Serial monitoring of circulating melanoma cells during neoadjuvant biochemotherapy for stage III melanoma: outcome prediction in a multicenter trial

Global gene expression profiling and validation in esophageal squamous cell carcinoma and its association with clinical phenotypes

PURPOSE

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with poor prognosis. Understanding molecular changes in ESCC will enable identification of molecular subtypes and provide potential targets for early detection and therapy.

EXPERIMENTAL DESIGN

We followed up a previous array study with additional discovery and confirmatory studies in new ESCC cases by using alternative methods. We profiled global gene expression for discovery and confirmation, and validated selected dysregulated genes with additional RNA and protein studies.

RESULTS

A total of 159 genes showed differences with extreme statistical significance (P < E-15) and 2-fold differences or more in magnitude (tumor/normal RNA expression ratio, N = 53 cases), including 116 upregulated and 43 downregulated genes. Of 41 genes dysregulated in our prior array study, all but one showed the same fold change directional pattern in new array studies, including 29 with 2-fold changes or more. Alternative RNA expression methods validated array results: more than two thirds of 51 new cases examined by real-time PCR (RT-PCR) showed 2-fold differences or more for all seven genes assessed. Immunohistochemical protein expression results in 275 cases which were concordant with RNA for five of six genes.

CONCLUSION

We identified an expanded panel of genes dysregulated in ESCC and confirmed previously identified differentially expressed genes. Microarray-based gene expression results were confirmed by RT-PCR and protein expression studies. These dysregulated genes will facilitate molecular categorization of tumor subtypes and identification of their risk factors, and serve as potential targets for early detection, outcome prediction, and therapy.

Genetic factors in metastatic progression of cutaneous melanoma: the future role of circulating melanoma cells in prognosis and management

The greatest potential for improvement of outcome for patients with Cutaneous Malignant Melanoma lies in the prevention of systemic metastasis. Despite extensive investigation, current prognostic indicators either alone or in combination, although related to melanoma progression, are not sufficient to accurately predict the pattern of progression and outcome for any individual patient. Metastasis related death has been recorded in patients initially diagnosed with early stage tumour as well as in patients many years after initial tumour removal. The trouble finding a predictable pattern in the puzzle of melanoma progression may be linked to the fact that most of the material studied for prognosis is either, cutaneous primaries or metastatic deposits, rather than the melanoma cells in the circulatory system which are responsible for disease progression. In this review article we discuss the potential use of circulating tumour cell (CTC) detection and quantification for identifying patients at risk of metastatic deposits. We also discuss current therapies for the treatment of metastatic melanoma and analyse how CTCs may be used to evaluate the effectiveness of current therapies and to pinpoint patients who require further treatment.

Molecular upstaging based on paraffin-embedded sentinel lymph nodes: ten-year follow-up confirms prognostic utility in melanoma patients

OBJECTIVE

To determine the long-term clinical significance of molecular upstaging in histopathology-negative, paraffin-embedded (PE) sentinel lymph nodes (SLNs) from melanoma patients.

BACKGROUND

Histopathologic evaluation can miss clinically relevant melanoma micrometastases in SLNs. This longitudinal correlative study is the first 10-year prognostic evaluation of a multimarker quantitative real-time reverse transcriptase-polymerase chain reaction (qRT) assay for PE melanoma-draining SLNs.

METHODS

The SLN sections (n = 214) were assessed by qRT assay for 4 established messenger RNA biomarkers: MART-1, MAGE-A3, GalNAc-T, and PAX3.

RESULTS

The qRT assay upstaged 48 of 161 histopathology-negative (hematoxylin-eosin and immunohistochemistry) SLN specimens. At a median follow-up of 11.3 years for the entire cohort, estimated rates of 10-year overall survival (OS) and melanoma-specific survival (MSS) were 82% and 94%, respectively, for histopathology-negative/qRT-negative patients; 56% and 61%, respectively, for histopathology-positive patients; and 52% and 60%, respectively, for histopathology-negative/qRT-positive patients (P < 0.001 for OS, P < 0.001 for MSS). In a multivariate analysis of known melanoma prognostic factors, qRT positivity was significant (P < 0.05) for disease-free survival (hazard ratio [HR], 4.3; 95% confidence interval (CI), 2.3-7.8), distant disease-free survival (HR, 6.6; 95% CI, 2.9-14.6), MSS (HR, 6.2; 95% CI, 2.6-14.4), and OS (HR, 2.8; 95% CI, 1.6-4.9).

