Ettore Seregni

Comparison of three different methods for radiolabelling human activated T lymphocytes

One approach in the treatment of ovarian cancer MOv18/anti-CD3 (biMAb OC/TR), which recognizes a 38-kDa glycoprotein expressed on ovarian carcinomas and the CD3 T cell receptor. However, little is known about the in vivo biodistribution of injected activated lymphocytes, information that could be obtained by scintigraphic imaging of radiolabelled T cells in order to visualize the migratory pattern. We compared the efficiency, stability and toxicity of technetium-99m hexamethylpropylene amine oxime (HMPAO),indium-111 oxine and fluorine-18 2-fluoro-2-deoxy-d-glucose (FDG) in radiolabelling activated lymphocytes targeted with biMAb OC/TR. The mean labelling efficiencies of111In-oxine and18F-FDG using 2.5×108 lymphocytes (68% and 64%, respectively) were more than twice that of99mTc-HMPAO (31%). Retention of the radionuclide in the cell was highest in the case of111In-oxine labelling (less than 25% of the initial cell-bound activity released after 240 min, as compared with 44% of the99mTc label in the same period and 45% of18F radionuclide released after 150 min). None of the three radiolabelling reagents induced any significant alteration in cell viability or immunophenotype. However, both111In-oxine and18F-FDG induced a loss of cytotoxic activity of lymphocytes against the ovarian carcinoma cell line IGROV1, and all three radiolabelling reagents caused a significant reduction in the proliferative ability of labelled lymphocytes compared to controls, with cell death occurring after 8–9 days. Radiolabelling with the more stable111In-oxine reagent using a higher number of lymphocytes (1.4x109) but the same total activity (around 55.5 MBq) resulted in improved labelled T cell viability and proliferative ability, although the mean labelling efficiency decreased (35.8%). Together the data suggest that111In-oxine at low activity per cell is the most appropriate reagent for radiolabelling activated retargeted T lymphocytes useful for in vivo biodistribution studies.

High-Dose Yttrium-90–Ibritumomab Tiuxetan With Tandem Stem-Cell Reinfusion: An Outpatient Preparative Regimen for Autologous Hematopoietic Cell Transplantation

PURPOSE To develop high-dose myeloablative therapy for CD20(+) non-Hodgkins lymphoma (NHL) as a safe and widely applicable regimen. PATIENTS AND METHODS Patients with relapsed/refractory (n = 25) or de novo high-risk (n = 5) NHL received one myeloablative dose of yttrium-90 ((90)Y)-ibritumomab tiuxetan after five chemotherapy courses, including three cycles of anthracycline- or platinum-containing regimens, one cycle of cyclophosphamide (4 to 7 g/m(2)), and one cycle of cytarabine (12 to 24 g/m(2)). The only exclusion criteria were CNS lymphoma and Eastern Cooperative Oncology Group performance status of more than 3. Primary end points were overall survival (OS) and event-free survival (EFS). Secondary end points included safety and applicability of high-dose (90)Y-ibritumomab tiuxetan. To minimize hematologic toxicity, stem cells were reinfused at days 7 and 14 after (90)Y-ibritumomab tiuxetan. RESULTS Thirteen patients received (90)Y-ibritumomab tiuxetan 0.8 mCi/kg, and 17 patients received 1.2 mCi/kg. At 1.2 mCi/kg, the radiation absorbed by critical nonhematologic organs approached the protocol-defined upper safety limit, defining this as the recommended dose for subsequent studies. Hematologic toxicity was mild to moderate and of short duration. Infections occurred in 27% of patients (none had a severity grade greater than 3). After a median observation time of 30 months (range, 22 to 48 months), no myeloid secondary malignancy or chromosomal abnormality was observed, the OS rate was 87%, and the EFS rate was 69%. CONCLUSION High-dose (90)Y-ibritumomab tiuxetan seems to be an innovative myeloablative regimen with unprecedented short-term toxicity and wide applicability. Further studies are required to assess its long-term safety and role in the management of CD20(+) NHL.

