Characterization of the levels of expression of retinoic acid receptors, galectin-3, macrophage migration inhibiting factor, and p53 in 51 adamantinomatous craniopharyngiomas

Adamantinomatous craniopharyngioma: evolution in the management

BACKGROUND

In spite of the continuous progresses in pediatric neurosurgery, adamantinomatous craniopharyngioma (AC) remains a challenging tumor due to its proximity to optic pathways, pituitary gland, hypothalamus, and Willis' circle, which can result in significant endocrine, cognitive, and neurological morbidity after treatment with subsequent impact on the patient's quality of life (QoL). The relevance that QoL has today explains the changes in the management of AC observed over the time. The goal of the present article is to provide a historical background, to show the milestones in the changes of the AC treatment, and to analyze the current main options to manage such a challenging tumor.

MATERIAL AND METHODS

The pertinent literature has been reviewed. Moreover, a comparison between the past and recent personal series is reported.

RESULTS

Three main eras have been identified. The first (named Cushing era) was characterized by the need to realize a harmless surgery and to define the best way to approach AC; the second (microscope era) was characterized by a tremendous technical and technological development, with remarkable results in term of safe tumor resection and control but relatively poor QoL outcomes; and the third one (current period) is characterized by an increasing integration between surgery and adjuvant treatments, with relatively minor tumor control but significant improvement of QoL (comparable overall survival). The authors' experience reflects these changes. Two groups of children were compared: 52 cases (mean follow-up: 17.5 years) belong to the historical series (group 1, 1985-2003, aggressive surgical management) and 41 (mean follow-up: 8.5 years) to the current one (Group 2, 2004-2021, integrated management). No significant differences between the two groups were detected about recurrence rate, surgical mortality, and overall survival. However, Group 2 showed significant lower rates of postoperative panhypopituitarism, obesity, and visual deterioration.

CONCLUSIONS

Radical surgery allows for a good AC control with a low rate of recurrence but high risk of permanent morbidity. Despite the greater number of recurrences and surgeries, the more conservative policy, based on a combination of treatments, seems to provide the same tumor control with a better QoL. The advances in trans-nasal and trans-ventricular endoscopy, in proton therapy and in the management of the AC cyst are the main factors that allowed such an improvement.

Treatment of Cystic Craniopharyngiomas: An Update

In spite of the significant technical and technological progress in neurosurgery and the continuous discoveries by the basic research, adamantinomatous craniopharyngioma remains a significant clinical challenge. Actually, the huge size of the tumor, its multiple cystic components, the encasement of Willis' circle and optic pathways, and the invasion of the hypothalamus often prevent its safe surgical resection. Moreover, the local aggressiveness of the tumor accounts for a high risk of recurrence even after a gross total resection. For these reasons, more and more efforts are being dedicated to enhance the knowledge about AC and improve the tools for its treatment.This paper is dedicated to the most recent advances concerning the AC management. Promising, new insights come for the basic research, thanks to the updates on the role of the WNT-β-catenin pathway (important for the tumor genesis and progression, not yet developed enough for a safe target therapy in children but useful for determining the prognosis) and the inflammatory mediators (widely overexpressed, especially by the cyst of the tumor, and for which target therapies are being developed). Moreover, further factors and pathways are under investigation.Also the development of new treatment strategies accounts for the improvement of the prognosis and the quality of life of AC patients. The enhancement of the experience with the endoscopic techniques (both transsphenoidal and transventricular approaches) actually allows to perform a less invasive but effective surgery that can be coupled with new modalities of radiation therapy aiming at obtaining a reliable control of the disease and protecting the endocrinological, ophthalmological, and neurological functions. A special mention is finally deserved by the techniques specifically designed for the intracystic therapy (as cyst fenestration alone or in combination with administration of radionuclides or bleomycin or interferon-α) that are here analyzed together with the aforementioned advances.

