Vaccination against cancer soon a therapeutic possibility. B-cell tumors, colonic cancer and melanoma may be suitable for this treatment

The theoretical basis of cancer vaccination having been well established during the past two decades, the translation of this knowledge into clinically applicable immunisation procedures is now an urgent need. Numerous antigenic preparations are available that are capable of inducing specific anti-tumour immunity which can be augmented by appropriate cytokines. Promising tumour vaccination results have been obtained in B-cell malignancies, colorectal carcinoma, and melanoma; tumour regression has been noted in myeloma, non-Hodgkin lymphoma, colorectal carcinoma, and melanoma patients, and significantly prolonged disease-freed survival in non-Hodgkin lymphoma and colorectal carcinoma patients. The presence of only minimal residual disease would seem to be a clinical prerequisite for tumour vaccination.     

Dying dogma: the pathological diagnosis of epidermotropic metastatic malignant melanoma

Distinguishing primary cancer from a metastasis is a fundamental task in surgical pathology that has crucial therapeutic and prognostic implications. When metastatic melanoma involves the skin and extends into the epidermis (epidermotropic), differentiating it from primary cutaneous melanoma may be particularly difficult. Early investigators dismissed this issue as a nonproblem and dogmatically declared that junctional change was requisite for the diagnosis of primary cutaneous melanoma. Epidermotropic metastases of malignant melanoma (EMMM) are now recognized to have many features in common with primary melanoma, which can include involvement of the dermal-epidermal junction, extension of the intraepidermal component beyond the dermal component, and even an epidermal-only pattern. This article traces the evolution in criteria used to diagnose EMMM and highlights why much of the original thinking is no longer accepted. Current concepts in EMMM morphology are elaborated and illustrated. The role of immunomicroscopy and molecular pathology in the detection of EMMM is also discussed.     

Malignant melanoma of the vagina in pregnancy: description of a clinical case

Vaginal melanoma in pregnancy is a rare but extremely malignant tumour for which the prognosis is worsened by the fact that pregnancy increases the secretion of Melanocyte-Stimulating Hormone (MSH). The clinical case is described of a malignant vaginal melanoma in a 27 year-old woman in her 38th week of gestation, who was referred for slight vaginal bleeding. Clinical examination revealed a 3 cm pedunculate tumour on the anterior wall of the vagina. Vaginal cytology suggested a melanoma and instrumental examination failed to reveal any lymph node involvement. The vaginal tumour was removed during a caesarean section and subsequent histological examination identified it as a Breslow Stage II malignant melanoma. A 24-month follow-up showed the patient to have been completely cured.     

Expression of platelet-derived growth factor (PDGF)-A, PDGF-B and the PDGF-alpha receptor, but not the PDGF-beta receptor, in human malignant melanoma in vivo

There has been considerable interest in the potential role of growth factors in the initiation and development of cutaneous malignant melanoma (CMM). Platelet-derived growth factor (PDGF) has been shown to be secreted by melanoma cell lines and by metastatic melanoma in vivo. PDGF also has been reported to stimulate the development of tumour stroma and new blood vessels. We studied the expression of PDGF and its receptors by both immunohistochemistry (IHC) and in situ hybridization (ISH) in primary and metastatic melanoma and in normal skin specimens. Cryostat sections were incubated with 35S-labelled riboprobes and antibodies for PDGF-AA, PDGF-alpha receptor, PDGF-BB and PDGF-beta receptor. Both primary and metastatic melanoma exhibited significant expression of PDGF-AA, PDGF-BB and PDGF-alpha receptor by both IHC and ISH, compared with only background expression in normal skin. We did not observe expression of PDGF-beta receptor in melanoma. Our results suggest that PDGF may function as an autocrine growth factor, as well as an angiogenesis factor, in CMM tumour development. This expression of the PDGF-alpha receptor rather than the beta receptor may be unique among solid tumours.     

