Aggressive nonfunctioning pituitary neuroendocrine tumors.

Nonfunctioning pituitary neuroendocrine tumors (NF-PitNETs) are tumors that are not associated with clinical evidence of hormonal hypersecretion. According to the World Health Organization (WHO), there are some subtypes of PitNETs that exhibit more aggressive behavior than others. Among the types of potentially aggressive PitNETs, three are nonfunctional: silent sparsely granulated somatotropinomas, silent corticotropinomas, and poorly differentiated PIT-1 lineage tumors. Several biological markers have been investigated in NF-PitNETs. However, there is no single biomarker able to independently predict aggressive behavior in NF-PitNETs. Thus, a more complex and multidisciplinary proposal of a comprehensive definition of aggressive NF-PitNETs is necessary. Here, we suggest a combined and more complete criterion for the NF-PitNETs classification. We propose that aggressiveness is due to a multifactorial combination, and we emphasize the need to include new emerging markers that are involved in the aggressiveness of NF-PitNETs and the need to identify.

Twist1 Correlates With Epithelial-Mesenchymal Transition Markers Fibronectin and Vimentin in Adrenocortical Tumors.

BACKGROUND/AIM: Although the knowledge regarding adrenocortical carcinomas (ACC) tumorigenesis has significantly improved during the last decade, it still remains to be completely determined. Epithelial-mesenchymal transition (EMT) is a well described transcription factor induced process, postulated as an essential step toward cancer progression and metastasis development. In this context, Twist1 has been described as the EMT master-regulator. The aim of this study was to assess the association among Twist1, fibronectin, vimentin and E-cadherin gene expression in adrenocortical tumor samples. MATERIALS AND METHODS: Twist1, fibronectin, vimentin and E-cadherin gene expression in 18 adrenal adenomas, 18 ACC, and 24 childhood onset adrenocortical tumors were assessed in formalin-fixed paraffin-embedded tissues. The fold expression was calculated according to the 2ΔCt method. RESULTS: A significant correlation between mRNA levels of Twist1, fibronectin and vimentin was evident. Although their expression was inversely proportional, no association was observed between Twist1 and E-cadherin expression. CONCLUSION: The expression of Twist1, the major regulator of EMT, is directly correlated to the expression of mesenchymal markers fibronectin and vimentin in ACC samples.

Impact of Weight Loss With Intragastric Balloon on Bone Density and Microstructure in Obese Adults.

The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1 ± 7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolutionperipheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect.

Pituitary Hyperplasia in a Female Patient with a Severe Childhood Abuse History.

A 24-year-old Caucasian female patient was referred to our endocrinology service to investigate a structural magnetic resonance imaging (sMRI) finding of "pituitary mass". The first two sMRI were identified as pituitary adenoma but the following two examinations suggested the possibility of pituitary hyperplasia (PH). The patient was referred to our service for diagnostic clarification and therapy due to the divergence in sMRI reports and the surgical procedure indicated by the neurosurgical team of the other institution. The patient had no complaints, laboratory tests were all normal, and the sMRI clearly showed a PH. However, what caught our attention was her behavior. During the interview she was intermittently talking and acting like a child even though her age was 24. She reported being a foster child and was severely mistreated during childhood. Parallel psychiatric evaluation was requested and an association between the PH and the childhood abuse was identified. Early life stress may be associated with accelerated pituitary gland volume development, but there is still a paucity of data in literature about this issue. We should be aware of other cases like this one, and a correct differential diagnosis may contribute to contraindicate transsphenoidal surgery. When a childhood abuse history is present, we recommend admission to a psychiatric facility for adequate treatment.

Recurrence and mortality prognostic factors in childhood adrenocortical tumors: Analysis from the Brazilian National Institute of Cancer experience.