Craniopharyngioma: a roadmap for scientific translation

OBJECTIVE Craniopharyngiomas are among the most challenging of intracranial tumors to manage because of their pattern of growth, associated morbidities, and high recurrence rate. Complete resection on initial encounter can be curative, but it may be impeded by the risks posed by the involved neurovascular structures. Recurrent craniopharyngiomas, in turn, are frequently refractory to additional surgery and adjuvant radiation or chemotherapy. METHODS The authors conducted a review of primary literature. RESULTS Recent advances in the understanding of craniopharyngioma biology have illuminated potential oncogenic targets for pharmacotherapy. Specifically, distinct molecular profiles define two histological subtypes of craniopharyngioma: adamantinomatous and papillary. The discovery of overactive B-Raf signaling in the adult papillary subtype has led to reports of targeted inhibitors, with a growing acceptance for refractory cases. An expanding knowledge of the biological underpinnings of craniopharyngioma will continue to drive development of targeted therapies and immunotherapies that are personalized to the molecular signature of each individual tumor. CONCLUSIONS The rapid translation of genomic findings to medical therapies for recurrent craniopharyngiomas serves as a roadmap for other challenging neurooncological diseases.

Molecular pathology of adamantinomatous craniopharyngioma: review and opportunities for practice

Since the first identification of CTNNB1 mutations in adamantinomatous craniopharyngioma (ACP), much has been learned about the molecular pathways and processes that are disrupted in ACP pathogenesis. To date this understanding has not translated into tangible patient benefit.

The recent development of novel techniques and a range of preclinical models now provides an opportunity to begin to support treatment decisions and develop new therapeutics based on molecular pathology.

In this review the authors summarize many of the key findings and pathways implicated in ACP pathogenesis and discuss the challenges that need to be tackled to translate these basic science findings for the benefit of patients.

High FABP5 Versus CRABPII Expression Ratio in Recurrent Craniopharyngiomas: Implications for Future Treatment

BACKGROUND AND OBJECTIVE

Recurrence is a major problem in craniopharyngioma (CP) management. Recent study shows that high FABP5/CRABPII may be related to tumor growth and that all-trans retinoic acid (ATRA) may suppress primary CP growth. We studied the expression profile of FABP5 and CRABPII in recurrent CP tissue and the effect of ATRA on recurrent CP cells.

METHODS

Fifty cases of patients with CP were enrolled in the retrospective study. Among them, 15 were recurrent. Fresh specimens were collected for immunohistochemistry, reverse transcription polymerase chain reaction, and western blotting analysis of FABP5 and CRABPII. Fresh specimens from 6 primary and recurrent CPs were collected and subjected to cell culture using an explants method. ATRA at various concentrations was applied to recurrent CP cell culture, and cell growth was recorded and analyzed.

RESULTS

Immunohistochemistry, reverse transcription polymerase chain reaction, and western blot study showed that FABP5 was expressed significantly higher in recurrent tumors, whereas CRABPII was expressed significantly higher in primary tumors. The FABP5/CRABPII ratio was significantly higher in recurrent rather than primary tumors. Recurrent CP cells grew faster than primary cells, and ATRA induced cellular apoptosis and inhibited CP cell growth in a dose-dependent manner.

CONCLUSIONS

A high expression ratio between FABP5 and CRABPII may be related to CP tumor recurrence and ATRA could be a potential therapeutic agent for CP chemotherapy.

Molecular oncogenesis of craniopharyngioma: current and future strategies for the development of targeted therapies

Craniopharyngiomas are benign intracranial tumors that arise in the suprasellar and intrasellar region in children and adults. They are associated with calcification on neuroimaging, endocrinopathies, vision problems, and recurrence following subtotal resection. Molecular studies into their genetic basis have been limited, and therefore targeted medical therapies for this tumor have eluded physicians. With the discovery of aberrant Wnt/β-catenin pathway signaling in the pathogenesis of the most common subtype of craniopharyngioma (adamantinomatous), the identification of candidate genes and proteins implicated in this cascade provide attractive targets for future therapies. The recent development of a genetically engineered animal model of this tumor may also serve as a platform for evaluating potential therapies prior to clinical trials in humans. Advances in understanding the molecular pathogenesis of tumor recurrence have also been made, providing clues to develop adjuvant and neoadjuvant therapies to couple with tumor resection for optimal response rates. Finally, advances in genomic technologies and next-generation sequencing will underlie the translation of these genetic and molecular studies from the bench to clinical practice. In this review, the authors present an analysis of the molecular oncogenesis of craniopharyngioma and current directions in the development of novel therapies for these morbid, yet poorly understood brain tumors.

