Britta Heinze

TP53 germline mutations in adult patients with adrenocortical carcinoma.

CONTEXT Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome associated with germline mutations in TP53. According to the Chompret criteria for LFS, any patient with adrenocortical cancer (ACC), irrespective of age and family history, is at high risk for a TP53 germline mutation. However, whereas such mutations have been detected with high frequency in childhood ACC, a large cohort of adult patients with ACC has never been investigated for TP53 germline mutations. OBJECTIVE The aim of the study was to evaluate the prevalence of TP53 germline mutations in adult patients with ACC. SUBJECTS AND METHODS In 103 adult Caucasian patients with ACC, TP53 germline mutation analysis was performed. In patients with a TP53 germline mutation, tumor tissue was analyzed for loss of heterozygosity of TP53 and p53 immunohistochemistry. Family history and clinical course were also evaluated. RESULTS In four patients, a total of five TP53 germline mutations were found. Two mutations occurred in exon 10 (R337H and I332M, respectively), outside the hot spot region. Here, three mutations are described for the first time in ACC, and one, which occurred combined with a second mutation (R202C) on the same allele, has never been reported before in the context of LFS. This combined mutation was associated with a remarkable family history of ACC also affecting the mother and uncle of the index patient. In the 23 patients with ACC below the age of 40 yr, 13% (95% confidence interval, 3.7-32.9%) carried a TP53 germline mutation, whereas such mutations were rare in older patients with ACC. CONCLUSION Our findings indicate a need to revise the Chompret criteria. However, in younger adults (<40 yr old) with ACC, screening for TP53 germline mutations may be justified.

Investigating the Chemokine Receptor 4 as Potential Theranostic Target in Adrenocortical Cancer Patients.

Purpose Adrenocortical carcinoma (ACC) is a rare but aggressive endocrine tumor with limited treatment options. Preclinical studies confirmed overexpression of the chemokine receptor 4 (CXCR4) in this cancer type. This study aimed to analyze the role of CXCR4 imaging using 68Ga-pentixafor for ACC staging and selection of patients for CXCR4-directed endoradiotherapy. Methods Thirty patients with histologically proven advanced, metastasized ACC underwent 18F-FDG PET/CT and 68Ga-pentixafor PET/CT within a time interval of 3 ± 4 days to evaluate suitability for CXCR4-directed endoradiotherapy. Scans were analyzed retrospectively for visual extent of ACC and SUVmax/mean of the tumor lesions. 68Ga-pentixafor PET was compared with 18F-FDG PET, the reference imaging standard. All patients were rated for suitability of CXCR4-directed endoradiotherapy considering patient’s history, previous treatment, and CXCR4 expression of FDG-positive lesions compared with background activity within the same organ. Results All patients had lesions that were positive for both 18F-FDG and 68Ga-pentixafor PET and were rated as positive for disease. In 2 patients (7%), 68Ga-pentixafor PET identified more lesions compared with 18F-FDG PET. In 5 patients (17%) and 10 patients (33%), complementary and comparable information, respectively, was provided by dual-tracer imaging. In 13 patients (43%), more tumor lesions were identified by 18F-FDG PET compared with 68Ga-pentixafor PET. The 18F-FDG uptake of the malignant lesions was significantly higher (P < 0.01) than the SUVmax/mean for 68Ga-pentixafor. Overall, 70% of the patients were rated as suitable or potentially suitable for CXCR4-directed treatment. Conclusions 68Ga-pentixafor allows in vivo imaging of CXCR4 expression in patients with advanced ACC and may serve as companion diagnostic tool in selecting patients for potential CXCR4-directed endoradiotherapy. Seventy percent of the patients with advanced, metastasized ACC may be suitable for a CXCR4-directed treatment after failure of standard treatment options.

Less common genotype variants of TP53 polymorphisms are associated with poor outcome in adult patients with adrenocortical carcinoma

CONTEXT The Li-Fraumeni tumor syndrome is strongly associated with adrenocortical carcinoma (ACC) and is caused by germline mutations in TP53 in 70% of cases. Also, TP53 polymorphisms have been shown to influence both cancer risk and clinical outcome in several tumor entities. We, therefore, investigated TP53 polymorphisms in a cohort of adult patients with ACC. OBJECTIVE Evaluation of the role of TP53 polymorphisms in adult patients with ACC. SUBJECTS AND METHODS Peripheral blood for DNA extraction was collected from 72 ACC patients. Polymorphism analysis was carried out by amplification and sequencing of exons and adjacent intron sections of TP53. Results were correlated with clinical data and the distribution of the polymorphisms was compared with published Caucasian control groups. RESULTS Compared with control groups, genotype frequencies of analyzed TP53 polymorphisms among ACC patients were significantly different in three out of four polymorphisms: IVS2+38G>C (G/G, P=0.0248), IVS3ins16 (NoIns/NoIns, P<0.0001; NoIns/Ins, P<0.0001), and IVS6+62A>G (G/G, P<0.0001; G/A, P<0.0001). Overall, the survival of ACC patients, which harbored at least one of the less frequent genotype variants of four analyzed polymorphisms (n=23), was significantly inferior (median survival: 81.0 months in patients with the common homozygous genotypes vs 20.0 months in patients with the less frequent genotypes, HR 2.56, 95% CI 1.66-7.07; P=0.001). These results were confirmed by multivariable regression analysis (HR 2.84, 95% CI 1.52-7.17; P=0.037). CONCLUSION Some TP53 polymorphisms seem to influence overall survival in ACC patients. This effect was observed for a combination of polymorphic changes rather than for single polymorphisms.