CONCLUSION

The multimarker qRT assay has prognostic significance for molecular upstaging of PE melanoma-draining SLNs. Molecular upstaging of histopathology-negative SLNs confers a prognosis similar to that associated with SLN micrometastasis, and the number of positive qRT biomarkers is correlated to disease outcome.

Methods of detection of circulating melanoma cells: a comparative overview

Disease dissemination is the major cause of melanoma-related death. A crucial step in the metastatic process is the intravascular invasion and circulation of melanoma cells in the bloodstream with subsequent development of distant micrometastases that is initially clinically undetectable and will eventually progress into clinically apparent metastasis. Therefore, the use of molecular methods to detect circulating melanoma cells may be of value in risk stratification and clinical management of such patients. Herein, we review the currently applied techniques for the detection, isolation, enrichment and further characterization of circulating melanoma cells from peripheral blood samples in melanoma patients. Furthermore, we provide a brief overview of the various molecular markers currently being evaluated as prognostic indicators of melanoma progression.

Prognostic value of microphthalmia-associated transcription factor and tyrosinase as markers for circulating tumor cells detection in patients with melanoma

The aim of this study was to analyze microphthalmia-associated transcription factor (MITF) as a marker for the detection of circulating melanoma cells, determine its prognostic value in melanoma patients, and compare it with tyrosinase. Blood samples from 201 melanoma patients in all stages of the disease and 40 healthy volunteers were analyzed. RNA was isolated from mononuclear cell fraction of the blood and assayed by reverse transcription-PCR for the expression of MITF and tyrosinase. All samples from healthy volunteers were negative for both MITF and tyrosinase. Out of 201 blood samples from melanoma patients 32 were positive for MITF, 20 for tyrosinase, and four for both MITF and tyrosinase. Analysis of MITF as an additional marker to tyrosinase allowed for detection of circulating melanoma cells in a larger number of melanoma patients in comparison to tyrosinase analysis alone (48 vs. 20 positive). A positive value of MITF was associated with shorter progression-free (P=0.005) and overall survival (P=0.042). A positive value of tyrosinase was associated with shorter overall survival (P=0.012), whereas there was no significant association between the value of tyrosinase and progression-free survival. The value of MITF was selected with multivariate analysis as the independent prognostic factor for progression-free survival, whereas the only independent prognostic factor for overall survival was the stage of disease. This study has shown that MITF is a specific marker for detection of circulating melanoma cells that has a prognostic value in melanoma patients. Determination of MITF in addition to tyrosinase improved the detection of circulating melanoma cells in melanoma patients.

Detection of melanoma cells in vitro using an optical detector of photoacoustic waves

BACKGROUND AND OBJECTIVE

Circulating tumor cells have been shown to correlate positively with metastatic disease state in patients with advanced cancer. We have demonstrated the ability to detect melanoma cells in a flow system by generating and detecting photoacoustic waves in melanoma cells. This method is similar to flow cytometry, although using photoacoustics rather than fluorescence. Previously, we used piezoelectric films as our acoustic sensors. However, such films have indicated false-positive signals due to unwanted direct interactions between photons from the high laser fluence in the flow system and the film itself. We have adapted an optical detection scheme that obviates the need for piezoelectric films.

STUDY DESIGN/MATERIALS AND METHODS

Our photoacoustic system comprised a tunable laser system with an output of 410-710 nm with a pulse duration of 5 nanoseconds. The light was delivered by optical fiber to a glass microcuvette that contained saline buffer suspensions of melanoma and white blood cells. We used a continuous HeNe laser to provide a probe beam that reflected off of a glass and water interface in close proximity to the microcuvette. The beam was detected by a high-speed photodiode. When a photoacoustic wave was generated in the microcuvette, the wave propagated and changed the reflectance of the beam due to index of refraction change in the water. This perturbation was used to detect the presence of melanoma cells.

RESULTS

We determined a detection threshold of about one individual melanoma cell with no pyroelectric noise indicated in the signals.

