Melanoma: Ruiter DJ

van Everdingen JJ, van der Rhee HJ, Koning CC, Nieweg OE, Kruit WH, Coebergh JW, Ruiter DJ, Anonymous00197. · Kwaliteitsinstituut voor de Gezondheidszorg CBO, Postbus 20.064, 3502 LB Utrecht. · Ned Tijdschr Geneeskd. · Pubmed #16128181 No free full text.

Abstract: The guidelines 'Melanoma' (3rd revision) are evidence-based in nature. A number of outcomes are summarised in this article. Dermatoscopy deserves a standard role in the clinical diagnosis of pigmented skin abnormalities. Pathological findings from a diagnostic excision should be recorded meticulously to include anatomical localisation, type of intervention used, excision margin, diagnosis, Breslow thickness, and the completeness of the removal. The sentinel node procedure should be reserved for patients who want to be as informed as possible about their prognosis. The procedure is not considered a part of standard diagnosis. Sentinel node assessment should include stains for specific markers and should be conducted in multiple sections. The following margins of non-affected skin are recommended for therapeutic re-excision of melanoma: in situ melanoma, 0.5 cm; Breslow thickness < or = 2 mm, 1 cm; Breslow thickness > 2 mm, 2 cm. Pathological assessment of a re-excised specimen depends on the completeness of the first excision. Systematic adjuvant treatment of patients with melanoma is not recommended outside the context of a clinical study. Patients with metastatic melanoma are preferably treated within a clinical study. Outside of a clinical study, these patients should be treated with dacarbazine. There is no evidence to suggest that survival is improved by frequent follow-up. However, follow-up can be a useful way to meet the information needs of patients and care requirements for physicians.

van Kempen LC, van Muijen GN, Ruiter DJ. · No affiliation provided · Eur J Cell Biol. · Pubmed #17241688 No free full text.

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Ruiter DJ, Spatz A, van den Oord JJ, Cook MG, Anonymous00132. · No affiliation provided · J Pathol. · Pubmed #11745686 No free full text.

Abstract: Recent papers have addressed critical issues regarding the microstaging of cutaneous melanoma. They concern the new staging proposal by the American Joint Committee on Cancer (AJCC), the presentation of new prognostic models than seem applicable in daily practice, and new immunohistochemical findings than demonstrate prognostic information independently of the conventional major factors. These issues are commented on by the Pathology Committee of the EORTC Melanoma Group.

Ruiter DJ, Testori A, Eggermont AM, Punt CJ. · No affiliation provided · Ann Oncol. · Pubmed #11249056 links to  free full text

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Clarijs R, Ruiter DJ, de Waal RM. · Department of Pathology, University Medical Centre, Nijmegen, The Netherlands. · J Pathol. · Pubmed #11180158 No free full text.

Abstract: The development of a vascular bed is essential for solid tumour growth and metastasis. In many tumours, mean vascular density can be related to the rate of metastasis and, therefore, to prognosis. In other tumour types, such as cutaneous melanoma and head-and-neck squamous cell carcinoma, this relation is absent. Until now, the reason for this has been unclear, but since these particular tumour types are also known for their propensity to spread via the lymphatic system, it may be speculated that the presence of a pre-existing lymphatic bed and the formation of new lymphatics (lymphangiogenesis) are important factors. Growth factors involved in lymphangiogenesis during embryogenesis have been recently identified and these are also expressed in many tumour types, but the existence of tumour-induced lymphangiogenesis has not so far been reported. Partly, this could be due to the lack of reliable endothelial markers, thereby hampering a consistent evaluation of lymphatic vasculature. This editorial discusses the role of the lymphatic bed in mediating the metastasis of solid tumours, summarizes known methods to detect lymphatics, and proposes a hypothetical mechanism of tumour-induced lymphangiogenesis.

Ruiter DJ, Herlyn M. · Department of Pathology, University Medical Center, Nijmegen, The Netherlands. · J Dtsch Dermatol Ges. · Pubmed #16281812 No free full text.

