Overexpression of Her-2 in patients with poorly differentiated carcinoma or poorly differentiated adenocarcinoma of unknown primary site

Intrathecal Trastuzumab for HER2-Positive Cancer of Unknown Primary Leptomeningeal Metastasis: A Case Report

Cancer of unknown primary (CUP) and leptomeningeal metastasis are difficult conditions with limited treatment options. We report a case of CUP leptomeningeal metastasis that was refractory to empirical chemotherapy but achieved a favorable response to intrathecal trastuzumab after the identification of human epidermal growth factor receptor-2 (HER2) amplification. A 59-year-old woman was diagnosed with CUP with metastasis of a poorly differentiated carcinoma to the left axillary, anterior mediastinal, peritoneal, and bilateral supraclavicular lymph nodes. Leptomeningeal metastasis was confirmed shortly after she started empiric chemotherapy; empiric therapy with intrathecal methotrexate failed to relieve her symptoms. Meanwhile, the lymph node specimen tested positive for HER2 amplification. She underwent intrathecal trastuzumab, then her neurological symptoms resolved the following day. We suggest that intrathecal trastuzumab is an effective treatment for HER2-positive CUP leptomeningeal metastasis.

The role of molecular profiling in the diagnosis and management of metastatic undifferentiated cancer of unknown primary✰: Molecular profiling of metastatic cancer of unknown primary

Cancer of unknown primary (CUP) refers to metastatic tumors for which the primary tumor of origin cannot be determined at the time of diagnosis, despite extensive clinicopathologic investigations. Molecular profiling is increasingly able to predict a probable primary tumor type for CUP when clinicopathologic workup is inconclusive. Numerous studies have explored the use of various molecular profiling techniques for identification of site/tissue of origin of CUP. These techniques include gene expression profiling utilizing microarray, reverse transcriptase polymerase chain reaction, RNA-sequencing, somatic gene mutation profiling with next-generation DNA sequencing, and epigenomics including DNA methylation profiling. Despite the generally poor prognosis of CUP, a minority of patients can expect to benefit from targeted therapy despite being agnostic to the tissue of origin. Studies have explored the use of various molecular profiling techniques to predict prognostic and therapeutic biomarkers, with the goal of improving outcome for patients with CUP. However, discordant results between non-randomized and randomized clinical trials in evaluating tumor-type specific therapies raise uncertainties of the benefits of molecularly-predicted tissue of origin-based treatment in routine clinical use. Nevertheless, the current overall trend is in favor of using molecular tools to refine the diagnosis and clinical management of patients with CUP. More large-cohort, randomized prospective studies are needed to assess and validate the utility and feasibility of molecular profiling to uncover potentially targetable genetic alterations. These efforts will also yield further biological insights into the biology and pathogenesis of CUP (Graphical Abstract).

The diagnostic challenges of patients with carcinoma of unknown primary

INTRODUCTION

Cancer of unknown primary (CUP) is a disease entity encompassing heterogeneous malignancies without a clinically-detectable anatomical primary. It is usually a poor prognosis malignancy with dismal prognosis where molecular and genetic testing were expected to be a major breakthrough.

AREAS COVERED

In this review, we provide an overview of the advances in the understanding of the carcinogenesis, biology, diagnosis and treatment of patients with CUP. This review focuses on the advantages and inconveniences of immunohistochemistry and CUP classifiers in assessing the progress in the management of CUP.

EXPERT OPINION

CUP classifiers were expected to gradually replace the classical multistep approach in identifying the culprit tumors to guide site-specific therapy. Immunohistochemistry staining led to the prediction of a single tissue of origin in 10.8-51%. CUP classifiers identified the primary site in 61-89% of these cases and were concordant with immunohistochemistry in 57.1-100%. Immunohistochemistry is cheap, fast and broadly available whereas CUP classifiers are less widely available and have not been validated in randomized control trials. The diagnostic recommendations consist of a standard pathology evaluation based on morphology and algorithmic immunohistochemistry assessment. Physicians should weigh in the input of the CUP classifier to the clinical picture and pathology investigations before performing additional investigations.

Progress in refining the clinical management of cancer of unknown primary in the molecular era

Cancer of unknown primary (CUP) is an enigmatic disease entity encompassing heterogeneous malignancies without a detectable primary tumour, despite a thorough diagnostic workup. A minority of patients with CUP (15-20%) can be assigned a putative primary tissue of origin according to clinical and histopathological findings and typically have a more favourable prognosis with the use of corresponding tumour type-specific therapies. Thus, the majority of patients with CUP have disease that cannot be assigned to a culprit primary tumour, are treated with empirical chemotherapy and have a poor prognosis. In the molecular era, the use of (epi)genomic or transcriptomic CUP classifiers and DNA or RNA sequencing offers two, sometimes overlapping, therapeutic strategies: tumour type-specific therapy and biomarker-guided therapy. Published data reveal that the accuracy of site-of-origin predictions made using CUP classifiers ranges between 54% and 98% when compared with the assignment made according to the recommended clinicopathological criteria. These advances have led to promising results in non-randomized prospective studies evaluating the efficacy of tumour type-specific therapy; however, the favourable outcomes were not confirmed in randomized controlled studies comparing this approach with standard empirical chemotherapy. Currently, the evidence supporting the use of biomarker-guided therapies is limited to case reports and small case series. In this Review, we discuss the clinical management of CUP in the era of precision medicine. We focus on the advances in understanding the biology of CUP, the implications for the diagnosis and classification of CUP according to the tissue of origin and the shift away from empirical therapy towards tailored therapy.

Exploring the biological hallmarks of cancer of unknown primary: where do we stand today?

