FAST: a randomised phase II study of zolbetuximab (IMAB362) plus EOX versus EOX alone for first-line treatment of advanced CLDN18.2-positive gastric and gastro-oesophageal adenocarcinoma.

BACKGROUND: Claudin 18.2 (CLDN18.2) is contained within normal gastric mucosa epithelial tight junctions; upon malignant transformation, CLDN18.2 epitopes become exposed. Zolbetuximab, a chimeric monoclonal antibody, mediates specific killing of CLDN18.2-positive cells through immune effector mechanisms. PATIENTS AND METHODS: The FAST study enrolled advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients (aged ≥18 years) with moderate-to-strong CLDN18.2 expression in ≥40% tumour cells. Patients received first-line epirubicin + oxaliplatin + capecitabine (EOX, arm 1, n = 84) every 3 weeks (Q3W), or zolbetuximab + EOX (loading dose, 800 mg/m2 then 600 mg/m2 Q3W) (arm 2, n = 77). Arm 3 (exploratory) was added after enrolment initiation (zolbetuximab + EOX 1000 mg/m2 Q3W, n = 85). The primary endpoint was progression-free survival (PFS) and overall survival (OS) was a secondary endpoint. RESULTS: In the overall population, both PFS [hazard ratio (HR) = 0.44; 95% confidence interval (CI), 0.29-0.67; P < 0.0005] and OS (HR = 0.55; 95% CI, 0.39-0.77; P < 0.0005) were significantly improved with zolbetuximab + EOX (arm 2) compared with EOX alone (arm 1). This significant PFS benefit was retained in patients with moderate-to-strong CLDN18.2 expression in ≥70% of tumour cells (HR = 0.38; 95% CI, 0.23-0.62; P < 0.0005). Significant improvement in PFS was also reported in the overall population of arm 3 versus arm 1 (HR = 0.58; 95% CI, 0.39-0.85; P = 0.0114) but not in high CLDN18.2-expressing patients; no significant improvement in OS was observed in either population. Most adverse events (AEs) related to zolbetuximab + EOX (nausea, vomiting, neutropenia, anaemia) were grade 1-2. Grade ≥3 AEs showed no substantial increases overall (zolbetuximab + EOX versus EOX alone). CONCLUSIONS: In advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients expressing CLDN18.2, adding zolbetuximab to first-line EOX provided longer PFS and OS versus EOX alone. Zolbetuximab + EOX was generally tolerated and AEs were manageable. Zolbetuximab 800/600 mg/m2 is being evaluated in phase III studies based on clinical benefit observed in the overall population and in patients with moderate-to-strong CLDN18.2 expression in ≥70% of tumour cells.

A multicentre, phase IIa study of zolbetuximab as a single agent in patients with recurrent or refractory advanced adenocarcinoma of the stomach or lower oesophagus: the MONO study.

BACKGROUND: Claudin 18.2 (CLDN18.2) is physiologically confined to gastric mucosa tight junctions; however, upon malignant transformation, perturbations in cell polarity lead to CLDN18.2 epitopes being exposed on the cancer cell surface. The first-in-class monoclonal antibody, zolbetuximab (formerly known as IMAB362), binds to CLDN18.2 and can induce immune-mediated lysis of CLDN18.2-positive cells. PATIENTS AND METHODS: Patients with advanced gastric, gastro-oesophageal junction (GEJ) or oesophageal adenocarcinomas with moderate-to-strong CLDN18.2 expression in ≥50% of tumour cells received zolbetuximab intravenously every 2 weeks for five planned infusions. At least three patients were enrolled in two sequential cohorts (cohort 1300 mg/m2; cohort 2600 mg/m2); additional patients were enrolled into a dose-expansion cohort (cohort 3600 mg/m2). The primary end point was the objective response rate [ORR: complete and partial response (PR)]; secondary end points included clinical benefit [ORR+stable disease (SD)], progression-free survival, safety/tolerability, and zolbetuximab pharmacokinetic profile. RESULTS: From September 2010 to September 2012, 54 patients were enrolled (cohort 1, n = 4; cohort 2, n = 6; cohort 3, n = 44). Three patients in cohort 1 and 25 patients in cohorts 2/3 received at least 5 infusions. Antitumour activity data were available for 43 patients, of whom 4 achieved PR (ORR 9%) and 6 (14%) had SD for a clinical benefit rate of 23%. In a subgroup of patients with moderate-to-high CLDN18.2 expression in ≥70% of tumour cells, ORR was 14% (n = 4/29). Treatment-related adverse events occurred in 81.5% (n = 44/54) patients; nausea (61%), vomiting (50%), and fatigue (22%) were the most frequent. CONCLUSIONS: Zolbetuximab monotherapy was well tolerated and exhibited antitumour activity in patients with CLDN18.2-positive advanced gastric or GEJ adenocarcinomas, with response rates similar to those reported for single-agent targeted agents in gastric/GEJ cancer trials. CLINICALTRIALS.GOV NUMBER: NCT01197885.

