Clinical relevance of gene mutations and rearrangements in advanced differentiated thyroid cancer.

BACKGROUND: Tumor genotyping is becoming crucial to optimize the clinical management of patients with advanced differentiated thyroid cancer (DTC); however, its implementation in clinical practice remains undefined. We herein report our single-center experience on molecular advanced DTC testing by next-generation sequencing approach, to better define how and when tumor genotyping can assist clinical decision making. MATERIALS AND METHODS: We retrospectively collected data on all adult patients with advanced DTC who received molecular profiling at the IRCSS Sant'Orsola-Malpighi Hospital from 2008 to 2022. The genetic alterations were correlated with radioactive iodide refractory (RAI-R), RAI uptake/disease status, and time to RAI resistance (TTRR) development. RESULTS: A significant correlation was found between RAI-R development and genetic alterations (P = 0.0001). About 48.7% of RAI-R cases were positive for TERT/TP53 mutations (as both a single event and comutations with other driver gene alterations, such as BRAF mutations, RAS mutations, or gene fusions), while the great majority of RAI-sensitive cases carried gene fusions (41.9%) or were wild type (WT; 41.9%). RAI uptake/disease status and time to TTRR were significantly associated with genetic alterations (P = 0.0001). In particular, DTC with TERT/TP53 mutations as a single event or as comutations displayed a shorter median TTRR of 35.4 months (range 15.0-55.8 months), in comparison to the other molecular subgroups. TERT/TP53 mutations as a single event or as comutations remained independently associated with RAI-R after Cox multivariate analysis (hazard ratio 4.14, 95% CI 1.51-11.32; P = 0.006). CONCLUSIONS: Routine testing for genetic alterations should be included as part of the clinical workup, for identifying both the subset of more aggressive tumors and the subset of tumors harboring actionable gene fusions, thus ensuring the appropriate management for all patients with advanced DTC.

HER2 Overexpression and Cytogenetical Patterns in Canine Mammary Carcinomas.

Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase receptor that promotes tumor cell growth and is implicated in the pathogenesis of human breast cancer. The role of HER2 in canine mammary carcinomas (CMCs) is not clear. Therefore, this study aimed to examine the protein expression and cytogenetic changes of HER2 and their correlation with other clinical-pathological parameters in CMC. We retrospectively selected 112 CMCs. HER2, ER, and Ki67 were assessed by immunohistochemistry. HER2 antibody validation was investigated by immunoblot on mammary tumor cell lines. Fluorescence in situ hybridization (FISH) was performed with probes for HER2 and CRYBA1 (control gene present on CFA9). HER2 protein overexpression was detected in 15 carcinomas (13.5%). A total of 90 carcinomas were considered technically adequate by FISH, and 8 out of 90 CMC (10%) were HER2 amplified, 3 of which showed a cluster-type pattern. HER2 overexpression was correlated with an increased number of HER2 gene copies (p = 0.01; R = 0.24) and overall survival (p = 0.03), but no correlation with ER, Ki67, grade, metastases, and tumor-specific survival was found. Surprisingly, co-amplification or polysomy was identified in three tumors, characterized by an increased copy number of both HER2 and CRYBA1. A morphological translocation-fusion pattern was recognized in 20 carcinomas (22%), with a co-localized signal of HER2 and CRYBA1. HER2 is not associated with clinical-pathological parameters of increased malignancy in canine mammary tumors, but it is suitable for studying different amplification patterns.

Pathological spectrum in recurrences of glioblastoma multiforme.

INTRODUCTION: Glioblastoma (GBM) is the most frequent primary malignant brain tumour. Despite advances in treatment its prognosis remains poor. Histological features of GBM are well known. On the contrary histological description of recurrences is still not available. The aim of this study was to describe the morphological, immunohistochemical and molecular features of recurrent GBMs. METHODS: 25 recurrent GBMs, diagnosed after 2005, were collected. All patients had undergone an adjuvant treatment regimen (temozolomide and/or radiotherapy). All cases were immunostained using anti-GFAP, Olig2 and Nogo-A antisera. MGMT and IDH1 status was reassessed. Features of the recurrences were compared with those of primary GBMs, time of recurrence and survival. RESULTS: Recurrences were divided morphologically into three groups: 1) recurrences displaying the same features of primary GBM, were highly cellular, had the fastest progression and the worst prognosis; 2) recurrences changing dramatically morphological appearance, had a slightly longer survival, 3) poorly cellular recurrences, with sparse neoplastic cells intermingled with reactive and necrotic tissue, displayed the slowest progression and longer survival. MGMT and IDH1 status remained unchanged between primary tumours and recurrences. DISCUSSION: GBM histological subtypes display different reactions to adjuvant treatments, offering a possible role in predicting different recurrence and survival time.

