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PubMed1997

Small deletions occur in highly conserved regions of the LAZ3/BCL6 major translocation cluster in one case of non-Hodgkin's lymphoma without 3q27 translocation.

The LAZ3/BCL6 gene encoding a Zinc-finger nuclear protein is altered in Non-Hodgkin's Lymphomas (NHLs) by translocations, mutations and/or deletions clustered in its 5' non coding region, in a 3.3 Kbp EcoRI fragment which thus defines the Major Translocation Cluster (MTC). In the present study, we describe at the molecular level the deletions found in the MTC of two (NHL) cases using, (i) DNA obtained from a patient (GUI) with a monosomy 3 and three microdeletions of 101, 22, 25 bp in its unique untranslocated 3q27 allele; (ii) a cell line derived from a patient (VAL) carrying a t(3;4) (q27;p11) translocation and a 2.4 Kbp deletion in the untranslocated allele. As the MTC is recurrently subject to alterations, we have cloned and sequenced the murine equivalent of the human MTC and promoter region in an attempt to identify sequences well conserved in mammals that may be thus important for the LAZ3/BCL6 gene regulation. We show that the human and mouse 5' upstream regions of the LAZ3/BCL6 gene although mainly intronic share a particularly high homology of 79% on the overall sequence. Strikingly, the small sequences which are deleted in patient (GUI) are highly conserved (81%, 100% and 92% respectively). Furthermore, they may play a role in the pathogenesis since proteins prepared from B cell lines and HeLa nuclear extracts bind to these sequences in gel retardation assays. Although a large part of this region is intronic, the high conservation of its sequence and the frequency of alterations in NHLs suggest that they are likely to be significant for the regulation of the LAZ3/BCL6 gene.

Animals↗
PubMed2000

Multiple endocrine neoplasia type 2B mutation in human RET oncogene induces medullary thyroid carcinoma in transgenic mice.

Multiple endocrine neoplasia type 2B (MEN 2B) is a familial cancer syndrome, in which the cardinal feature is medullary thyroid carcinoma (MTC), a malignant tumor arising from the calcitonin producing thyroid C-cells. MEN 2B is associated with a germline point mutation in the RET proto-oncogene, leading to a Met-->Thr substitution at codon 918 in the kinase domain, which alters the substrate specificity of the protein. We used the human calcitonin gene (CALC-I) promoter to generate transgenic mice expressing either the human RET oncogene with the MEN2B-specific 918 Met-->Thr mutation (CALC-MEN2B-RET) or the human non-mutated RET proto-oncogene (CALC-WT-RET) in the C-cells. At 20 - 22 months of age three out of eight CALC-MEN2B-RET transgenic founders presented with macroscopic bilateral MTC. In two founders nodular C-cell hyperplasia (CCH) was observed. Thyroid abnormalities were never observed in CALC-WT-RET transgenic mice or control non-transgenic mice analysed at this age. In some mice from established CALC-MEN2B-RET transgenic lines nodular CCH was observed from 8 months on whereas MTC was detected in 13% of mice from one CALC-MEN2B-RET line, from the age of 11 months on. These results show for the first time that the MEN2B mutation in the RET oncogene predisposes mice for MTC.

Animals↗
PubMed2002

Multigenerational familial medullary thyroid cancer (FMTC): evidence for FMTC phenocopies and association with papillary thyroid cancer.

BACKGROUND: Occurrence in a familial setting is well established for medullary thyroid carcinoma (MTC) and has been more recently reported for papillary thyroid cancer (PTC). Germline mutations or rearrangements of the RET proto-oncogene are the genetic background of the majority of hereditary MTCs and of about 25-40% of PTCs. PATIENTS: A large multigenerational familial medullary thyroid cancer (FMTC) family, comprised of four generations and a total of 60 subjects, has been fully evaluated. Studies on germline RET mutations and polymorphisms, on somatic RET activation and on haplotyping with RET-linked markers, were performed. RESULTS: RET mutational analysis revealed a rare missense point mutation in exon 15 of RET (A891S), associated with FMTC. Haplotype analysis showed a co-segregation between the allelic variant 5 of D10S578 marker (which is tightly linked to the RET locus) and the RET mutation. Two patients, from different branches of the family, did not harbour the point mutation A891S despite histological confirmation of MTC. In these cases, haplotype analysis excluded the involvement of the RET gene itself in the pathogenesis of the MTC. In three patients, the coexistence, in different foci, of medullary and papillary thyroid cancer was documented. The genetic studies did not show ret/PTC rearrangements. The microsatellite analysis excluded co-segregation of RET locus with the MTC/PTC phenotype. CONCLUSIONS: We report a full clinical and molecular analysis of a large FMTC kindred with an uncommon RET mutation. In two family members, phenotype and genotype were not concordant, representing the first evidence of FMTC phenocopies. Furthermore, the association of familial forms of medullary and papillary thyroid cancers has been found in 30% of patients undergoing thyroidectomy for MTC. In these situations, genetic analyses excluded the possible germline involvement of RET. Though FMTC phenocopies are likely to represent an exceptional finding, such a possibility should be taken into account in the genetic counselling for MEN 2 syndromes.

