Uveal Melanoma UK National Guidelines

The United Kingdom (UK) uveal melanoma guideline development group used an evidence based systematic approach (Scottish Intercollegiate Guidelines Network (SIGN)) to make recommendations in key areas of uncertainty in the field including: the use and effectiveness of new technologies for prognostication, the appropriate pathway for the surveillance of patients following treatment for primary uveal melanoma, the use and effectiveness of new technologies in the treatment of hepatic recurrence and the use of systemic treatments. The guidelines were sent for international peer review and have been accredited by NICE. A summary of key recommendations is presented. The full documents are available on the Melanoma Focus website.

Systematic review and meta-analysis of immunohistochemical prognostic biomarkers in resected oesophageal adenocarcinoma

BACKGROUND

Oesophageal adenocarcinoma (OAC) is one of the fastest rising malignancies with continued poor prognosis. Many studies have proposed novel biomarkers but, to date, no immunohistochemical markers of survival after oesophageal resection have entered clinical practice. Here, we systematically review and meta-analyse the published literature, to identify potential biomarkers.

METHODS

Relevant articles were identified via Ovid medline 1946-2013. For inclusion, studies had to conform to REporting recommendations for tumor MARKer (REMARK) prognostic study criteria. The primary end-point was a pooled hazard ratio (HR) and variance, summarising the effect of marker expression on prognosis.

RESULTS

A total of 3059 articles were identified. After exclusion of irrelevant titles and abstracts, 214 articles were reviewed in full. Nine molecules had been examined in more than one study (CD3, CD8, COX-2, EGFR, HER2, Ki67, LgR5, p53 and VEGF) and were meta-analysed. Markers with largest survival effects were COX-2 (HR=2.47, confidence interval (CI)=1.15-3.79), CD3 (HR=0.51, 95% CI=0.32-0.70), CD8 (HR=0.55, CI=0.31-0.80) and EGFR (HR=1.65, 95% CI=1.14-2.16).

DISCUSSION

Current methods have not delivered clinically useful molecular prognostic biomarkers in OAC. We have highlighted the paucity of good-quality robust studies in this field. A genome-to-protein approach would be better suited for the development and subsequent validation of biomarkers. Large collaborative projects with standardised methodology will be required to generate clinically useful biomarkers.

Afatinib use in non-small cell lung cancer previously sensitive to epidermal growth factor receptor inhibitors: the United Kingdom Named Patient Programme

INTRODUCTION

Afatinib prolongs progression-free survival (PFS) in patients with non-small cell lung cancer (NSCLC) who were previously sensitive to erlotinib or gefitinib. This study investigated experience of afatinib under a Named Patient Use (NPU) programme.

PATIENTS AND METHODS

Retrospective data for 63 patients were collected, including demographics, dose, toxicity and clinical efficacy.

RESULTS

Response rate and median PFS were 14.3% and 2.6months, respectively. Diarrhoea and rash were the most common toxicities; 46% of patients required a dose reduction and 41% had a dose delay.

CONCLUSIONS

Efficacy and safety in the NPU programme are consistent with the LUX-Lung 1 trial.

FOXO3 expression during colorectal cancer progression: biomarker potential reflects a tumour suppressor role

BACKGROUND

In previous studies, the Forkhead/winged-helix-box-class-O3 (FOXO3) transcription factor has displayed both tumour suppressive and metastasis-promoting properties.To clarify its role in human colorectal cancer (CRC) progression, we examined in vivo FOXO3 expression at key points of the metastatic cascade.

METHODS

Formalin-fixed paraffin-embedded resection specimens from normal colon, adenomas, primary CRC specimens of different pathological stage and CRC specimens with matched liver metastases were used to generate three separate custom-designed tissue microarray (TMA) representations of metastatic progression. Triplicate cores, immunostained for FOXO3 were scored semiquantitatively by two investigators.