Insulin-like growth factor receptor 1 (IGF1R) expression and survival in surgically resected non-small-cell lung cancer (NSCLC) patients.

BACKGROUND: The purpose of this study is to investigate the prognostic role of insulin-like growth factor receptor 1 (IGF1R) expression in surgically resected non-small-cell lung cancer (NSCLC). Patient characteristics and methods: This retrospective study was conducted in 369 stage I-II-IIIA, surgically resected, NSCLC patients. Patients exposed to anti-epidermal growth factor receptor (EGFR) agents were excluded. IGF1R expression was evaluated by immunohistochemistry in tissue microarray sections. RESULTS: A positive IGF1R expression (score > or = 100) was observed in 282 cases (76.4%) and was significantly associated with squamous cell histology (P = 0.04) and with grade III differentiation (P = 0.02). No difference in survival was observed between the positive and negative group when score 100 was used as cut-off for discriminating a positive versus a negative IGF1R result (52 versus 48 months, P = 0.99) or when median value of IGF1R expression was used (45 versus 55 months, P = 0.36). No difference in survival was observed between IGF1R-positive and -negative patients in a subgroup of stage I-II adenocarcinoma (n = 137) with known EGFR mutation and copy number status. CONCLUSIONS: IGF1R expression does not represent a prognostic factor in resected NSCLC patients. Patients with squamous cell carcinoma overexpress IGF1R more frequently than patients with nonsquamous histology, justifying the different sensitivity to anti-IGF1R agents observed in clinical trials.

Primary resistance to cetuximab therapy in EGFR FISH-positive colorectal cancer patients.

The impact of KRAS mutations on cetuximab sensitivity in epidermal growth factor receptor fluorescence in situ hybridisation-positive (EGFR FISH+) metastatic colorectal cancer patients (mCRC) has not been previously investigated. In the present study, we analysed KRAS, BRAF, PI3KCA, MET, and IGF1R in 85 mCRC treated with cetuximab-based therapy in whom EGFR status was known. KRAS mutations (52.5%) negatively affected response only in EGFR FISH+ patients. EGFR FISH+/KRAS mutated had a significantly lower response rate (P=0.04) than EGFR FISH+/KRAS wild type patients. Four EGFR FISH+ patients with KRAS mutations responded to cetuximab therapy. BRAF was mutated in 5.0% of patients and none responded to the therapy. PI3KCA mutations (17.7%) were not associated to cetuximab sensitivity. Patients overexpressing IGF1R (74.3%) had significantly longer survival than patients with low IGF1R expression (P=0.006), with no difference in response rate. IGF1R gene amplification was not detected, and only two (2.6%) patients, both responders, had MET gene amplification. In conclusion, KRAS mutations are associated with cetuximab failure in EGFR FISH+ mCRC, even if it does not preclude response. The rarity of MET and IGF1R gene amplification suggests a marginal role in primary resistance. The potential prognostic implication of IGF1R expression merits further evaluation.

Specific microRNAs are downregulated in human thyroid anaplastic carcinomas.

Thyroid carcinomas comprise a broad spectrum of tumors with different clinical behaviors. On the one side, there are occult papillary carcinomas (PTC), slow growing and clinically silent, and on the other side, rapidly growing anaplastic carcinomas (ATC), which are among the most lethal human neoplasms. We have analysed the microRNA (miR) profile of ATC in comparison to the normal thyroid using a microarray (miRNACHIP microarray). By this approach, we found an aberrant miR expression profile that clearly differentiates ATC from normal thyroid tissues and from PTC analysed in previous studies. In particular, a significant decrease in miR-30d, miR-125b, miR-26a and miR-30a-5p was detected in ATC in comparison to normal thyroid tissue. These results were further confirmed by northern blots, quantitative reverse transcription-PCR analyses and in situ hybridization. The overexpression of these four miRs in two human ATC-derived cell lines suggests a critical role of miR-125b and miR-26a downregulation in thyroid carcinogenesis, since a cell growth inhibition was achieved. Conversely, no effect on cell growth was observed after the overexpression of miR-30d and miR-30a-5p in the same cells. In conclusion, these data indicate a miR signature associated with ATC and suggest the miR deregulation as an important event in thyroid cell transformation.