Adolescent↗
PubMed2001

Complete surgical lymph node resection does not prevent authentic recurrences of medullary thyroid carcinoma.

BACKGROUND: Medullary thyroid carcinoma is a rare tumour derived from the thyroid parafollicular calcitonin-secreting cells. Calcitonin is a very specific marker of this cancer that allows preoperative diagnosis. Serum calcitonin assay is particularly useful to define the postoperative state of patients (cured, apparently cured, not cured) and, because of its great sensitivity, it has a major place in the postoperative follow-up. OBJECTIVE: To identify, among patients thyroidectomized for medullary thyroid carcinoma (MTC), the characteristics of authentic recurrent MTC [re-elevation of stimulated serum calcitonin (CT) level measured by a sensitive immunoradiometric assay, after postoperative normalization]. PATIENTS AND METHODS: We first collected, through the national registry of the French Calcitonin Tumour Study Group (GETC), patients who had undergone a total thyroidectomy with or without lymph node surgery and who were not cured at the last follow-up visit. Among 453 such patients included in the database, 15 patients met the criteria for authentic recurrence as defined in previous studies: they had been first considered as cured during the 6 months following the initial surgical procedure (basal and pentagastrin-stimulated serum calcitonin level <or= 10 ng/l) but had a secondary rerise of their pentagastrin-stimulated calcitonin level, over 10 ng/l. Eight of them even had an undetectable (< 2 ng/l) immediate postoperative CT, confirming the initial postoperative cure. The characteristics (age, nature of disease, stage at surgery and type of node dissection) of these 15 patients were studied. RESULTS: According to the Tumour Node Metastasis classification, nine patients were T1 and, among them, five patients had had complete lymph node surgery without any evidence of nodal metastases (N0). The recurrence was 3.2 +/- 2.2 years (range: 0.7-7.5) after the initial surgery. CONCLUSIONS: 3.3% of patients not cured at the last visit had a recurrent MTC. This recurrence occurred whatever the stage, and even if the primary surgery for MTC was a priori complete. These results emphasize the need for a regular biochemical follow-up because recurrence may appear many years after the initial surgery.

Adolescent↗
PubMed2003

Acceptable age for prophylactic surgery in children with multiple endocrine neoplasia type 2a.

AIMS: Germline mutated RET proto-oncogene, causing multiple endocrine neoplasia (MEN)-2a syndrome is the indication for prophylactic total thyroidectomy. Literature regarding the risk and the extent of early surgical intervention is scarce and the optimum age for surgery is still controversial. To optimize management in these young children we evaluate our experience and results. PATIENTS AND METHODS: From 1990 to 2001 preventive total thyroidectomy was performed in 13 MEN-2a gene carriers (4 boys and 9 girls; median age 7 (4-14) years). Preoperative assessment, surgical procedure, pathological examination, postoperative complications and treatment results were studied. RESULTS: Surgery existed of a total thyroidectomy alone (n=3) in children with normal basal calcitonin and in combination with tracheo-esophageal exploration (n=6) or central compartment dissection (n=4) in case of abnormal calcitonin levels. Eight children presented with medullary thyroid cancer (MTC), three (median: 5 (4-12) years) with microscopic MTC and five (median 6 (4-14) years) with frank invasive MTC. Four of these five patients were younger than 6 years. Except for long-lasting hypoparathyroidism in one patient there were no complications. At a median follow-up of 6.5 years all patients are disease free. CONCLUSION: MTC in RET mutated MEN-2a gene carriers in childhood are found at the age of 4 years. Therefore, DNA testing should be done preferably before that age. Preventive surgery can be performed safely at that age and may be limited to total thyroidectomy when baseline calcitonin levels are normal.