Treatment strategies in childhood craniopharyngioma

The surgical management of craniopharyngiomas in children remains one of the more controversial topics in pediatric neurosurgery. Theoretically, the benign histology implies that total surgical excision would be sufficient to provide a cure. It has been widely established however, that in certain cases total excision may lead to unacceptable hypothalamic injury. The therapeutic goals for pediatric craniopharyngiomas therefore, require not just cure of the disease but also preservation of function. Over the last 15 years, there has been a growing worldwide advocacy for less extensive resection and for the utilization of multimodality therapy to limit morbidity. With this in mind, risk-adapted strategies designed to preserve hypothalamic structures have been developed. The preliminary results of these strategies appear to be encouraging. However, the long-term clinical outcome in terms of post irradiation complications and management of relapses is currently unknown.

Molecular pathogenesis of craniopharyngioma: switching from a surgical approach to a biological one

Craniopharyngioma has long been considered a benign tumor because of its pathological aspect. This primordial view of craniopharyngioma fit with the primitive treatment attempts based on blind resection of the tumor each time it recurred. The limits of this management strategy were proven early by the high morbidity related to the resection and recurrence risk despite radical lesion removal. Nowadays, craniopharyngioma must be considered a complex molecular disease, and a detailed explanation of the mechanisms underlying its aggressive biological and clinical behavior, despite some benign pathological features, would be the first step toward defining the best management of craniopharyngioma. Indeed, advances in the knowledge of the molecular mechanisms at the base of craniopharyngioma oncogenesis will lead to comprehension of the critical checkpoints involved in neoplastic transformation. The final research target will be the definition of new biological agents able to reverse the neoplastic process by acting on these critical checkpoints. This biological approach will lead to a refined therapy combining higher efficacy and safety with lower morbidity. In this paper the authors reveal state-of-the-art comprehension of the molecular biology of craniopharyngioma and the consequent therapeutic implications.

Craniopharyngioma and hypothalamic obesity in children

BACKGROUND AND PURPOSE

Obesity is a major concern in children treated for craniopharyngioma and is caused by hypothalamic damage. The role of aggressive surgical removal has been questioned, leading some authors to recommend a minimalist approach. In order to test this hypothesis, we decided to study obesity in craniopharyngioma and the factors related to it.

MATERIALS AND METHODS

We reviewed retrospectively our series of pediatric craniopharyngiomas operated since 1981. The body-mass index (BMI) was calculated for each patient pre- and at several intervals postoperatively and expressed as standard deviations (SD) adjusted for age and gender.

RESULTS

We operated on 45 cases, which were followed up for a mean duration of 11.0 years. Initial resection was total in 25 cases (55.6%). No patient died because of surgery or tumor progression; two died with delay presumably because of endocrine failure. At last control, 28 patients (62%) had obesity (BMI over +2SD). Hypothalamic involvement was significantly correlated with preoperative and postoperative BMI. Subtotal tumor resection was significantly associated with obesity at last control. Reoperation for tumor recurrence was associated with a significantly higher BMI.

CONCLUSIONS

Our results suggest that obesity results from hypothalamic lesions caused by the tumor rather than by surgery. The postoperative weight gain appears to result from the continued impact of preoperative hypothalamic damage. The high rate of tumor recurrence in children, with the risk of additional damage to the hypothalamus, incites us to recommend total resection whenever it appears safe during initial surgery.

Craniopharyngiomas

Craniopharyngiomas are epithelial tumors arising along the path of the craniopharyngeal duct and presenting with a variety of manifestations. Their optimal management remains a subject of debate. Currently, surgical excision followed by external beam irradiation is the main treatment option. Craniopharyngiomas are associated with significant long-term morbidity and mortality rates.