Cancer of unknown primary (CUP) affects a small percentage of the general population. Nonetheless, a substantial number of these patients have a poor prognosis and consequently succumb to their illness within a year of diagnosis. The natural history of CUP is characterised by early metastasis from the unknown primary site, aggressive course and resistance to conventional chemotherapy. Unfortunately, the processes by which this orphan disease originates and progresses have not been fully elucidated and its biology remain unclear. Despite the conceptual progress in genetic and molecular profiling made over the past decade, recognition of the genetic and molecular abnormalities involved in CUP, as well as the identification of the tissue of origin remain unresolved issues. This review will outline the biology of CUP by exploring the hallmarks of cancer in order to rationalise the complexities of this enigmatic syndrome. This approach will help the reader to understand where research efforts currently stand and the pitfalls of this quest.

Skeletal Metastases of Unknown Primary: Biological Landscape and Clinical Overview

Skeletal metastases of unknown primary (SMUP) represent a clinical challenge in dealing with patients diagnosed with bone metastases. Management of these patients has improved significantly in the past few years. however, it is fraught with a lack of evidence. While some patients have achieved impressive gains, a more systematic and tailored treatment is required. Nevertheless, in real-life practice, the outlook at the beginning of treatment for SMUP is decidedly somber. An incomplete translational relevance of pathological and clinical data on the mortality and morbidity rate has had unsatisfactory consequences for SMUP patients and their physicians. We examined several approaches to confront the available evidence; three key points emerged. The characterization of the SMUP biological profile is essential to driving clinical decisions by integrating genetic and molecular profiles into a multi-step diagnostic work-up. Nonetheless, a pragmatic investigation plan and therapy of SMUP cannot follow a single template; it must be adapted to different pathophysiological dynamics and coordinated with efforts of a systematic algorithm and high-quality data derived from statistically powered clinical trials. The discussion in this review points out that greater efforts are required to face the unmet needs present in SMUP patients in oncology.

Prognostic significance of WNT and hedgehog pathway activation markers in cancer of unknown primary

BACKGROUND

Cancer of unknown primary (CUP) possesses distinct biology and peculiar natural history, in which the roles of the winged and hedgehog signalling pathways are unclear.

MATERIALS AND METHODS

We constructed tissue microarrays and studied the immunohistochemical (IHC) expression of β-catenin, smoothened (SMO) and the transcription factors TCF, LEF, GLI1 in 87 CUP cases for prognostic significance.

RESULTS

A low rate of IHC expression of proteins was seen, the cut-off used being any expression in ≥ 1% of tumour cells. At univariate analysis, only nuclear IHC SMO expression displayed a statistically significant association with favourable outcome [median Overall survival (OS) of 19 months in SMO-positive vs. 12 months in SMO-negative cases, P = 0·01]. An activated Wnt pathway, defined as IHC expression of any of nuclear β-catenin, TCF and LEF, was significantly associated with favourable progression free survival (median 9 vs. 5 months, P = 0·037) and OS (median 19 vs. 13 months, P = 0·04). This prognostic impact on OS was mainly driven by nuclear expression of TCF and/or LEF (P = 0·03). No prognostic significance of the hedgehog pathway activation status, defined as IHC expression of SMO or nuclear GLI1, could be established. A favourable prognostic impact of the concurrent activation of both pathways was observed. A trend for association of activated Wnt with response to chemotherapy (responders 67% among activated Wnt cases vs. 35% among nonactivated Wnt cases, P = 0·07) was observed in CUP adenocarcinomas.

CONCLUSIONS

Activation of the Wnt pathway was a positive prognostic factor in a small CUP series, possibly via enhanced chemosensitivity. Independent validation is warranted.

Gene expression profiling in patients with carcinoma of unknown primary site: from translational research to standard of care

Carcinoma of unknown primary site (CUP) is diagnosed in approximately 3 % of patients with advanced cancer, and most patients have traditionally been treated with empiric chemotherapy. As treatments improve and become more specific for individual solid tumor types, therapy with a single empiric combination chemotherapy regimen becomes increasingly inadequate. Gene expression profiling (GEP) is a new diagnostic method that allows prediction of the site of tumor origin based on gene expression patterns retained from the normal tissues of origin. In blinded studies in tumors of known origin, GEP assays correctly identified the site of origin in 85 % of cases and compares favorably with immunohistochemical (IHC) staining. In patients with CUP, GEP is able to predict a site of origin in >95 % of patients versus 35-55 % for IHC staining. Although confirmation of the accuracy of these predictions is difficult, the diagnoses made by IHC staining and GEP are identical in 77 % of cases when IHC staining predicts a single primary site. GEP diagnoses appear to be most useful when IHC staining is inconclusive. Site-specific treatment of CUP patients based on GEP and/or IHC predictions appears to improve overall outcomes; patients predicted to have treatment-sensitive tumor types derived the most benefit. GEP adds to the diagnostic evaluation of patients with CUP and should be included when IHC staining is unable to predict a single site of origin. Site-specific treatment, based on tissue of origin diagnosis, should replace empiric chemotherapy in patients with CUP.

Metabolic phenotypes in primary unknown metastatic carcinoma

Background

The purpose of this study is to evaluate expression of metabolism-related proteins in primary unknown metastatic carcinoma (PUMC) and associated implications for treatment.

Methods

A tissue microarray containing 77 cases of PUMC was constructed and immunohistochemical staining was used to evaluate expression of the following proteins: Glycolysis-related: Glut-1, carbonic anhydrase (CA) IX, and monocarboxylate transporter (MCT) 4; Glutaminolysis-related: glutaminase1 (GLS1), glutamate dehydrogenase (GDH), and amino acid transporter-2 (ASCT2); and Mitochondrial-related: ATP synthase, succinate dehydrogenase (SDH)A, and SDHB. The association between immunohistochemical staining results and clinicopathologic parameters was evaluated.

