Inflammatory Marker Testing Identifies CD74 Expression in Melanoma Tumor Cells, and Its Expression Associates with Favorable Survival for Stage III Melanoma

PURPOSE

Inflammatory marker expression in stage III melanoma tumors was evaluated for association with outcome, using two independent cohorts of stage III melanoma patients' tumor tissues.

EXPERIMENTAL DESIGN

Fifteen markers of interest were selected for analysis, and their expression in melanoma tissues was determined by immunohistochemistry. Proteins associating with either overall survival (OS) or recurrence-free survival (RFS) in the retrospective discovery tissue microarray (TMA; n = 158) were subsequently evaluated in an independent validation TMA (n = 114). Cox proportional hazards regression models were used to assess the association between survival parameters and covariates, the Kaplan-Meier method to estimate the distribution of survival, and the log-rank test to compare distributions.

RESULTS

Expression of CD74 on melanoma cells was unique, and in the discovery TMA, it associated with favorable patient outcome (OS: HR, 0.53; P = 0.01 and RFS: HR, 0.56; P = 0.01). The validation data set confirmed the CD74 prognostic significance and revealed that the absence of macrophage migration inhibitory factor (MIF) and inducible nitric oxide synthase (iNOS) was also associated with poor survival parameters. Consistent with the protein observation, tumor CD74 mRNA expression also correlated positively (P = 0.003) with OS in the melanoma TCGA data set.

CONCLUSIONS

Our data validate CD74 as a useful prognostic tumor cell protein marker associated with favorable RFS and OS in stage III melanoma. Low or negative expression of MIF in both TMAs and of iNOS in the validation set also provided useful prognostic data. A disease-specific investigation of CD74's functional significance is warranted, and other markers appear intriguing to pursue. Clin Cancer Res; 22(12); 3016-24. ©2016 AACR.

Brain metastasis is predetermined in early stages of cutaneous melanoma by CD44v6 expression through epigenetic regulation of the spliceosome

Melanoma brain metastasis (MBM) is frequent and has a very poor prognosis with no current predictive factors or therapeutic molecular targets. Our study unravels the molecular alterations of cell-surface glycoprotein CD44 variants during melanoma progression to MBM. High expression of CD44 splicing variant 6 (CD44v6) in primary melanoma (PRM) and regional lymph node metastases from AJCC Stage IIIC patients significantly predicts MBM development. The expression of CD44v6 also enhances the migration of MBM cells by hyaluronic acid and hepatocyte growth factor exposure. Additionally, CD44v6-positive MBM migration is reduced by blocking with a CD44v6-specific monoclonal antibody or knocking down CD44v6 by siRNA. ESRP1 and ESRP2 splicing factors correlate with CD44v6 expression in PRM, and ESRP1 knockdown significantly decreases CD44v6 expression. However, an epigenetic silencing of ESRP1 is observed in metastatic melanoma, specifically in MBM. In advanced melanomas, CD44v6 expression correlates with PTBP1 and U2AF2 splicing factors, and PTBP1 knockdown significantly decreases CD44v6 expression. Overall, these findings open a new avenue for understanding the high affinity of melanoma to progress to MBM, suggesting CD44v6 as a potential MBM-specific factor with theranostic utility for stratifying patients.

Abstract 1182: Patient derived xenograft (PDX) of human melanoma to predict clinical responses

The approval of three drugs targeting the MAPK pathway has led to new standard therapies for melanoma with BRAFV600E mutations. The excitement about these therapeutic successes is somewhat dampened by the relapse of most if not all treated patients due to the development of acquired (secondary) resistance. Early clinical trial results indicate that combining BRAF and MEK inhibitors can improve survival and delay the onset of resistance. Currently, there is a lack of good translational models to study resistance pathways found in patients. We have developed a patient-derived xenograft (PDX) bank for assessing patients' responses to therapies.

Human melanoma tissues were obtained following surgery, and small pieces were implanted subcutaneously with Matrigel® into NSG mice. This technique was advantageous over injecting single tumor cells. It also allows prior dissociation and freezing for extended time periods prior to injection. The xenografts maintained a histological architecture similar to the respective patients' lesions. NSG mice injected with tumor fragments and single cells allow a high rate of tumor growth of approximately 90%, even if few malignant cells from fine needle aspirates are injected. When injecting decreasing numbers of tumor cells after removal of endothelial cells, hematopoietic cells and red blood cells (but not fibroblasts), in 5 out of 7 cases single malignant cells induced tumors. Our current tumor bank contains 125 samples linked to patients' clinical data and characterized for mutational status and spontaneous metastasis rates (25%). DNA fingerprinting was matched to normal blood DNA if available to assure identity of the samples. The samples had a similar distribution pattern of genetic abnormalities to those in patients, thus allowing their use for mutation-specific therapy strategies. As an example, a PDX from a patient with intrinsic resistance to vemurafenib was grown to compare tumor growth on a 200 ppm BRAF inhibitor (PLX4720) diet, 200 ppm PLX4720 + 7 ppm MEK inhibitor (PD0325901) combination diet, or control diet for 21 days. As in the original patient, the BRAF inhibitor alone did not inhibit tumor growth, while the combination of BRAF and MEK inhibition showed significant tumor growth inhibition demonstrating that a PDX can predict clinical outcome.

