Adcitmer® , a new CD56-targeting monomethyl auristatin E-conjugated antibody, is a potential therapeutic approach in Merkel cell carcinoma.

BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive skin cancer, whose tumour cells often express CD56. While immune checkpoint inhibitors constitute a major advance for treating patients with MCC with advanced disease, new therapeutic options are still urgently required. OBJECTIVES: To produce and evaluate the therapeutic performance of a new antibody-drug conjugate (Adcitmer® ) targeting CD56 in preclinical models of MCC. METHODS: CD56 expression was evaluated in a MCC cohort (immunohistochemistry on a tissue microarray of 90 tumour samples) and MCC cell lines. Interaction of an unconjugated CD56-targeting antibody with CD56+ MCC cell lines was investigated by immunohistochemistry and imaging flow cytometry. Adcitmer® product was generated by the bioconjugation of CD56-targeting antibody to a cytotoxic drug (monomethyl auristatin E) using the McSAF Inside® bioconjugation process. The chemical properties and homogeneity of Adcitmer® were characterized by hydrophobic interaction chromatography. Adcitmer® cytotoxicity was evaluated in vitro and in an MCC xenograft mice model. RESULTS: Similar to previous reports, CD56 was expressed by 66% of MCC tumours in our cohort, confirming its relevance as a therapeutic target. Specific binding and internalization of the unconjugated CD56-targeting antibody was validated in MCC cell lines. The high homogeneity of the newly generated Adcitmer® was confirmed by hydrophobic interaction chromatography. The CD56-mediated cytotoxicity of Adcitmer® was demonstrated in vitro in MCC cell lines. Moreover, Adcitmer® significantly reduced tumour growth in a MCC mouse model. CONCLUSIONS: Our study suggests that Adcitmer® should be further assessed as a therapeutic option in patients with MCC, as an alternative therapy or combined with immune checkpoint inhibitors.

Fatal outcome after reactivation of inherited chromosomally integrated HHV-6A (iciHHV-6A) transmitted through liver transplantation.

HHV-6A and HHV-6B are found as inherited and chromosomally integrated forms (iciHHV-6A and -6B) into all germinal and somatic cells and vertically transmitted in a Mendelian manner in about 1% of the population. They were occasionally shown to be horizontally transmitted through hematopoietic stem cell transplantation. Here, we present a clinical case of horizontal transmission of iciHHV-6A from donor to recipient through liver transplantation. Molecular analysis performed on three viral genes (7.2 kb) in the recipient and donor samples supports transmission of iciHHV-6A from the graft. Transmission was followed by reactivation, with high viral loads in several compartments. The infection was uncontrollable, leading to severe disease and death, despite antiviral treatments and the absence of resistance mutations. This case highlights the fact that physicians should be aware of the possible horizontal transmission of iciHHV-6 and its consequences in case of reactivation in immunocompromised patients.

Prognostic value of antibodies to Merkel cell polyomavirus T antigens and VP1 protein in patients with Merkel cell carcinoma.

BACKGROUND: Merkel cell polyomavirus (MCPyV) is the main aetiological agent of Merkel cell carcinoma (MCC). Serum antibodies against the major MCPyV capsid protein (VP1) are detected in the general population, whereas antibodies against MCPyV oncoproteins (T antigens) have been reported specifically in patients with MCC. OBJECTIVES: The primary aim was to assess whether detection of serum antibodies against MCPyV proteins at baseline was associated with disease outcome in patients with MCC. The secondary aim was to establish whether evolution of these antibodies during follow-up was associated with the course of the disease. METHODS: Serum T-antigen and VP1 antibodies were assessed by enzyme-linked immunosorbent assay using recombinant proteins in a cohort of 143 patients with MCC, including 84 patients with serum samples available at baseline. RESULTS: Low titres of VP1 antibodies at baseline (< 10 000) were significantly and independently associated with increased risk of recurrence [hazard ratio (HR) 2·71, 95% confidence interval (CI) 1·13-6·53, P = 0·026] and death (HR 3·74, 95% CI 1·53-9·18, P = 0·004), whereas T-antigen antibodies were not found to be associated with outcome. VP1 antibodies did not differ between patients in remission and those with recurrence or progression during follow-up. However, T-antigen antibodies were more frequently detected in patients with recurrence or progression at 12 months (P = 0·020) and 24 months (P = 0·016) after diagnosis. CONCLUSIONS: VP1 antibodies constitute a prognostic marker at baseline, whereas T-antigen antibodies constitute a marker of disease recurrence or progression if detected > 12 months after diagnosis.