Metastatic follicular dendritic cell sarcoma of the stomach: a case report and review of the literature.

Follicular dendritic cell (FDC) sarcomas are rare tumours, typically seen in lymph nodes. However, in about one third of the reported cases, a FDC sarcoma presents as an extranodal mass. Involvement of the gastrointestinal tract is extremely rare, and only 3 cases have been described to date. We report on a 40-year-old female patient with a follicular dendritic cell sarcoma located in the stomach and the presence of a metastasis in the liver at the time of diagnosis. Severe asthenia, nausea, back pain and loss of weight were the presenting symptoms. A CT scan of the abdomen and an upper gastrointestinal endoscopy revealed a tumour mass in the stomach. The diagnosis of a FDC sarcoma was made on histological and immunohistochemical findings. We report the second case of a FDC sarcoma presenting in the stomach. Due to its rarity, a FDC sarcoma seldom enters the differential diagnosis of spindle cells neoplasms of the gastrointestinal tract. Complete surgical resection is the treatment of choice for FDC sarcoma.

Iodine-labeled tamoxifen uptake in primary human breast carcinoma.

UNLABELLED: Assessing tumor uptake and retention of (123)I-labeled tamoxifen (TX) could increase our understanding of TX's action and the mechanisms involved in resistance to the drug. METHODS: Nine untreated primary breast carcinoma patients underwent whole-body planar and tomographic (SPECT) imaging 30 min and 4-5 h after injection of 185 MBq (123)I-TX. Tumor-to-normal tissue uptake ratios (T/N) derived from SPECT images were related to estrogen receptor (ER) and progesterone receptor (PR) status. RESULTS: In 4 of 9 patients, all of whom were ER+/PR+, (123)I-TX tumor uptake was clearly depicted. In 2 of them, involved axillary lymph nodes were also visualized. T/N consistently increased over time. All ER+/PR- and ER-/PR- tumors as well as 2 ER+/PR+ tumors were (123)I-TX-. CONCLUSION: These preliminary findings suggest that (123)I-TX is preferentially taken up in alpha-ER+/PR+ breast tumors known to be more likely to respond to endocrine treatment.

Telomeres, telomerase and cancer: an up-date.

In the mid 1990s, the hypothesis emerged that the upregulation or re-expression of a telomere-synthesising ribonucleoprotein, called telomerase, is a critical event responsible for continuous tumour cell growth. In contrast to normal cells, in which gradual mitosis-related erosion of telomeres eventually limits replicative life span, tumour cells have telomerase and show no loss of these chromosomal ends. These data suggest that telomere stabilisation may be required for cells to escape replicative senescence and to proliferate indefinitely. Because of the close association between telomerase and malignancy, both pathologists and clinicians expect this molecule to be a useful malignancy-marker and a new therapeutic target. This review focuses on the components of the human telomere and of the human telomerase enzyme. A synopsis of reports studying the clinical-diagnostic value of telomere length measurements, of telomerase activity analyses and of the in situ telomerase detection is given. Finally, a summary of recent experimental work that sheds new light on the biological role of this fascinating molecule is presented.

Absence of telomerase activity and telemorase catalytic subunit mRNA in melanocyte cultures.

The classic model of activation of telomerase, for which activity has been found in most cancers including cutaneous malignant melanoma (CMM), dictates that enzyme activity is generated by pathological reactivation of telomerase in telomerase-negative somatic cells. However, recent data demonstrated physiological up-regulation in some normal cell types when established as proliferating cultures, indicating that, in some cancer types, telomerase is expressed by the process of up-regulation in telomerase-competent precursor cells. In this study, cultures of epidermal melanocytes, progenitor cells of CMM, were established and harvested in the logarithmic phase of growth. Telomerase activity was looked for using a non-isotopic variant of the telomeric repeat amplification protocol, and transcript expression of the hTERT gene, the rate-limiting catalytic telomerase subunit, was investigated by the reverse transcription polymerase chain reaction. Neither telomerase activity nor hTERT mRNA could be detected in proliferating melanocyte cultures. Our in vitro data argue against the model of telomerase as a common biomarker of cell proliferation. The results further suggest that telomerase is tightly controlled in normal melanocytes, and that telomerase is reactivated rather than up-regulated in melanocytic precursors during melanoma initiation or progression.