Adolescent↗
PubMed1997

Epidemiology and therapy of thyroid cancer in childhood and adolescence.

Thyroid cancer is a rare disease in childhood and adolescence. However, it represents the most frequent cancer type in this age group. Thyroid cancer amounts about 0.5%-1.5% of all malignancies in children and adolescents. In Germany 10-30 cases could be expected in a year. The most common histologic type for this age group is the differentiated thyroid cancer (DTC), i.e. the papillary and follicular subtypes (90%). In 10% of patients medullary thyroid cancer (MTC) will be diagnosed. DTC occur more often in girls than in boys (female/male-ratio 2:1), with a median age of about 12-13 years (yrs). An important aetiological factor of DTC is a former exposition to different kinds of radiation. In childhood and adolescence MTC mostly appears in patients suffering from the syndrome MEN-2, whereas the sporadic form is rare. As in DTC, more girls than boys can be diagnosed for MTC (female/male-ratio 2-3:1), with a median age about 10 yrs. The anaplastic/undifferentiated subtype occurs extremely rare. For all types of thyroid cancer the most important therapeutic approach is the surgical intervention. In most cases of DTC an optimal disease control could be achieved by radioiodine therapy. Prognosis of DTC in children and adolescents is favourable. However, therapeutic strategies and modalities reported in the literature are very different. In contrast, prognosis of MTC is rather poor, that of the anaplastic type is infaust. No other effective therapy option than surgery is available. To evaluate the therapeutic efficacy of a combined modality therapy by both radiotherapy and cytostatic drugs in children and adolescents with poor prognosis types of thyroid cancer, an interdisciplinary multicenter therapy study will now be started in Germany.

Adenocarcinoma, Follicular↗
PubMed2003

[Hereditary medullary thyroid carcinoma--genotype-phenotype characterization].

BACKGROUND AND OBJECTIVE: Hereditary medullary thyroid carcinoma (MTC) is caused by germline mutations of the RET proto-oncogene. A genotype - phenotype correlation has been established, showing clustering of mutations in exons 10 and 11 in classical MEN 2 A syndrome, in exon 16 codon 918 in MEN 2 B syndrome and in exons 13-15 in familial MTC. A line of evidence suggested that the development and the aggressiveness of MTC in the different cancer syndromes is variable. Aim of this study was to compare the phenotype of exon 13-15 mutations with that of exon 11 mutation and possibly draw therapeutical consequences. PATIENTS AND METHODS: We compared the phenotype of 47 patients with mutations in exon 13-15 with 66 patients with exon 11, codon 634 mutation, the classical MEN2A. Patients were further subdivided as index and screening patients. RESULTS: Mean age of 19 index patients with codon 790, 791, 804 or 891 mutation was significant higher compared with 18 index patients with codon 634 mutation (mean age at diagnosis 50+/-12 years; range 30-69 y vs mean age 31+/-9 years; range 17-49 y), tumor stage at operation was favourable (C-cell hyperplasia n = 1; stage I n = 8; II n = 3; III n = 2; IV n = 2; no operation n = 1; no information n = 2 vs stage I n = 3; stage II n = 6; stage III n = 4, no information n =5), cure rate was better (56 % vs 38 %) and the death rate was lower (n = 2 vs n = 4). In screening patients no differences concerning the age, tumor stage, cure and death rate between patients with exons 13-15 and codon 634 mutations were seen. CONCLUSIONS: MTC in patients with exon 790, 791, 804, 891 mutations displayed a late onset and an indolent course compared to codon 634 mutation, this has to be taken into account when recommending timing and extent of prophylactic surgery.

Adolescent↗
PubMed2002

Inhibition of medullary thyroid carcinoma cell proliferation and RET phosphorylation by tyrosine kinase inhibitors.