Craniopharyngiomas in children: recurrence, reoperation and outcome

INTRODUCTION

Craniopharyngioma bears a high rate of recurrence and morbidity in childhood. Although the outcome after recurrence and reoperation is an important parameter for the long-term evaluation of craniopharyngioma, it is poorly documented in literature.

MATERIALS AND METHODS

We studied children reoperated for recurrent craniopharyngioma in our institution since the advent of computed tomography (CT) scanner. Reoperation for tumor resection was decided whenever the recurrence was solid, with the aim total resection if possible and reasonable. Stereotactic techniques were used in case of cystic recurrence, and external irradiation was used only in case of recurrent tumor not amenable to surgery.

RESULTS

From September 1981 to January 2007, we performed one or more reoperations in 20 children presenting with recurrent craniopharyngiomas. The total number of reoperations was 29: resection was total in 12 cases, near-total in 8 cases, partial in 8 cases, and undocumented in 1. In addition, stereotactic procedures were performed in 11 cases, and 5 patients underwent external irradiation.

DISCUSSION

No patient died after surgery or because of tumor progression; one patient died abruptly of an undiagnosed cause during external irradiation. The event-free survival after reoperation was 49.9% at 5 years and 40.0% at 10 years. At last control, after a mean follow-up of 70.4 months after the last surgery, nine patients were tumor-free and ten had stable disease.

CONCLUSION

Reoperation for recurrent craniopharyngioma is an efficient method for tumor control and should be proposed whenever the recurrent tumor is solid. Morbidity results above all from tumor aggressiveness, rather than from surgical damage.

Animal model for cholesteatoma induced in the gerbil: will the profiles of differentiation/growth-regulatory markers be similar to the clinical situation?

INTRODUCTION

Cholesteatoma is a benign tumor of the middle ear characterized by an aggressive and invasive potential. The only current treatment being surgery, it is important to have access to a reliable animal model to study and better understand cholesteatoma pathogenesis. Our study aimed to examine the biological validity of the most common experimental model of cholesteatoma: the Mongolian gerbil.

MATERIAL AND METHODS

We have induced cholesteatoma by surgical ligature of the gerbil's external auditory duct. Quantitative comparison of eight biological markers involved in inflammation (macrophage migration inhibitory factor [MIF]), cell differentiation (retinoic acid receptors-alpha, -beta, and -gamma), and cell adhesion/apoptosis (galectins-1, -3, -7, and -8). The immunohistochemical staining was quantified by computer-assisted microscopy.

RESULTS

Two immunohistochemical parameters were determined in sections. The labeling index (LI) represents the percentage of tissue area specifically stained, and the mean optical density (MOD) denotes the staining intensity index. The LI reveals statistically significant differences for each marker tested. The MOD also shows statistically significant differences except for MIF (P = .259).

CONCLUSION

From the panel of markers, the majority of staining parameters was statistically significantly different between sections of the animal model and clinical specimen. These data do not support the concept of complete validity of the popular animal model.

Clinico-pathological and immunohistochemical characteristics associated to recurrence/regrowth of craniopharyngiomas

BACKGROUND

Craniopharyngioma is a rare, benign epithelial brain tumor of the suprasellar region with a high rate of recurrence. Clinical and histopathological features that might be predictors of recurrence/regrowth have not been clearly delineated.

METHODS

We compared recurrence/regrowth of the tumors with the clinico-pathological characteristics, vascular density, cell proliferation index, and immunohistochemical profile (cytokeratins, epithelial membrane antigen [EMA], carcinoembrionary antigen [CEA], and laminin) of 47 patients with craniopharyngioma followed for more than 5 years.

