Guadalupe Vargas

Expression of Ki-67, PTTG1, FGFR4, and SSTR 2, 3, and 5 in nonfunctioning pituitary adenomas: a high throughput TMA, immunohistochemical study.

CONTEXT Nonfunctioning pituitary adenomas (NFPA) are the most common pituitary neoplasms. There is no clinical, biochemical, or histopathological marker that would accurately predict recurrence of NFPA. OBJECTIVE The aim of this study was to evaluate a large group of NFPA for the presence of potential markers of biological behavior. DESIGN AND SETTING A cross-sectional study using a high throughput tissue microarray technology was conducted at tertiary care centers. MATERIALS AND METHODS Seventy-four gonadotroph and null cell adenomas were included in the tissue microarray. Using highly specific antibodies and appropriate controls, we determined the expression of Ki-67, pituitary tumor transforming gene 1, the N-terminally truncated pituitary tumor-derived fibroblast growth factor receptor-4 (FGFR4), as well as somatostatin receptor subtypes 2, 3, and 5 (SSTR2, -3, and -5), in an attempt to establish correlations and/or associations with clinical characteristics of the patients. RESULTS Median Ki-67 index was 1.49 (interquartile range, 0.62-2.49). Pituitary tumor transforming gene 1 nuclear immunoreactivity was found in all but one tumor (median percentage of positive nuclei, 11.44); immunopositivity for FGFR4 was found in the majority of the tumors, with variable levels of expression. The immunostaining score for SSTR2 was significantly higher than that for SSTR3 or SSTR5. FGFR4 expression correlated positively with SSTR2 and SSTR5 immunostaining scores (r = 0.59; P < 0.001; and r = 0.46; P < 0.001, respectively). Multivariate analysis revealed that the Ki-67 index was significantly associated with a tumor size greater than 3 cm (odds ratio, 2.32; 95% confidence interval, 1.17-4.58) as well as with tumor recurrence (odds ratio, 1.4; 95% confidence interval, 1.03-1.89). CONCLUSIONS Ki-67 is the most consistent marker of biological behavior in NFPA. The finding of significant amounts of SSTR2 and SSTR5 may have therapeutic implications regarding the use of somatostatin analogs in preventing tumor recurrence.

Clinical and Biochemical Impact of the d3 Growth Hormone Receptor Genotype in Acromegaly

CONTEXT Lack of exon 3 of the GH receptor (d3-GHR) has been associated with increased responsiveness to GH therapy. By analogy, we hypothesized that patients with acromegaly bearing the d3-GHR genotype may have a more morbid clinical and biochemical picture. OBJECTIVE Our objective was to determine whether the GHR genotype, by modifying tissue sensitivity to GH, influences the clinical/biochemical expression of acromegaly and its outcome after treatment. SETTING The study was conducted at a specialized clinic at a tertiary care hospital. DESIGN, PATIENTS, AND METHODS We conducted a prospective genotype investigation and retrospective analysis and correlation with clinical, biochemical, and outcome data from a group of 148 patients. Samples from 175 healthy blood donors were used as controls. GHR genotyping was performed by real-time PCR. MAIN OUTCOME MEASURES We assessed prevalence of the three GHR genotypes (fl/fl, d3/d3, and d3/fl), associations between the genotypes, and baseline as well as post-therapeutic characteristics. RESULTS Prevalence of the fl/fl, d3/d3, and d3/fl genotypes was 45, 22, and 32%, respectively, similar to what was found in the controls. Baseline characteristics were similar in carriers of the three genotypes. A positive correlation between IGF-I and log GH concentrations was significant only in homo- or heterozygous d3 carriers. Among d3-GHR carriers, diabetes, but no other comorbidities, was more prevalent (odds ratio = 2.02; 95% confidence interval = 0.96-4.2). d3-GHR carriers had significantly higher IGF-I concentrations after treatment. Multiple regression analysis revealed that the homo- or heterozygous lack of exon 3 was the strongest predictor of persistent biochemical activity (odds ratio = 1.29; 95% confidence interval = 0.65-2.58). CONCLUSIONS The absence of exon 3 of the GHR may be associated with a more morbid acromegalic clinical and biochemical picture and a lower chance of achieving IGF-I normalization after therapy.

