Autonomous histopathological regression of primary tumours associated with specific immune responses to cancer antigens

Management of the N0 neck in patients with laryngeal squamous cell carcinoma

Background: Neck lymph node status is the chief prognostic index in patients with head and neck squamous cell carcinoma (SCC), yet the management of a clinically negative neck in this setting is still controversial, especially in patients with laryngeal SCC (LSCC). Objectives: To evaluate the efficacy of selective neck dissection (SND) to control occult disease in patients with LSCC and clinically negative (cN0) necks. Materials and methods: Medical records of 1476 patients with cN0 LSCC were analyzed. In conjunction with primary treatment, 126 (8.5%) underwent at least unilateral elective neck dissection, whereas most 1350 (91.5%) followed a wait-and-see protocol. Prognostic significance was indicated by the Kaplan-Meier survival estimates. Results: The rate of occult neck disease was 15%. Five-year overall and disease-free survival rates were 74.4% and 66.7%, respectively. Prognosis was closely related to T stage, preoperative tracheotomy, and postoperative recurrence. There was no significant correlation with age, sex, or preoperative neck dissection; but in patients with supraglottic LSCC, the relation between prognosis and preoperative neck dissection was significant, with fewer neck and local recurrences than the wait-and-see group (p < .05). Conclusions and significance: Selective neck dissection is serving as an accurate prognostic tool in patients with supraglottic laryngeal cancers.

Tumor growth suppressive effect of IL-4 through p21-mediated activation of STAT6 in IL-4Rα overexpressed melanoma models

To evaluate the significance of interleukin 4 (IL-4) in tumor development, we compared B16F10 melanoma growth in IL-4-overespressing transgenic mice (IL-4 mice) and non-transgenic mice. In IL-4 mice, reduced tumor volume and weight were observed when compared with those of non-transgenic mice. Significant activation of DNA binding activity of STAT6, phosphorylation of STAT6 as well as IL-4, IL-4Rα and p21 expression were found in the tumor tissues of IL-4 mice compared to non-transgenic mice. Higher expression of IL-4, STAT6 and p21 in human melanoma tissue compared to normal human skin tissue was also found. Higher expression of apoptotic protein such as cleaved caspase-3, cleaved caspase-8, cleaved caspase-9, Bax, p53 and p21, but lower expression levels of survival protein such as Bcl-2 were found in the tumor of IL-4 mice. In vitro study, we found that overexpression of IL-4 significantly inhibited SK-MEL-28 human melanoma cell and B16F10 murine melanoma cell growth via p21-mediated activation of STAT6 pathway as well as increased expression of apoptotic cell death proteins. Moreover, p21 knockdown with siRNA abolished IL-4 induced activation of STAT6 and expression of p53 and p21 accompanied with reduced IL-4 expression as well as melanoma cell growth inhibition. Therefore, these results showed that IL-4 overexpression suppressed tumor development through p21-mediated activation of STAT6 pathways in melanoma models.

DNA comparison between operative and biopsy specimens to investigate stage pT0 after radical prostatectomy

PURPOSE

The aim was to eliminate, by DNA comparison, any identity mismatch between operative and biopsy specimens and to analyse the determinants of all pT0 prostate cancers occurred in a single institution.

METHODS

All prostate pT0 cases in a single institution over 20 years were investigated. None of the patients had been diagnosed after a transurethral resection of the prostate nor had they received neoadjuvant hormonal treatment. The biopsies performed in other centres had been referred for a centralized pathologic re-analysis. DNA analysis was performed in samples from operative and biopsy specimens, and pairs of tissues were blindly constituted. Correct matching was verified in each pair and compared to the original database in order to comment on the occurrence of identity mismatches in the series.

RESULTS

Nineteen patients (0.77 %) had been diagnosed as having pT0 prostate cancer among the 2,462 RP procedures performed over 19 years. The biopsy re-analysis invalidated the initial diagnosis of prostate cancer in one biopsy set performed elsewhere. Among 12 entirely processed cases, the biochemistry procedure evaluated as "very unlikely" the occurrence of an error in tissue identification in the biopsy setting, during the surgical procedure or the pathological analysis. No identification error of tissue samples was established in this first verified pT0 series.