Abstract: Cutaneous melanoma is an aggressive tumor which can metastasize early in its course. Not only the melanoma cells but also the tumor microenvironment play an important role in tumor development and progression. We review the structural and functional aspects of interactions between melanoma cells and the stroma and discuss some clinical implications.

van Kempen LC, van Muijen GN, Ruiter DJ. · Department of Pathology, Radboud University Nijmegen Medical Center, PO box 9101, 6500 HB Nijmegen, The Netherlands. · Front Biosci. · Pubmed #15970546 No free full text.

Abstract: Tumour development and progression has long been considered as the consequence of an imbalance between apoptosis and proliferation of transformed cells. However, whereas genetic aberrations leading to the activation of oncogenes and/or loss of tumour suppressor genes are crucial for the transformation towards aberrant cell growth, progression towards a full blown malignancy requires a dynamic interaction between tumour cells and the environment in which they thrive. Over the recent years, it has become evident that the (early) inflammatory and angiogenic response, and remodelling of the extracellular proteins are key factors in creating a microenvironment that sustains tumour growth and metastasis. The host response towards cutaneous melanoma has received relatively little attention, most likely because the majority of these tumours develop without evoking a strong stromal response as can be observed in, e.g., carcinomas. This review discusses potential critical modulators of melanoma growth: turn-over of the most abundant extracellular matrix protein in skin (i.e. type I collagen), the early inflammatory response and angiogenesis.

de Wit NJ, van Muijen GN, Ruiter DJ. · Department of Pathology, University Medical Centre St Radboud, Nijmegen, The Netherlands. · Histopathology. · Pubmed #15186267 No free full text.

Abstract: Melanoma incidence is rising worldwide. Early diagnosis is very important, as the most effective treatment for melanoma still consists of excision of the tumour before onset of the metastatic growth phase. Immunohistochemistry is a valuable tool for (dermato)pathologists to aid establishing diagnosis. Melanoma markers can be classified into two main categories: melanocytic differentiation markers and melanoma progression markers. Melanocytic differentiation markers are mostly used to distinguish poorly differentiated melanomas from non-melanocytic tumours and for staging of melanocytic proliferative lesions. Melanoma progression markers are most suitable to determine the level of malignancy and/or aggressiveness of tumour cells. This review describes the classification of melanoma markers, including commonly used and recently identified antigens with potential marker function. We characterize their expression profile in melanocytic proliferative lesions and their potential usefulness for diagnosis, prognosis, microstaging, immunotherapeutic purposes and evaluation of therapies.

van Kempen LC, Ruiter DJ, van Muijen GN, Coussens LM. · University Medical Center Nijmegen, Department of Pathology, Nijmegen, The Netherlands. · Eur J Cell Biol. · Pubmed #14703010 No free full text.

Abstract: Evolution of neoplastic cells has generally been regarded as a cumulative intrinsic process resulting in altered cell characteristics enabling enhanced growth properties, evasion of apoptotic signals, unlimited replicative potential and gain of properties enabling the ability to thrive in ectopic tissues and in some cases, ability to metastasize. Recently however, the role of the neoplastic microenvironment has become appreciated largely due to the realization that tumors are not merely masses of neoplastic cells, but instead, are complex tissues composed of both a non-cellular (matrix proteins) and a cellular 'diploid' component (tumor-associated fibroblasts, capillary-associated cells and inflammatory cells), in addition to the ever-evolving neoplastic cells. With these realizations, it has become evident that early and persistent inflammatory responses observed in or around many solid tumors, play important roles in establishing an environment suitable for neoplastic progression by providing diverse factors that alter tissue homeostasis. Using cutaneous melanoma and squamous cell carcinoma as tumor models, we review the current literature focussing on inflammatory and tumor-associated fibroblast responses as critical mediators of neoplastic progression for these malignancies.

Ruiter DJ, van Dijk MC, Ferrier CM. · Department of Pathology, University Medical Center Nijmegen, Nijmegen, The Netherlands. · Semin Cutan Med Surg. · Pubmed #12773012 No free full text.

