Concetta Sciammarella

The evolving field of kinase inhibitors in thyroid cancer

Most of the genetic events implicated in the pathogenesis of thyroid cancer (TC) involve genes with kinase activity. Thus, kinase inhibitors (KIs) are very relevant in this field. KIs are considered the most suitable treatment for patients with iodine-refractory differentiated TC; these patients comprise the subgroup with the poorer prognosis. To date, only sorafenib has been approved for this indication, but promising results have been reported with several other KIs. In particular, lenvatinib has demonstrated excellent efficacy, with both progression-free survival and objective tumour response being better than with sorafenib. Despite being considered to be well tolerated, both sorafenib and lenvatinib have shown a remarkable toxicity, which has led to dose reductions in the majority of patients and to treatment discontinuation in a significant proportion of cases. The role of KIs in differentiated TC may be revolutionised by the finding that selumetinib may restore a clinical response to radioactive iodine (RAI). Vandetanib and cabozantinib have been approved for the treatment of advanced, progressive medullary TC (MTC). Nevertheless, the toxicity of both compounds suggests their selective use in those patients with strong disease progression. Treatment with the mTOR-inhibitor everolimus, alone or in combination with somatostatin analogues, should be studied in metastatic MTC patients with slow progression of disease, these representing the vast majority of patients. KIs did not significantly impact on the clinical features of anaplastic TC (ATC).

Germline polymorphisms of the VEGF-pathway predict recurrence in non-advanced differentiated thyroid cancer

Context: Tumor angiogenesis is determined by host genetic background rather than environment. Germline single nucleotide polymorphisms (SNPs) of the vascular endothelial growth factor (VEGF) pathway have demonstrated prognostic value in different tumors. Objectives: Our main objective was to test the prognostic value of germline SNPs of the VEGF pathway in nonadvanced differentiated thyroid cancer (DTC). Secondarily, we sought to correlate analyzed SNPs with microvessel density (MVD). Design: Multicenter, retrospective, observational study. Setting: Four referral centers. Patients: Blood samples were obtained from consecutive DTC patients. Genotyping was performed according to the TaqMan protocol, including 4 VEGF-A (−2578C>A, −460T>C, +405G>C, and +936C>T) and 2 VEGFR-2 (+1192 C>T and +1719 T>A) SNPs. MVD was estimated by means of CD34 staining. Outcome Measures: Rate of recurrent structural disease/disease-free survival (DFS). Difference in MVD between tumors from patients with different genotype. Results: Two hundred four patients with stage I–II DTC (mean follow-up, 73 ± 64 months) and 240 patients with low- to intermediate-risk DTC (mean follow-up, 70 ± 60 months) were enrolled. Two “risk” genotypes were identified by combining VEGF-A SNPs −2578 C>A, −460 T>C, and +405 G>C. The ACG homozygous genotype was protective in both stage I–II (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.01 to 1.43; P = 0.018) and low- to intermediate-risk (OR, 0.14; 95% CI, 0.01 to 1.13; P = 0.035) patients. The CTG homozygous genotype was significantly associated with recurrence in stage I–II (OR, 5.47; 95% CI, 1.15 to 26.04; P = 0.018) and was slightly deleterious in low- to intermediate-risk (OR, 3.39; 95% CI, 0.8 to 14.33; P = 0.079) patients. MVD of primary tumors from patients harboring a protective genotype was significantly lower (median MVD, 76.5 ± 12.7 and 86.7 ± 27.9, respectively; P = 0.024). Conclusions: Analysis of germline VEGF-A SNPs could empower a prognostic approach to DTC.

Prognostic role of the CDNK1B V109G polymorphism in multiple endocrine neoplasia type 1.

CDKN1B encodes the cyclin‐dependent kinase inhibitor p27/Kip1. CDKN1B mutations and polymorphisms are involved in tumorigenesis; specifically, the V109G single nucleotide polymorphism has been linked to different tumours with controversial results. Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant syndrome, characterized by the development of different types of neuroendocrine tumours and increased incidence of other malignancies. A clear genotype–phenotype correlation in MEN1 has not been established yet. In this study, we assessed whether the CDKN1B V109G polymorphism was associated with the development of aggressive tumours in 55 consecutive patients affected by MEN1. The polymorphism was investigated by PCR amplification of germline DNA followed by direct sequencing. Baseline and follow‐up data of tumour types and their severity were collected and associated with the genetic data. MEN1‐related aggressive and other malignant tumours of any origin were detected in 16.1% of wild‐type and 33.3% of polymorphism allele‐bearing patients (P = NS). The time interval between birth and the first aggressive tumour was significantly shorter in patients with the CDKN1B V109G polymorphism (median 46 years) than in those without (median not reached; P = 0.03). Similarly, shorter was the time interval between MEN1 diagnosis and age of the first aggressive tumour (P = 0.02). Overall survival could not be estimated as 96% patients were still alive at the time of the study. In conclusion, CDKN1B V109G polymorphism seems to play a role in the development of aggressive tumours in MEN1.