RESULTS

Tumors were adamantinomatous in 42 cases (89%) and papillary squamous in 5 cases (11%). Immunoreactivity for cytokeratin 8/18/19 was positive in 64%; cytokeratin 5 in 42%; laminin 8 in 62%; and CEA in 21%. The cell proliferation index and vascular density were greater in adamantinomatous than in papillary tumors (22+/-6 versus 17+/-3, p=0.05; and 21+/-3 versus 17+/-3, p=0.037, respectively); they were neither related to recurrence nor to regrowth. No significant differences were found between adamantinomatous and papillary tumors regarding the presence of cytokeratin, laminin, CEA or glial fibrillary acidic protein (GFAP). Recurrence rate at 5 years was 59%. No relation was found between recurrence and adjuvant radiotherapy (AR). Residual tumor after surgery, whorl-like arrays (p=0.04) and immunoreactivity for p53 (p=0.022) were significantly related to recurrence/regrowth.

CONCLUSIONS

Residual tumor after surgery, immunoreactivity to p53 and presence of whorl-like arrays are associated to recurrence/regrowth of craniopharyngioma.

Craniopharyngiomas

Craniopharyngiomas are rare, mainly sellar/parasellar, epithelial tumors diagnosed during childhood or adult life. Histologically, two primary subtypes have been recognized (adamantinomatous and papillary) with an as yet, unclarified pathogenesis. They may present with a variety of manifestations (neurological, visual, and hypothalamo-pituitary). Despite their benign histological appearance, they often show an unpredictable growth pattern, which, combined with the lack of randomized studies, poses significant difficulties in the establishment of an optimal therapeutic protocol. This should focus on the prevention of recurrence(s), improvement of survival, reduction of the significant disease and treatment-related morbidity (endocrine, visual, hypothalamic, neurobehavioral, and cognitive), and preservation of the quality of life. Currently, surgical excision followed by external beam irradiation, in cases of residual tumor, is the main treatment option. Intracystic irradiation or bleomycin, stereotactic radiosurgery, or radiotherapy and systemic chemotherapy are alternative approaches; their place in the management plan remains to be assessed in adequately powered long-term trials. Apart from the type of treatment, the identification of clinical and imaging parameters that will predict patients with a better prognosis is difficult. The central registration of patients with these challenging tumors may provide correlates between treatments and outcomes and establish prognostic factors at the pathological or molecular level that may further guide us in the future.

Localized fibrous tumors (LFTs) of the pleura: clinical data, asbestos burden, and syntactic structure analysis applied to newly defined angiogenic/growth-regulatory effectors

This study was performed to add clinical data, to introduce new markers, and to perform syntactic structural analysis on localized fibrous tumors (LFTs) of the pleura. The material comprised clinical data and processed sections obtained from 36 patients. The results achieved from quantitative imaging techniques and syntactic structure analysis were correlated with clinical data, including patients' habits (smoking), asbestos exposure, survival, and tumor recurrence. The disease caused increasing chest pain and dyspnea in 47% of patients. Exposure to asbestos was noted in 13 out of 36 patients, whereas smoking posed no major risk factor. Two patients developed a recurrent tumor after 8 and 42 months, respectively; none of the other patients died of this tumor disease within the follow-up period of maximal 212 months. The cases were clearly discriminated from mesotheliomas by the marker profile. Frequent expression of accessible ligands for endogenous lectins galectins-1 and -3, the expression of the angiogenic macrophage migration inhibitory factor (MIF), and the dense vascularization intimate a functional relationship. The proliferation index (Nv) was computed to be 1.6% in line with the balance of galectin expression. Abnormal p53 was expressed in only 19.4% of the cases. The diagnosis of LFT can be aided by quantitative assessment of vimentin, CD34, MIF, vascularization, and proliferation. Considering the galectin network, differential expression was noted with preference to effectors limiting growth and aggressiveness.

Monitoring the Expression Profiles of Integrins and Adhesion/Growth-regulatory Galectins in Adamantinomatous Craniopharyngiomas: Their Ability to Regulate Tumor Adhesiveness to Surrounding Tissue and Their Contribution to Prognosis

OBJECTIVE

The purpose of this study was to identify biological markers that may be involved in the adhesiveness of craniopharyngiomas to optical chiasms and/or pituitary stalks.