Gefitinib in patients with progressive high-grade gliomas: a multicentre phase II study by Gruppo Italiano Cooperativo di Neuro-Oncologia (GICNO).

To investigate the role of gefitinib in patients with high-grade gliomas (HGGs), a phase II trial (1839IL/0116) was conducted in patients with disease recurrence following surgery plus radiotherapy and first-line chemotherapy. Adult patients with histologically confirmed recurrent HGGs following surgery, radiotherapy and first-line chemotherapy, were considered eligible. Patients were treated with gefitinib (250 mg day(-1)) continuously until disease progression. The primary end point was progression-free survival at 6 months progression-free survival at 6 months (PFS-6). Tissue biomarkers (epidermal growth factor receptor (EGFR) gene status and expression, phosphorylated Akt (p-Akt) expression) were assessed. Twenty-eight patients (median age, 55 years; median ECOG performance status, 1) were enrolled; all were evaluable for drug activity and safety. Sixteen patients had glioblastoma, three patients had anaplastic oligodendrogliomas and nine patients had anaplastic astrocytoma. Five patients (17.9%, 95% CI 6.1-36.9%) showed disease stabilisation. The overall median time to progression was 8.4 (range 2-104+) weeks and PFS-6 was 14.3% (95% CI 4.0-32.7%). The median overall survival was 24.6 weeks (range 4-104+). No grade 3-4 gefitinib-related toxicity was found. Gefitinib showed limited activity in patients affected by HGGs. Epidermal growth factor receptor expression or gene status, and p-Akt expression do not seem to predict activity of this drug.

Novel germline variants identified in the inner mitochondrial membrane transporter TIMM44 and their role in predisposition to oncocytic thyroid carcinomas.

Familial Non-Medullary Thyroid Carcinoma (fNMTC) represents 3-7% of all thyroid tumours and is associated with some of the highest familial risks among all cancers, with an inheritance pattern compatible with an autosomal dominant model with reduced penetrance. We previously mapped a predisposing locus, TCO (Thyroid tumour with Cell Oxyphilia) on chromosome 19p13.2, for a particular form of thyroid tumour characterised by cells with an abnormal proliferation of mitochondria (oxyphilic or oncocytic cells). In the present work, we report the systematic screening of 14 candidate genes mapping to the region of linkage in affected TCO members, that led us to identify two novel variants respectively in exon 9 and exon 13 of TIMM44, a mitochondrial inner membrane translocase for the import in the mitochondria of nuclear-encoded proteins. These variants were co-segregating with the TCO phenotype, were not present in a large group of controls and were predicted to negatively affect the protein (exon 9 change) or the transcript (exon 13 change). Functional analysis was performed in vitro for both changes and although no dramatic loss of function effects were identified for the mutant alleles, subtler effects might still be present that could alter Timm44 function and thus promote oncocytic tumour development. Thus we suggest that TIMM44 should be considered for further studies in independent samples of affected individuals with TCO.

Insulin-like growth factor receptor 1 (IGFR-1) is significantly associated with longer survival in non-small-cell lung cancer patients treated with gefitinib.