Abstract: The histopathological diagnosis of cutaneous melanocytic lesions may be difficult to assess. Frequently encountered diagnostic problems include: 1) Dysplastic nevus or melanoma in situ?; 2) Melanoma in situ or superficial spreading melanoma?; 3) Lentigo maligna or lentigo maligna melanoma?; 4) Compound nevocellular nevus or nevoid melanoma?; and 5) Spitz nevus or Spitzoid melanoma? Moreover, less frequently encountered diagnostic challenges are discussed: 1) Deep penetrating nevus or nodular melanoma?; and 2) Cellular blue nevus or melanoma metastasis? In this contribution, these problems are discussed after a systematic approach involving a concise histopathological description of the classic lesions considered in the differential diagnoses, a presentation of the deviating histopathological features that give rise to the diagnostic problems, and finally diagnostic recommendations on the classification of the problematic lesions. We also briefly discuss the contribution of additional immunohistochemistry and molecular pathology in aiding to establish a correct diagnosis.

Zendman AJ, Ruiter DJ, Van Muijen GN. · Department of Pathology, University Medical Center St. Radboud, Nijmegen, The Netherlands. · J Cell Physiol. · Pubmed #12548548 No free full text.

Abstract: Cancer/testis-associated genes (CTAs) are a subgroup of tumor antigens with a restricted expression in testis and malignancies. During the last decade, many of these immunotherapy candidate genes have been discovered using various approaches. Most of these genes are localized on the X-chromosome, often as multigene families. Methylation status seems to be the main, but not the only regulator of their specific expression pattern. In testis, CTAs are exclusively present in cells of the germ cell lineage, though there is a lot of variation in the moment of expression during different stages of sperm development. Likewise, there is also a lot of heterogeneity in the expression of CTAs in melanoma samples. Clues regarding functionality of CTAs for many of these proteins point to a role in cell cycle regulation or transcriptional control. Better insights in the function of these genes may shed light on the link between spermatogenesis and tumor growth and could be of use in anti-tumor therapies. This review outlines the CTA family and focuses on their expression and putative function during male germ cell development and melanocytic tumor progression.

Clarijs R, Ruiter DJ, De Waal RM. · Department of Pathology, University Medical Center Nijmegen, the Netherlands. · J Cell Physiol. · Pubmed #12548547 No free full text.

Abstract: Clinical outcome of cancer patients is mainly determined by the rate of metastasis and, also by primary tumor growth. Formation of extracellular matrix and interactions of neoplastic and non-neoplastic (host) cells in solid tumors have been shown to be essential for these processes. One result of such interactions is the outgrowth of new blood vessels from existing ones, angiogenesis, to provide the tumor tissue with oxygen and nutrients. It is assumed that the neovascular bed also facilitates the escape of metastatic cells from the primary lesions. In addition, recent reports suggested the existence of blood-conducting channels lined by melanoma cells (so-called "vascular channels") accompanied by depositions of extracellular matrix patterns in cutaneous and uveal melanoma. Since the presence of these matrix structures has been negatively associated with prognosis, we hypothesize that they play a role in melanoma outgrowth or metastasis. In this review, we will discuss the morphological and functional properties of the extracellular matrix patterns in that may underlie these clinical phenomena.

Ruiter DJ, Spatz A, van den Oord JJ, Cook MG, Anonymous00233. · Department of Pathology, University Medical Center St Radboud, Nijmegen, The Netherland. · Semin Oncol. · Pubmed #12170440 No free full text.

Abstract: The American Joint Committee on Cancer (AJCC) recently launched a new staging system for cutaneous melanoma that was based on clinical experience with a large number of patients treated in major centers worldwide. As this system includes various histopathologic parameters of the primary melanoma and of melanoma metastasis, including micrometastases in the sentinel lymph node (SLN), they are discussed here. Special attention is given to ulceration of the primary tumor, because it remains a dominant prognostic parameter in addition to tumor thickness. Molecular markers that may reflect aggressive behavior of the primary melanoma also are described. Finally, pathologic examination of SLNs is addressed with emphasis on the efficacy of various microstaging approaches.