CONCLUSIONS

The optical reflectance method provides sensitivity to detect small numbers of melanoma cells without created false-positive signals from pyroelectric interference, showing promise as a means to perform tests for circulating melanoma cells in blood samples.

Serial monitoring of circulating tumor cells predicts outcome of induction biochemotherapy plus maintenance biotherapy for metastatic melanoma

PURPOSE

Molecular biomarkers in blood are promising for assessment of tumor progression and treatment response. We hypothesized that serial monitoring of circulating tumor cells (CTC) with the use of multimarker quantitative real-time reverse transcriptase-PCR assays could be a surrogate predictor of outcome for melanoma patients enrolled in a multicenter phase II clinical trial of biochemotherapy (BCT) combined with maintenance biotherapy (mBT).

EXPERIMENTAL DESIGN

Blood specimens were collected from 87 patients before and during induction BCT and mBT for stage IV melanoma. Expression of five melanoma-associated CTC biomarkers (MART-1, GalNAc-T, PAX-3, MAGE-A3, and Mitf) was assessed by quantitative real-time reverse transcriptase-PCR, and correlated with treatment response and disease outcome.

RESULTS

The number of positive CTC biomarkers decreased overall during induction BCT (P < 0.0001). CTC biomarker detection after two cycles of BCT was correlated with treatment response (P = 0.005) and overall survival (P = 0.001): an increase in the number of CTC biomarkers was associated with poor response (P = 0.006) and overall survival (P < 0.0001). Multivariate analyses with the use of a Cox proportional hazards model identified the change in CTC biomarkers after two cycles of BCT as an independent prognostic factor for disease progression (risk ratio, 12.6; 95% confidence interval, 4.78-33.4; P < 0.0001) and overall survival (risk ratio, 6.11; 95% confidence interval, 2.37-15.7; P = 0.0005).

CONCLUSION

Serial monitoring of CTC during induction BCT may be useful for predicting therapeutic efficacy and disease outcome in patients receiving BCT and mBT for stage IV melanoma.

Aberrant fatty acid-binding protein-7 gene expression in cutaneous malignant melanoma

Fatty acid-binding protein-7 (FABP7) has been shown to be expressed in cutaneous melanoma; however, its role in tumor progression is unclear. Expression of FABP7 was assessed during melanoma progression through assessment of various clinicopathology stages of primary tumor progression and metastasis. FABP7 mRNA was highly expressed in 60 of 87 (69%) primary melanomas, compared with significant (P<0.0001) reduction in 13 of 68 (19%) metastatic melanomas. Analysis of 37 paired primary and metastatic melanomas by immunohistochemistry with anti-FABP7 Ab showed 73 and 27% positivity, respectively (P<0.001). FABP7 detection of metastatic tissues was inversely correlated with relapse-free (P<0.0001) and overall (P<0.0001) survival. To examine FABP7 expression loss in advanced melanomas, loss of heterozygosity (LOH) was assessed using microsatellite markers encompassing the FABP7 gene. LOH was identified in 10 of 20 (50%) metastatic melanomas at 6q22.31, compared with 0 of 14 primary melanomas (P=0.0017). FABP7 as a surrogate biomarker for circulating tumor cells (CTCs) in the blood was assessed by quantitative real-time (qRT)-PCR from melanoma patients' blood (n=134). Assessment of patients' blood showed that FABP7(+) CTC decreased with disease progression. FABP7 may function as a tumor progression gene and can be used as a potential diagnostic biomarker of early-stage melanoma systemic spreading in blood.