RESULTS

The FOXO3 expression is significantly reduced in CRC specimens compared with normal tissue, and progressive FOXO3 downregulation is associated with advancing pathological stage. In addition, recurrent stage I/II primary tumours show a significantly lower FOXO3 expression compared with stage-matched non-recurrent tumours. When stratified according to high and low FOXO3 expression, mean disease-free survival in the low-expressing group was 28 months (95% CI 15.8-50.6) compared with 64 months (95% CI 52.9-75.4) in the high-expressing group.

CONCLUSION

We have demonstrated an association between low FOXO3 expression and CRC progression in vivo using purpose-designed TMAs. Forkhead/winged-helix-box-class-O3 may represent a novel biomarker of nodal and distant disease spread with clinical utility in CRC.

Melanoma sentinel node biopsy and prediction models for relapse and overall survival

BACKGROUND

To optimise predictive models for sentinal node biopsy (SNB) positivity, relapse and survival, using clinico-pathological characteristics and osteopontin gene expression in primary melanomas.

METHODS

A comparison of the clinico-pathological characteristics of SNB positive and negative cases was carried out in 561 melanoma patients. In 199 patients, gene expression in formalin-fixed primary tumours was studied using Illumina's DASL assay. A cross validation approach was used to test prognostic predictive models and receiver operating characteristic curves were produced.

RESULTS

Independent predictors of SNB positivity were Breslow thickness, mitotic count and tumour site. Osteopontin expression best predicted SNB positivity (P=2.4 × 10⁻⁷), remaining significant in multivariable analysis. Osteopontin expression, combined with thickness, mitotic count and site, gave the best area under the curve (AUC) to predict SNB positivity (72.6%). Independent predictors of relapse-free survival were SNB status, thickness, site, ulceration and vessel invasion, whereas only SNB status and thickness predicted overall survival. Using clinico-pathological features (thickness, mitotic count, ulceration, vessel invasion, site, age and sex) gave a better AUC to predict relapse (71.0%) and survival (70.0%) than SNB status alone (57.0, 55.0%). In patients with gene expression data, the SNB status combined with the clinico-pathological features produced the best prediction of relapse (72.7%) and survival (69.0%), which was not increased further with osteopontin expression (72.7, 68.0%).

CONCLUSION

Use of these models should be tested in other data sets in order to improve predictive and prognostic data for patients.

Response definition criteria for ELISPOT assays revisited

No consensus has been reached on how to determine if an immune response has been detected based on raw data from an ELISPOT assay. The goal of this paper is to enable investigators to understand and readily implement currently available methods for response determination. We describe empirical and statistical approaches, identifying the strengths and limitations of each approach to allow readers to rationally select and apply a scientifically sound method appropriate to their specific laboratory setting. Five representative approaches were applied to data sets from the CIMT Immunoguiding Program and the response detection and false positive rates were compared. Simulation studies were also performed to compare empirical and statistical approaches. Based on these, we recommend the use of a non-parametric statistical test. Further, we recommend that six medium control wells or four wells each for both medium control and experimental conditions be performed to increase the sensitivity in detecting a response, that replicates with large variation in spot counts be filtered out, and that positive responses arising from experimental spot counts below the estimated limit of detection be interpreted with caution. Moreover, a web-based user interface was developed to allow easy access to the recommended statistical methods. This interface allows the user to upload data from an ELISPOT assay and obtain an output file of the binary responses.

Serum is not required for ex vivo IFN-gamma ELISPOT: a collaborative study of different protocols from the European CIMT Immunoguiding Program

The Cancer Immunotherapy Immunoguiding Program has conducted an IFN-γ ELISPOT proficiency panel to examine the influence of serum supplementation of test media on assay performance. Sixteen European laboratories analyzed the same PBMC samples using different locally established protocols. Participants generated two simultaneous data sets—one using medium supplemented with serum and one without serum. Performances of the two test conditions were compared by quantifying: (1) the number of viable cells, (2) background spot formation induced in the medium only control and (3) the ability to detect antigen-specific T cell responses. The study demonstrated that the number of viable cells recovered and the overall background spot production were not significantly different between the two conditions. Furthermore, overall laboratory performance was equivalent for the two test conditions; 11 out of 16 laboratories reported equal or greater detection rates using serum-free medium, while 5 laboratories reported decreased detections rates under serum-free conditions. These results show that good performance of the IFN-γ ELISPOT assay can be achieved under serum-free conditions. Optimization of the protocol for serum-free conditions should result in excellent detection rates and eliminate the requirement of serum batch and stability testing, allowing further harmonization of the assay.