Hofmann UB, Westphal JR, Van Muijen GN, Ruiter DJ. · Department of Pathology, University Hospital, Nijmegen, The Netherlands. · J Invest Dermatol. · Pubmed #10951266 links to  free full text

Abstract: Cutaneous melanoma is a highly invasive and metastatic tumor. Degradation of basement membranes and extracellular matrix is an essential step in melanoma cell migration, invasion, and metastasis formation. Matrix metalloproteinases and their tissue inhibitors play a crucial role in these complex multistep processes. Melanoma cells may express a number of matrix metalloproteinase family members (MMP-1, MMP-2, MMP-9, MMP-13, and MT1-MMP) as well as their tissue inhibitors (TIMP-1, TIMP-2, and TIMP-3). Numerous studies have examined matrix metalloproteinases, their tissue inhibitors, and the molecules that regulate their expression and/or activation in melanoma cell lines in vitro and in vivo, and in human melanocytic lesions. Recent results have indicated that adhesion molecules such as CD44 and integrin alphavbeta3 are involved in positioning activated matrix metalloproteinase molecules on the cell surface of invasive tumor cells. In this review we evaluate these novel aspects of the role of matrix metalloproteinases and their tissue inhibitors in melanoma progression. We conclude that the balance between levels of activated matrix metalloproteinases and expression levels of their tissue inhibitors, and the coexpression of activated matrix metalloproteinases and adhesion molecules are important factors in determining melanoma cell invasion, tumor growth, and metastasis formation.

Kroon BB, Bergman W, Coebergh JW, Ruiter DJ. · Department of Surgery, The Netherlands Cancer Institute/Antoni van Leeuwenhoek ziekenhuis, Amsterdam. · Melanoma Res. · Pubmed #10465575 No free full text.

Abstract: In 1996 the Dutch Melanoma Working Party, in co-operation with the National Organization for Quality Assurance in Hospitals in the Netherlands and the Dutch Association of Comprehensive Cancer Centres, organized the third consensus conference on the management of melanoma of the skin. The following guidelines were approved. The recommended margin for diagnostic excision is 2 mm of macroscopically normal skin around the lesion; the margins for therapeutic excision are 1 cm of normal skin for a Breslow thickness of < or = 2 mm and 2 cm for a Breslow thickness of > 2 and < or = 4 mm. A margin of at least 2 cm also appears to be justified for thicker melanomas. Elective lymph node dissection is not recommended. Sentinel node biopsy appears to be a promising method to detect occult metastases in the regional lymph nodes. If regional lymph node metastases are present, therapeutic regional lymph node dissection must be conducted. Isolated regional perfusion is indicated for inoperable tumour growth in an extremity. Radiotherapy can be applied curatively (for example, if surgery is not possible), palliatively (if desired in combination with hyperthermia) or postoperatively (if non-radical resection is suspected). Adjuvant systemic therapy for melanoma patients is still experimental. Atypical (dysplastic) naevi and congenital naevi are major risk factors for melanoma. No consensus has been reached about the prophylactic excision of all congenital naevi. A follow-up period of 5 years is sufficient for patients with a melanoma of < or = 1.5 mm Breslow thickness (provided there are no histological signs of regression) and of 10 years when the Breslow thickness is > 1.5 mm. The patient should be actively involved in the follow-up (inspection, palpation). Regular routine blood tests, radiological examination and ultrasound scanning are not considered to be worthwhile. There is no evidence that the growth of micro-metastases is stimulated by hormonal changes during pregnancy or contraceptive pill use. Excessive exposure to ultraviolet radiation should be discouraged. Regular population screening for melanoma is not considered to be worthwhile, owing to the relatively low frequency and the predominantly favourable stage at the time of diagnosis, particularly in young people.

Eggermont AM, Suciu S, MacKie R, Ruka W, Testori A, Kruit W, Punt CJ, Delauney M, Sales F, Groenewegen G, Ruiter DJ, Jagiello I, Stoitchkov K, Keilholz U, Lienard D, Anonymous00231. · Department of Surgical Oncology, Erasmus University Medical Centre-Daniel den Hoed Cancer Centre, 3008 AE Rotterdam, Netherlands. · Lancet. · Pubmed #16198768 No free full text.