Successful Mortality Reduction and Control of Comorbidities in Patients With Acromegaly Followed at a Highly Specialized Multidisciplinary Clinic

CONTEXT Acromegaly is usually due to the excessive secretion of GH by a pituitary adenoma. It is frequently accompanied by comorbidities that compromise quality of life and results in elevated mortality rates. OBJECTIVE To evaluate mortality and morbidity in patients with acromegaly receiving multimodal care. SETTING Tertiary care center. DESIGN, PATIENTS, AND METHODS Retrospective evaluation of 442 patients (65.4% women; mean age, 43.5 ± 13.1 y) followed for a median of 6 years (interquartile range [IQR], 3-10). RESULTS Twenty-two patients died during the study period (4.9%), representing a total standardized mortality ratio (SMR) of 0.72 (95% confidence interval [CI], 0.41-1.03). Standardized mortality ratios were 1.5 and 0.44 for patients whose last GH was above and below 2.5 ng/mL, respectively; 1.17 and 0.16 for those whose last GH was above and below 1 ng/mL, respectively; and 0.94 and 0.46 for those whose last IGF-1 was above and below 1.2 times the upper limit of normal (ULN), respectively. The prevalence of diabetes mellitus, hypertension, heart disease, and cancer was 30%, 35%, 8%, and 4.7%, respectively. The most common cause of death was cancer. On multivariate analysis, diabetes, heart disease, and cancer were related to a baseline GH > 10 ng/mL; the presence of cancer and the last IGF-1 were significant predictors of mortality. Survival decreased as the latest GH levels increased from < 1 ng/mL to > 5 ng/mL and as IGF-1 increased from < 1.2 to > 2 times the ULN. CONCLUSIONS Mortality in acromegaly can be successfully reduced, provided patients are treated using a multimodal approach with careful management of comorbidities.

Discontinuation of octreotide LAR after long term, successful treatment of patients with acromegaly: is it worth trying?

BACKGROUND Somatostatin analogs (SA) have been used for over 25 years in the treatment of acromegaly. A major disadvantage is the need to continue therapy indefinitely. OBJECTIVE To evaluate the feasibility of discontinuing therapy in well-controlled patients with acromegaly treated chronically with SA. DESIGN AND METHODS Of the 205 subjects on octreotide LAR, we selected those who met the following criteria: two or more years of treatment, a stable dose and injection interval of 20  mg every 8 weeks or longer for the previous year, no history of radiation, no cabergoline for the previous 6 months, a GH <1.5  ng/ml, and an IGF1 <1.2×upper limit of normal (ULN). Octreotide LAR was stopped and both GH and IGF1 were measured monthly for 4 months; a glucose-suppressed GH value and magnetic resonance imaging were obtained at the 4th month, thereafter, basal GH and IGF1 were measured q. 3 months, for 12-18 months. Patients were removed from the study if GH or IGF1 rose to 1.5  ng/ml or 1.2×ULN respectively. RESULTS Twelve patients (ten women, mean age 48±13 years) were studied. Seven patients (58.3%) relapsed biochemically within 1 year of having stopped the SA; two patients relapsed by GH and IGF1 criteria, the remaining five patients kept GH levels within target. Five patients (41.7%) remain in remission after 12 months of follow-up. Non-recurring patients were on longer injection intervals but no other characteristic was associated with a successful withdrawal. CONCLUSION Withdrawal of SA is possible in a small but distinct subset of patients, particularly in those who are very well controlled on relatively low doses administered at long intervals.

Efficacy and Safety of Radiotherapy in Acromegaly

BACKGROUND AND AIMS Transsphenoidal surgery remains the treatment of choice in acromegaly, yet 40-50% of patients require secondary forms of therapy such as radiation therapy (RT) and somatostatin analogues (SA). We undertook this study to evaluate the efficacy and safety of RT in acromegaly. METHODS Forty patients with acromegaly treated with RT (mean dose, 52 Gy) after failed pituitary surgery between 1993 and 2007 were analyzed; all were clinically and biochemically active. Patients were evaluated with yearly hormonal measurements [basal and glucose-suppressed growth hormone (GH), IGF-1, thyroid-stimulating hormone (TSH), free T4, cortisol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone or estradiol and prolactin (PRL)] and with magnetic resonance imaging every 2 years. RESULTS Mean age of patients was 52.9 ± 12.1 years and 85% were female. All subjects had been followed for 1 year, 75% for 3 years, 70% for 5 years and 35% for 10 years. The median basal GH level fell from a baseline of 8.8 ng/mL to 2.27 ng/mL at 5 years (p = 0.001) and to 1.88 ng/mL at 10 years (p = 0.001). A GH <1 ng/mL was achieved by 46% and 57% of the patients at 5 and 10 years of follow-up, respectively. The proportion of patients achieving a normal IGF-1 was 36% at 5 years and 43% at 10 years. Before RT, hypothyroidism, hypocortisolism and hypogonadism were present in 44%, 26% and 74% of patients, respectively. After 5 years of follow-up (n = 28), these figures increased to 51%, 41% and 79% and over a third of the group had panhypopituitarism. One patient developed optic neuritis and another patient was diagnosed with a meningioma 10 years after RT. No cerebrovascular events or deaths occurred. CONCLUSIONS RT is an effective, low-cost and reasonably safe means of controlling acromegalic activity, particularly useful in parts of the world where SA are not readily available.