BACKGROUND: The aim of the study was to assess whether loss of PTEN and expression of insulin-like growth factor receptor 1 (IGFR-1) could be responsible for intrinsic resistance to the tyrosine kinase inhibitor (TKI) gefitinib. PATIENTS AND METHODS: One hundred and twenty-four gefitinib-treated patients with advanced non-small-cell lung cancer (NSCLC) were analyzed for PTEN and IGFR-1 expression by immunohistochemistry. RESULTS: IGFR-1 was evaluated in 77 patients and resulted positive in 30 (39.0%). IGFR-1 expression was not significantly associated with clinical or biological characteristics. No difference in response to gefitinib treatment (16.7% versus 12.8%, P = 0.74) and time to progression (2.6 versus 3.06 months, P = 0.83) was observed between IGFR-1+ and IGFR-1-. Median survival was significantly longer in IGFR-1+ patients (17.8 versus 7.3 months, P = 0.013). PTEN expression was successfully evaluated in 93 cases. Loss of PTEN was detected in 19 tumors (20.4%) and was not associated with any clinical or biological characteristic. No difference in terms of response, time to progression and survival was observed between PTEN+ and PTEN- patients. In multivariable analysis IGFR-1 negative status was significantly associated with higher risk of death (hazard ratio 2.21, P = 0.012). CONCLUSIONS: IGFR-1 expression and loss of PTEN are not associated with intrinsic resistance to gefitinib. Clinical relevance of these two biomarkers as determinant for acquired resistance, and the prognostic role of IGFR-1 expression in patients not exposed to TKIs should be evaluated further.

BRAF T1796A transversion mutation in various thyroid neoplasms.

A high prevalence of activating mutation of the B type Raf kinase (BRAF) gene was recently reported in papillary thyroid cancer (PTC). However, the frequency of this mutation in several other types of thyroid neoplasms was not thoroughly investigated. In the present study, in addition to PTC, we evaluated various thyroid tumor types for the most common BRAF T1796A mutation by direct genomic DNA sequencing. We found a high and similar frequency (45%) of the BRAF T1796A mutation in two geographically distinct PTC patient populations: one composed of sporadic cases from North America, and the other from Kiev, Ukraine, that included individuals who were exposed to the Chernobyl nuclear accident. In contrast, we found BRAF mutation in only 20% of anaplastic thyroid cancers and no mutation in medullary thyroid cancers and benign thyroid hyperplasia. We also confirmed previous reports that the BRAF T1796A mutation did not occur in benign thyroid adenomas and follicular thyroid cancers. Specific analysis of the Ukraine patients with confirmed history of radiation exposure failed to show a higher incidence of BRAF mutation. Our results suggest that frequent occurrence of BRAF mutation is inherently associated with PTC, irrespective of geographic origin, and is apparently not a radiation-susceptible mutation. The lack or low prevalence of BRAF mutation in other thyroid neoplasms is consistent with the notion that other previously defined genetic alterations on the same signaling pathway are sufficient to cause tumorigenesis in most thyroid neoplasms.

Cigarette smoking and risk of non-Hodgkin lymphoma subtypes among women.

Previous studies of the relationship between cigarette smoking and non-Hodgkin lymphoma (NHL) have yielded conflicting results, perhaps because most studies have evaluated the risk for all NHL subtypes combined. Data from a population-based case-control study conducted among women in Connecticut were used to evaluate the impact of cigarette smoking on the risk of NHL by histologic type, tumour grade, and immunologic type. A total of 601 histologically confirmed, incident cases of NHL and 718 population-based controls provided in-person interviews. A standardised, structured questionnaire was used to collect information on each subject's current smoking status, age at initiation, duration and intensity of smoking, and cumulative lifetime exposure to smoking. Our data suggest that cigarette smoking does not alter the risk of all NHL subtypes combined. However, increased risk of follicular lymphoma appears to be associated with increased intensity and duration of smoking, and cumulative lifetime exposure to smoking. Compared with nonsmokers, women with a cumulative lifetime exposure of 16-33 pack-years and 34 pack-years or greater experience 50% increased risk (OR=1.5, 95% CI 0.9-2.5) and 80% increased risk (OR=1.8, 95% CI 1.1-3.2), respectively, of follicular lymphoma (P for linear trend=0.05). Our study findings are consistent with several previous epidemiologic studies suggesting that cigarette smoking increases the risk of follicular lymphoma. This research highlights the importance of distinguishing between NHL subtypes in future research on the aetiology of NHL.

Validity of thyroglobulin mRNA assay in peripheral blood of postoperative thyroid carcinoma patients in predicting tumor recurrences varies according to the histologic type: results of a prospective study.