Results

The expression of metabolism-related proteins was different depending on the histologic subtype. Compared to other subtypes, squamous cell carcinomas (SQ) expressed more Glut-1 (p = 0.028), while adenocarcinomas (AD) expressed more SDHB in the stroma (p = 0.025). The expression of metabolism-related proteins was also different depending on the clinical subtypes. Glut-1 was expressed most in the nodal type and the least in carcinomatosis type, when compared to other subtypes (p = 0.021). The metabolic phenotypes also showed other trends: when the stroma showed no glutaminolysis, the tumor mostly invaded lymph node, bone, and brain, while the tumor invaded regions other than lymph node, bone, and brain when the stroma showed glutaminolysis (p = 0.003). When the stroma showed the mitochondrial metabolic type, the histologic subtype was mainly AD, but the non-mitochondrial type was associated more with SQ (P = 0.049).

Conclusion

For PUMC, the expression of metabolism-related proteins, such as Glut-1 and SDHB, differs in the tumor or stroma depending on the clinical and histologic tumor subtype.

Exploring the biology of cancer of unknown primary: breakthroughs and drawbacks

BACKGROUND

Cancer of unknown primary (CUP) ranks among the ten most common malignancies worldwide. Cancer of unknown primary presents as disseminated disease, has a dismal prognosis and remains a diagnosis of exclusion. The natural history and biology of the disease is poorly understood, and efforts are focused on identifying the specific 'CUP signature'.

MATERIALS AND METHODS

We collected and analysed all published research in the biology of CUP from 1974 till present (Medline, Embase, ASCO and ESMO Congresses).

RESULTS

Current scientific evidence suggests that aneuploidy and karyotype changes are frequent, while more subtle molecular aberrations, such as epidermal growth factor receptor family proteins, cKit/PDGFR are frequently overexpressed, although without prognostic significance. Loss of function of tumour suppressor genes, active angiogenesis, a hypoxic genetic programme and a mesenchymal transitory phenotype have been reported in CUP and may be indicative of unfavourable prognosis. Molecular pathway analyses have identified various biomolecules impacting on survival (pAKT, pMAPK, c-Met, p21 and pPRS6). Finally, circulating tumour cells have recently been reported as a frequent phenomenon in CUP.

CONCLUSIONS

Overall, advances in understanding CUP biology have been weak and the application of gene expression profiling failed to identify an as yet elusive 'CUP molecular signature'. MicroRNA, epigenetic and proteomic studies are warranted to better characterize the biological profile of CUP and unravel its mystery.

Hypoxia-related protein expression and its clinicopathologic implication in carcinoma of unknown primary

Carcinoma of unknown primary (CUP) is a heterogeneous entity with different clinical and histological features. The aim of this study was to investigate the clinicopathological features and expression of proteins associated with carcinogenesis and tumor environment in different histological subtypes of CUP. Sixty-nine cases of CUP were subjected to immunohistochemistry for EGFR, phospho-EGFR, HER-2, phospho-HER-2, p53, ERCC1, RRM1, REDD1, HIF1α, COX-2, GLUT-1, 14-3-3σ, Phospho-mTOR, Phospho-S6, AMPKα1, Phospho-Akt, PDGF-β receptor, and caveolin-1, and fluorescence in situ hybridization for HER-2 gene amplification. Fourteen (20.3%) cases were poorly differentiated carcinoma, 24 (34.8%) were adenocarcinoma (AD), 17 (24.6%) were squamous cell carcinoma (SC), and 14 (20.3%) were undifferentiated carcinoma (UD). AD were mostly carcinomatosis type, while SC and UD were mostly nodal type (p < 0.001). SC showed more frequent EGFR overexpression (p < 0.001) and Glut-1 (p = 0.001). AD (p = 0.001) and carcinomatosis (p < 0.001) types showed shorter overall survival. SCs expressing Glut-1, HIF1α, and COX2 showed a poor prognosis (p = 0.048, 0.029, and 0.042, respectively). CUP shows various clinicopathological features according to the histological subtypes. SC is mainly associated with nodal metastasis in the head and neck, and frequent EGFR overexpression and Glut-1 expression. Glut-1, HIF1α, and COX2 expression in SC is associated with a poor prognosis.

Unknown primary tumors

An unknown primary tumor (UPT) is defined by the presence of a metastatic cancer without a known primary site of origin despite a standardized diagnostic workup. Clinically, UPTs show rapid progression and early dissemination, with signs and symptoms related to the metastatic site. The molecular bases of their biology remain largely unknown, with no evidence as to whether they represent a distinct biological entity. Immunohistochemistry remain the best diagnostic tool in term of cost-effectiveness, but the time-consuming "algorithmic process" it relies on has led to the application of new molecular techniques for the identification of the primary site of UPTs. For example, several microarray or miRNA classifications of UPTs have been used, with an accuracy in the prediction of the primary site as high as 90%. It should be noted that validating a prediction of tissue origin is challenging in these patients, since most of them will never have a primary site identified. Moreover, prospective studies to determine whether selection of treatment options based on such profiling methods actually improves patient outcome are still missing. In the last few years functional imaging (i.e. FDG-PET/CT) has gained a main role in the detection of the site of origin of UPTs and is currently recommended by the European Association of Nuclear Medicine. However, despite recent refinements in the diagnostic workup, the site of origin of UPT often remains elusive. As a consequence, treatment of patients with UPT is still empirical and inadequate.

[CUP syndrome: molecular pathogenesis and biology]

Carcinoma of unknown primary (CUP) is an intriguing clinical finding defined as biopsy-proven metastasis from a malignancy in the absence of an identifiable primary site after a complete clinical workup. CUP is a relatively common clinical entity, accounting for approximately 3-5% of all cancer diagnoses, and consists of a heterogeneous group of tumors that have acquired the capacity to metastasize before the development of a clinically evident primary lesion. The mechanisms responsible for early metastasis and lack of a detectable primary tumor are largely unknown. Although remarkable tools have been developed for immunohistological classification of CUP on the basis of the likely tissue of origin, data on molecular pathogenesis and biology of this disorder are rare. A wide variety of chromosomal aberrations are seen in CUP, with aberrations of chromosomes 1, 6, 7, and 11 having been most frequently described. 66-75% of CUP express epidermal growth factor receptor while overexpression of Her2/neu seems to be rare. In contrast to most other tumor entities p53 mutations have been found only in a minority of CUP tumors. Recently, several independent studies have demonstrated proof of principle for the use of gene expression microarrays in identifying a primary site for CUP. Therefore, gene expression and also genomic profiling tools represent promising analytical approaches to assist with the management of CUP patients.