Functional RET G691S polymorphism in cutaneous malignant melanoma

RET proto-oncogene encodes a receptor tyrosine kinase whose ligand is glial cell line-derived neurotrophic factor (GDNF), and its polymorphism at G691S juxtamembrane region (RETp) is a germline polymorphism. Cutaneous melanomas, particularly the desmoplastic subtype, are highly neurotropic; thus we sought to determine the frequency of RETp in cutaneous melanoma and its functional responsiveness to GDNF. RETp was assessed in 71 non-desmoplastic cutaneous melanomas (non-DMs) and 70 desmoplastic melanomas (DMs). Melanoma cell lines with RETp, RET wild-type (RETwt), BRAF V600E mutation (BRAFmt) or BRAF wild-type (BRAFwt) were assessed for functional activity. RETp frequency was significantly higher in DMs (61%) than in non-DMs (31%, P<0.001). BRAFmt was detected in only 11% of DMs. GDNF stimulation significantly amplified cell proliferation, migration, and invasion in RETp, but not in RETwt melanoma cells. GDNF stimulation of RETp cell lines enhanced phosphorylation of extracellular signal-regulated kinase (ERK) and Akt of the RET-RAS-RAF-ERK and RET-phosphatidylinositol 3-kinase (PI3K)-Akt pathways, respectively. GDNF response of RETp cells in signal transduction and other functional studies were not affected by BRAFmt. The study demonstrates that RETp are frequently found in cutaneous melanoma, particularly desmoplastic subtypes, and responds to GDNF inducing events favorable for tumor progression.

Regulation of RUNX3 tumor suppressor gene expression in cutaneous melanoma

PURPOSE

RUNX3 is a known tumor suppressor gene in several carcinomas. Aberration in RUNX3 expression has not been described for cutaneous melanoma. Therefore, we assessed the expression of RUNX3 in cutaneous melanoma and its regulatory mechanisms relative to tumor progression.

EXPERIMENTAL DESIGN

The expression of RUNX3 mRNA and miR-532-5p (microRNA) was assessed in melanoma lines and in primary and metastatic melanoma tumors.

RESULTS

RUNX3 mRNA expression was down-regulated in 11 of 11 (100%) metastatic melanoma lines relative to normal melanocytes (P < 0.001). Among 123 primary and metastatic melanoma tumors and 12 normal skin samples, RUNX3 expression was significantly down-regulated in primary melanomas (n = 82; P = 0.02) and in melanoma metastasis (n = 41; P < 0.0001) versus normal skin (n = 12). This suggested that RUNX3 down-regulation may play a role in the development and progression of melanoma. RUNX3 promoter region hypermethylation was assessed as a possible regulator of RUNX3 expression using methylation-specific PCR. Assessment of RUNX3 promoter region methylation showed that only 5 of 17 (29%) melanoma lines, 2 of 52 (4%) primary melanomas, and 5 of 30 (17%) metastatic melanomas had hypermethylation of the promoter region. A microRNA (miR-532-5p) was identified as a target of RUNX3 mRNA sequences. miR-532-5p expression was shown to be significantly up-regulated in melanoma lines and metastatic melanoma tumors relative to normal melanocytes and primary melanomas, respectively. To investigate the relation between RUNX3 and miR-532-5p, anti-miR-532-5p was transfected into melanoma lines. Inhibition of miR-532-5p up-regulated both RUNX3 mRNA and protein expression.

CONCLUSIONS

RUNX3 is down-regulated during melanoma progression and miR-532-5p is a regulatory factor of RUNX3 expression.

mRNA expression and BRAF mutation in circulating melanoma cells isolated from peripheral blood with high molecular weight melanoma-associated antigen-specific monoclonal antibody beads

BACKGROUND

The detection of circulating tumor cells (CTCs) in the peripheral blood of melanoma patients by quantitative real-time reverse-transcription PCR (qRT-PCR) analysis correlates with a poor prognosis. The assessment of CTCs from blood has been difficult because of lack of a good monoclonal antibody (mAb) directed against surface cell antigens to capture melanoma cells.

METHODS

Blood was collected prospectively from 57 melanoma patients (43 test and 14 test-development cases) and 5 healthy donors. High molecular weight melanoma-associated antigen (HMW-MAA)-specific mAbs bound to immunomagnetic beads were used to isolate CTCs. mRNA and/or DNA were extracted from CTCs. Testing for the expression of a melanoma-associated gene panel (MLANA, MAGEA3, and MITF) with qRT-PCR and for the presence of BRAFmt (a BRAF gene variant encoding the V600E mutant protein) verified the beads-isolated CTCs to be melanoma cells. A peptide nucleic acid-clamping PCR assay was used for BRAFmt analysis.