CONCLUSIONS

Although it must be suspected, specimen identification error was not a cause for pT0 prostate cancer. Only after a full pathological and DNA verification, the pT0 stage remains a sole entity, unexplained in most cases.

Spontaneous regression of breast carcinoma: review of English publications from 1753 to 1897

Regression is an important phenomenon in oncology. Two reviews in 2011 dealt at length with what in modern parlance may be called its permutations and combinations. Specifically, in both 1982 and 1987, when its occurrence in breast cancer was presented from two centers, the oldest accounts of it were dated back to 1900. Therefore, a search for much older English literature was undertaken in order to widen current knowledge of this important problem. Consequently, a published long case dating back to 1897 is abridged and a short 1846 case is also noted. Furthermore, general etiological concepts are exemplified as far back as 1753. It is concluded that the history of cancer regression is like fishing in an ocean of this illness. However, the findings are deemed to complement what modern historical accounts lack.

Association between natural killer cells and regression in melanocytic lesions

Mortality from melanoma, the deadliest of skin cancers, continues to increase in all age groups. A small number of melanomas spontaneously regress. In vitro studies suggest a role for the natural killer cell in effecting regression. In this study, the goal was to determine if natural killer cells are preferentially involved in the cytotoxic response in regressing lesions. Forty-two cases were selected: nevi with regression, nonregressing melanoma with brisk inflammation, and regressing melanoma. Sections were stained with hematoxylin and eosin and immunostained for CD8, CD56, and T-cell intracytoplasmic antigen 1. Numbers of total lymphocytes, CD8-positive lymphocytes, and T-cell intracytoplasmic antigen 1-positive lymphocytes did not differ among the 3 populations or based on location. CD56 positivity was significantly different among the 3 populations. Regressing melanomas showed the greatest CD56 activity, followed by regressing nevi, whereas inflamed, nonregressing melanomas showed the least. CD56(+) lymphocytes were mostly counted in areas of early regression. The natural killer cell could plausibly play a role in the occurrence of regression as a cytotoxic effector cell or as a mediator of the cytotoxic mechanism.

Enhanced anti-tumor activity of interferon-alpha in SOCS1-deficient mice is mediated by CD4⁺ and CD8⁺ T cells

Interferon-alpha (IFN-α) is an immunomodulatory cytokine that is used clinically for the treatment of melanoma in the adjuvant setting. The cellular actions of IFN-α are regulated by the suppressors of cytokine signaling (SOCS) family of proteins. We hypothesized that the anti-tumor activity of exogenous IFN-α would be enhanced in SOCS1-deficient mice. SOCS1-deficient (SOCS1(-/-)) or control (SOCS1(+/+)) mice on an IFN-γ(-/-) C57BL/6 background bearing intraperitoneal (i.p.) JB/MS murine melanoma cells were treated for 30 days with i.p. injections of IFN-A/D or PBS (vehicle). Log-rank Kaplan-Meier survival curves were used to evaluate survival. Tumor-bearing control SOCS1(+/+) mice receiving IFN-A/D had significantly enhanced survival versus PBS-treated mice (P = 0.0048). The anti-tumor effects of IFN-A/D therapy were significantly enhanced in tumor-bearing SOCS1(-/-) mice; 75% of these mice survived tumor challenge, whereas PBS-treated SOCS1(-/-) mice all died at 13-16 days (P = 0.00038). Antibody (Ab) depletion of CD8(+) T cells abrogated the anti-tumor effects of IFN-A/D in SOCS1(-/-) mice as compared with mice receiving a control antibody (P = 0.0021). CD4(+) T-cell depletion from SOCS1(-/-) mice also inhibited the effects of IFN-A/D (P = 0.0003). IFN-A/D did not alter expression of CD80 or CD86 on splenocytes of SOCS1(+/+) or SOCS1(-/-) mice, or the proportion of T regulatory cells or myeloid-derived suppressor cells in SOCS1(+/+) or SOCS1(-/-) mice. An analysis of T-cell function did reveal increased proliferation of SOCS1-deficient splenocytes at baseline and in response to mitogenic stimuli. These data suggest that modulation of SOCS1 function in T-cell subsets could enhance the anti-tumor effects of IFN-α in the setting of melanoma.