Prognostic Value of Circulating Tumor Markers in Patients with Pseudomyxoma Peritonei Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BackgroundEncouraging results have been recently reported in selected patients affected by pseudomyxoma peritonei (PMP) treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The selection factors predicting clinical outcome are still a matter of clinical investigation. We assessed the prognostic reliability of serum tumor markers in a large series of patients with PMP undergoing CRS and HIPEC.MethodsSixty-two patients with PMP were operated on at a single institution with the intent of performing adequate CRS (residual tumor nodules ≤2.5mm) and HIPEC. Baseline and serial marker measurements were prospectively collected and tested by multivariate analysis with respect to adequate cytoreduction, overall (OS) and progression-free (PFS) survival, along with the following variables: age, sex, performance status, prior surgical score, histological subtype, prior systemic chemotherapy, disease extent, completeness of cytoreduction.ResultsBaseline diagnostic sensitivity was 72.6% for CEA, 58.1% for CA19.9, 58.7% for CA125, 36.1% for CA15.3. Fifty-three patients underwent adequate CRS and HIPEC; gross residual tumor was left after surgery in nine. Adequate CRS was performed in 19/27 patients with elevated and in 19/19 with normal baseline CA125 (P = .0140). The other markers were unable to predict the completeness of CRS by univariate analysis. Baseline elevated CA19.9 was an independent predictor of reduced PFS; inadequate CRS and aggressive histology were independent prognostic factors for both reduced OS and PFS.ConclusionNormal CA125 correlated to the likelihood to achieve adequate CRS, which is a significant prognostic factor for PMP. Increased baseline CA19.9 was an independent predictor of worse PFS after CRS and HIPEC.

Circulating tumour markers in breast cancer

A large number of markers have been proposed for breast cancer, but among them only CA 15.3, CEA and cytokeratins (i.e. TPA, TPS and Cyfra 21.1) are currently used in clinical practice. Serum marker levels reflect tumour burden and for this reason they are not sensitive enough to be used for screening and early diagnosis of primary breast cancer. By contrast, the role of tumour markers is established in the diagnosis of recurrent disease and in the evaluation of response to treatment. In the former case, however, prospective randomised studies are required to demonstrate any survival benefit when earlier therapeutic interventions are instituted upon elevation of serum markers. In the second case, tumour marker evaluation represents a simple, objective method for monitoring of therapeutic response that seems to offer significant advantages over conventional imaging methods (e.g. objectivity, modifications in tumour biology). Furthermore, research studies are ongoing to identify and validate new biochemical parameters which can be of use not only in advanced disease but also in other stages of the diagnostic work-up of breast cancer.

Radionuclide imaging of neuroendocrine tumours: biological basis and diagnostic results

Abstract. Neuroendocrine tumours have been defined as APUD-omas in the past by authors who identified common metabolic characteristics (amine precursor uptake and decarboxylation) in a group of tumours thought to originate from cells of the neural crest and to be able to produce biogenic amines. The identification of neuroendocrine tumours with APUD-omas was not confirmed by subsequent investigators. At present it is known that a group of neuroendocrine tumours derive from pluripotent stem cells or from differentiated neuroendocrine cells, and that they have a particular pattern of histology due to the presence of some secretory products and particular cytoplasmic proteins. Many radiopharmaceuticals have been successfully used in nuclear medicine to visualise neuroendocrine tumours; most of them are based on specific uptake mechanisms, but some are non-specific probes. This review is focussed on the clinical application of radiolabelled metaiodobenzylguanidine, indium-111 pentetreotide, radiolabelled vasointestinal peptide, radiolabelled monoclonal antibodies and positron-emitting tracers. While many different types of neuroendocrine tumours are identified today, only the most common histotypes and those tumours of major relevance for nuclear medicine are considered in this review (anterior pituitary tumours and neuroblastoma are excluded). New knowledge in molecular biology, relevant biological and histological patterns, and the physiological and clinical behaviour are described for neuroendocrine tumours of the lung, tumours of the gastroenteropancreatic tract, medullary thyroid carcinoma, tumours of sympatho-adrenal lineage, and multiple endocrine neoplasia. The nuclear medicine results in diagnostic imaging are presented, and the major comparative studies with different tracers are reported. The study of further possible diagnostic approaches addressing the biological characteristics of these tumours could open the way to various new therapeutic options.

Papillary thyroid carcinoma of childhood and adolescence: A 30‐year experience at the istituto nazionale tumori in Milan

Survival rates are reportedly excellent for papillary thyroid carcinomas (PTCs) in childhood/adolescence, despite their strong tendency to spread. The aim of this study was to verify this assumption in a single‐institution series spanning a 30‐year period with a very long follow‐up.

The aromatase inhibitor letrozole in advanced breast cancer : Effects on serum insulin-like growth factor (IGF)-I and IGF-binding protein-3 levels

Serum insulin-like growth factor (IGF)-I and IGF-binding protein-3 levels were measured in two groups of postmenopausal women with advanced breast cancer, who received the aromatase inhibitor letrozole 0.5 or 2.5 mg p.o. once daily. Blood samples were obtained from 15 patients in each dose group at baseline, and one and three months after starting therapy. Circulating IGF-I and IGFBP-3 concentrations were determined by means of radioimmunoassay. In both dosage groups a statistically significant increase in the IGF-I levels was observed during three months of letrozole treatment (P=0.003). In addition, the multiple testing procedure yielded in the whole patient population a significant result in the comparison between mean IGF-I values after three months of therapy and those observed at baseline (P=0.004), the estimated average increase being of 24%. No significant result was obtained in the analysis for the dose effect (P=0.077) and for the time x dose interaction (P=0.208). Circulating IGFBP-3 levels did not appear to be affected by letrozole treatment in either of the dose groups. This is the first report concerning the short-term effects of letrozole on components of the IGF system in breast cancer patients; further investigations are warranted in order to confirm these preliminary data.