Prognostic markers that can help identifying precocious risk of unfavorable outcomes in patients with childhood adrenocortical tumors (ACTs) are still unclear. This observational and retrospective study aimed to identify clinical and pathology prognostic factors of recurrence and death in a tertiary cancer center population. Clinical, pathology, demographic, staging, and therapy data from patients with childhood ACT (median age: 3.6 years) treated at the Brazilian National Institute of Cancer between 1997 and 2015 were assessed. Univariate and bivariate analyses were used to study the association of clinical and pathology characteristics with recurrence and mortality. Recurrence and disease-related mortality were the main outcomes. Twenty-seven patients were included. Complete tumor resection was performed in 21 cases. The median tumor size was 8.2 cm. Mitotane was the most common adjuvant/palliative therapy (n = 13). Recurrence occurred in 6 patients, after a median time of 7.2 months, and was more common among those with larger tumors (P =.008), higher Weiss score (P =.001), and microscopic tumoral necrosis (P =.002). Ten patients died from the disease. Older age (P =.04), larger tumor size (P =.002), metastatic disease (P =.003), previous recurrence (P =.003), incomplete resection (P =.002), intraoperative tumor spillage (P =.005), higher Weiss score (P =.03), microscopic necrosis (P =.005), and capsular invasion (P =.02) were all associated with increased death risk. Even though complete tumor resection was performed in most cases, a considerable number of cases of childhood ACT resulted in recurrence and death. Early identification of unfavorable outcomes is essential to determine ideal therapy and appropriate surveillance.

ROLE OF IMAGING TESTS FOR PREOPERATIVE LOCATION OF PATHOLOGIC PARATHYROID TISSUE IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM.

OBJECTIVE: Primary hyperparathyroidism (PHPT) can be cured by parathyroidectomy, and the preoperative location of enlarged pathologic parathyroid glands is determined by imaging studies, especially cervical ultrasonography and scintigraphy scanning. The aim of this retrospective study was to evaluate the use of preoperative cervical ultrasonography and/or parathyroid scintigraphy in locating pathologic parathyroid tissue in a group of patients with PHPT followed in the same endocrine center. METHODS: We examined the records of 61 patients who had undergone parathyroidectomy for PHPT following (99m)Tc-sestamibi scintigraphy scan and/or cervical ultrasonography. Scintigraphic and ultrasonographic findings were compared to histopathologic results of the surgical specimens. RESULTS: Ultrasonography detected enlarged parathyroid glands in 87% (48/55) of patients with PHPT and (99m)Tc-sestamibi scintigraphy in 79% (37/47) of the cases. Ultrasonography was able to correctly predict the surgical findings in 75% (41/55) of patients and scintigraphy in 72% (34/47). Of 7 patients who had negative ultrasonography, scintigraphy correctly predicted the surgical results in 2 (29%). Of 10 patients who had negative scintigraphy, ultrasonography correctly predicted the surgical results in 4 (40%). When we analyzed only patients with solitary eutopic parathyroid adenomas, the predictive positive values of ultrasonography and scintigraphy were 90% and 86%, respectively. CONCLUSION: Cervical ultrasonography had a higher likelihood of a correct positive test and a greater predictive positive value for solitary adenoma compared to (99m)Tc-sestamibi and should be used as the first diagnostic tool for preoperative localization of affected parathyroid glands in PHPT. ABBREVIATIONS: Ca = calcium IEDE = Instituto Estadual de Diabetes e Endocrinologia Luiz Capriglione PHPT = primary hyperparathyroidism PTH = parathyroid hormone.

Insulin-like growth factor (IGF)-I, IGF binding protein-3, and prostate cancer: correlation with Gleason score.

INTRODUCTION: Non-androgenic growth factors are involved in the growth regulation of prostate cancer (PCa). OBJECTIVE: This is the first Brazilian study to correlate, in a population of patients operated for PCa, PSA, total testosterone, insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) with Gleason score and to compare with a control group with benign prostate hyperplasia (BPH). MATERIALS AND METHODS: This retrospective single-center study included 49 men with previously diagnosed PCa and 45 with previously diagnosed BPH. PSA, testosterone, IGF-I, IGFBP-3 were determined in both groups. RESULTS: PSA and IGFBP-3 levels were significantly higher in the PCa group as compared to the BPH group (p < 0.001 and p=0.004, respectively). There was a significant difference when we compared the PSA before surgery (p < 0.001) and at the inclusion in the study (p < 0.001) and IGFBP3 (0.016) among patients with Gleason < 7, ≥7 and BPH. In the PCa group, PSA, testosterone, IGF-I and IGFBP-3 levels were comparable between Gleason < 7 and ≥7. CONCLUSIONS: Our data suggest that in localized PCa, the quantification of PSA and, not of IGF-1, may provide independent significant information in the aggressiveness. IGFBP-3 could be a biochemical marker of disease control in PCa patients.

Truncated somatostatin receptor variant sst5TMD4 confers aggressive features (proliferation, invasion and reduced octreotide response) to somatotropinomas.