Molecular classification of unknown primary cancer

The diagnosis of unknown primary carcinoma is often the result of the failure of light microscopy and immunohistochemistry to elucidate the origin of adenocarcinoma or poorly differentiated carcinoma. Recent advances in gene expression profiling using either reverse transcription polymerase chain reaction (RT-PCR) or microarray have enabled researchers to develop expression profiles unique to a wide variety of well-characterized primary cancers and to compare these unique signatures with those from unknown primary cancers. As the gene expression profile is frequently conserved when the tumor metastasizes, it is often possible to analyze a biopsy specimen and genomically identify its tissue of origin. In fact, the overall accuracy of genomic cancer classification in patients with known primary cancers is 80% to 90%. This new system of molecular classification might be considered as "genomic taxonomy." The genomic classification is then available to the pathologist and clinician to aid in both the patient's diagnosis and treatment planning. The impact of this new technology on patient outcomes is currently under study.

Overview of patient management and future directions in unknown primary carcinoma

The management of patients with unknown primary carcinoma (UPC) has evolved over the last few years and the recently developed sophisticated diagnostic modalities and novel therapies present both an opportunity for and a challenge to treatment of patients with this heterogeneous group of neoplasms. Recognition of patients with favorable prognostic factors is critical as specific therapies benefit these patients. Current empiric chemotherapy can offer a minority of patients with unfavorable prognostic factors substantial clinical benefit and improved survival. A focused search for the primary cancer is recommended in most patients. With the emergence of robust immunohistochemical stains and the growing field of molecular profiling, there is an increasing need for validation of a tailored approach to therapy. Our current focus is to study the impact of genetic profiling studies on patient outcomes and understand the limitations of currently available diagnostic studies. Although there are barriers to progress including tumor heterogeneity, challenging study designs, concerns with patient sample size, and inadequate research support, it is now important that an approach tailored to unknown primary subsets defined by the combination of clinical features, immunohistochemical stains, and molecular profiling be rigorously evaluated.

Carcinoma of unknown primary (CUP)

Carcinoma of unknown primary (CUP) is one of the 10 most frequent cancers worldwide. It constitutes 3-5% of all human malignancies. Patients with CUP present with metastases without an established primary site. CUP manifests as an heterogeneous group of mainly epithelial cancers recognised by distinct clinicopathological entities. The diagnostic work-up includes extensive histopathology investigations and modern imaging technology. Nevertheless, the primary tumour remains undetected most of the time. Molecular diagnosis with DNA microarrays demonstrates high sensitivity, but its prognostic contribution is still uncertain. Certain clinicopathological CUP entities are considered as favourable sub-sets responding to systemic platinum-based chemotherapy or managed by locoregional treatment. These sub-sets are: the poorly differentiated carcinomas involving the mediastinal-retroperitoneal nodes, peritoneal papillary serous adenocarcinomatosis in females, poorly differentiated neuroendocrine carcinomas, isolated axillary node adenocarcinomas in females or cervical nodal involvement by a squamous cell carcinoma. Patients who belong to the non-favourable sub-sets have a worse prognosis.

Metastases in the Absence of a Primary Tumor: Advances in the Diagnosis and Treatment of CUP Syndrome

INTRODUCTION

The term cancer of unknown primary site (CUP) syndrome is used to describe malignancies in which a complete diagnostic work-up detects metastases in the absence of an identifiable primary tumor.

METHODS

Based on a selective literature review, national and international guidelines, and the experience of the "Arbeitskreis CUP-Syndrom der Arbeitsgemeinschaft Internistische Onkologie der Deutschen Krebsgesellschaft" (CUP Syndrome Committee of the Medical Oncology Joint Working Group of the German Cancer Society), developments in the diagnosis and treatment of CUP syndrome are reported.

RESULTS

Most patients diagnosed with CUP have an unfavorable prognosis, with a life expectancy of less than 12 months. Nevertheless, it is important to identify subsets of patients in whom specific treatment offers the chance of long-term survival or even full recovery.

DISCUSSION

Only rigorous further development of diagnostic tools and treatment protocols will enable an improvement of the poor prognosis of patients with CUP syndrome. Specific molecular treatment strategies have shown promising results.

Carcinoma of unknown primary with a colon-cancer profile-changing paradigm and emerging definitions

Carcinoma of unknown primary (CUP), which accounts for about 3-5% of all new cancers, is a challenging heterogeneous entity with an unmet research need. Traditionally, CUP has been managed with broad-spectrum chemotherapy, but with the increasing availability of sophisticated diagnostic techniques and the emergence of new treatments that have been shown to be effective in specific cancers the one-treatment-fits-all approach to CUP might eventually no longer be valid. CUP in association with a colon-cancer profile (CCP-CUP) is an example of an emerging, specific CUP subset that seems to benefit from a tailored approach. CCP-CUP is identified by CK20 and CDX2-positive and CK7-negative immunohistochemistry and a clinical course consistent with that of patients known to have metastatic colon cancer. Our findings suggest that patients with CCP-CUP derive substantial benefit from the use of specific treatments developed for colon cancer and larger clinical trials are warranted to more definitely test this finding. In the era of molecular profiling, we expect that additional work with CCP-CUP and other CUP subsets will provide attractive tailored treatment alternatives, with efficacies that exceed the current one-treatment-fits-all approach.

Carcinoma of an unknown primary: are EGF receptor, Her-2/neu, and c-Kit tyrosine kinases potential targets for therapy?