The oncomiR miR-197 is a novel prognostic indicator for non-small cell lung cancer patients.

BACKGROUND: MicroRNA expression signatures can promote personalised care for non-small cell lung cancer (NSCLC) patients. Our aim was to evaluate the previously unexplored prognostic potential of miR-197, a key oncogenic molecule for NSCLC. METHODS: Total RNA isolation (n=124 NSCLC and n=21 tumour-adjacent normal tissues), was performed using the QIAsymphony SP workstation. The quantity and quality of RNA were assessed by spectrophotometric analysis and an Agilent 2100 bioanalyzer. Polyadenylation and reverse transcription were subsequently carried out. MiR-197 expression levels were measured by qPCR, after quality control (inter-assay CV=7.8%). Internal validation procedures were followed by assigning training and test sets and robust biostatistical analyses were performed, including bootstrap resampling. RESULTS: MiR-197 is associated with larger tumours (P=0.042) and the squamous cell carcinoma histotype (P=0.032). Interestingly, after adjusting for important prognostic indicators, miR-197 expression was identified as a novel independent predictor of unfavourable prognosis for NSCLC patients (HR=1.97, 95% CI=1.10-3.38, P=0.013). We also demonstrate that miR-197 retains its prognostic performance in both early-stage I (P=0.045) and more advanced-stage individuals (P=0.036). CONCLUSIONS: The cost-effective expression analysis of miR-197 could constitute a novel molecular tool for NSCLC management.

Vitamin D deficiency is associated with greater tumor size and poorer outcome in Merkel cell carcinoma patients.

BACKGROUND: Merkel cell polyomavirus has been recognized to be associated with Merkel cell carcinoma (MCC), but the evolution of this cancer probably depends on various factors. Vitamin D deficiency, defined by serum 25-hydroxyvitamin D levels <50 nmol/L, seems to influence cancer behavior and progression, but has never been assessed in MCC patients. OBJECTIVES: First, to evaluate whether vitamin D deficiency was associated with tumor characteristics and prognosis in a cohort of MCC patients. Second, to assess expression of the vitamin D receptor (VDR) in MCC tumors. METHODS: Clinical findings, Merkel cell polyomavirus markers and vitamin D status were assessed in a cohort of French MCC patients. The study was limited to the 89 patients for whom the serum sample had been collected within 3 years after the diagnosis of MCC. Correlation between vitamin D deficiency and MCC characteristics and outcome were determined in regression analyses. VDR expression in MCC tumours was assessed by immunohistochemistry. RESULTS: Vitamin D deficiency was noted in 65.1% of the patients and was independently associated with greater tumor size at diagnosis (P = 0.006) and with metastasis recurrence (HR, 2.89; 95% CI, 1.03 to 8.13; P = 0.043), but not with death from MCC, although there was a trend (HR, 5.28; 95% CI, 0.75 to 36.96; P = 0.093). VDR was found to be strongly expressed in all 28 MCC tumor specimens investigated. CONCLUSION: The association between vitamin D deficiency and MCC characteristics and outcome, together with detection of the VDR in MCC cells, suggest that vitamin D could influence the biology of MCC.

Relevance of Ki-67 and prognostic factors for recurrence/progression of gonadotropic adenomas after first surgery.

