sex. After surgery 32 patients (37.6%) were cured and 53 patients (62.4%) required somatostatin analogue treatment. In patients cured by surgery, lower levels of basal GH (P<0.05), IGF-1 (P<0.001), GH at 120 min in OGTT and smaller size of pituitary tumour (P<0.05) were found at diagnosis, as compared to patients in whom surgery was unsuccessful. Significant correlation between basal serum level of GH at diagnosis and size of pituitary tumour was found (P<0.001). Invasive tumours were found in 45 of 53 (84.9%) patients not cured and in only 8 of 32 (25.0%) patients cured (P<0.001). Impaired function of pituitary anterior lobe after surgery was observed in 30% and 4% of patients with macro- and microadenoma, respectively (P<0.05). The efficacy of neurosurgery is affected by concentration of basal serum GH and IGF-1, GH at 120 min in OGTT, tumour size and invasiveness. Hypopituitarism after surgery is more frequent in patients with macroadenoma. Pituitary insufficiency, as a consequence of surgery, was found in 21% of patients with normal pituitary function prior to operation.

Prognostic significance of the Ki-67 labeling index in growth hormone-secreting pituitary adenomas

CONTEXT

Ki-67 is a marker of proliferation activity associated with invasiveness and prognosis in human tumors.

OBJECTIVE

The aim of the study was to evaluate the Ki-67 index prognostic relevance in a group of acromegalic patients who underwent transsphenoidal surgery for a GH-secreting pituitary adenoma.

MATERIAL AND METHODS

We selected 68 consecutive acromegalic patients referred to our hospital during a 5-yr period. The Ki-67 index was determined by immunohistochemistry on tissue samples obtained from each adenoma after surgery. Those patients who were not completely cured after surgery began medical therapy with somatostatin analogs (SSAs). Periodical pituitary magnetic resonance imaging and hormonal evaluation were performed during the follow-up.

RESULTS

Twenty-eight of 68 patients were cured after surgery (41%). Among the 40 patients treated with SSAs, 13 were considered uncontrolled. Pituitary magnetic resonance imaging showed residual/recurrent disease in 25 of 68 patients after 6 months. No correlation was found between Ki-67 index and age, tumor size, GH, or IGF-I plasma levels. Tumors described as having cavernous sinus invasion had a higher mean Ki-67 index as compared with noninvasive tumors (P < 0.01). The Ki-67 index was significantly lower in tumors in patients cured after surgery as compared with patients considered not cured (P < 0.01) and in tumors in patients controlled by SSA therapy as compared with patients considered as uncontrolled (P < 0.05).

CONCLUSION

The Ki-67 labeling index may predict clinical outcome in postsurgical management of acromegalic patients. We suggest routine Ki-67 evaluation in GH-secreting pituitary adenomas.

Goldmann perimetry in acromegaly: a survey of 307 cases from 1951 through 1996

OBJECTIVE

Because visual pathway lesions are a common complication of pituitary tumors, visual field examinations in patients with acromegaly were studied. Proportion and outcome of visual field defects in patients with acromegaly were evaluated.

DESIGN

Large, retrospective case series.

PARTICIPANTS

We reviewed 307 cases of acromegaly seen from 1951 through 1996 at a single referral center.

METHODS

Kinetic visual field testing had been performed with the Goldmann perimeter, and the frequency of visual field defects and their correlation with other clinical manifestations and characteristics of the adenoma were examined.

MAIN OUTCOME MEASURES

Repeat visual field examinations.

RESULTS

Of the 307 patients included in the analysis, a visual field defect that could be attributed to the pituitary adenoma was observed in 62 (20.2%) during follow-up. Visual field defects were bilateral in 38 (61.3%) of these cases. Patients with visual field abnormalities were significantly younger (P = 0.04), had larger tumors (P < 0.001), had more suprasellar extensions (P < 0.001), and had higher levels of growth hormone in their serum (P = 0.04) than patients free of visual field defects. At the end of the follow-up period, visual field examination remained abnormal in 32 (10.4%). Return to a normal visual field examination after treatment was more frequently observed in patients who were less than 40 years of age at the time of diagnosis (P = 0.004). Secondary empty sella syndrome was the main cause of visual field defects after treatment. Abnormal visual field, either at the time of diagnosis or during follow-up, decreased from 27% of patients between 1951 and 1975 to 15.4% of patients between 1976 and 1996, when modern neuroimaging techniques became available.

CONCLUSIONS

Endocrinologic and neuroimaging follow-up of patients with acromegaly should be accompanied by ophthalmic assessment. Factors predictive of visual field defects have been identified.

Invasive pituitary adenomas: significance of proliferation parameters

Although most pituitary adenomas behave in a purely benign fashion, microscopic invasion of the subjacent dura is very common, and clinically overt infiltration of the surrounding dura and bone is apparent at intraoperative inspection in about one third of cases. The factors governing invasive behavior remain unknown but are believed to be separate from those regulating cell proliferation. Histological features alone do not distinguish between benign, invasive, and malignant tumors of adenohypophyseal origin. Multiple attempts have been made to identify prognostic markers of aggressive behavior among these tumors. They include cytogenetic analysis of putative tumor suppressor genes or proto-oncogenes as well as immunohistochemical detection of cell-cycle specific antigens. At present, however, these analyses can neither distinguish the indolent pituitary adenoma from one that will pursue an invasive course, nor reliably predict the prognosis in individual patients.