The CIMT-monitoring panel: a two-step approach to harmonize the enumeration of antigen-specific CD8+ T lymphocytes by structural and functional assays

The interpretation of the results obtained from immunomonitoring of clinical trials is a difficult task due to the variety of methods and protocols available to detect vaccine-specific T-cell responses. This heterogeneity as well as the lack of standards has led to significant scepticism towards published results. In February 2005, a working group was therefore founded under the aegis of the Association for Immunotherapy of Cancer ("CIMT") in order to compare techniques and protocols applied for the enumeration of antigen-specific T-cell responses. Here we present the results from two consecutive phases of an international inter-laboratory testing project referred to as the "CIMT monitoring panel". A total of 13 centers from six European countries participated in the study in which pre-tested PBMC samples, synthetic peptides and PE-conjugated HLA-tetramers were prepared centrally and distributed to participants. All were asked to determine the number of antigen-specific T-cells in each sample using tetramer staining and one functional assay. The results of the first testing round revealed that the total number of cells analyzed was the most important determinant for the sensitive detection of antigen-specific CD8(+) T-cells by tetramer staining. Analysis by ELISPOT was influenced by a combination of cell number and a resting phase after thawing of peripheral blood mononuclear cells. Therefore, the experiments were repeated in a second phase but now the participants were asked to change their protocols according to the new guidelines distilled from the results of the first phase. The recommendations improved the number of antigen-specific T-cell responses that were detected and decreased the variability between the laboratories. We conclude that a two-step approach in inter-laboratory testing allows the identification of distinct variables that influence the sensitivity of different T-cell assays and to formally show that a defined correction to the protocols successfully increases the sensitivity and reduces the inter-center variability. Such "two-step" inter-laboratory projects could define rational bases for accepted international guidelines and thereby lead to the harmonization of the techniques used for immune monitoring.

An open-label phase II study of sorafenib and dacarbazine as first-line therapy in patients with advanced melanoma

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Background: Sorafenib (SOR) exerts anti-tumor and anti-angiogenic effects via inhibition of VEGFR-1,-2,-3, PDGFR-a, -β and Raf. In a phase I, study SOR + dacarbazine (DTIC) as first-line therapy for advanced melanoma patients (pts) was well-tolerated and had activity. Methods: In this multicenter, phase II, open-label, uncontrolled, 2-stage study, eligibility criteria included: measurable disease by RECIST, ECOG performance status 0 or 1, no prior chemotherapy. Prior immunotherapy was allowed. Planned sample size was 82 pts based on a Simon 2-stage optimal design. Pts were treated with oral SOR 400 mg bid daily combined with repeated 21-day cycles of iv DTIC 1,000 mg/m2 given on day 1 of each cycle until occurrence of progressive disease or intolerable toxicity. The primary endpoint was overall tumor response rate using RECIST. Secondary endpoints included progression-free survival (PFS), overall survival (OS), safety and toxicity. Results: 30 and 53 pts were treated in Stages I and II, respectively. Baseline characteristics were as follows: median age 56 yrs; 60% male, 34% ECOG 1, 80% AJCC Stage IV M1c; 31% elevated LDH. Eight (10%) pts had partial responses, 34 (41%) had stable disease, 32 (39%) had progressive disease and 9 (11%) were not evaluable. The median PFS was 14 wks (95% CI 12, 19; 28% censored). PFS rates at 3 & 6 mos were 56% (45%, 67%; 13% censored) and 33% (22%, 45%; 24% censored), respectively. Median OS was 41 wks (28, 59, 63% censored). Grade 3/4 drug-related adverse events included: neutrophils 33%, platelets 22%, hand-foot skin reaction 8%, fatigue 7% and abdominal pain 6%. 1 patient had febrile neutropenia. To correlate treatment response with mutational status, melanoma samples from 20 pts were analyzed for mutations in B-RAF (exon 15) and PI3Kinase (exons 9 & 20). 3 of 20 samples had V600E mutations in B- RAF; no PI3Kinase alterations were detected. Conclusions: Addition of SOR to DTIC was well-tolerated and resulted in encouraging PFS and OS rates in this poor prognostic cohort of patients. The data are promising as compared with published results of DTIC alone in metastatic melanoma (RR 7.5%, PFS 6 wks; Bedikian et al. 2006). A recently completed randomized Phase II trial will provide additional information on the efficacy of this combination regimen.