BACKGROUND: Most medullary thyroid carcinomas (MTCs) result from gain-of-function mutations in the RET proto-oncogene, which encodes a transmembrane tyrosine kinase receptor. Systemic therapies have not been effective in treating this disease. We evaluated the effects of 3 tyrosine kinase inhibitors (TKIs) on MTC cell growth and RET tyrosine kinase activity by using an in vitro model. METHODS: An MTC cell line (TT cells, RETc634 mutant) cultured in RPMI medium was exposed to varying concentrations of STI571, genistein, or allyl-geldanamycin with controls (no TKI) for 3 to 48 hours. Cellular protein was analyzed by immunoprecipitated Western blot analysis probing with a monoclonal antiphosphotyrosine antibody. Cell proliferation was determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and 5-bromo-2'-deoxyuridine (BrdU) assays. RESULTS: RET phosphorylation was inhibited at 24 hours of exposure to 5 to 20 micromol/L STI571 and 48 hours of exposure to genistein (200 micromol/L) and allyl-geldanamycin (6 micromol/L). RET protein was detected in equal concentrations in all experimental conditions. MTT and BrdU assays demonstrated a dose-dependent decrease in TT cell proliferation with exposure to the 3 TKIs. CONCLUSIONS: These TKIs selectively inhibit cell growth and RET tyrosine kinase activity of MTC cells in vitro in a dose manner. This study suggests the use of TKIs in human trials as a systemic therapy for MTC.

Benzamides↗
PubMed1987

Introduction of v-Ha-ras oncogene induces differentiation of cultured human medullary thyroid carcinoma cells.

Medullary thyroid carcinoma (MTC) is an endocrine tumor of the thyroid C cells that expresses high levels of the neuroendocrine peptide hormone calcitonin. During tumor progression in the host, there is an apparent loss of differentiation in MTC cells that involves a consistent decrease in calcitonin content of the tumor cells associated with decreased expression of the calcitonin gene and/or changes in a mRNA alternative-processing pattern away from that characteristic of the parent thyroid C cell. We now report that introduction of the viral Harvey ras (v-Ha-ras) oncogene into cultured human MTC cells can reverse such changes in gene expression and can induce endocrine differentiation of the tumor cells. The expression of v-Ha-ras is associated with decreased cellular proliferation and DNA synthesis. There is a marked increase in the number of cytoplasmic secretory granules that are a classic feature of differentiated thyroid C cells. v-Ha-ras expression induces increased expression of the calcitonin gene and the processing of the primary gene transcript is shifted to favor calcitonin mRNA rather than calcitonin-gene-related peptide (CGRP) mRNA production. These studies with cultured human MTC cells provide a model system to study the role of Ha-ras and related genes in neuroendocrine differentiation. The findings suggest an important approach for identifying genes in solid tumors whose altered expression may play a role in the impaired maturational capacity characteristic of cancer cells during tumor progression.

Calcitonin↗
PubMed1993

Identification of a human achaete-scute homolog highly expressed in neuroendocrine tumors.

Basic helix-loop-helix transcription factors of the achaete-scute family are instrumental in Drosophila neurosensory development and are candidate regulators of development in the mammalian central nervous system and neural crest. We report the isolation and initial characterization of a human achaete-scute homolog that is highly expressed in two neuroendocrine cancers, medullary thyroid cancer (MTC) and small cell lung cancer (SCLC). The human gene, which we have termed human achaete-scute homology 1 (hASH1), was cloned from a human MTC cDNA library. It encodes a predicted protein of 238 aa that is 95% homologous to mammalian achaete-scute homolog (MASH) 1, a rodent basic helix-loop-helix factor. The 57-residue basic helix-loop-helix domain is identical to that in the rodent gene, and the basic and helical regions, excluding the loop, are 72-80% identical to Drosophila achaete-scute family members. The proximal coding region of the hASH1 cDNA contains a striking 14-copy repeat of the triplet CAG that exhibits polymorphism in human genomic DNA. Thus, hASH1 is a candidate locus for disease-causing mutations via triplet repeat amplification. Analysis of rodent-human somatic cell hybrids permitted assignment of hASH1 to human chromosome 12. Northern blots revealed hASH1 transcripts in RNA from a human MTC cell line, two fresh MTC tumors, fetal brain, and three lines of human SCLC. In contrast, cultured lines of non-SCLC lung cancers and a panel of normal adult human tissues showed no detectable hASH1 transcripts. Expression of hASH1 may provide a useful marker for cancers with neuroendocrine features and may contribute to the differentiation and growth regulation of these cells.