Immunomodulatory cytokines as therapeutic agents for melanoma

Melanoma is the most aggressive form of skin cancer whose worldwide incidence is rising faster than any other cancer. Few treatment options are available to patients with metastatic disease, and standard chemotherapeutic agents are generally ineffective. Cytokines such as IFN-α or IL-2 can promote immune recognition of melanoma, occasionally inducing dramatic and durable clinical responses. Here, we discuss several immunomodulatory agents, the safety of which are being evaluated in clinical trials. Challenges include an incomplete understanding of signaling pathways, appropriate clinical dose and route, and systemic immunosuppression in advanced melanoma patients. We consider how targeted cytokine therapy will integrate into the clinical arena, as well as the low likelihood of success of single cytokine therapies. Evidence supports a synergy between cytokine immunotherapy and other therapeutic approaches in melanoma, and strengthening this area of research will improve our understanding of how to use cytokine therapy better.

Malignant melanoma of unknown primary site. To make the long story short. A systematic review of the literature

INTRODUCTION

Although more than 90% of melanomas have a cutaneous origin, occasionally it is discovered as a secondary deposit without evident primary site. The aim of this study was to systematically review published literature and analyse data on incidence, presentation, therapeutic interventions, survival and prognostic factors.

METHODS

We searched MEDLINE, (search terms Melanom*, unknown origin, unknown primary, indolent, occult) and the abstracts from major congresses of the last 4 years and perused the references of the retrieved relevant articles.

RESULTS

4348 patients with MUP were reported along with 132,643 patients with Melanoma of Known Primary (MKP). The incidence of MUP was 3.2%. The male to female ratio was 2:1 while the age peak was in the 4th and 5th decades. MUP patients harbouring nodal disease had a median overall survival ranging between 24 and 127 months, 5-year survival rate between 28.6% and 75.6% and 10-year survival rate between 18.8% and 62.9%. MUP patients with visceral disease had median survival times between 3 and 16 months, and 5-year survival rates between 5.9% and 18%. Presence of tumour regression in metastatic sites and low nodal burden were associated with favourable outcome. Potentially curative surgical treatment offered survival advantage in comparison to patients with residual metastatic foci. MUP patients who received adjuvant chemotherapy or radiotherapy paradoxically seemed to fare worse compared to patients observed.

CONCLUSIONS

This is the first review to bring together the information of 89 years and to analyze all the potential information accumulated. Although a well know entity no consensus is reached in order to describe MUP presentation, management or prognosis.

Burned-out testicular tumor with retroperitoneal lymph node metastasis: a case report

INTRODUCTION

A burned-out seminoma of the testis is an exceptionally rare clinical entity, with few reports found in the literature.

CASE PRESENTATION

A case of burned-out tumor of the testis in a 31-year-old man is reported. The tumor presented as a retroperitoneal mass with histological characteristic of a seminoma. The testes on clinical examination were normal, and a suspicious lesion in the scrotum was only identified after ultrasound. Incision of the abdominal mass was decided, followed by orchectomy. Histological examination of the testis revealed a suspicious lesion with characteristics of spontaneous regression of germ cell tumors.

CONCLUSION

We describe one of very few cases worldwide, where spontaneous regression of a primary testicular tumor occurred after demonstration of retroperitoneal lymph node metastasis, a phenomenon known as burned-out seminoma, which is hard to recognize and incompletely characterized by physicians.