Abstract: BACKGROUND: Individuals affected by melanoma with thick primary tumours or regional node involvement have a poor outlook, with only 30-50% alive at 5 years. High-dose and low-dose interferon alfa have been assessed for the treatment of these patients, with the former having considerable toxicity and a consistent effect on disease free survival, but not on overall survival, and the latter no consistent effect on either. Our aim was, therefore, to assess the effect of two regimens of interferon of intermediate dose versus observation alone on distant metastasis-free interval (DMFI) and overall survival in such patients. METHODS: We did a randomised controlled trial in 1388 patients who had had a thick primary tumour (thickness > or = 4 mm) resected (stage IIb) or regional lymph node metastases dissected (stage III) and had been assigned to 13-months (n=553) or 25 months (n=556) of treatment with subcutaneous interferon alfa 2b, or observation (n=279). Treatment comprised 4 weeks of 10 million units (MU) of interferon alfa (5 days per week) followed by either 10 MU three times a week for 1 year or 5 MU three times a week for 2 years, to a total dose of 1760 MU. Our primary endpoint was DMFI. Analyses were by intent to treat. FINDINGS: After a median follow-up of 4.65 years, we had recorded 760 distant metastases and 681 deaths. At 4.5 years, the 25-month interferon group showed a 7.2% increase in rate of DMFI (hazard ratio 0.83, 97.5% CI 0.66-1.03) and a 5.4% improvement in overall survival. The 13-month interferon group showed a 3.2% increase in rate of DMFI at 4.5 years (0.93, 0.75-1.16) and no extension of overall survival. Toxicity was acceptable, with 18% (195 of 1076) of patients going off study because of toxicity or as a result of refusal of treatment because of side-effects. INTERPRETATION: Interferon alfa as used in the regimens studied does not improve outcome for patients with stage IIb/III melanomas, and cannot be recommended. With respect to efficacy of the drug, duration of treatment seemed more important than dose, and should be assessed in future trials.

Kleeberg UR, Suciu S, Bröcker EB, Ruiter DJ, Chartier C, Liénard D, Marsden J, Schadendorf D, Eggermont AM, Anonymous00293. · Haematologisch-Onkologische Praxis Altona (HOPA), Max-Brauer-Allee 52, D-22765 Hamburg, Germany. · Eur J Cancer. · Pubmed #14746858 No free full text.

Abstract: Between 1988 and 1996, the European Organisation for Research and Treatment of Cancer Melanoma Group (EORTC-MG) performed a prospective, randomised phase III adjuvant trial to evaluate the efficacy and toxicity of low dose recombinant interferon-alpha 2 b (rIFN-alpha2b) (1 MU) or recombinant interferon gamma (rIFN-gamma), (0.2 mg) both given subcutaneously (s.c.), every other day (qod), for 12 months in comparison with an untreated control group. The German Cancer Society (DKG) added a fourth arm with Iscador M, a popular mistletoe extract. High-risk stage II patients (thickness >3 mm) and stage III patients (positive lymph nodes) without distant metastasis were randomised and followed until their first progression or death. An intention-to-treat analysis was performed. From 1988 to 1996, a total of 830 patients were randomised: 423 in the three-arm EORTC 18871 trial and 407 patients in the four-arm DKG 80-1 trial. The median follow-up was 8.2 years and a total of 537 relapses and 475 deaths were reported. At 8 years, the disease-free interval (DFI) rate was 32.4% and the overall survival (OS) rate was 40.0%. In terms of the DFI, the hazard ratio estimates (95% Confidence Intervals (CI)) were: 1.04 (0.84, 1.30) for the comparison of rIFN-alpha2b versus control, 0.96 (0.77, 1.20) for rIFN-gamma versus control, and 1.32 (0.93, 1.87) for Iscador M versus control. In terms of OS, the corresponding estimates (95% CI) for the 3 treatment comparisons were: for IFN-alpha2b 0.96 (0.76, 1.21), for rIFN-gamma 0.87 (0.69, 1.10) and for Iscador M 1.21 (0.84, 1.75), respectively. The results show no clinical benefit for adjuvant treatment with low dose rIFN-alpha2b or rIFN-gamma or with Iscador M in high-risk melanoma patients.

Spatz A, Cook MG, Elder DE, Piepkorn M, Ruiter DJ, Barnhill RL. · Institut Gustave-Roussy, Villejuif, France. · Eur J Cancer. · Pubmed #12932663 No free full text.