Influence of molecular weight on passive tumour accumulation of a soluble macromolecular drug carrier

The molecular weight-dependence of tumour capture of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers (fractions of mw 22,000-778,000) was studied in vivo using subcutaneous (s.c.) Sarcoma 180 or B16F10 melanoma models. At 10 min, all fractions were already detectable in the tumour (1.5-3% of dose administered per gram) and those of molecular weight greater than the renal threshold showed progressive tumour accumulation up to 20% of dose administered per gram after 72 h in the Sarcoma 180 model. Tumour-selective uptake was confirmed for all copolymer fractions in both tumour models and in the sarcoma 180 model, the ratio (accumulation index, AI) of the AUC in tumour to AUC in skeletal muscle (a typical normal tissue) increasing from six to 12 with increasing copolymer molecular weight. The tumour/blood AI was greater (1-3) in the Sarcoma 180 model than the B16F10 melanoma model (0.4-1.0).     

Role of metal-catalyzed oxidation reactions in the early pathogenesis of scleroderma

The value of the renal allograft biopsy has been significantly enhanced by several developments in 1997 including the following: the first convincing demonstration that molecular biology techniques can be applied to renal allograft tissue to obtain a diagnosis of acute rejection with high sensitivity and specificity; the development of an improved, internationally agreed classification of kidney transplantation pathology ('Banff 1997'); and significant new insights into the specific pathology of chronic rejection, involving splitting and lamination of peritubular capillary basement membranes and the presence of increased apoptotic cell death. Although it is predictable that long-term technology might eliminate the need for renal allograft biopsies altogether, in the short term these new breakthroughs will greatly increase the value of this procedure in the management of renal transplant patients.     

Comparison of several mouse and rat monoclonal antibodies against human fibrinogen

A rare case of desmoplastic melanoma arising from the maxillary gingiva of a 66-year-old woman is reported. This tumour metastasised to the submandibular lymph node 5 years after extirpation, and local recurrence was observed 2 years later. The gingival tumour showed the histopathological characteristics of desmoplastic melanoma and the metastasised tumour cells were immunohistochemically positive for S-100 protein, neuron specific enolase, HMB-45 highly specific for conventional melanoma, and Fontana-Masson staining. The gingival tumour, originally regarded as benign clinically, was actually a desmoplastic melanoma.     

Current status of melanoma vaccines

BACKGROUND: Malignant melanoma is increasing worldwide faster than any other cancer and the American lifetime risk is estimated to reach 1 in 75 by the year 2000. Active specific immunotherapy with vaccines is evolving as a promising new modality in the treatment of malignant melanoma. OBJECTIVE: To present a concise and understandable summary of the key molecular and clinical concepts of melanoma vaccines currently under investigation, the history that led to their development, and their anticipated clinical response. METHODS: The recent advances in the field of melanoma immunobiology and the newest experiment vaccines are reviewed. RESULTS: There is no effective melanoma vaccine that successfully treats or prevents melanoma. However, their use has been associated with regression or delayed disease progression in some cases. The minority of patients who do have a major clinical response to vaccine therapy experience an improvement in survival. Even in those patients in whom melanoma vaccines cannot improve survival, the paucity of severe side effects has provided a quality of life superior to standard multiagent chemotherapy. CONCLUSION: Melanoma vaccines are relatively safe immunotherapeutic modalities for the management of malignant melanoma. The clinical effectiveness of melanoma vaccines is unclear and adequately controlled studies need yet to be performed. Current melanoma vaccines manipulate antigen presentation networks and combine the best cellular and antibody antitumor immune response effective in mediating tumor protective immunity; these combination vaccines hold the most promise. The ideal melanoma vaccine will ultimately prevent melanoma.     