Expression profile of telomerase subunits in human pleural mesothelioma.

Using the TRAP assay, telomerase activity was previously detected in over 90% of human pleural mesotheliomas (MMs), but not in mesothelial cell cultures (MCCs), suggesting that telomerase re-activation occurs during multi-step mesothelioma carcinogenesis. The present study determined the expression of the telomerase RNA template (hTERC), the telomerase-associated protein (hTEP1), and the telomerase catalytic sub-unit (hTERT), in 16 pleural MMs and 4 MM-derived cell lines, in two pleural solitary fibrous tumours and in six MCCs. Reverse transcription-polymerase chain reaction analysis revealed that hTERT mRNA expression parallels the activity status documented by the TRAP assay, whereas hTERC and hTEP1 mRNA are commonly expressed in all malignant and non-malignant serosal cells and tissues. Three alternatively spliced hTERT transcripts were detected in all telomerase-positive samples, whereas neither variant could be detected in the MCCs. Detection of the hTERT protein with a commercially available antibody was not successful. These results indicate that hTERT expression is rate-limiting for human telomerase activity and that re-activation, rather than up-regulation, of hTERT expression can play a critical role in MM carcinogenesis. While waiting suitable anti-hTERT antibodies, these results provide information for the design of hTERT mRNA-specific in situ probes to study telomerase in archived pre-malignant serosal lesions.

SV40 large T-antigen and human pleural mesothelioma. Screening by polymerase chain reaction and tyramine-amplified immunohistochemistry.

DNA-like sequences of the p53 and pRB-inactivating simian virus 40 large T-antigen (SV40 LTag) have recently been found in mesotheliomas in the United States and several European countries. Nuclear expression of SV40 LTag, possibly in concert with detectable telomerase activity, could be responsible for immortalisation of (pre)malignant clones, as suggested by the mesothelioma-specific latency period. Depending on the antibody used, different results have been observed regarding the subcellular expression of SV40 LTag in mesotheliomas with SV40 LTag-like DNA sequences. In this study, we screened 28 Belgian mesothelioma tumour samples for the presence of SV40 LTag-like DNA and its gene product by polymerase chain reaction amplification, using the SV.for3/SV.rev primer set, and by tyramine-amplified immunohistochemistry, using the pAb419 and the pAb101 SV40 LTag antibodies. Amplicons were found in 13 of the 28 (46%) mesotheliomas. Cytoplasmic, but no nuclear, staining was found in 10 of these 13 cases. Although our study confirms the presence of SV40 LTag-like DNA sequences in Belgian mesotheliomas, we did not detect nuclear expression of the viral oncoprotein, which makes a pathogenic role of SV40 LTag in mesothelioma carcinogenesis questionable.

Diagnosis of cutaneous T-cell lymphoma detecting T-cell receptor gamma chain gene monoclonality by denaturing gradient gel electrophoresis.

Cutaneous T-cell lymphomas represent a group of malignant lymphoproliferative disorders characterised by the occurrence of a monoclonal population of T-lymphocytes. Diagnosis of early stages of this disease is a difficult challenge for both the dermatologist and the dermatopathologist. With the aid of the polymerase chain reaction it is possible to amplify specific regions of the T-cell receptor gamma gene. The amplification products can then be separated by denaturing gradient gel electrophoresis in order to detect a monoclonal population of T-lymphocytes in the infiltrate. We studied 4 patients with the clinicopathologic diagnosis of mycosis fungoides and 2 patients diagnosed as large plaque parapsoriasis. A monoclonal population was detected in 3 of the 4 mycosis fungoides cases and in 1 of the patients with large plaque parapsoriasis. This indicates that our analysis can help us establishing a diagnosis, and it can also help us to identify patients with a possible early stage of the disease, which clinically or histologically is not yet recognised as such.

Value of morphometry, texture analysis, densitometry, and histometry in the differential diagnosis and prognosis of malignant mesothelioma.