Adrenal Gland Neoplasms↗
PubMed1997

Development of medullary thyroid carcinoma in transgenic mice expressing the RET protooncogene altered by a multiple endocrine neoplasia type 2A mutation.

Multiple endocrine neoplasia type 2 (MEN 2) is a dominantly inherited cancer syndrome that comprises three clinical subtypes: MEN type 2A (MEN-2A), MEN type 2B (MEN-2B), and familial medullary thyroid carcinoma (FMTC). Medullary thyroid carcinoma (MTC), a malignant tumor arising from calcitonin-secreting thyroid C cells, is the cardinal disease feature of this syndrome, and mortality in affected MEN-2 patients is mainly caused by this malignancy. Germ-line mutations of the RET protooncogene, which encodes a receptor tyrosine kinase, are responsible for these three neoplastic-prone disorders. MEN2 mutations convert the RET protooncogene in a dominantly acting oncogene as a consequence of the ligand-independent activation of the tyrosine kinase. The majority of MEN2A and FMTC mutations are located in the extracellular domain and cause the replacement of one of five juxtamembrane cysteines by a different amino acid. To examine whether expression of a MEN2A allele of RET results in transformation of C cells, we have used the transgenic approach. Expression of the RET gene altered by a MEN2A mutation was targeted in C cells by placing the transgene under the control of the calcitonin gene-related peptide/calcitonin promoter. Animals of three independent transgenic mouse lines, which expressed the transgene in the thyroid, displayed overt bilateral C cell hyperplasia as early as 3 weeks of age and subsequently developed multifocal and bilateral MTC. Moreover, these tumors were morphologically and biologically similar to human MTC which afflicts MEN2 individuals. These findings provide evidence that the MEN2A mutant form of RET is oncogenic in parafollicular C cells and suggest that these transgenic mice should prove a valuable animal model for hereditary MTC.

Animals↗
PubMed2004

IFI16 is an essential mediator of growth inhibition, but not differentiation, induced by the leukemia inhibitory factor/JAK/STAT pathway in medullary thyroid carcinoma cells.

Activation of Ras or Raf in the human medullary thyroid carcinoma (MTC) cell line, TT, induces growth arrest and differentiation via two parallel, yet independent, pathways. One of these pathways is intracellular and the other is a cell-extrinsic, autocrine/paracrine pathway mediated by the leukemia inhibitory factor (LIF)/JAK/STAT pathway. Here, we show that IFI16 is a necessary and sufficient downstream effector for LIF effects in MTC cells, specifically required for the LIF/JAK/STAT pathway-induced growth inhibition in these cells. IFI16 was induced by Raf or LIF. Dominant-negative STAT3 could block the induction, indicating that Raf can induce IFI16 only via the cell-extrinsic pathway. Knock-down of IFI16 using siRNA abrogated LIF-induced changes in cellular levels of E2F1, cyclin D1, and p21WAF/CIP1, and cell cycle arrest. In addition, adenovirus-mediated overexpression of IFI16 was sufficient to induce growth arrest. In contrast to its essential role for LIF-mediated growth arrest, IFI16 was not required for differentiation induced by LIF. Knock-down of IFI16 could not block changes in differentiation markers of the MTC cells, including calcitonin, RET, and cell morphology. Our study identifies IFI16 as an essential growth-specific effector of the cell-extrinsic growth inhibitory pathway of Ras/Raf signaling in MTC cells.

Adenoviridae↗
PubMed2005

A modified therapeutic community for homeless persons with co-occurring disorders of substance abuse and mental illness in a shelter: an outcome study.

This article reports on a study conducted to determine the effectiveness of a modified therapeutic community (MTC) shelter on client outcomes. The seven-study hypotheses focused on whether greater effectiveness in the MTC would be demonstrated in longer periods of sobriety, fewer days of psychiatric hospitalization, shorter lengths of stay in a shelter, positive discharge from the shelter, medication compliance, housing placement within the first year, and appropriate housing placement according to level of functioning. The study utilized a quasi-experimental design with two groups: 1) an experimental group (E) homeless persons with co-occurring disorders (COD) of substance abuse/dependence and mental illness who reside in a modified therapeutic community (N = 70); and 2) a comparison group (C) of veterans with CODs living in a general shelter (N = 70). The data collection procedures involved a retrospective review of closed case records for subjects in the facilities from September 1, 1998-June 1, 2000 for the MTC shelter, and from June 1, 1999-June 1, 2000 for the general shelter. Baseline differences between the E and C groups were found in age, length of homelessness, years of education, years of work experience, veteran status, marital status, and psychiatric diagnosis; all except for veteran status were unrelated to outcomes and were controlled in subsequent analyses. Significant difference was found on medication compliance when controlled for both groups. Overall, this study showed some promise for the MTC approach. The study also raised a question as to the contribution of veteran status to the differences between groups and to treatment of CODs.