Epidemiology and prognosis of subungual melanoma in 34 Japanese patients

The incidence of malignant melanoma is much lower in the Japanese than in caucasians. However, amongst the various types of malignant melanoma, the subungual and periungual sites are commonly found in the Japanese. One hundred and fifty-one cases of cutaneous malignant melanoma were seen over a 25-year period at our hospital. We found that, in 34 patients (23%), the subungual region was involved, a high frequency for one institution. We have analysed these patients and looked at their treatment. The finger nails were affected in 21 cases (62%) and the toe nails in 13 cases (38%). The thumb nails or great toe nails were affected in 25 of the 34 patients (73%). In 25 patients, histopathological features of acral lentiginous melanoma were found, with four cases of superficial spreading melanoma and five of nodular amelanotic melanoma. Of the latter group, four mimicked fibrous histiocytic tumour, and one was a desmoplastic malignant melanoma. The proportion of patients presenting with stage III disease decreased after 1982, with a corresponding increase in patients whose tumour thickness was less than 4 mm (stage II). Concurrently, the prognosis for subungual malignant melanoma improved. The 5-year survival rate in each of the periods 1969-82 and 1983-93 was 53 and 87%, respectively. This is similar to that found in plantar malignant melanoma and is felt to be due to a greater public awareness of the condition and to the introduction of effective chemotherapy (the DTIC-AC nitrosurea-vincristine (DAV) regimen). Although the frequency of malignant melanoma is rather low in the Japanese, our data indicate that there is a high incidence of subungual malignant melanoma. Public awareness of the early stage of malignant melanoma seems to have improved prognosis.     

Comparative genomic hybridisation for the analysis of chromosomal imbalances in solid tumours and haematological malignancies

Comparative genomic hybridisation (CGH) is based on a two-colour, competitive fluorescence in situ hybridisation of differentially labelled tumour and reference DNA to normal metaphase chromosomes. This new technology has made a great impact in molecular tumour pathology due to its possible application to archival specimens and the ability to create copy number karyotypes throughout the whole genome from very small amounts of DNA. If chromosomal imbalances can be correlated with a etiological and clinical features of tumours, CGH could be able to provide new prognostic and diagnostic criteria. CGH findings further provide starting points for the molecular genetic characterisation of altered chromosomal regions harbouring yet unidentified genes involved in tumorigenesis and tumour progression. An overview of the results of published CGH studies on solid tumours and haematological malignancies is presented. Methodological limitations of the CGH technology are reported, as well as future developments which will improve its use in routine analysis.     

Altropane, a SPECT or PET imaging probe for dopamine neurons: II. Distribution to dopamine-rich regions of primate brain

Our understanding of the molecular pathology underlying the development and progression of ductal pancreatic cancer has been revolutionised during the last 5 years due to the spectacular development of novel molecular biological techniques. In the present article, we describe key molecular alterations of sporadic and inherited ductal pancreatic cancer. Overexpression of growth factors and growth factor receptors are present in a significant proportion of this tumour type. Mutation of the K-ras oncogene, and disruption of p53 or p16 tumour suppressor gene abrogates the control of the cyclin-dependent kinases (cdk) and retinoblastoma (Rb) gene pathway, causing continuous growth of the pancreatic tumour. Inactivation of the SMAD4 tumour suppressor gene leads to loss of the inhibitory influence of the transforming growth factor beta signalling pathway. Lost or decreased expression of retinoid receptors and failure of telomerase activity may play a role in pancreatic carcinogenesis. Tumour-associated proteinases, matrix metalloproteinases and plasminogen activators are reported to be involved in pancreatic cancer invasion and metastasis. Furthermore, the cytogenetic changes in this cancer are summarised. This molecular pattern distinguishes pancreatic cancer from other epithelial tumours and represents a promising basis for the development of diagnostic and other clinical applications.     

Survey of treatment practices for neonatal seizures

While the incidence of malignant melanoma is much lower in Japanese than in Caucasians, the commonest site of melanoma in Japanese has been reported to be the acral regions of the limbs. The survival rate for acral and nodular melanoma observed at the Department of Dermatology, Tohoku University Hospital in Sendai, Japan from 1969 to 1990 was reviewed. Among 150 melanoma patients 125 (83%) and 17 (11%) had primary cutaneous melanoma and mucous membrane melanomas, respectively. Frequent sites for cutaneous melanomas were the sole (31%) and subungual regions (15%). Comparison of the stages of plantar melanoma at diagnosis showed that the proportion of stages III and IV decreased after 1980 with a corresponding increase in those with a tumour thickness of less than 4 mm (stage II). Concurrently, the prognosis of plantar melanoma has improved; the 5-year survival rate in each of the three periods 1969-75, 1976-80 and 1981-85 was 21, 70 and 90%, respectively. This was also the case with subungual melanoma. Such improvements in the prognosis are thought to be mainly due to early detection through the growing public awareness of this life-threatening disease. By contrast cases of nodular melanoma increased sharply after 1980. Among these, the high proportion of patients in advanced stages (stages III and IV) remained static even after 1980, with a resultant low 5-year survival rate in the above mentioned periods of 33, 38 and 18%, respectively.     