Improved survival for stage IV melanoma from an unknown primary site

PURPOSE We previously demonstrated a survival advantage for nodal metastasis of melanoma from an unknown primary (MUP) versus melanoma from a known primary (MKP). We hypothesized that this survival benefit would extend to MUP patients with distant (stage IV) metastasis. PATIENTS AND METHODS We reviewed prospectively acquired data for 2,247 patients diagnosed with American Joint Committee on Cancer stage IV melanoma at our cancer center between 1971 and 2005. Cox regression analysis in a multivariate model identified prognostic factors significant for survival. MUP and MKP patients were then matched by significant covariates. Overall survival (OS) was estimated by Kaplan-Meier method and compared by log-rank analysis. Results There were 1,849 MKP and 398 MUP patients. Multivariate analysis of patients with complete data sets identified known/unknown primary (hazard ratio [HR], 1.141; P = .032) and five other significant covariates: age (HR, 1.148; P = .007), sex (HR, 1.17; P = .001), site of metastasis (HR, 1.336; P < .001), number of different metastatic sites (HR, 1.303; P < .001), and decade of diagnosis (HR, 0.713; P < .001). Prognostic matching yielded 392 MUP-MKP pairs. Median OS and 5-year OS rate were significantly greater (P < .001) for MUP patients than for all matched MKP patients or for MKP patients matched by M1 category (for M1b and M1c) or number of metastatic sites. CONCLUSION The survival advantage previously reported for patients with stage III MUP also applies to patients with stage IV MUP. The mechanism responsible for this improved survival may provide clues for more effective treatment of stage IV melanoma and therefore warrants further investigation. The improved results for MUP suggest that these patients deserve aggressive therapy.

Improved survival after lymphadenectomy for nodal metastasis from an unknown primary melanoma

PURPOSE

No primary lesion is identified in 10% to 20% of patients presenting with palpable evidence of regional metastatic melanoma. Because the prognostic significance of unknown primary melanoma (MUP) is unclear, we compared clinical outcomes of patients with MUP and known primary melanoma (MKP) with regional nodal metastases.

PATIENTS AND METHODS

We reviewed our 13,000-patient prospective melanoma database (1971 through 2005) to identify patients managed with regional lymphadenectomy for palpable nodal metastases from MUP or MKP. Multivariate analysis identified prognostic factors significant for survival. MUP and MKP were then matched by significant covariates. Overall survival (OS) was estimated by Kaplan-Meier method and compared by log-rank analysis.

RESULTS

Multivariate analysis of data from 1,571 study patients identified four significant covariates associated with worse prognosis: age >or= 60 years (hazard ratio [HR] = 1.294; P = .0017), male sex (HR = 1.335; P = .0004), nodal tumor burden >or= one (HR = 1.256; P < .0001), and known primary (HR = 1.507; 95% CI, 1.220 to 1.862; P = .0001). Five-year OS was significantly higher for 262 patients with MUP than for 1,309 patients with MKP (55% +/- 6% v 44% +/- 3%; P = .0021). Computerized matching of MUP and MKP by four significant covariates (age, sex, nodal tumor burden, and decade of diagnosis) yielded 221 matched pairs. Median and 5-year OS rates were 165 months and 58% +/- 7%, respectively, for MUP as compared with 34 months and 40% +/- 7%, respectively, for MKP (P = .0006).

CONCLUSION

Lymphadenectomy is effective for nodal metastasis from MUP. The significantly better postoperative survival for MUP versus MKP suggests a strong endogenous immune response against the primary melanoma. Immunologic studies to identify cell-mediated and antibody components of this response may lead to new approaches for determining melanoma prognosis and treatment.

Melanophages reside in hypermelanotic, aberrantly glycosylated tumor areas and predict improved outcome in primary cutaneous malignant melanoma

BACKGROUND

Previously, hypermelanotic regions of cutaneous malignant melanoma (CMM) were found to contain a mixture of highly melanized melanoma cells and melanophages. Both cell types produced beta1,6-branched oligosaccharides. These sugars are used for motility by myeloid cells and cancer cells alike and are associated with poor survival in carcinomas of the breast, colon and lung. This study further investigated associations between melanophages and beta1,6-branched oligosaccharides and their potential contributions to patient outcome.

METHODS

Individual archival melanomas and high-throughput melanoma tissue microarrays were stained for melanophages with azure blue/S100 and for beta1,6-branched oligosaccharides with the lectin leukocytic phytohemagglutinin (LPHA, a selective marker for beta1,6-branched oligosaccharides).

RESULTS

In primary CMM, melanophages were highly enriched in hypermelanotic, LPHA-positive tumor regions and correlated with improved outcome at 10- and 20-year follow ups. While the combination of melanophages, LPHA positivity and high pigmentation indicated better outcome, a subset of LPHA-positive cells not associated with melanophages indicated worse outcome.