Citation Format: Clemens Krepler, Katrin Sproesser, Patricia Brafford, Min Xiao, Marilda Beqiri, Wei Xu, Katherine Nathanson, Jennifer Wargo, Keith Flaherty, Donald L. Morton, Dave S. Hoon, Randall Ryan, Michael Guarino, Nicholas J. Petrelli, David Elder, Xiawei Xu, Giorgos Karakousis, Lynn Schuchter, Meenhard Herlyn. Patient derived xenograft (PDX) of human melanoma to predict clinical responses. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1182. doi:10.1158/1538-7445.AM2014-1182

DNA methylation and gene deletion analysis of brain metastases in melanoma patients identifies mutually exclusive molecular alterations

BACKGROUND

The brain is a common target of metastases for melanoma patients. Little is known about the genetic and epigenetic alterations in melanoma brain metastases (MBMs). Unraveling these molecular alterations is a key step in understanding their aggressive nature and identifying novel therapeutic targets.

METHODS

Genome-wide DNA methylation analyses of MBMs (n = 15) and normal brain tissues (n = 91) and simultaneous multigene DNA methylation and gene deletion analyses of metastatic melanoma tissues (99 MBMs and 43 extracranial metastases) were performed. BRAF and NRAS mutations were evaluated in MBMs by targeted sequencing.

RESULTS

MBMs showed significant epigenetic heterogeneity. RARB, RASSF1, ESR1, APC, PTEN, and CDH13 genes were frequently hypermethylated. Deletions were frequently detected in the CDKN2A/B locus. Of MBMs, 46.1% and 28.8% had BRAF and NRAS missense mutations, respectively. Compared with lung and liver metastases, MBMs exhibited higher frequency of CDH13 hypermethylation and CDKN2A/B locus deletion. Mutual exclusivity between hypermethylated genes and CDKN2A/B locus deletion identified 2 clinically relevant molecular subtypes of MBMs. CDKN2A/B deletions were associated with multiple MBMs and frequently hypermethylated genes with shorter time to brain metastasis.

CONCLUSIONS

Melanoma cells that colonize the brain harbor numerous genetically and epigenetically altered genes. This study presents an integrated genomic and epigenomic analysis that reveals MBM-specific molecular alterations and mutually exclusive molecular subtypes.

Clinical Benefit from Ipilimumab Therapy in Melanoma Patients may be Associated with Serum CTLA4 Levels

Stage IV metastatic melanoma patients historically have a poor prognosis with 5–10% 5-year survival. Ipilimumab, a monoclonal antibody against cytotoxic T-lymphocyte antigen 4 (CTLA4), is one of the first treatments to provide beneficial durable responses in advanced melanoma. However, less than 25% of those treated benefit, treatment is expensive, and side effects can be fatal. Since soluble (s) CTLA4 may mediate inhibitory effects previously ascribed to the membrane-bound isoform (mCTLA4), we hypothesized patients benefiting from ipilimumab have higher serum levels of sCTLA4. We found that higher sCTLA4 levels correlated both with response and improved survival in patients treated with ipilimumab in a small patient cohort [patients with (n = 9) and without (n = 5) clinical benefit]. sCTLA4 levels were statistically higher in ipilimumab-treated patients with response to ipilimumab. In contrast, sCTLA4 levels did not correlate with survival in patients who did not receive ipilimumab (n = 11). These preliminary observations provide a previously unrecognized link between serum sCTLA4 levels and response to ipilimumab as well as to improved survival in ipilimumab-treated melanoma patients and a potential mechanism by which ipilimumab functions.

A 20-year experience of hepatic resection for melanoma: is there an expanding role?

BACKGROUND

Melanoma liver metastasis is most often fatal, with a 4- to 6-month median overall survival (OS). Over the past 20 years, surgical techniques have improved in parallel with more effective systemic therapies. We reviewed our institutional experience of hepatic melanoma metastases.

STUDY DESIGN

Overall and disease-specific survivals were calculated from hepatic metastasis diagnosis. Potential prognostic factors including primary tumor type, depth, medical treatment response, location, and surgical approach were evaluated.