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Vinflunine -- an active chemotherapy for treatment of advanced non-small-cell lung cancer previously treated with a platinum-based regimen: results of a phase II study

A multicentre, single-arm, phase II trial designed to determine the efficacy of single-agent vinflunine in patients with advanced non-small-cell lung cancer (NSCLC) previously treated with a platinum-based regimen. The objectives were to assess efficacy in terms of tumour response rate (primary end point), duration of response, progression-free survival (PFS) and overall survival (OS), and to evaluate the toxicity associated with this treatment. Patients with advanced NSCLC with progressive disease having failed prior platinum-based first-line treatment for advanced disease. Five responses out of the 63 treated patients were documented by WHO criteria and validated by an independent panel review (IRP), yielding a response rate of 7.9% (95% CI: 2.6–17.6) in the intent-to-treat analysis and 8.3% (95% CI: 2.8–18.4) in the evaluable population. Disease control was achieved in 35 out of 60 evaluable patients (58.3%). The median duration of response (complete response+partial response), according to modified WHO criteria was 7.8 months (95% CI: 4.6–NR). Median PFS was 2.6 months (95% CI: 1.4–3.8), and the median survival was 7.0 months (95% CI: 5.8–9.2). Grades 3–4 neutropenia was reported in 50% of patients; febrile neutropenia was observed in two patients (3.2%); grades 3–4 myalgia and grade 3 constipation were experienced by 10 (15.9%) and six (9.5%) of patients, respectively. Constipation was manageable, noncumulative and could be prevented with laxative prophylaxis. The encouraging results from this phase II study with vinflunine warrant further investigations in phase III trials as second- or first-line treatment of advanced non-small-cell lung carcinoma, as a single agent or in combination with other active drugs.

Phase I/II trial of a PrimeBoost therapeutic vaccine in stage III/IV metastatic melanoma

8030

Background: This trialevaluated the safety, immunogenicity and tumour response of increasing doses of DNA plasmid (DNA.Mel3) and MVA viral vector (MVA.Mel3), containing 7 melanoma epitopes. Methods: 41 HLA-A2 positive stage III/IV melanoma patients with unresectable measurable disease were enrolled. Immunisations were administered three weeks apart with continued MVA.Mel3 boosting in patients with tumour control. Epitope-specific CD8+ T cell responses were evaluated using ex vivo tetramer staining and interferon gamma (IFN-γ) ELISPOT assay. Results: DNA.Mel3 was well tolerated at all doses. Dose-related grade 3 local skin reactions and systemic immune-associated reactions were observed following MVA.Mel3, no reactions led to early study discontinuation. Melan-A tetramer responses were observed in 23/36 (64%) evaluable patients, of which 9/36 showed an IFNγ response to at least one epitope in ELISPOT assay. Seven patients (17%) showed tumour control (PR, MR, or SD >6 months), of which 3/7 patients had associated immune responses, including one with PR > 21 months who underwent extended MVA.Mel3 boosting. Overall median progression free survival was 9 weeks (16 weeks for immune responders). Median overall survival for the intention-to-treat population is 11.7 months with follow up of 16 patients continuing. Conclusions: High dose heterologous PrimeBoost immunisation was safe and stimulated immune responses in >50% of late stage metastatic melanoma patients treated. Tumour control was observed with some evidence of association with immune response.