BACKGROUND: The objective of the current study was to evaluate the ability of serum thyroglobulin mRNA assay in detecting local and distant recurrences in patients who underwent surgery for thyroid carcinoma. METHODS: Sixty-six consecutive patients were studied. One year after surgery, all patients underwent clinical examination and radioiodine scan, and a blood sample was taken for serum thyroglobulin (Tg) immunoassay and for Tg mRNA assay by reverse transcription-polymerase chain reaction (RT-PCR). RNA was extracted from cells pellet and analyzed by RT-PCR using specific primers for Tg. RESULTS: Thyroglobulin mRNA was detected in 14 (21.2%) patients. Seven of 16 patients with elevated serum thyroglobulin had detectable Tg mRNA. Six of 30 (20%) patients with absent or minimal thyroid bed radioiodine uptake and 7 of 36 (19.4%) patients with significant thyroid bed uptake had detectable Tg mRNA. Among 5 patients with metastases, only 1 (20%) showed circulating Tg mRNA. Overall, the sensitivity, specificity, and accuracy of Tg mRNA assay in predicting the results of the (131)I whole-body scans was 25%, 80%, 25%, respectively. Fourteen of 53 (26.4%) patients with papillary thyroid carcinoma had detectable thyroglobulin mRNA whereas none of the patients with other histologic types did. The sensitivity, specificity, and accuracy of Tg mRNA assay in predicting the results of the (131)I whole-body scans in patients with papillary thyroid carcinoma was 100%, 75%, and 100%, respectively. Of note, the percentage of cases with detectable Tg mRNA was similar among patients who did not receive postoperative (131)I and those who had postoperative radioiodine treatment. CONCLUSIONS: The current study suggests that the validity of the Tg mRNA assay varies according to the histologic type of thyroid carcinoma and that this assay may play a role in the identification of metastatic disease in the subgroup of patients affected by papillary thyroid carcinoma but does not appear to be sensitive or active enough to direct clinical management.

RET oncogene activation in papillary thyroid carcinoma.

The RET proto-oncogene encodes a cell membrane tyrosine-kinase receptor protein whose ligands belong to the glial cell line-derived neurotrophic factor. RET functions as a multicompetent receptor complex that includes alphaGFRs and RET. Somatic rearrangements of RET designated as RET/PTC (from papillary thyroid carcinoma) were identified in papillary thyroid carcinoma before RET was recognized as the susceptibility gene for MEN2. There are now at least at least 15 types of RET/PTC rearrangements involving RET and 10 different genes. RET/PTC1 and RET/PTC3 are by far the most common rearrangements. All of the rearrangements are due to DNA damage and result in the fusion of the RET tyrosine-kinase (RET-TK) domain to the 5'-terminal region of heterologous genes. RET/PTC rearrangements are very common in radiation-induced tumors but have been detected in variable proportions of sporadic (i.e., non-radiation associated) papillary carcinomas. It is estimated that up to approximately half the papillary thyroid carcinomas in the United States and Canada harbor RET/PTC rearrangements, most commonly RET/PTC-1, followed by RET/PTC-3 and occasionally RET/PTC-2. The cause of these rearrangements in sporadic papillary carcinomas is not known, but the close association between their presence and the papillary carcinoma phenotype indicates that they play a causative role in tumor development. The proposed mechanisms of RET/PTC-induced tumorigenesis and the clinical and pathologic implications of RET/PTC activation are discussed.

[Spindle cell lipoma and 13q deletion: diagnostic utility of cytogenetic analysis]. / Lipomes à cellules fusiformes et délétion 13q: apport de la cytogénétique dans l'aide au diagnostic.

AIM: Spindle cell lipomas are rare adipose tissues tumors. Histologically, these lesions are composed of mature adipocytes and spindle cells associated with collagen bundles. Spindle cell lipomas are benign tumors that can be difficult to distinguish from malignant tumors such as spindle cell liposarcomas, myxoid liposarcomas or well-differentiated liposarcomas. RESULTS: We report herein the description of two new cases. The first case was a deeply situated and infiltrating tumor located in the retromastoidian area. The karyotype showed the presence of two chromosomal abnormalities, a partial deletion of the long arm of chromosome 13, del(13)(q12) and a balanced reciprocal translocation t(2;6)(p16~21;p21). The second case was a subcutaneous tumor of posterior cervical localization. The karyotype showed a 13q deletion associated with a complex rearrangement of chromosomes 5, 6 and 10. The presence of the 13q deletion allowed us to confirm the diagnosis of spindle cell lipoma in both cases. This deletion has been previously described in six out the eleven published karyotype reports. The 13q deletion is usually associated with partial monosomy 16. The present case confirms that it can occur independently. The 6p21 rearrangement may also play a role in the pathobiology of this tumor, as suggested by the positive HMGIY expression detected by immunohistochemistry. CONCLUSION: Our study further illustrates that spindle cell lipomas can infiltrate the surrounding muscle and emphasizes the usefulness of cytogenetic analysis in the differential diagnosis of soft tissue tumors.