RESULTS

Among 1,078 patients with melanoma liver metastases treated at our institution since 1991, 58 (5.4%) received surgical therapy (resection with or without ablation). Median and 5-year OS were 8 months and 6.6 %, respectively, for 1,016 nonsurgical patients vs 24.8 months and 30%, respectively, for surgical patients (p < 0.001). Median OS was similar among patients undergoing ablation (with or without resection) relative to those undergoing surgery alone. On multivariate analysis of surgical patients, completeness of surgical therapy (hazard ratio [HR] 3.4, 95% CI 1.4 to 8.1, p = 0.007) and stabilization of melanoma on therapy before surgery (HR 0.38, 95% CI 0.19 to 0.78, p = 0.008) predicted OS.

CONCLUSIONS

In this largest single-institution experience, patients selected for surgical therapy experienced markedly improved survival relative to those receiving only medical therapy. Patients whose disease stabilized on medical therapy enjoyed particularly favorable results, regardless of the number or size of their metastases. The advent of more effective systemic therapy in melanoma may substantially increase the fraction of patients who are eligible for surgical intervention, and this combination of treatment modalities should be considered whenever it is feasible in the context of a multidisciplinary team.

Genome-wide characterization of circulating tumor cells identifies novel prognostic genomic alterations in systemic melanoma metastasis

BACKGROUND

Circulating tumor cells (CTC) have been found in patients with metastatic melanoma and are associated with advanced melanoma stage and poor patient outcome. We hypothesize that CTC harbor genomic changes critical in the development of distant systemic metastasis. Here, we present the first genome-wide copy-number aberration (CNA) and loss of heterozygosity (LOH)-based characterization of melanoma CTC.

METHODS

CTC were isolated from peripheral blood monocytes of 13 melanoma patients with regional metastasis stage IIIB/C using antibodies against melanoma-associated cell surface gangliosides.

RESULTS

We characterized 251 CNA in CTC. Comparative analysis demonstrated >90% concordance in single-nucleotide polymorphism profiles between paired CTC and tumor metastases. In particular, there were notable recurring CNA across patients. In exploratory studies, the presence of several top CTC-associated CNA was verified in distant metastasis (stage IV) from 27 patients, suggesting that certain genomic changes are propagated from regional metastasis to CTC and to distant systemic metastases. Lastly, an exploratory biomarker panel derived from 5 CTC-associated CNA [CSMD2 (CUB and Sushi multiple domains 2), 1p35.1; CNTNAP5 (contactin associated protein-like 5), 2q14.3; NRDE2 (NRDE-2, necessary for RNA interference, domain containing), 14q32.11; ADAM6 (ADAM metallopeptidase domain 6, pseudogene), 14q32.33; and TRPM2 (transient receptor potential cation channel, subfamily m, member 2), 21q22.3] conferred prognostic utility for melanoma recurrence [hazard ratio (HR), 1.14; CI, 1.00-1.44; P = 0.0471] and death (HR, 2.86; CI, 1.23-14.42; P = 0.0014) in 35 patients with stage IIIB/C melanoma, with a 5-year disease-free survival of 13% vs 69% (P = 0.0006) and overall survival of 28% vs 94% between high-risk and low-risk groups defined by the biomarker panel, respectively.

CONCLUSIONS

This study provides the first detailed CNA-based profile of melanoma CTC and illustrates how CTC may be used as a novel approach for identification of systemic metastasis.

Age as a predictor of sentinel node metastasis among patients with localized melanoma: an inverse correlation of melanoma mortality and incidence of sentinel node metastasis among young and old patients

PURPOSE

We have previously reported that older patients with clinical stage I and II primary cutaneous. Melanoma had lower survival rates compared to younger patients. We postulated that the incidence of nodal metastasis would therefore be higher among older melanoma patients.

METHODS

The expanded American Joint Committee on Cancer melanoma staging database contains a cohort of 7,756 melanoma patients who presented without clinical evidence of regional lymph node or distant metastasis and who underwent a sentinel node biopsy procedure as a component of their staging assessment.

RESULTS

Although older patients had primary melanoma features associated with more aggressive biology, we paradoxically observed a significant decrease in the incidence of sentinel node metastasis as patient age increased. Overall, the highest incidence of sentinel node metastasis was 25.8 % in patients under 20 years of age, compared to 15.5 % in patients 80 years and older (p < 0.001). In contrast, 5-year mortality rates for clinical stage II patients ranged from a low of 20 % for those 20-40 years of age up to 38 % for those over 70 years of age. Patient age was an independent predictor of sentinel node metastasis in a multifactorial analysis (p < 0.001).