Targeting CXCR4 (CXC Chemokine Receptor Type 4) for Molecular Imaging of Aldosterone-Producing Adenoma

Primary aldosteronism is the most frequent cause of secondary hypertension and is associated with increased morbidity and mortality compared with hypertensive controls. The central diagnostic challenge is the differentiation between bilateral and unilateral disease, which determines treatment options. Bilateral adrenal venous sampling, currently recommended for differential diagnosis, is an invasive procedure with several drawbacks, making it desirable to develop novel noninvasive diagnostic tools. When investigating the expression pattern of chemokine receptors by quantitative real-time polymerase chain reaction and immunohistochemistry, we observed high expression of CXCR4 (CXC chemokine receptor type 4) in aldosterone-producing tissue in normal adrenals, adjacent adrenal cortex from adrenocortical adenomas, and in aldosterone-producing adenomas (APA), correlating strongly with the expression of CYP11B2 (aldosterone synthase). In contrast, CXCR4 was not detected in the majority of nonfunctioning adenomas that are frequently found coincidently. The specific CXCR4 ligand 68Ga-pentixafor has recently been established as radiotracer for molecular imaging of CXCR4 expression and showed strong and specific binding to cryosections of APAs in our study. We further investigated 9 patients with primary aldosteronism because of APA by 68Ga-pentixafor–positron emission tomography. The tracer uptake was significantly higher on the side of increased adrenocortical aldosterone secretion in patients with APAs compared with patients investigated by 68Ga-pentixafor–positron emission tomography for other causes. Molecular imaging of aldosterone-producing tissue by a CXCR4-specific ligand may, therefore, be a highly promising tool for noninvasive characterization of patients with APAs.

Prevalence of Malignancies in Patients With Primary Aldosteronism

CONTEXT Primary aldosteronism (PA) is the most common cause of secondary hypertension. Aldosterone excess can cause DNA damage in vitro and in vivo. Single case reports have indicated a coincidence of PA with renal cell carcinoma and other tumors. However, the prevalence of benign and malignant neoplasms in patients with PA has not yet been studied. PATIENTS AND DESIGN In the multicenter MEPHISTO study, the prevalence of benign and malignant tumors was investigated in 335 patients with confirmed PA. Matched hypertensive subjects from the population-based Study of Health in Pomerania cohort served as controls. RESULTS Of the 335 PA patients, 119 (35.5%) had been diagnosed with a tumor at any time, and 30 had two or more neoplasms. Lifetime malignancy occurrence was reported in 9.6% of PA patients compared to 6.0% of hypertensive controls (P = .08). PA patients with a history of malignancy had higher baseline aldosterone levels at diagnosis of PA (P = .009), and a strong association between aldosterone levels and the prevalence of malignancies was observed (P = .03). In total, 157 neoplasms were identified in the PA patients; they were benign in 61% and malignant in 25% of the cases (14% of unknown dignity). Renal cell carcinoma was diagnosed in five patients (13% of all malignancies) and was not reported in controls CONCLUSION Compared to hypertensive controls, the prevalence of malignancies was positively correlated with aldosterone levels, tended to be higher in PA patients, but did not differ significantly.

Eya4 Induces Hypertrophy via Regulation of p27kip1

Background—E193, a heterozygous truncating mutation in the human transcription cofactor Eyes absent 4 (Eya4), causes hearing impairment followed by dilative cardiomyopathy. Methods and Results—In this study, we first show Eya4 and E193 alter the expression of p27kip1 in vitro, suggesting Eya4 is a negative regulator of p27. Next, we generated transgenic mice with cardiac-specific overexpression of Eya4 or E193. Luciferase and chromatin immunoprecipitation assays confirmed Eya4 and E193 bind and regulate p27 expression in a contradictory manner. Activity and phosphorylation status of the downstream molecules casein kinase-2&agr; and histone deacetylase 2 were significantly elevated in Eya4- but significantly reduced in E193-overexpressing animals compared with wild-type littermates. Magnetic resonance imaging and hemodynamic analysis indicate Eya4-overexpression results in an age-dependent development of hypertrophy already under baseline conditions with no obvious functional effects, whereas E193 animals develop onset of dilative cardiomyopathy as seen in human E193 patients. Both cardiac phenotypes were aggravated on pressure overload. Finally, we identified a new heterozygous truncating Eya4 mutation, E215, which leads to similar clinical features of disease and a stable myocardial expression of the mutant protein as seen with E193. Conclusions—Our results implicate Eya4/Six1 regulates normal cardiac function via p27/casein kinase-2&agr;/histone deacetylase 2 and indicate that mutations within this transcriptional complex and signaling cascade lead to the development of cardiomyopathy.