CONCLUSION

This is the first report of an anti-tumor role for the melanophage in melanoma biology. There appeared to be two classes of beta1,6-branched oligosaccharide-producing melanoma cells with opposing effects on outcome: one that attracted melanophages (better) and another that did not (worse). The findings disclose new aspects of the immune system and aberrant glycosylation in CMM.

Vanishing Endometrial Carcinoma

Three cases of histologically proven endometrial carcinoma (EmCa) demonstrated no residual carcinoma or biopsy site on the subsequent hysterectomy specimen. The shared identity of both endometrial biopsy and hysterectomy specimen was proven, and specimen misidentification was excluded in all 3 cases through successful DNA profiling. Just as vanishing cancer in prostatic carcinoma has recently been defined and accepted, it is suggested that vanishing EmCa can also be defined using specific pathological and clinical criteria. DNA profiling may serve to confirm the diagnosis. Vanishing EmCa is only a small subset within hysterectomy specimens that show no EmCa after a histological diagnosis of EmCa. The concept of vanishing EmCa may be useful in both clinical and medicolegal practice.

Beta1,6-branched oligosaccharides regulate melanin content and motility in macrophage-melanoma fusion hybrids

In previous studies, fusion of peritoneal macrophages or blood monocytes with mouse melanoma cells produced hybrids with upregulated expression of the glycosyltransferase beta1,6-N-acetylglucosaminyltransferase V (GnT-V) and its enzymatic product, beta1,6-branched oligosaccharides. This correlated with marked increases in motility, metastatic potential and, surprisingly, melanin content. This study was designed to establish direct roles for beta1,6-branched oligosaccharides in melanogenesis and motility. The levels of beta1,6-branched oligosaccharides were lowered by transfecting beta1,4-N-acetylglucosaminyltransferase III, a competitive inhibitor of GnT-V. beta1,4-N-acetylglucosaminyltransferase III transfection virtually eliminated melanin production and markedly decreased chemotactic motility. This implied that the metastatic and melanogenic phenotypes in hybrids were each upregulated by beta1,6-branched oligosaccharides. Although roles for beta1,6-branched oligosaccharides in motility and metastasis have been reported previously, this is the first study to directly implicate these structures in melanogenesis. Although drawn from experimental models, the findings might explain the well known hypermelanotic regions of human cutaneous malignant melanoma as hypermelanotic cutaneous malignant melanoma cells are rich in beta1,6-branched oligosaccharides. They might also explain why melanogenesis pathways differ between malignant and normal melanocytes as GnT-V is a myeloid-associated enzyme that is aberrantly expressed in melanoma cells but not in normal melanocytes.

An update on malignant melanoma vaccine research: insights into mechanisms for improving the design and potency of melanoma therapeutic vaccines

Currently, cancer vaccine therapy for melanoma has a 2-fold focus. On the one hand, advances have been aimed at improving the effectiveness of melanoma vaccines based on a greater understanding of melanoma tumor cell biology. On the other hand, there is increasing evidence that the immune system, our defense against tumors, also inadvertently plays a supportive role in promoting the development and progression of tumors. Hence, two opposing forces 'hanging in the balance' dictate patients' responses to melanoma: tumor cell biology and the status of the immune system. Recent developments in our understanding of both of these aspects have provided new leads and insights for novel ways to improve vaccine design and add to the melanoma vaccine armory. As the focus of immunotherapy shifts its aim towards the tumor microenvironment, we are now developing the ability to program the immune responses raised by vaccination against melanoma. The aim here is to prevent myeloid and regulatory T-cell-mediated immune suppression as well as to counteract tumor-derived factors capable of suppressing immune responses. A redirected strategy for vaccine immunotherapy is proposed based on our greater understanding of tumor immunity. Using a combination therapy of immune-potentiating melanoma vaccines together with adjuvants for overcoming the immunosuppressive forces will allow us to activate protective immunity against melanoma. Other cancer vaccines (i.e. colon or renal) are already offering reasons for hope and expectation that vaccine immunotherapy will also produce successful outcomes for patients with melanoma.