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The classification of lymphomas and leukemias

Classifications of lymphomas and leukemias have developed from two distinct clinical needs - to understand the natural history of these diseases in order to predict outcome and to make treatment decisions in a rational fashion. The utility of classifications for research on etiology of these diseases has not guided their development in the past. The classification of leukemias and lymphomas has undergone dramatic changes with increasing understanding of the development of the normal immune cells. Historically, the first entity to be recognised was Hodgkin disease. Other malignancies of the lymphatic system were then called 'Non-Hodgkin Lymphomas' (NHL), a distinction that remains valid even today. Cancers that tend not to form distinct masses but usually present with a raised white blood cell count were called leukemias. As knowledge has improved, however, the early juxtaposition of leukemias versus lymphomas has lost relevance, since often the same entity can present in either way. With better understanding the terms 'lymphosarcoma' and 'reticulosarcoma', which were earlier widely applied have been replaced by more precise terminology. Different classifications have been put forward over the years. The 'Revised European and American Classification of Lymphoid Neoplasms' and the derived WHO classification are structured to mirror normal B/T-cell differentiation. In these modern classifications, distinct disease entities are defined based on the combination of morphology, immunological and molecular techniques and clinical features. The proposed major groups of lymphoid neoplasms are B-cell lymphomas/leukemias, T/Natural Killer-cell lymphomas/leukemias and Hodgkin disease. About 20 entities are recognised. This provides for the first time a truly international view of lymphomas and leukemias. It has emerged that such a classification can be used successfully by expert hematopathologists and yields highly reproducible results. It is also clear that no single marker, be it morphology, genetic analysis or immunophenotyping can be used as the 'gold standard' for diagnosis but that a combination of techniques is needed.

Immunocytochemical assessment of bone marrow aspirates for monitoring response to chemotherapy in small-cell lung cancer patients

Recent reports have suggested that tumour cell immunodetection in bone marrow of small-cell lung cancer patients is by far more frequent than found cytohistologically and may have clinical relevance. This study evaluates primarily the efficacy of chemotherapy as method of in vivo purging, but also the relationship of marrow involvement with survival. A total of 112 bone marrow aspirates from 30 chemo-naïve patients were stained twice using anti-NCAM antibodies, first at diagnosis and then after chemotherapy (24 patients) or at disease progression (six patients). Marrow contamination was associated with lower survival (P = 0.002), and was also detected in 7/17 patients conventionally staged as having limited disease. At multivariate analysis, marrow involvement was an independent factor of unfavourable prognosis (P = 0.033). The amount of tumour contamination, before and after chemotherapy, remained unchanged also in responders and even in the subset of patients with apparent limited disease. Following chemotherapy, bone marrow became tumour negative only in 25% of initially positive responders and in none of non-responders. Our results indicate that (i) chemotherapy is not effective in purging bone marrow even in chemo-responsive patients and (ii) a subset of patients with limited disease and negative bone marrow aspirates might have a more favourable prognosis.

Insight into the origin and clonal history of B-cell tumors as revealed by analysis of immunoglobulin variable region genes

Recombination of VH, DH and JH genes is a unique first step in normal B-cell development. Subsequent differentiation to a mature plasma cell is accompanied by further events in the Ig genes, including VL-JL joining, somatic hypermutation and isotype switching. Chromosomal changes leading to B-cell tumors can occur at many points in this sequence, and may be partly a consequence of the genetic mobility and mutability permitted in order to generate a diverse antibody repertoire. V genes of neoplastic B cells may reflect the point of maturation reached by the B cell of origin, prior to transformation. Analysis of tumors therefore provides useful information on V-gene patterns in normal B cells, and may add another dimension to classification of B-cell tumors. Transformation may also preserve cell populations normally destined to die by apoptosis. Tumor cells arrested in the site where somatic hypermutation and isotype switch are occurring can still be subject to these processes, and could be influenced by persisting antigen. However, mutation is silenced at the point of exit to the periphery, leading to fixed mutational patterns in tumors of mature B cells. V-gene analysis provides an invaluable tool for understanding the genesis of neoplastic change. It also has a clear clinical relevance in tracking tumor cells, measuring residual disease, and finally in offering the opportunity of developing vaccines for treatment.