Carcinomas of an unknown primary site (CUP) are heterogeneous tumours with a median survival of only 8 months. Tyrosine kinase inhibitors are promising new drugs. The aim of this study was to determine the expression of EGF-receptor, Her-2/neu, and c-Kit tyrosine kinases in CUP. Paraffin-embedded specimens were obtained from 54 patients with a CUP who were included in the GEFCAPI 01 randomised phase II trial. Immunohistochemistry was performed using the Dako autostainer with antibodies directed against HER-2/neu protein, EGFR protein, and c-Kit protein (CD117). EGFR expression was found in 36 out of 54 samples (66%). In contrast, Her-2/neu overexpression and c-Kit positivity were only detected in 4 and 10% of patients, respectively. No significant association was found between the expression of the tyrosine kinase receptors and prognosis. EGFR expression was significantly associated with response to cisplatin-based chemotherapy: the response rates were 50 and 22% in patients with EGFR-positive tumours and EGFR-negative tumours, respectively (P<0.05). This study shows that EGFR is frequently expressed in CUP. This finding may prompt clinical trials investigating EGFR inhibitors in this setting. In contrast, c-Kit expression and Her-2/neu overexpression occur infrequently in CUP. EGFR expression was correlated to tumour chemosensitivity.

Forty years experience of treating cancer of unknown primary

Cancer of unknown primary site (CUP) is not a rare tumour. It accounts as the seventh to eighth most frequently diagnosed cancer in a general medical oncology service. Since CUP is not a homogeneous disease and it consists of different favourable and unfavourable sub-sets, treatment of each clinicopathological entity requires a unique approach. The spectrum of therapeutic management includes both locoregional and systemic therapy and should intend to offer optimal benefit to favourable CUP patients and palliative care to unfavourable cases. This review article provides both a historical outline of CUP treatment as well as a helpful therapeutic guide to every oncologist who treats CUP patients.

Cancer of unknown primary site: missing primary or missing biology?

Cancer of unknown primary site (CUP) ranks as the fourth most common cause of cancer deaths and represents both a diagnostic and a management challenge. In CUP, the regression or dormancy of the primary tumor, the development of early, uncommon, systemic metastases, and the resistance to therapy are hallmarks of this heterogeneous clinical entity. Still, no consensus exists on whether CUP is simply a group of metastatic tumors with unidentified primaries or a distinct entity with specific genetic/phenotypic aberrations that define it as "primary metastatic disease." In this review, we present karyotypic analyses as well as the single-gene, single-protein studies done on the expression of oncogenes, tumor- or metastasis-suppressor genes, as well as angiogenesis effectors. These studies show frequent expression of oncoproteins, lack of activating epidermal growth factor receptor/c-Kit mutations or amplification, uncommon presence of tumor- or metastasis-suppressor gene mutations and highly active angiogenesis in CUP. Informative as they may be, these data have been observed in several solid tumors of known primary and failed to identify a CUP-specific molecular signature. The latter, if it exists, probably consists of a multigene expression pattern not captured by single-gene studies. Gene and protein microarray technologies offer promise for the unraveling of complex genetic programs that would either identify each CUP's primary tissue of origin or instead define the CUP-specific molecular signature. Confirmation of one of the two hypotheses would either improve primary disease-oriented therapy or develop CUP-oriented treatments targeting molecular aberrations that drive neoplastic growth/dissemination.

Progressive ataxic gait disorder

Paraneoplastic cerebellar degeneration (PCD) is a well-described paraneoplastic syndrome. In patients with anti-Yo associated PCD, neurological symptoms precede the diagnosis of the underlying cancer in approximately 60% of cases. Ovarian, breast and other gynaecological malignancies are most frequently found as causative malignancies. Antitumour treatment should be commenced at an early stage of the disease. Identification of the tumour is a diagnostic challenge in many of these patients. In the case reported herein, a secondary tumour with unknown primary was suggested after detection of a pathological lymph node in the right axilla by a positron emission tomography scan. Microscopic examination of the ultrasound-guided resected tissue was a poorly differentiated adenocarcinoma strongly positive for the C-ERB 2 oncoprotein. A micro-invasive mammary carcinoma was unable to be localized, even with the aid of magnetic resonance mammography and axillary clearance. Intravenous gamma-globulin and steroid treatment and rehabilitation failed to influence the neurological symptoms. The present patient also demonstrated diffuse increase on the T2 signal in the cerebellum, which may provide a useful diagnostic clue in the assessment of PCD.

Perspectives for targeted therapies in cancer of unknown primary site

Cancer of unknown primary site (CUP) ranks as the fourth most common cause of cancer deaths. Regression of the primary, early development of systemic metastases and resistance to therapy are hallmarks of this heterogeneous clinical entity. Targeted therapy offers promise for improvement of outcome of such patients, but it is currently hindered by lack of known molecular targets on which tumours are dependent for growth. In this review, we present the gene and protein profiling studies done on expression of oncogenes, tumour-suppressor genes and angiogenesis effectors and discuss the therapeutic potential of developed targeted agents. Existing data show occasional overexpression of Ras, BCL2 oncoproteins, absence of active EGFR/c-KIT/PDGFR signalling, uncommon presence of tumour-suppressor gene mutations and highly active angiogenesis in CUP. High-throughput multi-gene, multi-protein platforms offer promise for unravelling the complex molecular pathophysiology of CUP, for identification of targets suitable for modulation and ultimately hope for abrogation of its aggressive natural history.

Les carcinomes de primitif inconnu

PURPOSE

Carcinoma of unknown primary site is a common clinical syndrome, accounting for 2% of cancer patients. Diagnosis is a recurrent challenge for internists. Treatment is difficult and prognosis is still poor. This review presents one synthesis of diagnosis strategies and therapeutic trials. It envisages the interest of new molecular biology methods as well as therapeutic perspectives.