Malignant mesothelioma is a tumour with increasing incidence due to widespread use of its causative agent, asbestos, in the past decades. The poor survival necessitates a correct differentiation from other lesions at the same site, such as hyperplastic mesothelium and carcinomas metastatic to pleura or peritoneum. Since genetic and immunohistochemical markers are not absolutely differentiating, the diagnosis is based on the histology complemented with (immuno)histochemistry. However, as the tumour presents itself in numerous heterogeneous histological forms, visual evaluation is extremely difficult. In order to evaluate the prognostic and diagnostic performance of syntactic structure analysis (SSA), chromatin texture analysis, densitometry, and morphometry, an automated KNN-classification system has been used to compare Feulgen-stained tissue sections of hyperplastic mesothelium, malignant mesothelioma, and pulmonary adenocarcinoma. In addition, we also studied most discriminative aspects in the differentiation, typing, and prediction of survival. The results indicate that for the diagnosis of malignant mesothelioma, chromatin texture parameters outperform SSA, densitometry, and morphometry (recognition score=96.8 per cent). Most discriminative parameters highlight spatial patterns of the chromatin distribution that are hard to appraise visually and directly show the benefits of a quantitative approach. Typing of the tumour is best described by SSA parameters, relating to the spatial arrangement of the cells in the tissue (recognition score=94.9 per cent). In survival time classifications, chromatin texture yields the highest recognition score (82.9 per cent), although accurate estimations are unreliable due to a large degree of misclassification.

Diagnosis of Cutaneous T-Cell Lymphoma Detecting T-Cell Receptor γ Chain Gene Monoclonality By Denaturing Gradient Gel Electrophoresis.

Cutaneous T-cell lymphomas represent a group of malignant lymphoproliferative disorders characterised by the occurrence of a monoclonal population of T-lymphocytes. Diagnosis of early stages of this disease is a difficult challenge for both the dermatologist and the dermatopathologist. With the aid of the polymerase chain reaction it is possible to amplify specific regions of the T-cell receptor gamma gene. The amplification products can then be separated by denaturing gradient gel electrophoresis in order to detect a monoclonal population of T-lymphocytes in the infiltrate. We studied 4 patients with the clinicopathologic diagnosis of mycosis fungoides and 2 patients diagnosed as large plaque parapsoriasis. A monoclonal population was detected in 3 of the 4 mycosis fungoides cases and in 1 of the patients with large plaque parapsoriasis. This indicates that our analysis can help us establishing a diagnosis, and it can also help us to identify patients with a possible early stage of the disease, which clinically or histologically is not yet recognised as such.

Standard versus extended lymphadenectomy associated with pancreatoduodenectomy in the surgical treatment of adenocarcinoma of the head of the pancreas: a multicenter, prospective, randomized study. Lymphadenectomy Study Group.

OBJECTIVE: The study was conducted to determine whether the performance of an extended lymphadenectomy and retroperitoneal soft-tissue clearance in association with a pancreatoduodenal resection improves the long-term survival of patients with a potentially curable adenocarcinoma of the head of the pancreas. SUMMARY BACKGROUND DATA: The usefulness of performing an extended lymphadenectomy and retroperitoneal soft-tissue clearance in conjunction with a pancreatoduodenal resection in the treatment of ductal adenocarcinoma of the head of the pancreas is still unknown. Published studies suggest a benefit for the procedure in terms of better long-term survival rates; however, these studies were retrospective or did not prospectively evaluate large series of patients. MATERIALS AND METHODS: Eighty-one patients undergoing a pancreatoduodenal resection for a potentially curable ductal adenocarcinoma of the head of the pancreas were randomized to a standard (n = 40) or extended (n = 41) lymphadenectomy and retroperitoneal soft-tissue clearance in a prospective, multicentric study. The standard lymphadenectomy included removal of the anterior and posterior pancreatoduodenal, pyloric, and biliary duct, superior and inferior pancreatic head, and body lymph node stations. In addition to the above, the extended lymphadenectomy included removal of lymph nodes from the hepatic hilum and along the aorta from the diaphragmatic hiatus to the inferior mesenteric artery and laterally to both renal hila, with circumferential clearance of the origin of the celiac trunk and superior mesenteric artery. Patients did not receive any postoperative adjuvant therapy. RESULTS: Demographic (age, gender) and histopathologic (tumor size, stage, differentiation, oncologic clearance) characteristics were similar in the two patient groups. Performance of the extended lymphadenectomy added time to the procedure, although the difference did not reach statistical significance (397 +/- 50 minutes vs. 372 +/- 50 minutes, p > 0.05). Transfusion requirements, postoperative morbidity and mortality rates, and overall survival did not differ between the two groups. When subgroups of patients were analyzed, using an a posteriori analysis that was not planned at the time of study design, there was a significantly (p < 0.05) longer survival rate in node positive patients after an extended rather than a standard lymphadenectomy. The survival curve of node positive patients after an extended lymphadenectomy could be superimposed onto the curves of node negative patients. Survival curves in node negative patients did not differ according to the magnitude of the lymphadenectomy. Multivariate analysis of all patients showed that long-term survival was affected by tumor differentiation (well vs. moderately vs. poorly differentiated, p > 0.001), diameter (< or = 2.0 cm. vs. > 2.0 cm., p < 0.01), lymph node metastasis (absent vs. present, p < 0.01) and need for 4 or more units of transfused blood (< 4 vs. > or = 4, p <0.01). CONCLUSIONS: The addition of an extended lymphadenectomy and retroperitoneal soft-tissue clearance to a pancreatoduodenal resection does not significantly increase morbidity and mortality rates. Although the overall survival rate does not differ in the two groups, there appears to be a trend toward longer survival in node positive patients treated with an extended rather than a standard lymphadenectomy.