CXCR4/CXCL12/CXCR7 axis is functional in neuroendocrine tumors and signals on mTOR

Objective To evaluate the possible crosstalk between C-X-C chemokine receptor 4 (CXCR4)/C-X-C motif chemokine 12 (CXCL12)/C-X-C chemokine receptor 7 (CXCR7) axis with the mammalian target of rapamycin (mTOR) pathway in neuroendocrine tumors (NETs). Methods Sixty-one human NETs were included into the study. CXCR4/CXCL12/CXCR7 axis and mTOR pathway were assessed by qRT-PCR and immunohistochemistry (IHC). The effect of mTOR inhibitor, RAD001, was evaluated on CXCR4 pathway through proliferation and p-Erk and p-AKT induction. Results: CXCR4/CXCL12/CXCR7 axis and p-mTOR were found to be active and correlated with grading, Ki67 index and tumor stage. mTOR pathway activation significantly correlated with poor prognosis. In human NET cells, CXCL12 induced mTOR signalling while AMD3100 (CXCR4-antagonist) impaired it. The mTOR-antagonist, RAD001, impaired the CXCL12-dependent induction of CXCR4 downstream effectors. Combination of AMD3100 and RAD001 potentiate cell growth inhibition. Conclusions CXCR4/CXCL12/CXCR7 axis is active in NETs and signals on mTOR. CXCR4 might be considered a prognostic factor in NETs. Combined treatment with AMD3100 and RAD001 may provide clinical benefits in NET patients with drug-resistant.

Second-line sunitinib as a feasible approach for iodine-refractory differentiated thyroid cancer after the failure of first-line sorafenib

About 5 % of patients with differentiated thyroid cancer (DTC) show RAI-refractory disease, thus having a poor prognosis [1, 2]. Tyrosine-kinase inhibitors (TKIs) has represented a revolution in the management of iodinerefractory DTC [3]. Sorafenib has been the most studied TKI in this field, showing encouraging results in several retrospective and phase II studies [4–8]. Effectiveness of sorafenib in RAI-refractory DTC has been definitely demonstrated in the phase III trial DECISION, where a significant improvement of median progression-free survival (PFS) in the treatment group, as compared with placebo, was reported (10.8 vs 5.8 months; HR 0.58, 95 % CI 0.45–0.75, p\ 0.0001) [9]. Following this finding, sorafenib has became the first TKI approved by the US Food and Drug Administration (FDA) for the treatment of RAIrefractory DTC. Given that the study cohort of the DECISION trial included only TKIs-naive patients, sorafenib can be fully considered the first-line systemic therapy for this clinical setting. Nevertheless, sorafenib has some crucial limits. As reported for all TKIs, it is never curative and has a temporally limited effect. Furthermore, sorafenib induced the development of adverse events leading to drug withdrawal in about 20 % of patients [9]. To date, clear indications about management of RAI-refractory DTC patients after the failure of first-line sorafenib are lacking. Sunitinib is a TKI with a pharmacodynamic profile similar to sorafenib, but broader, targeting RET, c-Kit, VEGFR1, -2, PDGFR-a and -b [10]. Despite few studies have been performed so far, sunitinib seems to be effective for the treatment of RAI-refractory DTC [11–14]. Furthermore, several trials of renal cancer have showed that sunitinib was effective in achieving clinical benefit in the majority of patients who experienced the failure of first-line sorafenib [15], even inducing a longer median PFS. Hence, sunitinib may represent a feasible option as salvage treatment after sorafenib failure also in iodine-refractory DTC. Here we report clinical histories of 3 patients (followed at Federico II University, Department of Clinical Medicine and Surgery, Section of Endocrinology, Naples) with iodinerefractory DTC who were treated with sunitinib after the failure of first-line sorafenib.

Chromogranin A as circulating marker for diagnosis and management of neuroendocrine neoplasms: more flaws than fame

Owing to the heterogeneity of neuroendocrine neoplasms (NENs), the availability of reliable circulating markers is critical for improving diagnostics, prognostic stratification, follow-up and definition of treatment strategy. This review is focused on chromogranin A (CgA), a hydrophilic glycoprotein present in large dense core vesicles of neuroendocrine cells. Despite being long identified as the most useful NEN-related circulating marker, clinical application of CgA is controversial. CgA assays still lack standardization, thus hampering not only clinical management but also the comparison between different analyses. In the diagnostic setting, clinical utility of CgA is limited as hampered by (a) the variety of oncological and non-oncological conditions affecting marker levels, which impairs specificity; (b) the fact that 30-50% of NENs show normal CgA, which impairs sensitivity. Regarding the prognostic phase, there is prospective evidence which demonstrates that advanced NENs secreting CgA have poorer outcome, as compared with those showing non-elevated marker levels. Although the identification of cut-offs allowing a proper risk stratification of CgA-secreting patients has not been performed, this represents the most important clinical application of the marker. By contrast, based on prospective studies, the trend of elevated circulating CgA does not represent a valid indicator of morphological evolution and has therefore no utility for the follow-up phase. Ultimately, current knowledge about the role of the marker for the definition of treatment strategy is poor and is limited by the small number of available studies, their prevalent retrospective nature and the absence of control groups of untreated subjects.