The GH/IGF1 response of somatotropinomas to somatostatin analogues (SSA) is associated with their pattern of somatostatin receptor (sst1-sst5) expression. Recently, we demonstrated that expression of a truncated sst5-variant (sst5TMD4) can influence the secretory response of somatotropinomas to SSA-therapy; however, its potential relationship with aggressive features (e.g. invasion/proliferation) is still unknown. Here, we show that sst5TMD4 is present in 50% of non-functioning pituitary-adenomas (NFPA) (n = 30) and 89% of somatotropinomas (n = 36), its expression levels being highest in somatotropinomas > > NFPAs > > > normal pituitaries (negligible expression; n = 8). In somatotropinomas, sst5TMD4 mRNA and protein levels correlated positively, and its expression was directly associated with tumor invasiveness (cavernous/sphenoid sinus), and inversely correlated with age and GH/IGF1 reduction after 3-6 months with octreotide-LAR therapy. GNAS+ somatotropinomas expressed lower sst5TMD4 levels. ROC analysis revealed sst5TMD4 expression as the only marker, within all sst-subtypes, capable to predict tumor invasiveness in somatotropinomas. sst5TMD4 overexpression increased cell viability in cultured somatotropinoma (n = 5). Hence, presence of sst5TMD4 associates with increased aggressive features and worse prognosis in somatotropinomas, thereby providing a potentially useful tool to refine somatotropinoma diagnosis, predict outcome of clinical response to SSA-therapy and develop new therapeutic targets.

Ki-67 is a predictor of acromegaly control with octreotide LAR independent of SSTR2 status and relates to cytokeratin pattern.

INTRODUCTION: Only one study has evaluated Ki-67 as a predictor of the response to somatostatin analog therapy in acromegaly; however, other predictors like somatostatin receptor type 2 (SSTR2) and cytokeratin pattern expressions were not considered. OBJECTIVE: To evaluate whether Ki-67 is a predictor of octreotide LAR (OCT-LAR) response in somatotropinomas independent of SSTR2 and cytokeratin expression patterns. METHODS: Protein expression was analyzed by immunohistochemistry. The percentage of cell nuclei that were immunolabeled for Ki-67 and the percentage of cells with positive SSTR2 staining were calculated. SSTR2 expression was considered high when ≥25%, and a cutoff of 2.3% was designated for Ki-67. Tumors were classified as densely or sparsely granulated according to the cytokeratin pattern. RESULTS: Thirty-one somatotropinomas were studied. Fourteen patients (45.2%) were controlled with OCT-LAR therapy. The median Ki-67 labeling index (LI) was higher in patients not controlled with OCT-LAR than in those controlled (1.63 and 0.15 respectively, P=0.002). Higher SSTR2 expression and densely granulated tumors were correlated with control as well (P=0.04 and 0.038 respectively). There was no difference in Ki-67 levels between patients with high and low SSTR2 expression (P=0.651). After multivariate analysis, both Ki-67 and SSTR2 remained statistically significant as predictors of OCT-LAR response (P=0.017 and 0.012 respectively). The Ki-67 LI was higher in sparsely than in densely granulated tumors (P=0.047). CONCLUSIONS: Ki-67 is a predictor of response to OCT-LAR in acromegaly, independent of SSTR2 expression and relates to cytokeratin patterns.

Association of dengue hemorrhagic fever with multiple risk factors for pituitary apoplexy.

OBJECTIVE: To describe pituitary apoplexy that developed during the course of dengue hemorrhagic fever. METHODS: We describe the clinical findings, laboratory test results, imaging findings, and clinical course of the study patients. RESULTS: Patient 1 was a 40-year-old man who developed clinical signs and symptoms of dengue, which was confirmed by serologic testing. He presented with thrombocytopenia and developed severe headache and vomiting. During hospitalization, acromegaly was suspected because of the characteristic disease phenotype. Magnetic resonance imaging confirmed the diagnosis of pituitary apoplexy. Subsequently, the biochemical diagnosis of acromegaly was confirmed, and the patient underwent transsphenoidal surgery. Histopathologic examination showed signs of recent bleeding. Patient 2 was a 38-year-old man with a macroprolactinoma, who had been treated with cabergoline for 10 weeks and had shown improvement on laboratory testing and imaging. The patient then presented with clinical symptoms of dengue (confirmed serologically) and thrombocytopenia. He developed bilateral hemianopsia, and magnetic resonance imaging showed enlargement of the pituitary adenoma with signs of intratumoral bleeding. The patient underwent transsphenoidal surgery, and histopathologic examination documented a pituitary adenoma diffusely infiltrated by blood cells. CONCLUSIONS: We describe dengue as a probable novel condition for pituitary apoplexy because it may be associated with multiple risk factors for pituitary infarction or bleeding. Physicians should suspect pituitary apoplexy in patients with dengue hemorrhagic fever who develop a rapid onset of severe headache and vision defects, even in those without known pituitary adenomas.