Chromosomal translocation t(8;12) induces aberrant HMGIC expression in aggressive angiomyxoma of the vulva.

Benign mesenchymal neoplasms associated with rearrangements of the DNA architectural factor gene HMGIC on chromosome 12 include lipomas, uterine leiomyomata, pulmonary chondroid hamartomas, endometrial polyps, salivary gland pleomorphic adenomas, and breast fibroadenomas. Although HMGIC also has been implicated in the pathobiology of aggressive angiomyxoma of the vulva, the molecular mechanisms pertaining to this neoplasm are unclear. Tissue from a recurrent aggressive angiomyxoma was investigated by cytogenetic and expression analysis for HMGIC and HMGIY. The trypsin-Giemsa-banded karyotype showed a clonal translocation between chromosomes 8 and 12 [46,XX,t(8;12)(p12;q15)]. Fluorescence in situ hybridization (FISH) analysis with whole chromosome paint probes for chromosomes 8 and 12 excluded cryptic involvement of other chromosomes. The chromosome 12 breakpoint was mapped with two-color FISH analysis using cosmid probes at the 5' and 3' termini of HMGIC. Both cosmid probes showed hybridization to the normal chromosome 12 and the der(12) chromosome, indicating that the breakpoint was 3' (telomeric) to the gene. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed HMGIC expression in the tumor, and immunohistochemistry localized HMGIC expression to the tumor's spindle cells. Like numerous benign mesenchymal tumors, this locally aggressive tumor is associated with rearrangements near or within HMGIC, but chimeric gene formation was not required for tumorigenesis. Inappropriate expression of this DNA binding protein, however, may be important in the pathobiology of this tumor. Understanding the pathogenetic mechanism may also be helpful in developing new diagnostic tools for identifying residual disease.

The tumor-associated gene HMGIC is expressed in normal and osteoarthritis-affected synovia.

Chromosomal rearrangements involving chromosome bands 12q13-15 are very frequent findings in benign solid tumors, and recently, the primary molecular target for these aberrations was identified as the gene HMGIC. However, mutations in this gene have also been observed in nonneoplastic tissues. In a previous study, we reported breakpoints within HMGIC of synovia affected by osteoarthritis (OA) in two cases with 12q15 aberrations. To analyze further the role of HMGIC in this disease, we have performed cytogenetic, fluorescent in situ hybridization (FISH), RNA, and protein expression analyses on synovial samples from patients with OA and individuals without signs of the disorder. Cytogenetic analysis of short-term cultured cells revealed clonal 12q13-15 aberrations in 2/36 cases of OA synovia and no rearrangement in any of the five controls. With FISH analysis, it was shown that the chromosomal breakpoints in the two aberrant cases were located outside the HMGIC locus. In contrast, at RNA and protein expression analyses, OA-affected as well as normal synovia displayed transcription and translation of the gene. We also analyzed whether immunoreactivity for HMGIC was associated with the proliferation-specific antigen Ki-67, but no correlation between the staining patterns of these proteins was observed. From the results of the present study, it is evident that expression of HMGIC cannot simply be considered a sign of neoplasia or an effect of proliferation.