Abstract: In the recently revised melanoma staging system proposed by the American Joint Committee on Cancer (AJCC), ulceration assessment by the pathologist is a pivotal parameter. Patients upstaged because of ulceration might be included in adjuvant trials conducted in AJCC stage II melanoma patients. Therefore, accuracy based on interobserver reproducibility for melanoma ulceration assessment is crucial for proper clinical management. In some cases, it is extremely difficult, even for an experienced pathologist, to distinguish between trauma-induced ulceration, artifact and tumoral ulceration. Whether this difficulty may be resolved by the use of a more precise definition of ulceration has not been evaluated. Therefore, we have proposed a refined definition of melanoma ulceration and we tested whether this definition might improve the interobserver interpretative reproducibility of ulceration in primary cutaneous melanomas. The results of this study support the need for a more precise definition of melanoma ulceration that rules out biopsy trauma or processing artifact and could be incorporated into a standardised pathology worksheet for reporting primary melanomas.

Eggermont AM, Keilholz U, Testori A, Cook M, Lienard D, Ruiter DJ. · EORTC-Melanoma Group, Brussels, Belgium. · Ann Surg Oncol. · Pubmed #11599896 No free full text.

Abstract: Last year the Melanoma Group of the European Organization for Research and Treatment of Cancer (EORTC-MG) completed accrual (1418 patients) for trial EORTC 18952, a three-arm phase III trial evaluating adjuvant therapy with two different intermediate doses of interferon (IFN) alfa-2b versus observation for stage IIB-III melanoma. About 25% of the patients entered the trial with tumor-positive sentinel nodes (SNs). Prognosis was significantly better in SN-positive patients than in patients with palpable regional node involvement (P < .00001). Subsequently the EORTC-MG embarked on two large phase III trials of adjuvant therapy based on the tumor status of the SN. In trial EORTC 18961 for stage II melanoma, GM2-KLH/QS-21 vaccination is compared with observation (1300 patients); in trial EORTC 18991 for stage III melanoma, 5-year treatment with pegylated interferon alfa-2b (PEG-Intron) is compared with observation (900 patients). Translational research projects will compare SN assessment by hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the relative accuracy of each method and its correlation to relapse and survival of patients with stage II melanoma. In stage III patients, a similar workup of the most proximal nonsentinel node in the full lymph-node dissection specimen will indicate the accuracy of each methodology to detect nodal metastasis beyond the SN and the prognostic significance thereof. These findings will be correlated to the results of sequential blood testing by RT-PCR and by tumor marker assays for S100, TA90, and angiostatin. In addition, tumor-positive and tumor-negative SNs will be assessed for activated cytotoxic T lymphocytes and downregulation of dendritic cell functions.

van Dijk MC, Aben KK, van Hees F, Klaasen A, Blokx WA, Kiemeney LA, Ruiter DJ. · Department of Pathology, University Medical Centre Nijmegen, Nijmegen, and Department of Pathology, University Medical Centre Groningen, Groningen, The Netherlands. · Histopathology. · Pubmed #18184263 No free full text.

Abstract: AIMS: To assess the type of problems encountered in diagnosing melanocytic lesions and to evaluate the contribution of expert review. METHODS AND RESULTS: Data from 1887 lesions submitted for consultation to one of the expert pathologists of the Dutch Melanoma Working Group Pathology Panel between 1991 and 2004 were analysed. Referring pathologists can voluntarily submit lesions which are difficult to classify to the panel. Most cutaneous melanocytic lesions (n = 1217) were submitted with a presumed diagnosis by the referring pathologists. Relevant underdiagnoses of melanoma (in situ) and overdiagnoses of naevi were prevented in 12% (144/1217) and 15% (178/1217) of cases, respectively. Problematic melanocytic lesions were (i) spitzoid and dysplastic lesions, (ii) lesions with histological features that hampered the diagnosis such as regression, lymphocytic infiltrate, or a combination with other melanocytic lesions, and (iii) lesions with unusual clinical features, e.g. childhood melanoma. Remarkably, the features of the lesions that were submitted and the types of over- and under-diagnosis remained consistent from 1991 to 2004. CONCLUSIONS: A second opinion from an expert pathologist on problem-prone melanocytic lesions improves patient care, in our series in 27% of cases.

van Kempen LC, Rijntjes J, Mamor-Cornelissen I, Vincent-Naulleau S, Gerritsen MJ, Ruiter DJ, van Dijk MC, Geffrotin C, van Muijen GN. · Department of Pathology, Radboud University Nijmegen - Medical Center, Nijmegen, The Netherlands. · Int J Cancer. · Pubmed #17957794 No free full text.