RESULTS

Spiking of peripheral blood cells (PBCs) with melanoma cells showed that the beads-based detection assay can detect approximately 1 melanoma cell in 5 x 10(6) PBCs. qRT-PCR analysis detected MLANA, MAGEA3, and MITF expression in 19 (44%), 29 (67%), and 19 (44%) of the patients, respectively. At least one biomarker of the panel was positive in 40 (93%) of the 43 melanoma patients. BRAFmt was detected in 17 (81%) of the 21 assessed stage IV melanoma patients.

CONCLUSION

The assay of bead capture coupled with the PCR has utility for assessing CTCs in melanoma patients, which can then be characterized for both genomic and transcriptome expression.

Activation of Toll-like receptors 2, 3, and 4 on human melanoma cells induces inflammatory factors

Toll-like receptors (TLR) have been shown to be expressed on various types of cancers; however, their functional activity is not known. We examined TLR profiles of human melanoma cells and showed that TLR2, TLR3, and TLR4 were found to be highly expressed. By PCR array analysis, specific stimulation of TLR2, TLR3, and TLR4 on melanoma cells showed significant activation of the adaptor protein MyD88, as well as downstream signal transduction factors nuclear factor-kappaB and inflammatory response-related factors. Specific ligand activation of TLR2, TLR3, and TLR4 was shown to induce cell migration. Peripheral blood lymphocytes and melanoma purified RNA was shown to activate TLR3 on melanoma cells. These studies show expression and functional activity of specific TLRs on melanoma cells and as potential therapeutic targets to control tumor progression.

Prognostic relevance of occult nodal micrometastases and circulating tumor cells in colorectal cancer in a prospective multicenter trial

PURPOSE

Nodal micrometastasis and circulating tumor cells detected by multimarker quantitative real-time reverse transcription-PCR (qRT-PCR) may have prognostic importance in patients with colorectal cancer.

EXPERIMENTAL DESIGN

Paraffin-embedded sentinel lymph nodes from 67 patients and blood from 34 of these patients were evaluated in a prospective multicenter trial of sentinel lymph node mapping in colorectal cancer. Sentinel lymph nodes were examined by H&E staining and cytokeratin immunohistochemistry. Sentinel lymph nodes and blood were examined by a four-marker qRT-PCR assay (c-MET, melanoma antigen gene-A3 family, beta1-->4-N-acetylgalactosaminyltransferase, and cytokeratin-20); qRT-PCR results were correlated with disease stage and outcome.

RESULTS

In H&E-negative sentinel lymph node patients that recurred, cytokeratin immunohistochemistry and qRT-PCR detected metastasis in 30% and 60% of patients, respectively. Disease-free survival differed significantly by multimarker qRT-PCR upstaged sentinel lymph node (P = 0.014). qRT-PCR analysis of blood for circulating tumor cells correlated with overall survival (P = 0.040).

CONCLUSION

Molecular assessment for micrometastasis in sentinel lymph node and blood specimens may help identify patients at high risk for recurrent colorectal cancer, who could benefit from adjuvant therapy.

Activation of CCR9/CCL25 in cutaneous melanoma mediates preferential metastasis to the small intestine

PURPOSE

Specific chemokines and their respective receptors have been implicated in distant tumor cell metastasis. Cutaneous melanoma has a distinct pattern of metastasis, preferentially targeting the submucosa of the small intestine. However, the underlying pathogenic mechanism remains unknown. Migration of CCR9(+) lymphocytes to the small intestine is known to occur in response to the chemoattractant effects of CCL25 (thymus-expressed chemokine). The integrin heterodimers alphabeta are also known to be important mediators of cellular adhesion. We hypothesize that the mechanism of small intestinal metastasis by melanoma is via the CCR9-CCL25 axis and specific integrins.

EXPERIMENTAL DESIGN

Quantitative reverse transcription-PCR, flow cytometry, and immunohistochemistry were used to assess melanoma tumors for CCR9 and CCL25. Integrin expression was assessed using flow cytometry. CCR9 expression by quantitative reverse transcription-PCR was assessed in primary (n = 23) and metastatic (n = 198) melanomas, and melanoma lines derived from small intestinal metastases (n = 23).