Beta-catenin dysregulation in thyroid neoplasms: down-regulation, aberrant nuclear expression, and CTNNB1 exon 3 mutations are markers for aggressive tumor phenotypes and poor prognosis.

beta-catenin has a role in cell adhesion and Wnt signaling. It is mutated or otherwise dysregulated in a variety of human cancers. In this study we assess beta-catenin alteration in 145 thyroid tumors samples from 127 patients. beta-catenin was localized using immunofluorescence and mutational analysis was performed by single-strand conformational polymorphism. Membrane beta-catenin expression was decreased in eight of 12 (66%) adenomas and in all 115 carcinomas (P: < 0.0001). Among carcinomas, reduced membrane beta-catenin was associated with progressive loss of tumor differentiation (P: < 0.0001). CTNNB1 exon 3 mutations and nuclear beta-catenin localization were restricted to poorly differentiated [7 of 28 (25%) and 6 of 28 cases (21.4%), respectively] or undifferentiated carcinomas [19 of 29 (65.5%) and 14 of 29 (48.3%) cases, respectively]. Poorly differentiated tumors always featured mutations involving Ser and Thr residues and were characterized by Thr to Ile amino acid substitutions (P: = 0.0283). The association between CTNNB1 exon 3 mutations and aberrant nuclear immunoreactivity (P: = 0.0020) is consistent with Wnt activation because of stabilizing beta-catenin mutations. Low membrane beta-catenin expression as well as its nuclear localization or CTNNB1 exon 3 mutations are significantly associated with poor prognosis, independent of conventional prognostic indicators for thyroid cancer but not of tumor differentiation. Analysis of beta-catenin dysregulation may be useful to objectively subtype thyroid neoplasms and more accurately predict outcomes.

Prognostic role of cyclin D1 in retroperitoneal sarcomas.

PURPOSE: Cyclin D1 regulates the G1 checkpoint of the cell cycle and is overexpressed in a number of cancers. This study was designed to determine if cyclin D1 overexpression had prognostic value in patients undergoing surgery with curative intent for primary retroperitoneal soft-tissue sarcoma. METHODS: Tissue was available for analysis on 79 patients who underwent resection between September 1983 and May 1997. Clinicopathologic data and follow-up was obtained from a prospective sarcoma database and a patient and family interview. Immunohistochemical analysis was used to determine overexpression (> or = 5% of nuclei labeled). Survival was analyzed using the Kaplan-Meier method, and statistical analysis was performed by using log rank testing and the Cox regression model. RESULTS: Median follow-up was 3.5 years. On univariate analysis of disease-specific mortality, significant prognostic factors were high grade (n = 42, 53%), positive microscopic margins (n = 36, 46%) or macroscopic margins (n = 15, 19%), and cyclin D1 overexpression (n = 37, 47%). On multivariate analysis, macroscopically positive margins (P = 0.02) and the combination of high grade and cyclin D1 overexpression (P = 0.04) both were associated independently with poor survival. CONCLUSION: High grade retroperitoneal sarcomas demonstrating cyclin D1 overexpression have had an extremely poor prognosis. Continued study of multiple biological markers, exemplified by cyclin D1, may aid characterization of tumor behavior and response to treatment in this diverse group of tumors.

Cytogenetic-morphologic correlations in aneurysmal bone cyst, giant cell tumor of bone and combined lesions. A report from the CHAMP study group.

Aneurysmal bone cyst and giant cell tumor of bone are relatively rare bone tumors that sometimes coexist. We examined the karyotypes of 3 aneurysmal bone cysts, 12 giant cell tumors, and 3 combined lesions. All aneurysmal bone cysts showed involvement of chromosome segments 17p11-13 and/or 16q22. In addition, in 1 of the 3 giant cell tumors with secondary aneurysmal bone cyst, both chromosome bands were rearranged as well, albeit not in a balanced translocation. Seven out of 12 giant cell tumors were characterized by telomeric associations. One giant cell tumor showed a dup(16)(q13q22), suggesting the presence of a (minor) secondary aneurysmal bone cyst component, despite the absence of histological proof. Our results, combined with literature data further substantiate that segments 16q22 and 17p11-13 are nonrandomly involved in at least some aneurysmal bone cysts, irrespective of subtype (primary, secondary, intra/extraosseous, solid or classic). These findings strongly suggest that some aneurysmal bone cysts are true neoplasms. In addition, telomeric associations are the most frequent chromosomal aberrations in giant cell tumor of bone, the significance of which remains elusive. In combined giant cell tumor/aneurysmal bone cyst each component seems to retain its own karyotypic abnormality.