Abstract: Tumors are complex tissues composed of neoplastic cells, soluble and insoluble matrix components and stromal cells. Here we report that in melanoma, turn-over of type I collagen (Col(I)), the predominant matrix protein in dermal stroma affects melanoma progression. Fibroblasts juxtaposed to melanoma cell nests within the papillary dermis display high levels of Col(I) mRNA expression. These nests are enveloped by collagen fibers. In contrast, melanoma-associated fibroblasts within the reticular dermis express Col(I) mRNA at a level that is comparable to its expression in uninvolved dermis and reduced amount of collagen protein can be observed. To determine the significance of Col(I) expression in melanoma, we pharmacologically inhibited its transcription in a porcine cutaneous melanoma model by oral administration of halofuginone. When administered before melanoma development, it reduced melanoma incidence and diminished the transition from microinvasive toward deeply invasive growth by limiting the development of a tumor vasculature. Whereas invasive melanoma growth has been correlated with increased blood vessel density previously, our data for the first time demonstrate that the proangiogenic effect of Col(I) expression by fibroblasts and vascular cells precedes the development of invasive melanomas in a de novo tumor model.

De Vries IJ, Bernsen MR, van Geloof WL, Scharenborg NM, Lesterhuis WJ, Rombout PD, Van Muijen GN, Figdor CG, Punt CJ, Ruiter DJ, Adema GJ. · Department of Tumor Immunology, Medical Oncology and Pediatric Hemato-Oncology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands. · Cancer Immunol Immunother. · Pubmed #17440724 No free full text.

Abstract: Application of tetrameric MHC class I-peptide complexes has significantly improved the monitoring of antigen-specific T cell immune responses in mouse models as well as in clinical studies. Especially MHC class I tetramer analysis of tumor-specific T cells in suspension or on thick vibratome sections from viable tissue has been proven extremely useful. Using the well-characterized mouse tyrosinase-related-protein-2 specific cytotoxic T cell (CTL) clone LP9, we now developed a method that allows for specific identification of T cells with MHC class I tetramers in 8 mum thick, chemically fixed cryosections. The protocol was validated in a murine influenza virus-infection model. Moreover, analysis of delayed type hypersensitivity (DTH) skin biopsies from melanoma patients vaccinated with peptide-loaded mature dendritic cells, revealed the presence and location of anti-tumor CTLs. The specificity of the CTLs detected in situ correlated with both the DTH challenge specificity and reactivity of cell suspensions derived from the same biopsies. Collectively, our data demonstrate that in situ MHC class I tetramer staining provides a valuable tool to reveal the presence and anatomical location of specific CTLs in frozen tissue following immune-based treatment strategies in cancer patients.

Küsters B, Kats G, Roodink I, Verrijp K, Wesseling P, Ruiter DJ, de Waal RM, Leenders WP. · 1Department of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. · Oncogene. · Pubmed #17353901 No free full text.

Abstract: How and why tumors metastasize is still a matter of debate. The assumption is that mutations render tumor cells with a metastatic phenotype, enabling entrance in and transport through lymph or blood vessels. Distant outgrowth is thought to occur only in a suitable microenvironment (the seed and soil hypothesis). However, the anatomical location of most metastases in cancer patients suggests entrapment of tumor cells in the first microcapillary bed that is encountered. We here investigated how vascular endothelial growth factor-A (VEGF-A) attributes to the metastatic process. We describe here that VEGF-A enhances spontaneous metastasis by inducing intravasation of heterogeneous tumor cell clusters, surrounded by vessel wall elements, via an invasion-independent mechanism. These tumor clusters generate metastatic tissue embolisms in pulmonary arteries. Treatment of tumor-bearing mice with the antiangiogenic compound ZD6474 prevented the development of this metastatic phenotype. This work shows that tumors with high constitutive VEGF-A expression metastasize via the formation of tumor emboli and provides an alternative rationale for anti-VEGF-A therapy, namely to inhibit metastasis formation.