Genetic basis of susceptibility to melanoma

The search for candidate genes involved in the genesis of common cancers has traditionally been hampered by ambiguities in the process of determining by reliable, clinical criteria which persons harbor the genetic lesion that confers malignant susceptibility. In the case of cutaneous melanoma, the existence of genetic susceptibility has long been evident from its tendency to cluster in families, but it has been unclear until recently whether the genetic basis of familial melanoma derives from the concerted interaction of multiple genes or from a major locus with properties of a tumor suppressor gene. The original strategy used to circumvent difficulties in identifying those who harbor the genetic defect exploited a proposed melanoma precursor lesion, the dysplastic nevus, as the phenotypic marker from which the presence of the melanoma-associated genotype was inferred. That strategy in genetic linkage studies provided the first indication of a major gene for melanoma and assigned the locus to the short arm of chromosome 1. In part because the criteria for the dysplastic nevus have been neither well-defined nor generally agreed upon, multiple independent attempts to confirm the assignment of a gene to that location have failed. The probable map position of a major gene became clear when the most frequently deleted region of the human genome in melanoma tumors was localized to chromosome 9p. The significance of this assignment was established when genetic linkage studies of multiple melanoma kindreds subsequently evaluated the correlated inheritance between melanoma gene carriers, as assigned by a history of melanoma, and molecular markers for DNA polymorphisms near the 9p candidate region; this analysis provided strong statistical evidence of linkage to a melanoma susceptibility locus. Once this candidate tumor suppressor gene) as well as other relevant suppressor loci that may exist is actually cloned and characterized, rapid advances can be expected in our understanding of the pathophysiologic basis for development of melanoma. This will provide opportunities for exploring the mechanisms underlying defects in the gene and the molecular consequences of its loss of function. It will then be possible to identify precisely those persons with a genetic risk for melanoma; as a result, surveillance efforts can be more appropriately focused than has heretofore been possible.     

Inactivation of ribonucleotide reductase in tumour cells and inhibition of tumour cell growth by p-alkoxyphenols

A significant correlation between the inactivation of the growth-regulating enzyme ribonucleotide reductase (RR) with the growth inhibition of four different tumour cell lines has been found for seven different p-alkoxyphenol derivatives with varying lengths of alkyl side chain. In Novikoff hepatoma and human leukaemia cells, inactivation of RR by p-alkoxyphenols was monitored by electron paramagnetic resonance (EPR) spectroscopy of the catalytically essential tyrosyl radical in the subunit R2 of RR. A significant inhibition of cellular growth of Novikoff hepatoma cells, human leukaemia cells and two human melanoma cell lines (MeWo and M5) by p-alkoxyphenols was also observed by growth inhibition assays. Inactivation of RR in whole tumour cells as well as inhibition of cellular growth of tumour cell lines by p-alkoxyphenols both show an increase in inhibition with increasing length of the alkyl side chain; the most effective inhibitors are p-isobutoxyphenol, p-butoxyphenol and p-propoxyphenol. The enzyme RR, and in particular the catalytically essential tyrosyl radical in the active site, is recognized as an important cellular target for growth inhibition of Novikoff hepatoma cells, human leukaemia cells and melanoma cells by p-alkoxyphenols. Thus, the most potent RR inhibitors-p-isobutoxyphenol, p-butoxyphenol and p-propoxyphenol-may be considered as future antiproliferative drugs for the systemic treatment of melanoma as well as leukaemia and possibly other malignancies.     