METHODS

We determined the complete pattern of integrin expression in three craniopharyngiomas by means of a complementary deoxyribonucleic acid microarray. We quantitatively determined the levels of immunohistochemical expression of the different integrins in a series of 37 cases and the pattern of immunohistochemical expression of 10 extracellular matrix components (acting as integrin ligands) in 7 optical chiasms and 11 pituitary stalks. We also quantitatively (computer-assisted microscopy) determined the levels of immunohistochemical expression of galectin-1, -3, -4, -7, and -8 in 50 adamantinomatous craniopharyngiomas.

RESULTS

The present study shows that at both the ribonucleic acid and protein levels, adamantinomatous craniopharyngiomas express the alpha2, alpha6, alpha(v), beta1, beta5, and beta8 integrin subunits, whereas optical chiasms and pituitary stalks express vitronectin, thrombospondin, and various forms of collagens.

CONCLUSION

Our data suggest that at least part of the adhesiveness of craniopharyngiomas to the surrounding tissue, such as optical chiasms and pituitary stalks, could be explained by the interactions between alpha(2beta1) integrin expressed by craniopharyngiomas and collagens on the one hand, and vitronectin expressed by the surrounding tissue on the other hand. In addition, a Cox regression analysis has revealed that the levels of galectin-4 contribute significant information toward the delay in recurrence independently of surgical status.

Cathepsin B, D and K expression in adamantinomatous craniopharyngiomas relates to their levels of differentiation as determined by the patterns of retinoic acid receptor expression

AIMS

To investigate the potential predictive value of cathepsins B, D and K in a series of 51 adamantinomatous craniopharyngiomas. While almost always benign, craniopharyngiomas exhibit a high propensity to recur postsurgically and biological markers are therefore needed to predict their recurrence. We have previously demonstrated the potential predictive value of retinoic acid receptors (RARs) (Lefranc et al., J. Neurosurg. 2003; 98; 145-153).

METHODS AND RESULTS

Computer-assisted microscopy was used to determine quantitatively the immunohistochemical levels of expression of the alpha, beta and gamma RAR subtypes and cathepsins B, D and K. The levels of expression of cathepsin D and of cathepsin B correlated significantly with the levels of expression of RARbeta. The levels of expression of cathepsin K correlated significantly with the levels of expression of RARgamma.

CONCLUSIONS

Recurrent adamantinomatous craniopharyngiomas are characterized by low levels of RARbeta and high levels of RARgamma. The tendency to recurrence seems, at least partly, to relate to the fact that (i) craniopharyngiomas with low levels of RARbeta express low levels of cathepsin D, and (ii) craniopharyngiomas with high levels of RARgamma express high levels of cathepsin K.

Immunohistochemical analysis of the p53 family members in human craniopharyngiomas

Craniopharyngiomas are intracranial tumors that usually arise in the site around the sella turcica. They are composed of distinctive sheets of epithelial cells showing adamantinomatous or squamous-papillary histologic types. Because little is known about the tumorigenesis of craniopharyngiomas, we retrieved samples from 15 tumor cases to investigate the functional significance of the p53 family of transcription factors, which are known to be expressed in various human epithelia. Immunohistochemical analysis of these cases demonstrated similar expression profiles of p53 family members in the two histologic types of the tumor; i.e., strong nuclear expression of p63 was observed in all cell layers, and moderate to intense nuclear expression of p73 was observed in the basal cell layers. In contrast to p63 and p73, the reactivity of an archetypal tumor suppressor, p53, was occasional and weak in the two histologic types. Because p63 was widely expressed in the tumors, reverse transcription-polymerase chain reaction (RT-PCR) analysis was conducted to elucidate which spliced variant of p63 was expressed. The results showed that deltaNp63, lacking a terminal transactivation domain of p63, was the dominant isoform. Together with the reported evidence that the deltaNp63 isoform is highly expressed in human squamous-cell carcinomas, these data suggest that the cellular architecture characteristic of the expression of p53 family members may be required for the histogenesis of craniopharyngiomas, where deltaNp63 has a possible role in maintaining proliferative activity of the tumor cells, like squamous-cell carcinomas in other tissues.