Adult↗
PubMed2003

Antitumor capacity of a dominant-negative RET proto-oncogene mutant in a medullary thyroid carcinoma model.

Gain-of-function mutations in the RET proto-oncogene resulting in a constitutively active receptor tyrosine kinase have been identified as responsible for three subtypes of multiple endocrine neoplasia type 2 (MEN-2) and the development of sporadic medullary and papillary thyroid carcinoma. An important strategy in cancer gene therapy is the inhibition of oncogenic signal transduction by interfering with the molecular mechanisms of activation. In the present study, we tested the therapeutic capacity of an adenovirus expressing a dominant-negative (dn) RET mutant, RET(51).flag, under the control of a synthetic C cell-selective calcitonin promoter (TSE2.CP1) against human medullary thyroid cancer (MTC). Infection of human MTC-derived TT cells with Ad-TSE2.CP1-dn-RET(51).flag resulted in the accumulation of immature RET protein in the endoplasmic reticulum and a strong reduction of oncogenic RET receptor on the cell surface, indicating that RET(51).flag exhibits a dominant-negative effect over endogenous oncogenic protein. Analysis of potential downstream mechanisms associated with the inhibition of oncogenic RET signaling by overexpression of mutant RET(51).flag revealed a significant loss of cell viability in TT cells due to the induction of apoptosis. Finally, we examined the antitumor activity of the dominant-negative RET approach in vivo. Inoculation of Ad-TSE2.CP1- dn-RET(51).flag-expressing MTC cells into nude mice led to complete suppression of tumor growth. Moreover, a single intratumoral injection of Ad-TSE2.CP1-dn-RET(51).flag into established thyroid tumors resulted in prolonged survival of treated mice compared with the controls. Our data suggest that adenoviral delivery of dn-RET(51).flag may be a reliable strategy of effective molecular intervention for RET oncogene-related MTC.

Adenoviridae↗
PubMed2004

Lack of elevated serum carcinoembryonic antigen and calcitonin in medullary thyroid carcinoma.

OBJECTIVE: Medullary thyroid carcinoma (MTC) originates from C-cells. A wide variety of tumor markers including calcitonin (CT), carcinoembryonic antigen (CEA), and chromogranin A are produced by MTC. Surgery remains the only potentially curative therapy, and early detection of the primary remains the most important prognostic factor for a positive outcome for the patient. The following case concerns a 50-year-old woman with histologically proven MTC, who completely lacked serum elevation of both CT and CEA. METHODS: We performed a total thyroidectomy with lymphadenectomy in the central compartment. Histologic sections were stained for CT, CEA, and chromogranin A. Additionally we examined the patient's blood for mutations in the RET proto-oncogene. RESULTS: Serum CT and CEA were below the detection level in the serum. The tumor showed weak staining for CT, but strong staining for CEA and chromogranin A. Sequencing of the RET-proto-oncogene revealed no mutations. Five years after the operation, the patient remains well and shows no signs of tumor recurrence. CONCLUSIONS: We hereby report of a patient with neither plasma elevation of CT nor CEA. From the clinical standpoint, it is important to determine how this subgroup of MTC should be followed because CT and CEA are of no clinical use.

Calcitonin↗
PubMed2003

Technetium-99m-sestamibi scintimammography to detect breast cancer in patients with paraffinomas or siliconomas after breast augmentation.