Growth of an aggressive tumor during pregnancy in an acromegalic patient.

Pregnancy in acromegalic patients is a rare event, but is usually uneventful, with stable GH and IGF-I levels and no tumor enlargement. Medical treatment can usually be withdrawn without problems and although no major adverse event has been reported, the suspension of drug treatments is generally recommended. No case report exists in the literature regarding evolution of a somatotropinoma with invasiveness markers throughout pregnancy. We report a case of an acromegalic patient who was submitted to surgery and treated with octreotide LAR maintaining a stable residual tumor and an IGF-I close to the normal levels. Her tumor presented with a high Ki-67 (11.6%) and a low aryl hydrocarbon receptor-interacting protein (AIP) expression. When she became pregnant, octreotide LAR was withdrawn, and despite remaining asymptomatic during pregnancy, tumor growth occurred with compression of surrounding structures. In conclusion, pregnancy in acromegalic patients has usually a favorable prognosis with no tumor growth. However, in the presence of high Ki-67 labeling index and low AIP expression, tumor enlargement may occur and somatostatin analogue treatment throughout the pregnancy should be considered.

Impact of gsp oncogene on the mRNA content for somatostatin and dopamine receptors in human somatotropinomas.

INTRODUCTION: It has been reported in some series that gsp+ somatotropinomas are more sensitive to somatostatin analogues (SA) and dopamine's actions which may be related to their somatostatin receptor (SSTR) and dopamine receptor (DR) profile. No previous studies have been undertaken to evaluate the SSTR and DR profile related with the gsp status in somatotropinomas. OBJECTIVES: To determine if (1) gsp status is correlated with response to octreotide LAR (LAR) and tumor expression patterns of SSTR1-5 and DR1-5 and (2) cAMP level can directly modulate SSTR and DR mRNA levels. METHODS: Response to SA was evaluated by GH and IGF-I percent reduction after 3 and 6 months of treatment with LAR. Conventional PCR and sequencing were used to identify gsp+ tumors. Quantitative real-time PCR was used to determine SSTR and DR tumor expression. Primary pituitary cell cultures of primates were used to study whether SSTR and DR expression is regulated by forskolin. RESULTS: The response to LAR did not significantly differ between patients with gsp+ and gsp- tumors; however, gsp+ tumors expressed higher levels of SSTR1, SSTR2, DR2 and a lower level of SSTR3. Forskolin increased SSTR1, SSTR2, DR1 and DR2 expression in cell cultures. CONCLUSION: Elevated SSTR1, SSTR2, and DR2 tumor expression may help improve responsiveness to SA and DA therapy; however, this study may not have been appropriately powered to observe significant effects in the clinical response. Elevated cAMP levels could be directly responsible for the upregulation in SSTR1, SSTR2 and DR2 mRNA levels observed in gsp+ patients.

Germ cell tumor presenting as sellar mass with suprasellar extension and long history of hypopituitarism.

OBJECTIVE: Primary central nervous system germ cell tumors are rare neoplasms usually located in the pineal and/or suprasellar region. Pure germinomas do not usually secrete beta-human chorionic gonadotropin hormone (beta-HCG) or alpha-fetoprotein (AFP) and diagnosis is made a few weeks or months after beginning of symptoms. CASE: Here we report a case of a pure germinoma in a 20 year-old woman presenting as a sellar mass with suprasellar extension, abnormal serum beta-HCG and a long history of polyuria and polydipsia (4 years), that was initially diagnosed as a pituitary macroadenoma. CONCLUSION: This presentation highlights the importance of thinking in alternative diagnosis to pituitary adenoma when diabetes insipidus is the initial symptom.

Expression analysis of dopamine receptor subtypes in normal human pituitaries, nonfunctioning pituitary adenomas and somatotropinomas, and the association between dopamine and somatostatin receptors with clinical response to octreotide-LAR in acromegaly.