Post-Synthesis Incorporation of 64Cu in CuS Nanocrystals to Radiolabel Photothermal Probes: A Feasible Approach for Clinics

We report a simple method for the incorporation of Cu(I) or (64)Cu(I) radionuclides in covellite nanocrystals (CuS NCs). After the in situ reduction of Cu(II) or (64)Cu(II) ions by ascorbic acid, their incorporation in PEG-coated CuS NCs takes place at room temperature. In all the reaction steps, the stability of the NCs under physiological conditions was ensured. The copper incorporation reaction could also take place on CuS NCs bearing biotin molecules at their surface, with no detrimental effects on the specific binding affinity of the NCs toward streptavidin after incorporation. At low loading of Cu ions, the strong near-infrared (NIR) absorption band of the starting CuS NCs was essentially preserved, which allowed for efficient plasmonic photothermal therapy. The combined presence in the NCs of (64)Cu ions, well suitable for positron emission tomography, and of free carriers responsible for the NIR absorption, should enable their theranostic use as radiotracers and as photothermal probes in tumor ablation treatments. Moreover, the simplicity of the preparation scheme, which involves the use of radioactive species only as a last step, makes the protocol easily transferable to the clinical practice.

Feasibility of somatostatin receptor scintigraphy in the detection of occult primary gastro-entero-pancreatic (GEP) neuroendocrine tumours.

The aim of this study was to assess the feasibility of somatostatin receptor scintigraphy (SRS) for the detection of the site of unknown primary neuroendocrine neoplasms in patients in whom clinical examination and conventional radiological imaging had failed to do so. From 1996 to 2000, 36 patients were referred with gastro-entero-pancreatic (GEP) neuroendocrine tumours. In these patients, no clinical, radiological or endoscopic diagnostic modalities had been able to identify the primary tumour. Twenty-nine patients had liver metastases. Of the others, one had skin and one had lymph node metastases, three had diffuse metastatic involvement and two had carcinoid syndrome. SRS was carried out with both whole-body and single-photon emission tomography (SPET) acquisition, 24 and 48 h after the intravenous administration of 111In-pentetreotide. SRS findings were suggestive of the possible site of the primary lesion in 14 patients (39%). Six patients underwent surgery on the basis of the SRS findings and, therefore, the final, i.e. pathological, diagnosis was reached. In two patients, the final diagnosis was obtained within 6 months of SRS by means of a follow-up computed tomography (CT) scan. In the remaining six patients, the final diagnosis was reached after at least 2 years of follow-up by means of clinical, radiological and/or nuclear medicine findings. In all eight patients, the primary site identified during follow-up was consistent with the SRS findings. It can be concluded that SRS modified management in the six patients who had surgery. However, the most important finding was that SRS prompted surgical management in 17% of cases.

177Lu- labeled MOv18 as compared to 131I- or 90Y-labeled MOv18 has the better therapeutic effect in eradication of alpha folate receptor-expressing tumor xenografts

INTRODUCTION The mouse monoclonal antibody MOv18, directed against the alpha-isoform of folate receptor (FR), was investigated to identify the optimal radioconjugate for radioimmunotherapy of minimal residual disease in ovarian cancer. METHODS Pharmacokinetics, biodistribution, long-term therapeutic efficacy and toxicity of MOv18, labeled with the beta-emitters (131)I, (90)Y and (177)Lu, were compared in a xenografted mouse model, composed by two cell lines, A431FR and A431MK, differing only for FR expression. RESULTS A shorter blood clearance and a higher tumor uptake were observed for (90)Y- and (177)Lu- compared to (131)I-MOv18, and a shorter blood pharmacokinetics was recorded in A431FR-bearing animals. At equitoxic maximum tolerable doses, the general irradiation by (131)I- and (90)Y-MOv18 gives rise to strong targeted effects on A431FR and nontargeted effects on A431MK tumors, while (177)Lu-MOv18 was able to eradicate small size tumor masses expressing the antigen of interest exerting only mild non-targeted effects. CONCLUSION (177)Lu-MOv18 at the maximal tolerated dose is the immunoradioconjugate with the best therapeutic window in experimental conditions of small tumor volume.