RESULTS

We showed CCR9 expression in 88 of 102 paraffin-embedded metastatic melanomas from the small intestine, 8 of 8 melanoma lines derived from metastases in the small intestine, and 0 of 96 metastatic melanomas from other sites. In vitro migration and invasion studies done on CCR9(+) melanoma lines showed migration in response to CCL25 that was inhibited by anti-CCR9 antibody or by short interfering RNA CCR9. Flow cytometric analysis confirmed CCR9 expression by melanomas to the small intestine and showed concomitant alpha(4)beta(1) integrin expression.

CONCLUSIONS

Our findings show that functionally active CCR9 on melanoma cells facilitates metastasis to the small intestine. The CCR9-CCL25 axis may explain the high incidence of melanoma metastasis to this specific location.

Detection of circulating tumor cells in early-stage breast cancer metastasis to axillary lymph nodes

PURPOSE

Clinical and pathologic prognostic factors do not always accurately predict disease outcome. Patients with early-stage breast cancer may harbor clinically significant but undetected systemic disease. We hypothesized that a multimarker quantitative real-time reverse transcription-PCR (qRT) assay could detect circulating tumor cells (CTC) in patients with early-stage breast cancer and correlate with sentinel lymph node (SLN) and non-SLN metastasis status.

EXPERIMENTAL DESIGN

Blood samples from 90 women with the American Joint Committee on Cancer stages I to III breast cancer and 39 age-matched normal healthy volunteers were assessed by qRT for mRNA expression of three markers: stanniocalcin-1 (STC-1), N-acetylgalactosaminyltransferase (GalNacT), and melanoma antigen gene family-A3 (MAGE-A3). CTC biomarker detection was correlated with overall axillary LN (ALN), SLN, and non-SLN histopathology status.

RESULTS

CTCs were detected in 39 of 90 (43%) patients, but not in normal volunteers. At least one CTC biomarker was detected in 10 of 35 (29%) stage I patients, 19 of 42 (45%) stage II patients, and 10 of 13 (77%) stage III patients. In multivariate analysis, only lymphovascular invasion and >or=2 CTC biomarkers detected significantly correlated with ALN metastasis [odds ratio (OR), 12.42; 95% confidence interval (95% CI), 3.52-43.77, P<0.0001; and OR, 3.88; 95% CI, 1.69-8.89, P=0.001, respectively]. The number of CTC biomarkers detected similarly correlated with SLN and non-SLN metastasis status (P=0.0004). At least one CTC biomarker was detected in 10 of 11 (91%) patients with non-SLN metastases.

CONCLUSION

The detection of CTCs offers a novel means to assess the presence of systemic disease spreading relative to SLN and ALN histopathology status.

Molecular markers of circulating melanoma cells

Of all skin cancers, cutaneous malignant melanoma (CMM) is the most aggressive and the life expectancy of patients with lymphatic or systemic metastases is dramatically reduced. Understandably therefore, scientists and clinicians have focused on improving diagnostic and prognostic techniques. Of these, perhaps the most promising are multimarker real-time RT-PCR and microarray for detection of circulating CMM cells in peripheral blood. While the optimal set of markers is still to be identified that can accurately assess disease severity and progression at all clinical stages of the disease, recent progress has been dramatic. Here we provide an exhaustive review of recent studies in which a variety of markers are assessed. Moreover, the efficacy of the markers relative to clinical stage is discussed in light of experimental findings. From these studies, it is apparent that researchers are now much closer to defining a set of markers of circulating cells that can be utilized in routine diagnostic tests.

Association of circulating tumor cells with serum tumor-related methylated DNA in peripheral blood of melanoma patients

Although previous studies have separately shown the utility of circulating tumor cells (CTC) or cell-free tumor-related DNA in blood of cancer patients, there has been no investigation of their association and/or the prognostic value of combining these assessments. To date, the true source of tumor-related DNA in serum remains unknown. We hypothesized that CTC is a possible origin of serum tumor-related methylated DNA and their combination can predict disease outcome. To test this hypothesis, we obtained matched pairs of peripheral blood lymphocytes and serum specimens simultaneously from 50 American Joint Committee on Cancer stage IV melanoma patients before administration of biochemotherapy. Peripheral blood leukocytes were analyzed for three mRNA markers of CTC: MART-1, GalNAc-T, and MAGE-A3. Sera were analyzed for two methylated DNA markers: RASSF1A and RAR-beta2. CTC were detected in 13 of 15 (86%) patients with serum tumor-related methylated DNA and only in 13 of 35 (37%) patients without methylated DNA (P = 0.001). The number of CTC markers detected significantly correlated with methylated DNA (P = 0.008). CTC and methylated DNA were significantly correlated with biochemotherapy-treated patients' outcome. Patients with both CTC and methylated DNA showed significantly poorer response to biochemotherapy (P = 0.02) and worse time to progression and overall survival (P = 0.009 and 0.02, respectively). The correlation between CTC and serum tumor-related methylated DNA and the significant effect of this correlation on disease outcome indicate that a composite molecular assessment in blood may be a useful determinant of disease status and efficacy of systemic therapy for melanoma.