Clinical Characteristics and Treatment Outcome of 485 Patients with Nonfunctioning Pituitary Macroadenomas

Background. Nonfunctioning pituitary adenomas (NFPAs) are the most common benign lesions of the pituitary gland. Objective. To describe our experience with the management of NFPA. Study Design and Methods. Retrospective evaluation of NFPA patients managed between 2008 and 2013. We analyzed data regarding clinical presentation, imaging diagnosis, hormonal status, surgical, radiotherapeutic, and pharmacological treatment, and outcome. Results. 485 patients (54% men, mean age 53 ± 14 years) were followed for a median of 6.5 years. Visual field abnormalities and headaches were the presenting complaints in 87% and 66%, respectively. The diagnosis of NFPA was made incidentally in 6.2%, and 8% presented with clinical evidence of apoplexy. All patients harbored macroadenomas, with a median volume of 10306 mm3; 57.9% had supra- or parasellar invasion and 19.6% had tumors larger than 4 cm. Central hypothyroidism, hypogonadism, and hypocortisolism were present in 47.2%, 35.9%, and 27.4%, respectively. Surgical resection was performed at least once in 85.7%. Tumor persistence was documented in 27% and was related to the size and invasiveness of the lesion. In selected cases, radiotherapy proved to be effective in controlling or preventing tumor growth. Conclusions. The diagnosis and treatment of NFPA are complex and require a multidisciplinary approach.

Pituitary apoplexy in nonfunctioning pituitary macroadenomas: a case-control study.

OBJECTIVE Pituitary apoplexy (PA) is an endocrinologic emergency characterized by headache, visual abnormalities, and hemodynamic instability in the context of hemorragic infarction of a pituitary adenoma. Our goal was to estimate the incidence, precipitating factors, clinical characteristics, and outcome of PA in a cohort of patients with nonfunctioning pituitary macroadenomas (NFPMAs). METHODS A retrospective, case-control study of 46 patients with PA and 47 controls matched for age, gender, and tumor invasiveness. Clinical, hormonal, and tumoral charactersitics, as well as the presence of potential precipitating factors and long-term outcome were evaluated using both bivariate and multivariate analysis. RESULTS The prevalence of PA was 8%. Cases and controls were similar in regards to the prevalence of diabetes, hypertension, use of antiplatelet agents, and the presence of headaches and visual field defects. Oculomotor paralysis was present in 18% of cases and in none of the controls (P = .001). Prior use of dopamine agonists was significantly more frequent among cases than in controls on both bivariate and multivariate analysis. Pituitary hormone deficiencies were more common among cases than in controls on bivariate but not on multivariate analysis. Early and late surgical treatment was carried out in 11 and 25 patients, respectively; 11 patients were managed conservatively. Visual and endocrine outcomes were similar among the 3 groups. CONCLUSION PA represents a life-threatening medical emergency. Prior use of dopamine agonists and the presence of oculomotor abnormalities clearly distinguished patients with NFPMA who developed PA from those who did not.