Absence of constitutive EGF receptor activation in ovarian cancer cell lines

Previous investigators have noted that certain ovarian cancer cell lines secrete and respond to transforming growth factor-alpha (TGF-alpha), suggesting that endogenous activation of the epidermal growth factor (EGF) receptor through autocrine or paracrine mechanisms might contribute to the proliferative response. In order to determine whether autocrine stimulation was partly responsible for the proliferative response in ovarian cancer, we investigated whether the EGF receptor expressed by ovarian cancer cell lines was constitutively activated as assessed by the presence of tyrosine phosphorylation. A specific anti-phosphotyrosine antibody was used in conjunction with an immunoblotting technique in order to detect EGF receptor phosphorylation in ovarian cancer cell lines in the absence and presence of exogenous EGF. The effects of neutralising anti-EGF receptor antibody on the proliferation of ovarian cancer cell lines was also examined. We found no evidence for constitutive tyrosine phosphorylation of the p170 EGF receptor in eight epithelial ovarian cancer cell lines tested, although each line demonstrated inducible phosphorylation in response to exogenous EGF. The absence of constitutive EGF receptor activation was also noted when cells were grown under high density conditions, thus excluding a role for membrane-bound EGF or TGF-alpha in this process. Media conditioned by five ovarian cancer cell lines, as well as malignant ascites obtained from 12 different ovarian cancer patients, were not capable of stimulating EGF receptor phosphorylation. Finally, the proliferation of ovarian cancer cell lines was not significantly inhibited in the presence of neutralising anti-EGF receptor antibody. These data suggest that EGF receptor activation through autocrine pathways is not a major mechanism for the growth of many ovarian cancer cell lines. Other pathways of signal transduction which bypass the requirement for EGF receptor activation may be important in the proliferation for ovarian cancer cells. Such EGF receptor-independent pathways may limit the effectiveness of strategies designed to inhibit ovarian cancer cell growth through disruption of EGF receptor function.

CD44 variant expression is a common feature of epithelial ovarian cancer: lack of association with standard prognostic factors

PURPOSE

CD44 is a hyaluronic acid receptor that exists as a standard 90-kd form (CD44S) as well as several CD44 variant isoforms produced through alternative splicing. Expression of CD44 variants is associated with clinically aggressive behavior in some human tumors. The purpose of the present study is to define the expression of CD44 variant isoforms in ovarian cancer and to investigate whether the expression of these molecules is associated with adverse prognosis.

MATERIALS AND METHODS

Six specimens of normal ovarian surface epithelium (NOSE) and 31 separate cases of newly diagnosed ovarian cancer were studied by a combination of reverse-transcription polymerase chain reaction (RT-PCR) and immunoperoxidase staining. Clinical correlation was made between CD44 variant expression and stage (I/II v III/IV), residual disease (< or = 2.0- v > 2.0-cm mass), age (< or = 65 v > 65 years), histology (papillary serous v other), grade, and survival.

RESULTS

RT-PCR analysis revealed that NOSE predominantly expressed transcripts for CD44S, as well as a restricted pattern of transcripts characteristic of CD44 splice variants. CD44S and CD44 variant exon nine sequences (CD44-9v) were focally expressed in one of two NOSE specimens examined by immunoperoxidase staining. In comparison, the majority (71%) of ovarian cancer specimens expressed a complex pattern of CD44 splice variants by RT-PCR analysis. Immunoperoxidase studies revealed that the majority of ovarian cancer specimens expressed both CD44S and CD44-9v, whereas expression of sequences from variant exons 3, 4, and 6 was uncommon. There was no association between CD44 variant expression (transcript or protein) and stage, residual disease, age, histology, grade, or survival.

CONCLUSION

Expression of CD44S and CD44-9v is a common feature of epithelial ovarian cancer cells. The lack of a significant association between CD44 variant expression and prognosis suggests that other factors may be more important in determining the clinical behavior of this disease.