Comparative analysis of regulatory and effector T cells in progressively growing versus rejecting tumors of similar origins

Although regulatory T cells (Tregs) have been detected in clinically apparent and experimentally induced tumors, the significance of their presence is obscured because past studies examined late-stage tumors that had formed in immunocompetent hosts and thus had evolved mechanisms to escape immunologic recognition and/or elimination. Herein, we report the first comparative analysis of the antitumor response to 3'-methylcholanthrene-induced tumors, which either grow progressively (progressor tumors) or are rejected by the immune system (regressor tumors). Surprisingly, we found that both progressor and regressor tumors harbored proliferating (i.e., activated) Foxp3+CD25+Tregs. However, progressor tumors contained a higher percentage of Tregs in the lymphocyte subset versus regressor tumors. The Tregs in progressor tumors were derived from peripheral CD25+ natural Tregs, accumulated early after tumor challenge and were actively proliferating, suggesting that progressor tumors recruited and/or activated endogenous Tregs as a mechanism of escaping immune destruction. To explore whether Tregs directly contributed to the progressive growth phenotype of progressor tumors, we monitored tumor outgrowth in naive wild-type recipients pretreated with either a control monoclonal antibody (mAb) or a depleting CD25-specific mAb. In mice predepleted of CD25+ cells, the tumors that subsequently developed displayed an increased accumulation of proliferating CD8+ T cells and were rejected. These results show that, although Tregs are activated in both regressor and progressor tumors, the ratio of regulatory to effector T cells is critical in determining whether the host successfully rejects the tumor or eventually succumbs to tumor outgrowth.

Tumor stroma-associated antigens for anti-cancer immunotherapy

Immunotherapy has been widely investigated for its potential use in cancer therapy and it becomes more and more apparent that the selection of target antigens is essential for its efficacy. Indeed, limited clinical efficacy is partly due to immune evasion mechanisms of neoplastic cells, e.g. downregulation of expression or presentation of the respective antigens. Consequently, antigens contributing to tumor cell survival seem to be more suitable therapeutic targets. However, even such antigens may be subject to immune evasion due to impaired processing and cell surface expression. Since development and progression of tumors is not only dependent on cancer cells themselves but also on the active contribution of the stromal cells, e.g. by secreting growth supporting factors, enzymes degrading the extracellular matrix or angiogenic factors, the tumor stroma may also serve as a target for immune intervention. To this end several antigens have been identified which are induced or upregulated on the tumor stroma. Tumor stroma-associated antigens are characterized by an otherwise restricted expression pattern, particularly with respect to differentiated tissues, and they have been successfully targeted by passive and active immunotherapy in preclinical models. Moreover, some of these strategies have already been translated into clinical trials.

Gastrointestinal bleeding as the first manifestation of a burned-out tumour of the testis

We discuss the clinical presentation and course of the disease of a 25-year-old male who had gastrointestinal (GIT) symptoms secondary to retroperitoneal lymph node proliferation of a germ-cell tumour of the testis. The pathology evaluation of the orchiectomy specimen classified it as a burned-out tumour of the testis, given the lack of tumour elements and the presence of typical scarring tissue. Biological is-sues leading to tumour regression are discussed, as well.

Chaperoning antigen presentation by MHC class II molecules and their role in oncogenesis

Tumor vaccine development aimed at stimulating the cellular immune response focuses mainly on MHC class I molecules. This is not surprising since most tumors do not express MHC class II or CD1 molecules. Nevertheless, the most successful targets for cancer immunotherapy, leukemia and melanoma, often do express MHC class II molecules, which leaves no obvious reason to ignore MHC class II molecules as a mediator in anticancer immune therapy. We review the current state of knowledge on the process of MHC class II-restricted antigen presentation and subsequently discuss the consequences of MHC class II expression on tumor surveillance and the induction of an efficient MHC class II mediated antitumor response in vivo and after vaccination.

HLA class I antigen expression in malignant cells: why does it not always correlate with CTL-mediated lysis?