CONTEXT: Dopamine receptor (DR) and somatostatin receptor subtype expression in pituitary adenomas may predict the response to postsurgical therapies. OBJECTIVES: Our objectives were to assess and compare the mRNA levels of DR1-5 and somatostatin receptors 1-5 in normal pituitaries (NPs), nonfunctioning pituitary adenomas (NFPAs), and somatotropinomas. In addition, we determined whether the level of DR expression correlates with the in vivo response to octreotide-LAR in acromegalic patients. DESIGN AND PATIENTS: Eight NPs, 30 NFPAs, and 39 somatotropinomas were analyzed for receptor mRNA levels by real-time RT-PCR. The DR2 short variant was estimated as the DR2 long/DR2 total (DR2T). The relationship between DR expression and the postsurgical response to octreotide-LAR was assessed in 19 of the acromegalic patients. RESULTS: DR3 was not detected. The relationship between expression levels of DR subtypes in NPs and somatotropinomas was DR2T>>>DR4>>DR5>DR1, whereas in NFPAs, DR2T>>>DR4>>DR1>DR5. The DR2 short variant was the predominant DR2 variant in the majority of samples. In acromegalics treated with octreotide-LAR, DR1 was negatively correlated with percent GH reduction (3 months: r = -0.67, P = 0.002; and 6 months: r = -0.58, P = 0.009), and DR5 was positively correlated with percent IGF-I reduction (3 months: r = 0.55, P = 0.01; and 6 months: r = 0.47, P = 0.04). CONCLUSIONS: DR2 is the predominant DR subtype in NPs, NFPAs, and somatotropinomas. The fact that DR1, DR4, and DR5 are also expressed in many adenomas tested suggests that these receptors might also play a role in the therapeutic impact of postsurgical medical therapies in patients with NFPA and acromegaly. This was supported by the finding that the in vivo response to octreotide-LAR was negatively associated with DR1 and positively associated with DR5.

Utility of [(18)F] fluoro-2-deoxy-D: -glucose positron emission tomography in the localization of ectopic ACTH-secreting tumors.

Ectopically ACTH producing tumors may be difficult to localize by conventional radiology and functional imaging may be helpful. Case 1: 31-year-old man was diagnosed with ectopic ACTH-dependent Cushing's syndrome (ECS). Thorax CT revealed a 1.3 cm nodular opacity in upper left lobe, suggestive of residual lesion. [(18)F] fluoro-2-deoxy-D: -glucose ([(18)F] FDG) positron emission tomography ([(18)F] FDG PET) scan revealed mild glycolytic metabolic activity. Pathological examination confirmed an ACTH-positive carcinoid tumor. Case 2: 53-year-old woman presented with very rapid onset ECS. Pituitary MRI was normal. Thorax CT revealed no tumoral lesion. Abdominal and pelvic MRI showed images suggestive of hepatic and iliac, femoral and lumbar secondary implants. [(18)F] FDG PET scan revealed intense uptake in uterus, especially cervix, suggesting this to be the primary tumor site. These cases illustrate the role of [(18)F] FDG PET in the investigation of an ECS where conventional imaging studies were not elucidative in the search for a responsible tumor.

Prevalence of discordant GH and IGF-I levels in acromegalics at diagnosis, after surgical treatment and during treatment with octreotide LAR.

BACKGROUND: Acromegalic patients are considered "discordant" if their insulin-like growth factor type I (IGF-I) levels are increased for their age with "safe" growth hormone (GH) levels or if their IGF-I levels are normal for their age with "unsafe" GH levels. The prevalence of discordance in acromegalics has been described to vary from 9.4% to 39%, and it may be observed at diagnosis or during the follow up. OBJECTIVE: To evaluate the prevalence of discordant levels of IGF-I and GH in our acromegalic population. METHODS: Hormonal evaluation was made with an oral glucose tolerance test (OGTT) with the IGF-I being assessed in the basal sample at diagnosis and after 3 months of the adenomectomy. During treatment with octreotide LAR, a GH curve (for the calculation of mean GH) and IGF-I assessment were made every 3 months. RESULTS: Among the 51 patients evaluated at diagnosis, the prevalence of discordance was 13.7% (7/51). Among the 58 patients evaluated after the surgical procedure, eight (13.8%) had discordant GH and IGF-I levels. Among the 42 patients evaluated during treatment with octreotide LAR, the prevalence of discordant GH and IGF-I levels was 33.3% (14/42). Using 1 microg/L as a cut off level for "safe" GH, the prevalence of discordance was 3.9%, 8.6% and 28.6% at diagnosis, after surgery and during treatment with octreotide LAR, respectively. No difference of sex, age or treatment modality was observed among discordant and concordant patients with any GH cut off level. CONCLUSION: We observed a prevalence of discordance similar to that previously described in the literature. We believe that studies evaluating morbidity and mortality in discordant patients are also necessary and will enlighten the true impact of this condition in the follow up of acromegaly.