Expression and function of beta 1 and alpha v beta 3 integrins in ovarian cancer

Ovarian cancer cells disseminate by implanting onto the peritoneal mesothelial cell surface of the abdominal cavity. A common feature of these peritoneal implants is the presence of tumor cell invasion into the submesothelial extracellular matrix (ECM). In view of the important role of integrins in ECM recognition and cell migration, we were interested in defining the pattern of integrin expression and function in ovarian cancer cell lines and primary tissue samples. The beta 1 integrin chain was expressed by CAOV-3, SKOV-3, OVCAR-3, and SW626 ovarian cancer cell lines, associated with expression of alpha 1, -2, -3, -5, and -6 chains. The alpha 4 chain was also expressed by two of the four lines. In addition to beta 1 integrins, the alpha v beta 3 integrin was also expressed, although there was no expression of beta 2, -4, and -7 chains. Immunoprecipitation of surface-labeled CAOV-3 cells with an anti-beta 1 antibody revealed a band at approximately 110-130 kDa consistent with the known molecular mass of the beta 1 chain, as well as several associated bands consistent with noncovalently linked integrin alpha chains. A similar pattern of beta 1 and alpha v beta 3 integrin expression was observed for primary ovarian cancer tissue samples. Ovarian cancer cell lines exhibited significant binding to collagen type I and laminin which was primarily mediated by beta 1 integrins. In contrast, ovarian cancer cell binding to fibronectin was mediated by both alpha 5 beta 1 and alpha v beta 3 integrins. Even though mesothelial cells were observed to express fibronectin mRNA and protein, binding of ovarian cancer cells to peritoneal mesothelium was not blocked by neutralizing antibodies to beta 1 or alpha v beta 3 integrins. These data suggest that functional integrins are commonly expressed by ovarian cancer cells, although they do not appear to mediate ovarian cancer cell implantation onto peritoneal mesothelium. The role that integrins play in the invasion of ovarian cancer cells into the submesothelial ECM deserves further investigation.

Vascular cell adhesion molecule-1 expressed by peritoneal mesothelium partly mediates the binding of activated human T lymphocytes

Adhesion molecules such as selectins and integrins are known to mediate leukocyte attachment and transmigration through activated vascular endothelium. However, the molecules that mediate subsequent leukocyte entry into nonvascular spaces such as the abdominal cavity during states of peritoneal inflammation have not been identified. Because the peritoneal mesothelial lining represents the final barrier to leukocyte migration into the abdomen, it is likely that adhesion molecules expressed by mesothelial cells are involved in this process. We have developed an in vitro binding assay using confluent layers of normal human mesothelial cells to determine which adhesion molecules might be involved in T lymphocyte-mesothelial recognition. Normal peripheral blood T lymphocytes exhibit low-level specific binding to mesothelium (mean 13% specific binding, n = 4), which is enhanced by phorbol myristate acetate (PMA) treatment (mean 38% specific binding, n = 4). This binding is significantly inhibited in the combined presence of antibodies reactive with CD29 and CD18, suggesting a role for beta 1 and beta 2 integrins, respectively, in this interaction. Interestingly, cultured human mesothelial cells were shown to express vascular cell adhesion molecule-1 (VCAM-1), suggesting that this molecule might function as a counter-receptor for alpha 4 beta 1 expressed by T lymphocytes. Mesothelial cells were also noted to express ICAM-1, CD29, and CD44, but not CD18 or selectins. VCAM-1 expression was not a constitutive property of freshly obtained mesothelial cells but was inducible upon culture in the presence of either interleukin-1 (IL-1), tumor necrosis factor (TNF), or PMA. Neutralizing antibodies reactive with either alpha 4, VCAM-1, or CD29 were all equally capable of inhibiting the binding of activated leukocytes to mesothelial cells (in the presence of anti-CD18 antibody). Mesothelial VCAM-1 was found to have a molecular mass of 110 kD and an mRNA transcript of approximately 3.2 kb, consistent with the predominant VCAM-1 species found in activated endothelium. These data suggest that functional VCAM-1 is expressed on activated mesothelial cells and may play a role in the distal arm of leukocyte trafficking to the abdominal cavity.