OBJECTIVE: Gonadotropin-secreting pituitary adenomas carry a high risk of local recurrence or progression (R/P) of remnant tumor after first surgery. The clinical characteristics and the long-term outcome of these silent adenomas, which show no signs of endocrine hyperfunction, differ from those of other types of pituitary adenomas. However, to date, no study has focused specifically on gonadotropic adenomas. MATERIALS AND METHODS: To identify prognostic factors of R/P of remnants, we studied the postoperative outcome of 32 gonadotropic pituitary adenomas, defined on immunohistochemical staining, according to their clinical and radiological characteristics as well as the Ki-67 labeling index (LI). RESULTS: The Ki-67 LI failed to provide independent information for the identification of patients at risk of progression of remnants or recurrence. Multivariate survival analysis (Cox regression) showed that neither invasiveness nor remnant tumors nor hyposomatotropism influenced tumor recurrence. The strongest predicting factors of R/P were the antero-posterior (AP) diameter in the sagittal plane (P = 0.014), and the age of the patient at surgery (P = 0.047), with younger patients being at greater risk. Hazard ratios were 2.11 for each 5 mm increase in AP diameter and 0.57 for every 10 years of age. CONCLUSION: The two simple clinical criteria revealed by our study, the AP diameter of the tumor and the age of the patient, should be helpful in planning clinical management and radiological monitoring after first surgery of gonadotropic adenomas, while awaiting the identification of other pathological parameters.

C-cell hyperplasia.

Routine calcitonin assay programs and recent studies on the natural history of familial medullary thyroid carcinoma (MTC) have greatly added to our understanding of C-cell hyperplasia (CCH) and refined its classification. This article is an update on CCH physiopathology related to clinical presentation. With this combined approach, two types of CCH that differ by their physiological characteristics can be identified: neoplastic CCH and reactive (also called physiological) CCH. Neoplastic CCH is caused by a germline mutation of the RET protooncogene in a multiple endocrine neoplasia type 2 (MEN 2) syndrome. It progresses to MTC following a time line that depends on the RET mutation involved. CCH may actually be a misnomer for a neoplastic condition that some authors have proposed to call "in situ-MTC". Reactive CCH is considered to be caused by a stimulus that is external to the C-cell, and its premalignant potential is not documented. Many situations such as hypercalcemia, hyperparathyroidy, chronic lymphocytic thyroiditis or follicular tumors have been associated with reactive CCH, the pathogenesis of which remains unclear. But C-cell density in normal patients is subject to important variability, and several studies have demonstrated the dramatic male predominance in physiological CCH when hypercalcitoninemia was a random discovery. These data suggest that a number of conditions which were previously associated with reactive CCH might be purely fortuitous. Our clinical/pathological confrontation contributes to appropriately distinguishing between various CCH types, and in turn to identify the best way of managing patients.

Defective mitochondrial ATP synthesis in oxyphilic thyroid tumors.

Oxyphilic tumors (oncocytomas or Hürthle cell tumors) form a rare subgroup of thyroid tumors characterized by cells containing abundant mitochondria. The relationship between the mitochondrial proliferation and the pathogenesis of these tumors is unknown. We have assessed the expression of the mitochondrial ND2 and ND5 (subunits of the nicotinamide adenine dinucleotide dehydrogenase complex) genes and the nuclear UCP2 (uncoupling protein 2) gene in 22 oxyphilic thyroid tumors and matched controls. The consumption of oxygen in mitochondria from tumors was determined by polarography. ATP assays were used to explore the mitochondrial respiratory chain activity and the oxidative phosphorylation coupling in seven fresh thyroid tumors and controls. Adenosine triphosphate synthesis was significantly lower in all the tumors, compared with controls, suggesting that a coupling defect in oxidative phosphorylation may be a cause of mitochondrial hyperplasia in oxyphilic thyroid tumors.

Sex-related C cell hyperplasia in the normal human thyroid: a quantitative autopsy study.

We report a prospective quantitative image analysis study of C cells in 57 normal autopsy thyroid glands, serially sectioned and wholly embedded in paraffin; all slides were immunohistochemically stained for calcitonin. Computerized quantitative image analysis was performed on 47 cases to measure C cell surface area and parenchymatous surface area after immunoperoxidase staining for calcitonin. The method was time-effective, with a good reproducibility. C cells were mainly found in the middle third of each lobe. Important inter-individual variations were observed; the maximum C cell surface area in a section (Amax) ranged from 28 x 10(3) to 470 x 10(3) microns2 (mean, 167 x 10(3) microns2) among 42 adults. Of particular interest was the important difference observed between sexes; Amax was twice as high in men (mean, 201 x 10(3) microns2) as in women (mean, 91 x 10(3) microns2; P = 0.0009). Moreover, 14 (33%) adult subjects [2 women (15%) and 12 men (41%)] fulfilled C cell hyperplasia criteria, i.e. at least 3 fields at x 100 magnification containing more than 50 C cells, suggesting that a substantial part of the normal adult population could have C cell hyperplasia.