Tyramine-amplified immunohistochemical testing using "homemade" biotinylated tyramine is highly sensitive and cost-effective.

Immunohistochemical testing using biotinylated tyramine is a recently described technique that results in a strong amplification of the detection signal using antibodies at very high dilutions. In this report we compare the sensitivity and cost-effectiveness of the technique using "homemade" biotinylated tyramine with those of two commercially available kits. The technique using homemade tyramine was easy to follow and highly sensitive and resulted in a 2.5- to 5-fold reduction in costs compared with the commercial kits. Tyramine-amplified immunohistochemical testing using homemade biotinylated tyramine is a valuable and inexpensive tool for both the diagnostic and experimental histopathology laboratory.

Telomerase activity in human pleural mesothelioma.

BACKGROUND: Gradual telomere erosion eventually limits the replicative life span of somatic cells and is regarded as an ultimate tumour suppressor mechanism, eliminating cells that have accumulated genetic alterations. Telomerase, which has been found in over 85% of human cancers, elongates telomeres and may be required for tumorigenesis by the process of immortalisation. Malignant mesothelioma is an incurable malignancy with a poor prognosis. The disease becomes symptomatic decades after exposure to carcinogenic asbestos fibres, suggesting the long term survival of pre-malignant cell clones. This study investigated the presence of telomerase in pleural malignant mesothelioma, which may be the target for future anti-telomerase drugs. METHODS: Telomerase activity was semiquantitatively measured in extracts from 22 primary pleural mesotheliomas, two benign solitary fibrous tumours of the pleura, four mesothelioma cell lines, and six short term mesothelial cell cultures from normal pleura using a non-isotopic dilution assay of the telomeric repeat amplification protocol. RESULTS: Twenty of the 22 primary mesotheliomas (91%) and all tumour derived mesothelioma cell lines were telomerase positive. Different levels of enzyme activity were observed in the tumours of different histological subtypes. Telomerase activity could not be detected in the six normal mesothelial cell cultures or in the two mesotheliomas. Both benign solitary fibrous tumours showed strong telomerase activity. CONCLUSIONS: Telomerase activity is found in a high proportion of mesotheliomas and anti-telomerase drugs might therefore be useful clinically. The results are consistent with the hypothesis that telomerase activity may be a feature of carcinogenesis in mesotheliomas and possibly in many other cancers.

Syndecan-1 expression in malignant mesothelioma: correlation with cell differentiation, WT1 expression, and clinical outcome.

Syndecan-1 binds basic fibroblast growth factor (bFGF), modulates neovascularization, plays a role in epithelial differentiation and is up-regulated by WT1. Malignant mesothelioma of the pleura is one of the most aggressive tumours known and expresses high levels of angiogenic growth factors. This study has analysed syndecan-1 expression in mesothelioma tumours and cell lines by immunohistochemistry and immunoblotting, using anti-syndecan-1 antibody directed against the core protein, and has examined its relation to morphology, bFGF, WT1, and intra-tumoural microvascular density (IMD). Shedding of syndecan-1 in the conditioned medium of mesothelioma cell lines was detected in variable amounts. These studies indicate that (1) there is no correlation of syndecan-1 with either bFGF expression or IMD in mesotheliomas in vivo; (2) syndecan-1 is strongly expressed in the epithelial type of mesothelioma and in the epithelial component of biphasic mesotheliomas and the expression is reduced or lost in sarcomatoid differentiation; together with the finding that (3) syndecan-1 correlates with WT1 immuno-expression, this suggests that syndecan-1 might relate to the differentiation state of mesothelial/mesothelioma cells; and (4) syndecan-1-positive tumours are associated with a longer survival (p = 0.02) than mesotheliomas with no or little syndecan-1 expression, on univariate analysis. These findings therefore indicate that syndecan-1 can be an important prognostic indicator in mesotheliomas and its loss may be important in the epithelial-mesenchymal transformation of mesothelioma cells.