Binding of ovarian cancer cells to peritoneal mesothelium in vitro is partly mediated by CD44H

Epithelial cancer of the ovary spreads by implantation of tumor cells onto the mesothelial lining of the peritoneal cavity. We have developed an in vitro binding assay using confluent monolayers of normal peritoneal mesothelial cells in order to assess the role of known adhesion proteins in this process. Cells from normal ovarian surface epithelium and the ovarian cancer cell lines CAOV-3 and SKOV-3 exhibited significant adhesion to mesothelium in vitro (range 33-56% specific binding). Although these cells expressed several adhesion molecules, including CD44 and integrins such as alpha 4 beta 1, alpha 5 beta 1, and alpha v beta 3, only anti-CD44 antibody was capable of inhibiting mesothelial binding (range 42-44% inhibition). Adhesion molecule expression was also determined for fresh ovarian specimens, with CD44 being expressed in 2 of 2 cases of normal ovarian epithelium, 15 of 16 (94%) cases of tissue-derived tumor (from primary sites or peritoneal implants), and only 2 of 8 (25%) cases of free-floating tumor cells from ascites. Three of three CD44-positive cases derived from peritoneal implants exhibited significant mesothelial binding which was partly blocked by anti-CD44 antibody, whereas 2 of 2 CD44-negative cases derived from ascites showed minimal binding. CD44-mediated binding of ovarian cancer cells was determined to be due to recognition of mesothelium-associated hyaluronate, suggesting that the CD44H isoform was involved in this process. Immunoprecipitation of the CD44 species expressed by ovarian cancer cells revealed 2 major bands at 85-90 and 180 kDa, consistent with the known molecular masses of CD44H. These results suggest that CD44H may be an important mediator of ovarian cancer cell implantation and that decreased CD44H expression may be associated with release of cells into the peritoneal space during ascites formation. It is possible that strategies to interfere with CD44H function may result in decreased intraabdominal spread of this highly lethal neoplasm.

Interleukin-2 followed by fluorouracil and folinic acid in refractory colorectal cancer--results of a clinical phase II study

In a clinical phase II study, 23 patients with progressive metastatic colorectal cancer and failure after first-line chemotherapy with fluorouracil (5-FU) and folinic acid (FA) were treated with a 5-day continuous infusion of recombinant interleukin-2 (IL-2), 3 x 10(6) cetus U/m2/d, followed after a rest period of 2 days by 5-FU, 600 mg/m2/d, and FA, 300 mg/m2/d over an additional 3 days. After two to four treatment cycles, eight of 22 evaluable patients (36%) revealed antitumor responses, with three partial remissions and five minor responses or stable disease. Side effects consisted most frequently of fever, nausea and vomiting, an elevation of liver enzymes, hypotension, and skin toxicity, and required a 50% reduction of IL-2 dose in 17 of 71 treatment courses (24%). In four of the 23 patients (18%), treatment had to be stopped completely. These data indicate a significant antitumor activity of IL-2 combined with 5-FU/FA therapy in chemotherapy-resistant colorectal cancer. Hence, in spite of a substantial treatment-related toxicity, further studies are warranted to substantiate these findings and to elucidate the underlying mechanisms of the IL-2-5-FU/FA combination therapy.

Treatment of advanced chronic lymphocytic leukemia by fludarabine. Results of a clinical phase-II study

In a clinical phase-II study fludarabine phosphate was given to 20 patients with advanced chronic lymphocytic leukemia who had failed on prior conventional therapy. Fludarabine was administered at a dose of 25 mg/m2/d for 5 days. Treatment cycles were repeated every 4 weeks until maximal response, followed by two cycles for consolidation. Four of the 20 patients achieved complete remission and seven patients partial remission, resulting in an overall response rate of 55% (11/20). Fludarabine therapy was well tolerated, with mild myelosuppression and secondary infections comprising the predominant side effects. These data warrant further confirmation and a randomized comparison of fludarabine with established regimens, which is currently underway.