The prognostic value of circulating tumor cells in patients with melanoma: a systematic review and meta-analysis

BACKGROUND

The detection of circulating tumor cells (CTC) in patients with melanoma represents an appealing prognostic tool, but no consensus exists on this topic. We aimed to comprehensively and quantitatively summarize the evidence for the use of CTC to predict patients' clinical outcome.

METHODS

Fifty-three studies enrolling 5,433 patients were reviewed. Correlation of CTC status with tumor-node-metastasis disease stage and patients' overall (OS) and progression-free (PFS) survival was assessed by means of association statistics and meta-analysis, respectively.

RESULTS

CTC status correlated with both tumor-node-metastasis stage (stage I, 32%; stage II, 41.7%; stage III, 41.1%; stage IV, 47.4%; P(trend) < 0.0001) and survival (OS: hazard ratio, 2.42; 95% confidence interval, 1.7-3.45, P < 0.0001; PFS: hazard ratio, 2.45; 95% confidence interval, 1.78-3.38; P < 0.0001). However, statistical heterogeneity was significant for both OS and PFS, likely underscoring the wide variability in study design. Furthermore, CTC positivity rates in early stages were higher and in the metastatic setting were lower than expected, which indicates an unsatisfactory accuracy of currently available CTC detection assays.

CONCLUSIONS

Our findings suggest that CTC might have a clinically valuable prognostic power in patients with melanoma. However, the heterogeneity of the studies thus far published warrants caution not to overestimate the favorable results of pooled data.

Molecular upstaging of sentinel lymph nodes in melanoma: where are we now?

The presence of lymph node metastasis is the best predictor of disease progression and overall survival in patients who have melanoma. Lymphatic mapping and selective lymphadenectomy allows directed pathologic analysis of the node or nodes most likely to have metastatic disease. To diagnose metastatic disease in SLNs reliably requires a coordinated effort by nuclear medicine physicians, surgeons, and pathologists. Errors may occur if quality assurance is not emphasized at any point during the process. This, along with the presence of occult metastatic disease, may lead to disease recurrence and progression, even when SLN histologically are free of disease. Molecular up-staging of occult malignant disease has the potential to provide important information to facilitate the diagnosis, surveillance, and treatment of cancer. The detection of occult tumor cells in SLNs and blood provides a powerful tool for assessing early regional and systemic disease spread in patients who have AJCC stage II and III-not only melanoma but also other solid tumors. The use of varying panels of markers from different laboratories has hampered the interpretation of data and made it difficult to unravel the merits of molecular up staging. Molecular approaches have made a major impact on the field of infectious disease and should one day be of equal usefulness in the diagnosis of cancer.