C-cell hyperplasia associated with chronic lymphocytic thyroiditis: a retrospective quantitative study of 112 cases.

Since the first description by Wolfe et al of C-cell hyperplasia (CCH) in asymptomatic relatives of patients suffering from a medullary thyroid carcinoma (MTC), several investigators have described CCH associated with a chronic lymphocytic thyroiditis (CLT) not within the context of MTC or multiple endocrine neoplasia (MEN). We report the study of C-cell density in 112 cases of CLT on retrospective surgical material to determine the frequency of the association between CCH and CLT. The cases of CLT were compared with 19 normal thyroid glands obtained at necropsy. C cells, immunoreactive with a polyclonal anti-calcitonin (CT) antibody, were counted at high magnification (X400) and the number of low-power magnification (X100) microscopic fields (LPFs) containing at least 50 C cells per slide was assessed. Image analysis was performed to determine the C-cell density expressed in number of C cells/cm2. C-cell hyperplasia was defined by the following criteria: C-cell density > 40 cells/cm2 and the presence of at least three LPFs containing more than 50 C cells. Twenty percent of the cases of CLT showed a CCH thus defined, and four of them had an elevated serum CT level. Statistical analysis showed no clinical or biological correlation with the presence of CCH. However, the frequency of CCH was higher if a follicular cell carcinoma was associated with CLT. This study confirms a pathological association between CCH and CLT, provides new criteria for the definition of CCH on surgical pathology material, and reports four cases with an elevated serum CT level not within the context of MTC or MEN.

Medullary thyroid microcarcinoma: a clinicopathologic retrospective study of 38 patients with no prior familial disease.

Thirty-eight patients (25 women, 13 men; mean age, 57.8 [32 to 91]) showing one or more medullary thyroid microcarcinomas (ie, < 1 cm), with no prior MEN II or medullary thyroid carcinoma history in their family, were reviewed. Follow-up was available for 29 patients (mean, 53.6 months [1 to 147]). 21 patients (72.4%) are alive and free of disease, four patients (13.8%) died during follow-up without disease, 2 patients are alive with disease (local recurrence and persistent hypercalcitoninemia) after 80 and 99 months, respectively, and 2 patients died of disease after 24 and 46 months. Most tumors were incidental pathological findings (19 of 38) or were discovered by systematic blood calcitonin measurement for a nodular thyroid disease (15 of 38). Only the four patients who had an unfavorable outcome were symptomatic cases (palpable micro-MTC, diarrhea, cervical lymph node metastasis and pulmonary metastatic disease). The two patients with metastatic disease at diagnosis died during follow-up. In univariate analysis, a symptomatic medullary thyroid carcinoma was a strong predictor of an unfavourable outcome (p < .00008), as were the preoperative calcitonin level (P = .007) and an elevated postoperative calcitonin level (P = .004). Among 30 histopathological criteria, only the presence of amyloid correlated with an unfavorable outcome (P = .018).

No evidence of thyrotropin receptor and G(s alpha) gene mutation in high iodine uptake thyroid carcinoma.

Usually, thyroid carcinoma presents as a cold nodule on radioiodine scintigraphy. High-uptake nodules on iodine thyroid scans are associated with an exceedingly low incidence of malignancy. Only 29 cases of carcinomas appearing as hot or warm nodules have as yet been reported. From 1993 to 1999, we have observed eight similar cases (4 hot and 4 warm thyroid nodules) suggesting that thyroid carcinomas may not be as rare as usually considered in these circumstances. Four tumors were available for molecular analysis on paraffin-embedded sections. Because no mutations were found in the whole coding portions of thyrotropin-receptor (TSH-R) gene and fragments encompassing the mutational hot spots of the G(s alpha) gene, it is unlikely that activating mutations of the TSH-R or G(s alpha) genes were involved in these carcinomas.

Histopathology of bone marrow after allogeneic bone marrow transplantation for chronic myeloid leukaemia.