High expression of immunotherapy candidate proteins gp100, MART-1, tyrosinase and TRP-1 in uveal melanoma

In the treatment of cutaneous melanoma, provisional therapeutic strategies have been designed to combat tumour load using T cells that are sensitized with peptides derived from melanoma autoantigens, such as glycoprotein 100 (gp100), melanoma antigen recognized by T cells 1 (MART-1 or MelanA), tyrosinase and tyrosinase-related protein 1 (TRP-1). We recently found that gp100, MART-1 and tyrosinase are heterogeneously expressed in human cutaneous melanoma (De Vries et al (1997) Cancer Res 57: 3223-3229). Here, we extended our investigations on expression of these immunotherapy candidate proteins to uveal melanoma lesions. Cryostat sections from 11 spindle-type, 21 mixed and epithelioid tumours and four metastasis lesions were stained with antibodies specifically recognizing gp100, MART-1, tyrosinase and TRP-1. In addition, we used the DOPA reaction to detect tyrosinase enzyme activity as a confirmation of the tyrosinase immunohistochemical results. High expression of gp100, MART-1 and tyrosinase was found in the uveal melanoma lesions: 80% of the lesions displayed 75-100% positive tumour cells. TRP-1 positivity was slightly less: approximately 65% of the lesions stained in the 75-100% positive tumour cell category. All uveal melanoma lesions were positive for the four markers studied, this being in contrast to cutaneous melanoma where 17% of the advanced primary lesions and metastases were negative. The presence of these antigens was a little lower in metastases. We conclude that uveal melanomas and their metastases express melanocyte-lineage immunotherapy candidate proteins very abundantly. Uveal melanomas differ in this respect from cutaneous melanoma, in which the expression of these immunotherapy antigens was much more heterogeneous. This makes uveal melanoma a suitable candidate tumour for immunotherapeutic approaches.     

The molecular genetics of endocrine tumours

The molecular genetics of endocrine tumours is an area of great interest, due to the heterogeneity of endocrine tumour types, the association of hormone over-production in some cases, and the wide variation in tumour behaviour. Genes implicated fall into functional categories such as oncogenes, in which mutations tend to cause activation, and tumour suppressor genes, in which mutations lead to loss of function. Oncogenes include the receptor tyrosine kinases such as RET, signal transduction proteins and other molecules such as cell cycle regulators and nuclear proteins. Tumour suppressor genes include cell cycle regulators such as p53 and other molecules such as the MEN 1 gene. Loss of heterozygosity studies help in the initial localisation of the latter. Endocrine tumours, as with other tumours, develop as a result of a combination of genetic events, and in the paediatric age group they often occur in the setting of familial cancer syndromes. In this review we analyse the main genetic lesions which have been described in endocrine tumours. There has been an explosion of knowledge in the last 5 years including the identification of the causative genes for MEN 2 and most recently for MEN 1. Characterisation of such genes also aids in the study of somatic mutations in sporadic versions of the same tumour types as occur in the familial syndromes. Identification of a genetic predisposition to a certain tumour has management implications that are still to be clarified in most cases, although in the case of MEN 2 the guidelines for prophylactic thyroidectomy are generally well accepted.     

Screening for tumour suppressor p16(CDKN2A) germline mutations in Israeli melanoma families

Approximately ten percent of patients with malignant melanoma have family histories of the disease, suggesting a genetic predisposition. Germline mutations in tumour suppressor p16 gene have been implicated as disease causing mutations in some of the melanoma families. The frequency of families with p16 germline mutations among melanoma prone families varies from eight to fifty percent. The range of the variability is influenced apparently by the number of melanoma affected individuals within the family, as well as by other, yet unidentified factors. Ethnic background is known to determine both the frequency and the nature of germline alterations. Recently, specific mutations in tumour suppressor genes involved in breast cancer and in colon cancer were found at elevated frequency among Ashkenazi Jews. This report describes results of a screening for p16 germline alterations in a collection of Israeli melanoma families. We have analyzed genomic DNA from thirty one Ashkenazi and non-Ashkenazi Jewish melanoma families, as well as from thirty melanoma patients without an apparent family history of the disease. The entire coding region of the p16 gene was screened by single strand conformation polymorphism analysis and direct DNA sequencing. We have detected a number of carriers with the Ala148 Thr polymorphism at the end of the second exon and several instances of 500(G=>C) substitution at the 3' untranslated portion of the gene.     