CURRENT KNOWLEDGE AND KEY POINTS

Pathologic examination completed with immunohistochemical tests, and, depending on cases, with electron microscopy, cytogenetics, and molecular biology is a key-point for diagnosis. Diagnosis work-up, based on histological type and on individualization of some clinical presentation, proceeds in three steps. Positron emission tomography is recommended when a curative treatment is planed, particularly in cases of isolated metastasis. Functional status analysed using the performance status and simple biologic parameters (serum lactate dehydrogenase, serum alkaline phosphatase) permit us to assess prognosis. Chemotherapy is offered for patients with a good general health status.

FUTURE PROSPECTS AND PROJECTS

Further evaluation of positron emission tomography, as well as cost-benefit analyses, is warranted. Further randomised trials are necessary to determine the optimal chemotherapy regimen in good-risk patients and the interest of chemotherapy in patients with poor-risk disease. Gene expression profiling and proteomic evaluation, as well as pharmacogenomic offer new investigation fields.

Matrix metalloproteinases in carcinoma of unknown primary

BACKGROUND

The purpose was to study proteolysis-related molecules, matrix metalloproteinase-2 (MMP-2) and MMP-9 and tissue inhibitor of metalloproteinases-1 (TIMP-1), in carcinoma of unknown primary (CUP).

METHODS

Paraffin-embedded tumor material from 75 patients diagnosed with CUP was used. Tumor histologies were adenocarcinoma (77%), undifferentiated carcinoma (19%), and squamous cell carcinoma (4%) and patients were categorized into favorable (62%) and unfavorable (38%) subsets. The tissue expression of MMP-2, MMP-9, and TIMP-1 was assessed by use of specific monoclonal antibodies and evaluated by means of a visual staining score. The expression of molecules studied was analyzed against clinicopathological data.

RESULTS

MMP-2 was found expressed in 69% (strong expression in 49%), MMP-9 in 49% (strong in 36%), and TIMP-1 in 79% (strong in 44%) of studied cases. The expression of MMP-2 correlated positively with MMP-9. TIMP-1 was significantly higher in unfavorable compared with favorable tumors and was associated with a shorter survival of patients (7.5 vs. 12 mos). No other associations were detected.

CONCLUSIONS

MMP-2, MMP-9, and TIMP-1 are widely expressed in CUP, suggesting an essential role of proteolysis in these tumors. TIMP-1 may be considered a possible marker of poor prognosis in CUP patients.

Cancer of unknown primary (CUP)

Carcinoma of unknown primary (CUP) is one of the 10 most frequent cancers worldwide. It constitutes 3-5% of all human malignancies. Patients with CUP present with metastases without an established primary site. CUP manifests as an heterogenous group of mainly epithelial cancers recognised by distinct clinicopathological entities. The diagnostic work-up includes extensive histopathology investigations and modern imaging technology. Nevertheless, the primary tumour remains undetected most of the time. Certain clinicopathological CUP entities are considered as favourable subsets responding to systemic platinum-based chemotherapy or managed by locoregional treatment. These subsets are: the poorly differentiated carcinomas involving the mediastinal-retroperitoneal nodes, peritoneal papillary serous adenocarcinomatosis in females, poorly differentiated neuroendocrine carcinomas, isolated axillary node adenocarcinomas in females or cervical nodal involvement by a squamous cell carcinoma. Patients who belong to the non-favourable subsets have a worse prognosis.

Carboplatin, doxorubicin and etoposide in the treatment of tumours of unknown primary site

The aim of this study was to assess the activity and toxicity of a platinum-based treatment on a group of patients with unknown primary tumours (UPTs). Patients with a diagnosis of UPT underwent a standard diagnostic procedure. Treatment was started within 2 weeks from diagnosis and consisted of carboplatin 400 mg m(-2) day 1, doxorubicin 50 mg m(-2) day 1, etoposide 100 mg m(-2) days 1-3, every 21 days. Response was evaluated after three courses and treatment continued in case of objective response (OR) or symptom control. A total of 102 patients were eligible. The median age was 59 years, sex male/female 54/48, histology was mainly adenocarcinoma or poorly differentiated carcinoma. Nodes, bone, liver and lung were the most frequently involved sites. In all, 79 patients received at least three courses of treatment; 26 patients received six courses or more. Six complete responses and 21 partial responses were observed, for a total of 27 of 102 ORs or 26.5% (95% confidence interval 18.2-36.1%). The median survival was 9 months and median progression-free survival was 4 months. Toxicity was moderate to severe, with 57.8% of patients experiencing grade III-IV haematological toxicity, mainly leucopenia. The regimen employed has shown activity in tumours of unknown primary site, but was associated with significant toxicity. Such toxicity may be considered unjustified, given the large proportion of patients with tumours not likely to respond. Efforts should therefore be addressed to identify predictors of response to chemotherapy, thus limiting aggressive treatment to those patients who could benefit from it.

Diagnostic strategies for unknown primary cancer

Unknown primary cancer (UPC) is defined by the presence of metastatic disease for which a primary site is undetectable on presentation. Computed tomography scan of the body was performed routinely in search of the primary cancer and invasive procedures were pursued in selective cases. Magnetic resonance imaging of the breast enables identification of an occult breast primary tumor in < or = 75% of women who present with adenocarcinoma in the axillary lymph nodes and can influence surgical management. Positron emission tomography scan also can be used in the diagnosis of UPCs, but its value is controversial. Cytokeratins 7 and 20 and thyroid transcription factor are some of the histochemical markers used in most patients who present with metastatic adenocarcinoma. Some of the newly discovered immunohistochemical markers further assist in narrowing the differential diagnosis. The role of molecular profiling to make the diagnosis, establish the prognosis, and assess the response to treatment in UPCs is evolving. The authors discuss the role of histochemical markers in the diagnosis of UPC and the most recent data regarding the use of imaging and invasive diagnostic modalities and gene expression profiles.