The histopathology of bone marrow after allogeneic bone marrow transplantation for chronic myeloid leukaemia (CML) was studied in 20 bone marrow biopsy specimens from 14 patients. Biopsies were performed at day 30 post-transplantion (5 biopsies), between day 90 and day 100 (14 biopsies), and one year post-transplantation (1 biopsy). Eight biopsies taken at day 30 post-transplantation for lymphoproliferative disorder were studied as controls. Granulopoiesis was predominant in all day 30 bone marrows in patients treated for CML. In 2 cases, rejection was suspected because of marrow hypoplasia at day 30: one case developed acute leukaemia soon after persistant hypoplasia at day 90 while the evolution of the other case was good. Two day 30 biopsies showed granulocytic hyperplasia but follow-up proved complete remission of CML. Thus, in our series, early biopsies at day 30 did not have any prognostic value. Twelve cases at day 90-100 showed little modifications, such as minor dyserythropoiesis and dysmegakaryopoiesis. One case showed granulocytic hyperplasia at day 100 but bone marrow was normal one year later and the patient in complete remission. The haematopoietic reconstitution after allogeneic bone marrow transplantation may present a transient granulocytic hyperplasia that must not be diagnosed as a persistence of CML.

[Prognostic value of Fürhman's grade in renal cell carcinoma. A study of 170 cases]. / Valeur pronostique du grade de Führman dans le carcinome à cellules rénales.

In order to evaluate the prognostic value of the anatomical stage (pTNM 1992) and of the histological factors (Führman's grade, cellular and architectural types), 170 renal cell carcinoma diagnosed between 1971 and 1991 were reviewed. In univariate analysis, the prognosis was correlated with the anatomical stage and Führman's grade: for the 125 patients without metastasis, grades 1 and 2 had a good prognosis, whereas grades 3 and 4 did poorly. The cellular type was not related to survival. Among architectural types, only the pseudo-sarcomatous type was correlated with prognosis. Multivariate analysis revealed that grade and metastasis at diagnosis were two independent predictors of survival; the grade was prognostically superior to metastasis. Führman's grade is essential in determining prognosis; its statistical value is superior to anatomical stage in multivariate analysis.

[Hyperthyroidism induced by amiodarone and hyperthyroidism induced by iodine. Histologic, immunohistochemical and ultrastructural aspects]. / Hyperthyroïdies induites par l'amiodarone et hyperthyroïdies induites par l'iode. Aspects histologiques, immunohistochimiques et ultrastructuraux.

Amiodarone is a widely-used anti-arythmic drug that induces an iodine overload and, in 1 to 23% of the patients, a thyrotoxicosis. In a few cases, the thyrotoxicosis may be refractory to conventional pharmacological therapy, thus leading to thyroidectomy. We report the thyroid gland pathology in 5 thyroidectomies that were performed for uncontrolled thyrotoxicosis, induced by amiodarone (4 cases) and by Colchimax, another iodine-rich drug (1 case). Two cases have been studied by electron microscopy. Pathologic findings were: [1] colloid transformation of the parenchyma, [2] areas of follicular disruption with numerous foamy macrophages in the colloid, [3] regenerative areas and [4] a moderate T lymphocytic infiltration. No lysosomal lamellar inclusion body was found by electron microscopy. These lesions may be rather specific of an iodine toxicity. The pathogeny is still misunderstood, and probably complex. It may essentially involve toxic mechanisms, as well as immunologic or allergic mechanisms.

[Non-neoplastic hypercalcitoninemia. Pathological anatomy]. / Hypercalcitoninémies non tumorales. Anatomie pathologique.