Cytoplasmic expression of SSTR2 and 5 by immunohistochemistry and by RT/PCR is not associated with the pharmacological response to octreotide

OBJECTIVE To evaluate expression of somatostatin receptor subtypes 2 and 5 (SSTR 2 and 5) by RT/PCR and immunohistochemistry (IHC) in GH-secreting adenomas, seeking correlations with response to octreotide. METHODS SSTR2 and 5 expression was tested by IHC (n=37), RT/PCR (n=36) or both (n=13) in GH-secreting adenomas from 60 patients with acromegaly who had undergone pituitary surgery; 36 had been treated preoperatively with octreotide LAR for 3-6 months, and were categorized as responders (achievement of GH <2.5ng/mL and a normal age-adjusted IGF-1), partial responders (GH and IGF-1 reduction >50% and >30%, respectively) or non-responders. IHC was performed on a tissue microarray using specific antibodies directed to the carboxyl terminus of SSTR2 and 5. RESULTS SSTR5 was the predominantly expressed receptor subtype by both IHC and RT/PCR in all tumors tested, regardless of whether they came from octreotide-naïve, octreotide-responsive, or octreotide-resistant patients. Immunostaining was concentrated in the cytoplasm. Neither SSTR2 nor SSTR5 expression correlated with baseline or post-octreotide GH or IGF-1 levels or tumor volume by either method. The agreement rate between RT/PCR and IHC was 77% in all 13 adenomas in which both methods were used. CONCLUSION Expression of these receptors does not guarantee an adequate response to somatostatin analogs; other functional aspects of this interaction, such as receptor homo- and heterodimerization, and the resulting signaling cascade, probably play a role in determining whether a patient will respond or not to these agents.

Inflammatory Cytokine Profile Associated with Metabolic Syndrome in Adult Patients with Type 1 Diabetes

Objective. To compare the serum concentration of IL-6, IL-10, TNF, IL-8, resistin, and adiponectin in type 1 diabetic patients with and without metabolic syndrome and to determine the cut-off point of the estimated glucose disposal rate that accurately differentiated these groups. Design. We conducted a cross-sectional evaluation of all patients in our type 1 diabetes clinic from January 2012 to January 2013. Patients were considered to have metabolic syndrome when they fulfilled the joint statement criteria and were evaluated for clinical, biochemical, and immunological features. Methods. We determined serum IL-6, IL-8, IL-10, and TNF with flow cytometry and adiponectin and resistin concentrations with enzyme linked immunosorbent assay in patients with and without metabolic syndrome. We also compared estimated glucose disposal rate between groups. Results. We tested 140 patients. Forty-four percent fulfilled the metabolic syndrome criteria (n = 61), 54% had central obesity, 30% had hypertriglyceridemia, 29% had hypoalphalipoproteinemia, and 19% had hypertension. We observed that resistin concentrations were higher in patients with MS. Conclusion. We found a high prevalence of MS in Mexican patients with T1D. The increased level of resistin may be related to the increased fat mass and could be involved in the development of insulin resistance.

SURGICAL REINTERVENTION IN ACROMEGALY: IS IT STILL WORTH TRYING?

BACKGROUND AND OBJECTIVE There has not been a formal evaluation of how frequently and to what extent surgical reintervention in patients with persistently active acromegaly may achieve significant, albeit incomplete, reductions in growth hormone (GH) and insulinlike growth factor-I (IGF-I) levels. Of importance, recent studies suggest that the response to radiotherapy and pharmacotherapy is better with lower degrees of hypersomatotropism. The objective of this study was to evaluate the outcome of surgical reintervention in patients with active acromegaly at our institution between 1995 and 2005. METHODS We retrospectively evaluated the outcome in 53 patients with active acromegaly (49 with macroadenomas) who underwent a second operation a mean of 24.1 +/- 25.2 months after the first intervention. Basal and postglucose GH as well as IGF-I levels were analyzed at diagnosis and after the first and second pituitary procedures. RESULTS Basal GH decreased in 38 patients (72%): to <10 ng/mL in 17 and to <2.5 ng/mL in 11. The mean IGF-I index and basal GH decreased significantly after surgical reintervention: 1.7 +/- 0.4 to 1.4 +/- 0.4 (P = .0001) and 13.0 +/- 12.8 to 8.3 +/- 11.3 ng/mL (P = .0001), respectively. Some decrement in IGF-I was observed after surgical reintervention in 30 patients (57%), being greater than 30% in 9 (17%). Only 5 patients (9%) achieved complete biochemical cure (normal IGF-I and a postglucose GH level of <1 ng/mL). Reoperation achieved a significant decline in basal and postglucose GH levels as well as in IGF-I index only in patients with noninvasive macroadenomas. CONCLUSION Pituitary surgical reintervention in patients with acromegaly results in a low percentage of biochemical cure. If a remnant of a noninvasive macroadenoma is visible and accessible, however, such a procedure may significantly reduce GH and IGF-I levels.