Cisplatin in combination with either gemcitabine or irinotecan in carcinomas of unknown primary site: results of a randomized phase II study--trial for the French Study Group on Carcinomas of Unknown Primary (GEFCAPI 01)

PURPOSE

To evaluate the efficacy and toxicity of novel chemotherapy combinations including cisplatin with gemcitabine (GC) or irinotecan (IC) for patients with carcinomas of an unknown primary site.

PATIENTS AND METHODS

Eighty patients were randomly assigned to receive GC or IC. In the GC arm, chemotherapy consisted of cycles combining gemcitabine 1,250 mg/m2 intravenously (IV) on days 1 and 8, and cisplatin 100 mg/m2 IV on day 1 at 3-week intervals. Patients in the IC arm originally received 3-week cycles of irinotecan 200 mg/m2 IV on day 1 and cisplatin 80 mg/m2 IV on day 1. After the inclusion of 15 patients in that arm, the toxicity profile required the irinotecan doses to be reduced to 150 mg/m2 per cycle. Independent histologic and radiologic reviews were done.

RESULTS

A total of 78 patients were assessable for efficacy and toxicity. The median number of cycles was four in each arm. Objective responses were observed in 21 patients (55%) in the GC arm (95% CI, 34% to 66%) and in 15 patients (38%) in the IC arm (95% CI, 23% to 54%). Treatment had to be stopped because of toxicity in seven patients in the GC arm and in eight patients in the IC arm. With a median follow-up of 22 months, the median survivals were 8 and 6 months in the GC and IC arms, respectively.

CONCLUSION

This study demonstrates the activity of both the GC and IC regimens. There was toxicity associated with both regimens. Additional studies of combination chemotherapy regimens are required.

Diagnostic and therapeutic management of cancer of an unknown primary

Metastatic Cancer of Unknown Primary Site (CUP) accounts for approximately 3% of all malignant neoplasms and is therefore one of the 10 most frequent cancer diagnoses in man. Patients with CUP present with metastatic disease for which the site of origin cannot be identified at the time of diagnosis. It is now accepted that CUP represents a heterogeneous group of malignancies that share a unique clinical behaviour and, presumably, unique biology. The following clinicopathological entities have been recognised: (i) metastatic CUP primarily to the liver or to multiple sites, (ii) metastatic CUP to lymph nodes including the sub-sets involving primarily the mediastinal-retroperitoneal, the axillary, the cervical or the inguinal nodes, (iii) metastatic CUP of peritoneal cavity including the peritoneal papillary serous carcinomatosis in females and the peritoneal non-papillary carcinomatosis in males or females, (iv) metastatic CUP to the lungs with parenchymal metastases or isolated malignant pleural effusion, (v) metastatic CUP to the bones, (vi) metastatic CUP to the brain, (vii) metastatic neuroendocrine carcinomas and (viii) metastatic melanoma of an unknown primary. Extensive work-up with specific pathology investigations (immunohistochemistry, electron microscopy, molecular diagnosis) and modern imaging technology (computed tomography (CT), mammography, Positron Emission Tomography (PET) scan) have resulted in some improvements in diagnosis; however, the primary site remains unknown in most patients, even on autopsy. The most frequently detected primaries are carcinomas hidden in the lung or pancreas. Several favourable sub-sets of CUP have been identified, which are responsive to systemic chemotherapy and/or locoregional treatment. Identification and treatment of these patients is of paramount importance. The considered responsive sub-sets to platinum-based chemotherapy are the poorly differentiated carcinomas involving the mediastinal-retroperitoneal nodes, the peritoneal papillary serous adenocarcinomatosis in females and the poorly differentiated neuroendocrine carcinomas. Other tumours successfully managed by locoregional treatment with surgery and/or irradiation are the metastatic adenocarcinoma of isolated axillary nodes, metastatic squamous cell carcinoma of cervical nodes, or any other single metastatic site. Empirical chemotherapy benefits some of the patients who do not fit into any favourable sub-set, and should be considered in patients with a good performance status.

Cancer from an unknown primary site

Cancer from an unknown primary site (CUP) is frequently encountered in clinical practice. This review is designed to help physicians identify those patients with CUP that benefit from specific therapeutic approaches. The utility of pathologic and diagnostic tests in patients with CUP will also be discussed, as will the prognosis and appropriate treatment of these patients.

The unknown biology of the unknown primary tumour: a literature review

The unknown primary tumour (UPT) is an intriguing clinical phenomenon found in approximately 5% of all newly diagnosed patients with cancer. It is unclear whether UPT forms a distinct biological entity with specific genetic and phenotypic characteristics, or whether it is merely a clinical presentation of metastases in patients in whom the primary tumour cannot be detected and does not result in any visible clinical signs. Understanding the basic biology of UPT may shed light on this issue and, moreover, may have a direct impact on clinical care. A review of the literature revealed only a limited number of publications describing the genetic and phenotypic features of UPT, most of which focus only on the potential of these markers to predict prognosis. The question as to whether the biology of UPT is different from tumours of known primaries therefore remains unanswered. Further insight into the molecular mechanisms underlying the oncogenesis of UPT, e.g. by applying newly available DNA and gene profiling microarray techniques, will be necessary to understand its specific biology and to develop more effective treatments.

Cytogenetic profile of unknown primary tumors: clues for their pathogenesis and clinical management

Unknown primary tumors (UPTs) represent an entity of great clinical and biological interest, whose origin cannot be determined even after medical workup. To better understand their pathogenesis by outlining their genetic composition, 20 UPTs were investigated by G-banding, supplemented with Fluorescence In Situ Hybridization and Comparative Genomic Hybridization analyses. The data obtained were sufficient to reach a diagnosis in five cases-four lymphomas and one Ewing sarcoma-demonstrating that in a subset of UPTs, cytogenetics can be an adjunct for differential diagnosis. In the remaining 15 UPTs, an aggressive cytogenetic pattern was revealed. The most frequently rearranged chromosome regions were 1q21, 3p13, 6q15-23, 7q22, 11p12-5, and 11q14-24, pinpointing gene loci probably associated with the peculiar pathogenesis of UPTs. The preferential involvement of 4q31, 6q15, 10q25, and 13q22 in adenocarcinomas (whereas 11q22 is involved in the rest of the carcinomas)-in addition to the marked divergence in the mean average of chromosomal changes, 16 and 3, respectively-demonstrates genotypic differences between the two histologic subgroups. Furthermore, the significantly shorter survival in cases displaying massive chromosome changes compared with those having a few changes indicates that the cytogenetic pattern might be used as a tool to assess prognosis in UPTs, even without the detection of their primary site.