Synergistic antitumour effect of recombinant human tumour necrosis factor alpha with melphalan in isolated limb perfusion in the rat

The efficacy of isolated limb perfusion (ILP) for 'intransit' metastases from malignant melanoma and irresectable soft tissue sarcoma has been improved considerably by the addition of tumour necrosis factor (TNF) alpha. A rat sarcoma tumour model was, therefore, developed to evaluate the effects of TNF-alpha, melphalan and the combination of these drugs in the treatment of sarcoma. In BN rats bearing the non-immunogenic BN 175 sarcoma ILPs were performed with perfusate only, TNF-alpha, melphalan alone, or in combination when tumours had grown to approximately 1.5 cm in diameter. All rats treated with sham perfusion or perfusion with 50 micrograms TNF-alpha showed progressive disease. After perfusion with 40 micrograms melphalan no change in tumour diameter was observed in any rats at 4 days. After a combined perfusion with 40 micrograms melphalan and 50 micrograms TNF-alpha complete remission was noted in 12 of 16 rats. This synergistic effect in vivo between relatively ineffective doses of TNF-alpha and melphalan was not observed in vitro.     

Factors associated with melanoma incidence and prognosis

Melanoma has a reputation as an unpredictable disease, but investigation has demonstrated a multiplicity of factors which are independently associated with melanoma incidence and prognosis. Major factors associated with melanoma incidence include those related to race and ethnicity, sunlight exposure, and genetic and familial predisposition. Major factors associated with melanoma prognosis include tumor thickness, ulceration, anatomic location, and patient's sex. These factors are clinically important in designing appropriate screening and prevention programs, as well as in selecting appropriate treatment and follow-up for the individual melanoma patient. There is an increasing need to identify the molecular mechanisms underlying these clinically defined etiologic and prognostic factors so that we may treat patients more effectively and more selectively. Available evidence indicates that the mechanisms of melanoma etiology include a loss of tumor suppressor genes. Mechanisms of melanoma progression include the accumulation of oncogene mutations, perhaps as a result of sun exposure, the development of autocrine and paracrine loops involving cytokines and growth factors, and alterations in cell-surface antigen expression. Finally, an antigen-specific immune response to melanoma appears to be important in the prognosis of some patients. Critical regulatory components of the melanoma immune response include antibodies, T-cells, and human leukocyte antigen (HLA) molecules.     

Management of cutaneous melanoma M0: state of the art and trends

This article reviews the epidemiology, diagnosis and treatment of cutaneous melanoma, including the most recent developments. The combination of positive family history, fair complexion, number of nevi, exposure to sun and/or chromosomal alterations seem to be implicated in the pathogenesis of cutaneous melanoma. Melanomas can be classified according to their growth patterns, and tumour microstaging is of straightforward predictive value for survival and risk of metastasis, although new factors are also being investigated. As yet, surgical excision is the only effective treatment available for primary tumours, resection margins varying according to tumour thickness. Elective node dissection is, however, no longer advocated for melanomas thinner than 1.5 mm, and there is disagreement as to its role for thicker lesions. In contrast, selective node dissection at the time of definitive surgery is becoming more widely accepted, with regional node dissection being restricted to positive cases. Therapeutic dissection is required for lymph node involvement, the most common pattern of recurrence from melanoma, which affects nearly 30% of all patients. Complete remission rates from isolated limb perfusion, which has been employed in patients with multiple recurrences or in-transit metastases, range from 40 to 90%, depending on drugs and techniques used in different series; the best responses so far have been obtained with tumour necrosis factor in combination with melphalan. Patients with thick lesions (> 4 mm) or lymph node metastases have a high risk of micrometastases that would warrant adjuvant therapy. The only agent found to affect survival is interferon alpha-2.