Epigenetics in medullary thyroid cancer: From pathogenesis to targeted therapy

BACKGROUND Medullary thyroid carcinoma (MTC) originates from the parafollicular C cells of the thyroid gland. Mutations of the RET proto-oncogene are implicated in the pathogenesis of MTC. Germline activating mutations of this gene have been reported in about 88-98% of familial MTCs, while somatic mutations of RET gene have been detected in about 23-70% of sporadic forms. Although these genetic events are well characterized, much less is known about the role of epigenetic abnormalities in MTC. OBJECTIVE The present review reports a detailed description of epigenetic abnormalities (DNA methylation, histone modifications and miRNA profile), probably involved in the pathogenesis and progression of MTC. METHODS A systematic review was performed using Pubmed and Google patents databases. RESULTS We report the current understanding of epigenetic patterns in MTC and discuss the potential use of current knowledge in designing novel therapeutic strategies through epigenetic drugs, focusing on recent patents in this field. CONCLUSION Taking into account the reversibility of epigenetic alterations and the recent development in this field, epigenetic therapy may emerge for clinical use in the near future for patients with advanced MTC.

Circulating tumor cells and mirnas as prognostic markers in neuroendocrine neoplasms

The prognosis of neuroendocrine neoplasms (NENs) is widely variable and has been shown to associate with several tissue- and blood-based biomarkers in different settings. The identification of prognostic factors predicting NEN outcome is of paramount importance to select the best clinical management for these patients. Prognostic markers have been intensively investigated, also taking advantage of the most modern techniques, in the perspective of personalized medicine and appropriate resource utilization. This review summarizes the available data on the possible role of circulating tumor cells and microRNAs as prognostic markers in NENs.

Potential role of cinacalcet hydrochloride in sporadic primary hyperparathyroidism without surgery indication

Primary hyperparathyroidism (PHPT) is characterized by the chronic elevation of serum calcium (Ca) levels induced by a long-standing increase of PTH concentrations [1]. Surgical removal of the hyperfunctioning parathyroid tissue represents the only curative approach in this field [2, 3]. Besides symptomatic forms [4], parathyroidectomy (PTx) is indicated in asymptomatic PHPT subjects who have a more advanced disease status. According to the latest update [5], criteria for surgical intervention in asymptomatic PHPT are as follows: (a) serum Ca levels [ 1 mg/dl (0.25 mmol/l) above upper limits of normal; (b) a calculated creatinine clearance \ 60 ml/min; (c) a BMD T score of -2.5 or less at any site or previous fragility fracture (or both); or (d) age \ 50 years. Nevertheless, the management of those patients not having surgery indication is still a point of discussion. Indeed, the 15-year observational study by Rubin et al. [3] has found disease progression in 38 % of this subgroup. This suggests that current surgery criteria are effective in identifying a population with more advanced disease, but cannot effectively predict disease evolution. Cinacalcet hydrochloride is an allosteric modulator of the Ca-sensing receptor (CaSR), where it acts by mimicking an increase in levels of extracellular Ca [6]. In PHPT, this should result in the suppression of PTH secretion [7]. Cinacalcet has been approved in Europe and USA for the management of moderate-to-severe hypercalcemia in patients with PHPT who fulfill surgery indication but are unable to undergo parathyroidectomy [8]. Hence, careful monitoring represents the only indication in PHPT without surgery criteria. We here reported a retrospective, single-center analysis of sporadic PHPT patients who were subjected to treatment with cinacalcet, independently of the surgical indication. Our objective was to provide preliminary insights about the role of cinacalcet in PHPT patients without surgery indication by performing a comparative assessment with PHPTs fitting surgery criteria.

Expression of p40 (∆Np63) protein in meningiomas, an unexpected finding: immunohistochemical study and evaluation of its possible prognostic role

According to the 2007 WHO (World Health Organization) Classification, meningiomas are divided into three grades of malignancy, with different recurrence rate, based exclusively on histopathological parameters. Loss/reduction of PgR (Progesterone Receptor) expression and increased Ki67 L.I. (Labeling Index) have been proven as possible prognostic factors able to predict the relapse of the disease. However, they sometimes result unreliable, especially when discordant. p40 is the short form of the p53 homologue gene p63, also named ∆Np63, and its antibody has recently been introduced as a highly specific diagnostic marker of the squamous cell carcinoma of the lung. Nevertheless its expression has been found in many other unconventional sites (e.g. placenta, urotheluim, etc). Herein we assessed the immuno-expression of p40 protein in a series of 72 meningiomas (35 grade I and 37 grade II) and analyzed its correlation with clinicopathological parameters, overall survival and recurrence free interval. We found that a high p40 score correlated with high histological grade, presence of recurrence, increased Ki67 L.I. and loss/reduction of PgR signal. Moreover, a higher expression of p40 was shown to be a significant prognostic factor for the development of recurrences and resulted a prognostic independent variable in multivariate analysis. Overall, for the first time, we investigated the expression of p40 protein in meningiomas and explored its usefulness as prognostic marker in addition to PgR and Ki67 L.I.