HER2 overexpression in muscle-invasive urothelial carcinoma of the bladder: prognostic implications

The HER2 (c-erbB-2) receptor is overexpressed in a variety of human malignant tumors and, in breast carcinoma, has been identified as a target for anti-HER2-directed therapy with the monoclonal antibody (MAb) trastuzumab. The aim of this retrospective study was to evaluate immunohistochemic HER2 expression in a large cohort of muscle-invasive urothelial cell carcinomas of the urinary bladder and to compare the results to pathologic characteristics and survival. Paraffin-embedded tumor specimens from 138 patients undergoing radical cystectomy for muscle-invasive bladder carcinoma were studied immunohistochemically with the Food and Drug Administration (FDA)-approved HercepTest (Dako, Glostrup, Denmark). HER2 overexpression was observed in 57 of 138 tumors (41%) and occurred more frequently in high-grade carcinomas than in low-grade carcinomas (p = 0.036). No significant relationship with HER2 overexpression was registered for tumor staging and lymph node status. Kaplan-Meier curves showed a significantly worse disease-related survival (p = 0.034) in patients with HER2-overexpressing tumors compared to those without HER2 overexpression. In addition to lymph node status (p = 0.0001; relative risk [RR] = 2.93), HER2 status (p = 0.020; RR = 2.22) was identified as an independent predictor for disease-related survival in a multivariate analysis. These results suggest that HER2 expression might provide additional prognostic information in patients with muscle-invasive bladder carcinomas. Because many of these patients harbor HER2-overexpressing tumors, clinical trials evaluating the efficacy of trastuzumab in bladder carcinoma are warranted.

Gemcitabine, carboplatin, and paclitaxel for patients with carcinoma of unknown primary site: a Minnie Pearl Cancer Research Network study

PURPOSE

To evaluate the efficacy and toxicity of the novel chemotherapy combination that includes gemcitabine, carboplatin, and paclitaxel in the treatment of patients with carcinoma of unknown primary site.

PATIENTS AND METHODS

One hundred twenty patients were treated with the following regimen, administered every 21 days for a planned four courses: gemcitabine 1,000 mg/m(2) intravenously (i.v.) on days 1 and 8, carboplatin at an estimated area under the concentration-time curve of 5 mg min/mL i.v. on day 1, and paclitaxel 200 mg/m(2) i.v. on day 1. After four courses, stable and responding patients were given weekly paclitaxel 70 mg/m(2) i.v. for 6 weeks for three 8-week courses. All patients had relatively poor prognostic features. Sixty-three patients had well-differentiated adenocarcinoma, 56 patients had poorly differentiated carcinoma, and 104 patients had performance status of 0 or 1.

RESULTS

Twenty-eight (25%) of 113 assessable patients (95% confidence interval, 22% to 30%) had major objective responses to treatment. Response rates were similar in the two major histologic types. Response rate did not seem to be improved by continued therapy with weekly paclitaxel. The median progression-free survival time was 6 months. Median survival for the entire group was 9 months, and the actuarial survival at 1 and 2 years was 42% and 23%, respectively.

CONCLUSION

Combination chemotherapy with gemcitabine, carboplatin, and paclitaxel followed by weekly paclitaxel is an active and tolerable treatment for patients with carcinoma of unknown primary site. The survival seen in this poor-prognosis group of patients in this multicenter community-based trial is notable and similar to other taxane-based regimens for these patients. Study of additional combinations or sequences of newer drugs, as well as the exploration of targeted biologic agents for patients with an identified target in their tumors, is warranted.

Alternative bimonthly cycles of doxorubicin, cyclophosphamide, and etoposide, cisplatin with hematopoietic growth factor support in patients with carcinoma of unknown primary site

BACKGROUND

Because carcinomas of unknown primary origin are highly malignant tumors with a bad prognosis (median survival, 6-12 months) and no current optimal therapy, the authors designed a prospective dose-dense chemotherapy regimen with the objective of improving the results observed in patients who receive conventional treatment.

METHODS

Eighty-two patients received alternative bimonthly cycles of doxorubicin 50 mg/m(2) with cyclophosphamide 1000 mg/m(2) (AC) and etoposide 300 mg/m(2) with cisplatin 100 mg/m(2) (EP). Cycles were given at 2-week intervals with granulocyte-macrophage-stimulating factor support (5 microg/kg per day) from Day 4 to Day 10. Patients without measurable lesions were included, because the major end point was survival.

RESULTS

The median number of alternative cycles of AC and EP was 4 cycles (range, 1-12 cycles). An objective response was observed in 24 of 62 patients (39%; 95% confidence interval, 30-48%) with measurable lesions, including 6 patients who achieved a complete response. Among 20 patients with nonmeasurable disease, 9 patients (45%) had no evidence of progressive disease at the end of chemotherapy. The overall median survival of 82 patients was 10 months, with 5 patients surviving clinically disease free at 17 months, 29 months, 45 months, 64 months, and 70 months after the end of treatment. Myelosuppression was the most common toxicity. Two toxic deaths occurred.

CONCLUSIONS

Using these doses and schedules, a dose-dense chemotherapy regimen did not appear to improve the outcome of patients with carcinoma of unknown primary site. Alternative studies dealing with news drugs will be required.