HLA class I antigen defects are frequently found in malignant cells. They appear to play a role in the clinical course of the disease, probably because they provide tumor cells with a mechanism to escape cytotoxic T lymphocyte (CTL) recognition and destruction. Expression of HLA class I antigens, however, is not always associated with the susceptibility of tumor cells to CTL lysis. Many mechanisms may underlie this finding, including the lack of tumor antigen (TA)-derived peptide presentation by a given HLA class I allospecificity, and/or the expression of immunosuppressive molecules such as HLA-G. These findings emphasize the need to develop probes to measure HLA class I allospecificity-TA peptide complex expression in malignant cells. Furthermore, the evaluation of the role of HLA class I antigens in the interaction of malignant cells with host immune cells should take into account the potential interference of tumor-derived immunomodulators.

'Burned-out' primary testicular cancer

OBJECTIVE

To report the natural history of 'burned-out' testicular tumour (a testicular tumour that has regressed spontaneously with no treatment and that generally presents at the stage of metastases).

PATIENTS AND METHODS

We report five cases of burned-out testicular tumours to illustrate the clinical, radiological and histopathological features, and discuss the hypothesis of natural history of these neoplasms.

RESULTS

The findings in the five patients tended to indicate that metastatic progression appears to induce spontaneous regression of the previous tumour site. Patients explored for extragonadal germ cell tumour present with various clinical features depending on the site of the metastases.

CONCLUSION

Despite the controversial hypotheses of the origin of these tumours, extragonadal germ cell tumours should be considered to be metastases of a 'burned-out' primary testicular tumour that must be investigated. When a primary testicular tumour is detected, the testis must be removed, and standard chemotherapy yields good long-term results. The hypothesis of an immunological reaction against the tumour inducing the spontaneous necrosis of the primary tumour and possibly the metastases should be considered. Immunological screening should be proposed in patients to investigate this interesting model of spontaneous tumour regression.

Multilineage progression of genetically unstable tumor subclones in cutaneous T-cell lymphoma

Molecular analysis of solid malignant tumors has suggested multilineage progression of genetically unstable subclones during early stages of tumorigenesis as a common mechanism of tumor cell evolution. We have investigated whether multilineage progression is a feature of cutaneous T-cell lymphoma (CTCL). To identify individual tumor cell subclones, we determined the pattern of mutations within microsatellite DNA obtained from multiple histomorphologically confined tumor cell nests of mycosis fungoides (MF) and lymphomatoid papulosis (LyP) lesions. Tumor cells were isolated by laser microdissection, and allelotypes were determined at microsatellite markers D6S260, D9S162, D9S171, D10S215, TP53.PCR15, and D18S65. Nine cases of MF and one patient with anaplastic large cell lymphoma (ALCL) originating from LyP were analyzed at 277 different microdissected areas obtained from 31 individual lesions. Three specimens of cutaneous lichen planus microdissected at 26 areas served as the control tissue. Microsatellite instability in microdissected tissue [MSI(md-tissue)] was detected in tumor tissues of all CTCL patients. One hundred and fifty-seven of 469 analyzed polymerase chain reaction (PCR) amplifications contained mutated microsatellite alleles (34%). In lichen planus, MSI(md-tissue) was seen in only four of 76 PCR products (5%) (P < 0.0001). The distribution of allelotypes in tumor cells from different disease stages was consistent with multilineage progression in five MF cases, as well as in the LyP/ALCL patient. Our results suggest that CTCL may evolve by multilineage progression and that tumor subclones in MF can be detected in early disease stages by mutation analysis of microsatellite DNA obtained from multiple microdissected areas.

Regulation of the trafficking of tumour-infiltrating dendritic cells by chemokines

To anticipate and initiate immune responses, dendritic cells follow a migratory route from their recruitment as sentinels into tissues, including solid tumors, then to secondary lymphoid organs where they profile the immune response. Migratory capacities--and especially chemokine responsiveness--are therefore key elements in dendritic cell biology. Here, we will review our current knowledge about tumour-infiltrating dendritic cells and the chemokine-driven migration flows in and out from tumors. Then we will discuss the consequences of the interactions between dendritic cells and tumors and the perspectives for translating our experimental knowledge of manipulating dendritic cell migratory flows into anti-cancer therapies.