As the mechanism of (99)mTc-MIBI scintimammography is different from that of anatomic modalities, the detection of breast cancer should not be affected by prior breast augmentation. The aim of this study was to compare the diagnostic accuracy of (99)mTc-MIBI scintimammography for breast cancer in patients with or without paraffinomas or siliconomas. Twenty-eight women with a history of paraffin or silicone injection into the breasts and 17 without were included. All patients received intravenous injection of 1110 MBq (99)mTc-MIBI and were subsequently examined using high-resolution planar and SPECT imaging 5 minutes after the injection. In the 45 patients with 87 breasts, 21 abnormal breasts were found at scintigraphy. The sensitivity, specificity, and accuracy to detect cancer in these breasts with paraffinomas or siliconomas were 100% (5/5), 92% (46/50), and 93% (51/55), respectively. For the breasts without paraffinomas or siliconomas, the sensitivity, specificity, and accuracy were 92% (11/12), 95% (19/20), and 94% (30/32), respectively, not significantly different (p = 0.51, 0.66, and 0.86, respectively). (99)mTc-MIBI scintimammography is both sensitive and specific for the detection of breast cancer, whether or not paraffinomas or siliconomas are present. The accuracy of scintimammography did not seem to be affected by prior breast augmentation.

Adult↗
PubMed2004

Receptor radionuclide therapy with 90Y-DOTATOC in patients with medullary thyroid carcinomas.

UNLABELLED: Metastatic medullary thyroid cancer (MTC) shows a progressive course. Surgery is the only curative treatment. In advanced disease, chemo- and radiotherapy show poor results. Newly developed somatostatin analogue [DOTA0,Tyr3]octreotide (DOTATOC) labeled to 90Y is administered in patients with endocrine tumors expressing somatostatin receptors, like MTC. Preliminary studies demonstrated that 90Y-DOTATOC could be safely administered, resulting in objective responses in 27% of patients. AIMS: To evaluate the efficacy of 90Y-DOTATOC therapy in metastatic MTC patients with positive OctreoScan, progressing after conventional treatments. Twenty-one patients were retrospectively evaluated after therapy, receiving 7.5-19.2 GBq in 2-8 cycles. RESULTS: Two patients (10%) obtained a complete response (CR), as evaluated by CT, MRI and/or ultrasound, while a stabilization of disease (SD) was observed in 12 patients (57%); seven patients (33%) did not respond to therapy. The duration of the response ranged between 3-40 months. Using biochemical parameters (calcitonin and CEA), a complete response was observed in one patient (5%), while partial response in five patients (24%) and stabilization in three patients (14%). Twelve patients had progression (57%). Complete responses were observed in patients with lower tumor burden and calcitonin values at the time of the enrollment. CONCLUSIONS: This retrospective analysis is consistent with the literature, regarding a low response rate in medullary thyroid cancers treated with 90Y-DOTATOC. Patients with smaller tumors and higher uptake of the radiopeptide tended to respond better. Studies with 90Y-DOTATOC administered in earlier phases of the disease will help to evaluate the ability of this treatment to enhance survival. New more specific peptides and new isotopes will also represent the key of a better treatment of MTC.

Adult↗
PubMed1999

Carcinoembryonic antigen as a target for radioimmunotherapy of human medullary thyroid carcinoma: antibody processing, targeting, and experimental therapy with 131I and 90Y labeled MAbs.

The poor prognosis of patients with advanced medullary thyroid carcinoma (MTC) has prompted a search for new treatment modalities. In this report we explore the characteristics of carcinoembyronic antigen (CEA) as a target for radioimmunotherapy (RAIT) of MTC, with respect to antibody processing, targeting, and experimental therapy. In vitro studies showed a high level of CEA expression on the cell surface of the MTC cell line TT. MAbs bound to the cell were predominantly retained for several days, although there was also a significant level of internalization and catabolism. Immunohistology of frozen sections of tumor xenografts demonstrated that approximately half of the cells were darkly stained, however, some cells expressed little or no CEA. In biodistribution studies in nude mice bearing TT tumors, the mean percent injected dose per gram of tumor observed at three days post injection (time of maximum uptake) of 125I-MN-14 was 19.7%. When the MAb was labeled with 88Y, a residualizing label, a much higher accretion, 50.5%, was observed at the time of maximum uptake (7 days). Significant anti-tumor effects were seen at the maximum tolerated doses of 131I- and 90Y-MN-14, compared with relatively rapid tumor growth in untreated animals or those treated with the same dose of control MAbs. Importantly, it was observed that 90Y-MN-14 yielded significantly improved therapeutic efficacy in comparison to 131I-MN-14, which may have important implications for design and conduct of future clinical trials for the treatment of MTC.

Animals↗