De Raeve LE, Claes A, Ruiter DJ, van Muijen GN, Roseeuw D, van Kempen LC. · Academisch Ziekenhuis, Vrije Universiteit Brussel, Department of Dermatology, Belgium. · Br J Dermatol. · Pubmed #16445780 No free full text.

Abstract: BACKGROUND: Giant congenital melanocytic naevi (GCMN) convey a 14-fold increased melanoma risk. In contrast, medium congenital melanocytic naevi (MCMN) are rarely associated with malignant transformation. Management of patients with GCMN is challenging and there is no consensus on the most appropriate strategy for treating these patients. OBJECTIVES: To provide a rationale for performing curettage of GCMN in the neonatal period in order to reduce the risk of malignant transformation to melanoma. METHODS: Twenty-six infants with GCMN who underwent biopsies before excisional surgery (n = 7) or curettage (n = 19) during the past 14 years (Academic Hospital, Vrije Universiteit Brussel) and 10 MCMN patients who underwent excision biopsies (Radboud University Nijmegen Medical Centre) were included in this study. Using these biopsies, we performed genetic and detailed immunohistochemical evaluations of changes that are associated with malignant transformation. Variables of interest included melanoma-associated BRAF mutations, proliferative activity, vascularity, cellular context and extracellular matrix architecture. RESULTS: GCMN and MCMN did not show oncogenic BRAF mutation and displayed similar features with respect to the amount of nonmelanocytic cells within the naevus and matrix architecture. Naevus cells in the superficial component of the GCMN, however, were more proliferative, and this component was more vascular compared with its deep component and with MCMN. In this study, none of the 19 newborn patients who underwent curettage developed a melanoma within a mean follow-up time of 7 years. CONCLUSIONS: The data presented here support the idea that curettage of GCMN in neonates has the potential for lowering the risk of developing cutaneous melanoma by not only obtaining an important numerical reduction of naevus cells but also removing the 'active' melanocytes.

Clarijs R, van Dijk M, Ruiter DJ, de Waal RM. · Department of Pathology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. · Invest Ophthalmol Vis Sci. · Pubmed #16123395 links to  free full text

Abstract: PURPOSE: In primary uveal and cutaneous melanoma lesions, extracellular matrix (ECM) is often deposited in arcs, loops, and network patterns. Based on prognostic relevance, these patterns appear to play a significant role in facilitating metastasis. It has been demonstrated that these patterns were capable of transmitting fluid. The current study was undertaken to elucidate further the functional role of these patterns in tumor perfusion and to examine the composition of the patterns by immunohistochemistry. METHODS: To study the role of these patterns in perfusion, fluorochrome-labeled bovine serum albumin, bovine insulin, and dextrans of different molecular sizes were injected intravenously into nude mice bearing subcutaneous human cutaneous melanoma xenografts. Distribution of the human melanoma cells and murine host cells was analyzed by DNA in situ hybridization. To elucidate the composition of these patterns, human uveal melanoma tissues were analyzed for expression of ECM components by immunohistochemistry. RESULTS: Small molecules (Stokes' radius <4.4 nm) crossed the vessel wall and spread along the ECM patterns within 2 to 10 minutes, whereas larger molecules (Stokes' radius approximately 5.8 nm) required 30 to 45 minutes to enter. Murine host cells were found exclusively in the ECM pattern compartment. In primary uveal melanoma, different types of collagen, ECM-associated heparan sulfate proteoglycans, and different types of cells were present in the patterns. CONCLUSIONS: The data suggest that the ECM deposited as arcs, loops, and network patterns, accommodate the transport of plasma-derived molecules, (e.g., nutrients), to the tumor lesion, thus enhancing tumor growth and progression, and facilitating infiltration of tumor tissue by host-derived cells.