Caracterización de tumores secretores de hormona de crecimiento de acuerdo al patrón granular y su rol en el pronóstico / Prognostic value of granular pattern of growth hormone secreting tumors

Background: Classification of growth hormone (GH) - secreting tumors by the granular pattern might predict their clinical behavior in acromegalic patients. There are several other prognostic factors. Aim: To compare the features at presentation and cure rates of patients with GH secreting tumors according to the granular pattern, and to define independent prognostic factors for surgical treatment in these patients. Material and Methods: A retrospective, observational study of 85 active acromegalic patients surgically treated in two medical centers. Results: Seventy-four patients (87%) were classified as having densely granulated (DG) and 11 (13%) as sparsely granulated (SG) tumors. The latter were less active biochemically, had a higher rate of macroadenoma and cavernous sinus invasion and had a lower rate of biochemical cure than the DG group. Several characteristics were associated with disease persistence but only age (Odds ratio (OR) = 0.93) and cavernous sinus invasion (OR = 21.7) were independently associated in the logistic regression model. Conclusions: The sparsely granulated pattern is associated with a more aggressive behavior, but the main determinants of prognosis are age and cavernous sinus invasion.

Study of major genetic factors involved in pituitary tumorigenesis and their impact on clinical and biological characteristics of sporadic somatotropinomas and non-functioning pituitary adenomas

Genetic and functional aberrations of guanine nucleotide-binding protein, alpha stimulating (GNAS), aryl hydrocarbon receptor interacting protein (AIP), and pituitary tumor transforming gene (PTTG) are among the most prominent events in pituitary tumorigenesis. A cohort of Brazilian patients with somatotropinomas (n=41) and non-functioning pituitary adenomas (NFPA, n=21) from a single tertiary-referral center were evaluated for GNAS and AIP mutations and gene expression of AIP and PTTG. Results were compared to the clinical and biological (Ki67 and p53 expression) characteristics of tumors and their response to therapy, if applicable. Genetic analysis revealed that 27% of somatotropinomas and 4.8% of NFPA harbored GNAS mutations (P=0.05). However, no differences were observed in clinical characteristics, tumor extension, response to somatostatin analog therapy, hormonal/surgical remission rates, Ki67 index, and p53 expression between mutated and non-mutated somatotropinomas patients. PTTG overexpression (RQ mean=10.6, min=4.39, max=11.9) and AIP underexpression (RQ mean=0.56, min=0.46-max=0.92) were found in virtually all cases without a statistically significant relationship with clinical and biological tumor features. No patients exhibited somatic or germline pathogenic AIP mutations. In conclusion, mutations in GNAS and abnormal PTTG and AIP expression had no impact on tumor features and treatment outcomes in this cohort. Our data support some previous studies and point to the need for further investigations, probably involving epigenetic and transcriptome analysis, to improve our understanding of pituitary tumor behavior.

Resultados do tratamento cirúrgico na acromegalia com um único neurocirurgião e meta-análise cumulativa / Outcome of surgical treatment for acromegaly performed by a single neurosurgeon and cumulative meta-analysis / Outcome of surgical treatment for acromegaly performed by a single neurosurgeon and cumulative meta-analysis

Avaliamos retrospectivamente os resultados da cirurgia transesfenoidal num grupo de acromegálicos operados por um único neurocirurgião, comparando-os com uma meta-análise cumulativa de 10 séries (1.632 pacientes) publicadas entre 1992-2005. Estudamos 28 pacientes (17M/11F; 44,1 ± 12,7 anos; 27 com macroadenomas, sendo 86 por cento invasivos), acompanhados por 21,4 ± 17,6 meses após a cirurgia; eles foram classificados de acordo com a atividade da acromegalia em: 1) doença controlada (DC): GH basal ou médio < 2,5 ng/ml ou GH nadir no TTOG < 1ng/ml e IGF-1 normal; 2) não controlada (DNC): GH basal ou médio > 2,5 ng/ml ou nadir no TTOG > 1 ng/ml e IGF-1 elevado; 3) inadequadamente controlada (DIC): GH normal e IGF-1 elevado ou GH elevado e IGF-1 normal. Após a cirurgia, os níveis de GH reduziram de 61,7 ± 101,1 ng/ml para 7,2 ± 13,7 ng/ml (p< 0,001), e os de IGF-1 de 673,1 ± 257,7 ng/ml para 471,2 ± 285 ng/ml (p= 0,01). A taxa de remissão bioquímica foi de 57 por cento [10 pacientes (35,5 por cento) com DC e 6 (21,5 por cento) com DIC], similar àquela obtida na meta-análise de cirurgias de macroadenomas. Sete dos 28 pacientes foram submetidos à re-intervenção (4 operados em outro hospital e 3 pelo nosso neurocirurgião), sendo 5 (71,5 por cento) classificados como DC no pós-operatório. Invasão de seio cavernoso foi mais prevalente nos DNC e DIC, e desvio de haste hipofisária no grupo DNC. A taxa de remissão foi maior nas séries em que apenas um único cirurgião realizou os procedimentos (66 por cento vs. 49 por cento; p< 0,05). Em conclusão, esses dados comprovam que a experiência do neurocirurgião pode aumentar significativamente as taxas de remissão do tratamento cirúrgico da acromegalia, especialmente em tumores maiores e mais invasivos, e que a re-intervenção realizada por cirurgião experiente deve ser considerada nos algoritmos de abordagem terapêutica desta doença.

The aim of this retrospective study was to evaluate the results of transsphenoidal surgery in a group of patients with acromegaly who were operated by the same neurosurgeon. Our results were compared to those from a cumulative meta-analysis of 10 series (1,632 patients) published between 1992­2005. We followed 28 patients (17M/11F; 44.1 ± 12.7 yr; 27 with macroadenomas; 86 percent being invasive) during 21.4 ± 17.6 months after treatment. Patients were classified according to disease activity as follows: 1) controlled (CD): basal or mean GH < 2.5 ng/ml or nadir GH (OGTT) < 1 ng/ml and normal IGF-1; 2) uncontrolled (UCD): basal or mean GH > 2.5 ng/ml or nadir GH > 1 ng/ml and elevated IGF-1; 3) inadequately controlled (ICD): normal GH and elevated IGF-1 or elevated GH and normal IGF-1. After surgery, GH levels decreased from 61.7 ± 101.1 ng/ml to 7.2 ± 13.7 ng/ml (p< 0.001) and mean IGF-1 from 673.1 ± 257.7 ng/ml to 471.2 ± 285 ng/ml (p= 0.01). Biochemical remission rate was 57 percent [10 (35.5 percent) patients with CD and 6 (21.5 percent) with ICD], similar to the mean remission rate observed in the meta-analysis of surgical outcome of macroadenomas. Seven of 28 patients were submitted to surgical re-intervention (4 had been previously operated elsewhere and 3 by our neurosurgeon), with CD observed in 5 (71.5 percent) on follow-up. Cavernous sinuses invasion was more prevalent in UCD and ICD, whereas infundibular stalk deviation occurred only in patients with UCD. Remission rate was significantly higher in series where all surgical procedures were performed by the same surgeon (66 percent vs. 49 percent; p< 0.05). Thus, the surgeon's experience significantly improves the surgical outcome in acromegaly, especially in patients harboring large and invasive tumors, and re-intervention performed by an experienced surgeon should be considered in the algorithms for clinical management of this disease.