Normal C-cells are classically concentrated between the upper and middle thirds of each thyroid lobe and account for less than 1% of the thyroid gland volume. C-cell hyperplasia (CCH), defined as the presence of at least 3 low-power magnification (x100) microscopic fields containing more than 50 C-cells and at least 40 cells/cm2 was first described in a familial context of MEN2. It was then observed in many other conditions, especially in association with chronic lymphocytic thyroiditis or with thyroid tumors other than medullary thyroid carcinoma (MTC). In members of a MEN2 family, carrying a RET mutation, CCH is constant and associated with micro-MTC. At least 20% of patients with chronic lymphocytic thyroiditis or with a thyroid tumor other than MTC have CCH that, in a few cases, is associated with hypercalcitoninemia. 20 % normal subjects meet quantitative criteria of CCH. Patients belonging to a MEN2 family, without a RET mutation but presenting hypercalcitoninemia, could belong to this group. HCC appears to be a pre-neoplastic condition only in patients carrying a RET mutation. Under other circumstances, HCC may be either a reactive or even a normal condition.

[Histopathology of neuroendocrine tumors]. / Histopathologie des tumeurs neuro-endocrines.

Neuroendocrine (NE) tumors are a heterogeneous group of neoplasms arising in various organs and sharing the features of the NE cell system. The term "neuroendocrine" is used for cells characterized by their secretory products and some cytoplasmic proteins rather than by their localization and embryological derivation. Some tumor types can show a characteristic pattern on conventional histology but, to obtain an accurate diagnosis of many NE tumors it is necessary to employ various special methods, mainly electron microscopy and immuno-histochemistry. The classification of NE tumors in four categories according to Travis et al. is largely used: typical carcinoid and atypical carcinoid are low grade neoplasms; small cell NE carcinoma and large cell NE carcinoma are high grade neoplasms. The size, extension into surrounding tissues, angioinvasion and hormonal function are also important to consider in the prognostic evaluation of some NE tumors. Tumors exhibiting multidirectional differentiation must be classified in carcinoma with interspersed NE cells, carcinoid with interspersed non NE cells, composite tumors and amphricine tumors. Finally, some NE tumors may present features suggesting a Multiple Endocrine Neoplasia, ie. multifocality and association with hyperplasia of endocrine cells.

[Chronic autoimmune thyroiditis and C-cell hyperplasia. Study of calcitonin secretion in 24 patients]. / Thyroïdite chronique auto-immune et hyperplasie des cellules C. Etude de la sécrétion de calcitonine chez 24 patients.

Serum calcitonin (CT) was determined by radioimmunoassay, using two monoclonal antisera, in 22 women and two men, who had Hashimoto's thyroiditis as confirmed by echographic, immunological or cytological criteria; in 23 patients, serum CT levels were measured after intravenous infusion of pentagastrin (Pg). In 21 cases, basal and Pg stimulated serum CT concentrations were normal. A 61-year-old woman and a 63-year-old man, both euthyroid, had high serum basal CT: 12 pg/ml and 35 pg/ml; infusion of Pg resulted in abnormal increases in serum CT levels: respectively 64 pg/ml and 115 pg/ml. Another patient, a 65-year-old woman with primary hypothyroidism had high serum basal CT: 90 pg/ml (the Pg stimulation test was not done because of ischemic heart disease). Each of these 3 patients had a total thyroidectomy. Pathological examination of the thyroid showed typical features of Hashimoto's thyroiditis and extensive C-cell hyperplasia. After surgery, serum CT levels fell to normal. Therefore, a high serum CT can be observed as the consequence of C-cell hyperplasia in Hashimoto's thyroiditis.

[Isolated thyroid nodule. Comparative value of cyto-puncture and scintigraphy]. / Nodule thyroïdien isolé. Intérêt comparé de la cytoponction et de la scintigraphie.

OBJECTIVES: Nodular thyroid disease, indicated by the presence of single or multiple nodules within the thyroid gland is a common clinical problem, the main question remains the malignancy. Radionuclide scanning, ultrasonography and fine needle aspiration biopsy have been helpful to distinguish benign from malignant nodules and to select patients for surgery. METHODS: We performed a prospective study to assess the comparative value of fine needle nonaspiration biopsy and thyroid scinti scan in the management of 412 patients operated for solitary thyroid nodule. RESULTS: Sensitivity and negative predictive values were the same for both methods, but specificity of cytology was greater than that of thyroid scinti scan (80.53% vs. 10.47%, p < 0.001). DISCUSSION: Thyroid radionuclide scanning remains valuable in the evaluation of a cytological benign solitary thyroid nodule when TSH value is low, in order to distinguish toxic adenoma from cold nodule in Graves' disease.