Estrogen receptor-alpha methylation predicts melanoma progression

The role of estrogen receptor alpha (ER-alpha) in melanoma is unknown. ER-alpha expression may be regulated in melanoma via hypermethylation of promoter CpG islands. We assessed ER-alpha hypermethylation in primary and metastatic melanomas and sera as a potential tumor progression marker. ER-alpha methylation status in tumor (n = 107) and sera (n = 109) from American Joint Committee on Cancer (AJCC) stage I to IV melanoma patients was examined by methylation-specific PCR. The clinical significance of serum methylated ER-alpha was assessed among AJCC stage IV melanoma patients receiving biochemotherapy with tamoxifen. Rates of ER-alpha methylation in AJCC stage I, II, and III primary melanomas were 36% (4 of 11), 26% (5 of 19), and 35% (8 of 23), respectively. Methylated ER-alpha was detected in 42% (8 of 19) of stage III and 86% (30 of 35) of stage IV metastatic melanomas. ER-alpha was methylated more frequently in metastatic than primary melanomas (P = 0.0003). Of 109 melanoma patients' sera in AJCC stage I, II, III, and IV, methylated ER-alpha was detected in 10% (2 of 20), 15% (3 of 20), 26% (5 of 19), and 32% (16 of 50), respectively. Serum methylated ER-alpha was detected more frequently in advanced than localized melanomas (P = 0.03) and was the only factor predicting progression-free [risk ratio (RR), 2.64; 95% confidence interval (95% CI), 1.36-5.13; P = 0.004] and overall survival (RR, 2.31; 95% CI, 1.41-5.58; P = 0.003) in biochemotherapy patients. Hypermethylated ER-alpha is a significant factor in melanoma progression. Serum methylated ER-alpha is an unfavorable prognostic factor.

Phase II Multicenter Study of Neoadjuvant Biochemotherapy for Patients With Stage III Malignant Melanoma

Purpose

To determine the relapse-free survival, overall survival, and response rate of patients with stage III melanoma treated with neoadjuvant biochemotherapy in a multicenter setting.

Patients and Methods

Patients with pathologically proven stage III melanoma, either via clinical detection or sentinel lymph node positivity, were eligible for enrollment. Patients received two cycles of preoperative biochemotherapy followed by complete regional lymphadenectomy and two postoperative courses of biochemotherapy. The biochemotherapy regimen consisted of the following: cisplatin 20 mg/m2 on days 1 to 4, dacarbazine 800 mg/m2 on day 1 only, vinblastine 1.6 mg/m2 on days 1 to 4, interleukin-2 total dose of 36 MU/m2 during 4 days, and interferon alfa 5 MU/m2 on days 1 to 5. Growth factor support was administered with each cycle.

Results

Ninety-two patients were eligible for the study. At a median follow-up of 40.4 months, relapse-free survival and overall survival are 64% and 78%, respectively. There was a lower relapse rate and improved survival for patients with a positive sentinel lymph node compared with patients with clinically detected lymph nodes, although this difference did not reach statistical significance. Of the 50 patients with measurable disease, the overall response rate was 26%. Toxicity of the biochemotherapy was high but generally manageable.

Conclusion

The current study has expanded the preliminary evidence on neoadjuvant biochemotherapy for stage III melanoma.

Microphthalmia transcription factor as a molecular marker for circulating tumor cell detection in blood of melanoma patients

PURPOSE

Microphthalmia transcription factor (Mitf), which is important in melanocyte development and melanoma growth, was assessed using real-time quantitative reverse transcription-PCR assay to investigate its expression as a marker for circulating melanoma cells in blood and determine the correlation with disease stage and survival in melanoma patients.

EXPERIMENTAL DESIGN

In optimization studies for Mitf, we tested 15 melanoma cell lines, 41 peripheral blood lymphocytes from healthy volunteers, and 21 metastatic melanoma tissues. Blood specimens were procured from 90 patients with stage I (n = 20), stage II (n = 20), stage III (n = 28), and stage IV (n = 22) melanoma. Blood specimens were also obtained at four bleed intervals from 58 patients enrolled in a prospective multicenter trial of biochemotherapy before and after surgical treatment of American Joint Committee on Cancer stage III melanoma.

RESULTS

Under the optimized conditions, Mitf was negative in healthy peripheral blood lymphocytes and positive in all melanoma cell lines and 18 (86%) melanoma tissues. In the 90 patients, the rate of Mitf detection was higher with increasing American Joint Committee on Cancer stage (P < 0.0001). In the 58 patients treated with biochemotherapy and surgery, Mitf detection decreased with treatment (P = 0.019). Mitf detection after treatment was associated with a significantly lower relapse-free (P < 0.0001) and overall (P = 0.001) survival and was a significant independent prognostic factor for relapse-free (risk ratio, 5.63; P = 0.0004) and overall (risk ratio, 5.36; P = 0.005) survival.

CONCLUSIONS

Mitf detection in blood can indicate subclinical metastatic disease and predict treatment outcome in melanoma patients.