Quantitative analysis of somatostatin receptor subtypes (1-5) gene expression levels in somatotropinomas and correlation to in vivo hormonal and tumor volume responses to treatment with octreotide LAR.

OBJECTIVE: To determine whether the somatostatin receptor subtype (SSTR) expression profile correlates with hormonal and tumor volume responses to postsurgical octreotide long acting repeatable (OCT LAR) treatment. DESIGN AND METHODS: Quantitative real-time RT-PCR was used to evaluate the absolute mRNA copy numbers for all five SSTR subtypes in 22 somatotropinomas. Response to OCT LAR was studied by hormone levels (GH and IGF-I) and tumor volume (sella turcica magnetic resonance imaging). RESULTS: SSTR5 was present at the highest level followed by SSTR2, SSTR3, SSTR1, and SSTR4 (2327 (1046-5555), 2098 (194-23 954), 97 (0-460), 14 (0-29 480), and 0 (0-652) copies respectively). Positive correlations were found between SSTR2 levels and the percentage decrease of GH and IGF-I after 3 (r=0.49, P<0.027 and r=0.49, P<0.029 respectively) and 6 (r=0.59, P<0.006 and r=0.58, P<0.008 respectively) months of OCT LAR. A negative correlation was found between SSTR5 mRNA levels and the percentage decrease of GH after 3 months of OCT LAR (r=-0.52, P=0.016, n=21). A higher SSTR2/SSTR5 ratio was observed among patients who obtained hormonal control with OCT LAR, when compared with those uncontrolled (2.4 (0.7-10) vs 0.3 (0.1-7.7), P=0.001). A ROC curve analysis showed a SSTR2/SSTR5 ratio of 1.3 as the best predictor of disease control, with a sensitivity of 88% and a specificity of 92% - area under curve, 0.9. A positive correlation was also found between SSTR2 mRNA levels and the percentage decrease in tumor volume after 6 months of OCT LAR (r=0.79, P=0.002, n=12). CONCLUSIONS: Somatostatin receptor subtype 2 mRNA expression levels in somatotropinomas correlate positively with in vivo hormonal and tumor volume responses to OCT LAR.

Two hour mean GH is not superior to basal GH for the follow-up of acromegalic patients treated with Octreotide LAR.

BACKGROUND: GH secretion, in acromegaly, is characterized by increased basal levels, as well as by increased frequency and amplitude of pulses. Evaluation of disease activity during follow-up of treated patients is frequently done with mean GH levels, although there is no established protocol for sample collection. OBJECTIVE: Determine mean GH value of 5 blood samples collected 30 min apart for 2 consecutive hours in the follow-up of acromegalic patients treated with octreotide LAR. METHODS: Ninety-one GH curves of 44 patients (25 women) were evaluated as were the respective IGF-I values (basal). Normal IGF-I for age and sex was considered standard for control of disease activity. Correlations between basal and mean GH were studied as were correlations between both values and %IGF-I above the upper limit of reference values (%ULRV). RESULTS: Median age of the group was 45.5 years (range 28-73). Twenty-five patients (56.8%) had previous surgery and 7 (15.9%) had both surgery and radiotherapy. A positive correlation was found between mean and basal GH (r=0.953; p<0.001). Both basal and mean GH were correlated to %ULRV (r=0.645 and 0.661; p<0.001 for both). In only 3 of the 91 curves (3.3%) there were discordances between basal GH and IGF-I, however the latter was concordant with mean GH. In 3 other curves there was concordance between basal GH and IGF-I although the latter was discordant with mean GH. CONCLUSIONS: There was no benefit to perform GH curves with the present protocol. It may be due to our established outpatient follow up protocol. The use of more complex protocols and the cost of multiple GH assays should be acknowledged, and probably reserved for patients with basal GH levels between 1 and 5 microg/L with discordant GH and IGF-I.