CONCLUSIONS

Patients with clinical stage I and II melanoma under 20 years of age had a higher incidence of sentinel lymph node metastasis but, paradoxically, a more favorable survival outcome compared to all other age groups. In contrast, patients >70 years had the most aggressive primary melanoma features and a higher mortality rate compared to all other age groups but a lower incidence of sentinel lymph node metastasis.

Final trial report of sentinel-node biopsy versus nodal observation in melanoma

BACKGROUND

Sentinel-node biopsy, a minimally invasive procedure for regional melanoma staging, was evaluated in a phase 3 trial.

METHODS

We evaluated outcomes in 2001 patients with primary cutaneous melanomas randomly assigned to undergo wide excision and nodal observation, with lymphadenectomy for nodal relapse (observation group), or wide excision and sentinel-node biopsy, with immediate lymphadenectomy for nodal metastases detected on biopsy (biopsy group). Results No significant treatment-related difference in the 10-year melanoma-specific survival rate was seen in the overall study population (20.8% with and 79.2% without nodal metastases). Mean (± SE) 10-year disease-free survival rates were significantly improved in the biopsy group, as compared with the observation group, among patients with intermediate-thickness melanomas, defined as 1.20 to 3.50 mm (71.3 ± 1.8% vs. 64.7 ± 2.3%; hazard ratio for recurrence or metastasis, 0.76; P=0.01), and those with thick melanomas, defined as >3.50 mm (50.7 ± 4.0% vs. 40.5 ± 4.7%; hazard ratio, 0.70; P=0.03). Among patients with intermediate-thickness melanomas, the 10-year melanoma-specific survival rate was 62.1 ± 4.8% among those with metastasis versus 85.1 ± 1.5% for those without metastasis (hazard ratio for death from melanoma, 3.09; P<0.001); among patients with thick melanomas, the respective rates were 48.0 ± 7.0% and 64.6 ± 4.9% (hazard ratio, 1.75; P=0.03). Biopsy-based management improved the 10-year rate of distant disease-free survival (hazard ratio for distant metastasis, 0.62; P=0.02) and the 10-year rate of melanoma-specific survival (hazard ratio for death from melanoma, 0.56; P=0.006) for patients with intermediate-thickness melanomas and nodal metastases. Accelerated-failure-time latent-subgroup analysis was performed to account for the fact that nodal status was initially known only in the biopsy group, and a significant treatment benefit persisted.

CONCLUSIONS

Biopsy-based staging of intermediate-thickness or thick primary melanomas provides important prognostic information and identifies patients with nodal metastases who may benefit from immediate complete lymphadenectomy. Biopsy-based management prolongs disease-free survival for all patients and prolongs distant disease-free survival and melanoma-specific survival for patients with nodal metastases from intermediate-thickness melanomas. (Funded by the National Cancer Institute, National Institutes of Health, and the Australia and New Zealand Melanoma Trials Group; ClinicalTrials.gov number, NCT00275496.).

Epigenome-wide DNA methylation landscape of melanoma progression to brain metastasis reveals aberrations on homeobox D cluster associated with prognosis

Melanoma brain metastasis (MBM) represents a frequent complication of cutaneous melanoma. Despite aggressive multi-modality therapy, patients with MBM often have a survival rate of <1 year. Alteration in DNA methylation is a major hallmark of tumor progression and metastasis; however, it remains largely unexplored in MBM. In this study, we generated a comprehensive DNA methylation landscape through the use of genome-wide copy number, DNA methylation and gene expression data integrative analysis of melanoma progression to MBM. A progressive genome-wide demethylation in low CpG density and an increase in methylation level of CpG islands according to melanoma progression were observed. MBM-specific partially methylated domains (PMDs) affecting key brain developmental processes were identified. Differentially methylated CpG sites between MBM and lymph node metastasis (LNM) from patients with good prognosis were identified. Among the most significantly affected genes were the HOX family members. DNA methylation of HOXD9 gene promoter affected transcript and protein expression and was significantly higher in MBM than that in early stages. A MBM-specific PMD was identified in this region. Low methylation level of this region was associated with active HOXD9 expression, open chromatin and histone modifications associated with active transcription. Demethylating agent induced HOXD9 expression in melanoma cell lines. The clinical relevance of this finding was verified in an independent large cohort of melanomas (n = 145). Patients with HOXD9 hypermethylation in LNM had poorer disease-free and overall survival. This epigenome-wide study identified novel methylated genes with functional and clinical implications for MBM patients.

Staging of regional lymph nodes in melanoma: a case for including nonsentinel lymph node positivity in the American Joint Committee on Cancer staging system

IMPORTANCE

Survival varies widely in patients with stage III melanoma. The existence of clinical significance for positive nonsentinel lymph node (NSLN) status would warrant consideration for incorporation into the American Joint Committee on Cancer staging system and better prediction of survival.

OBJECTIVE

To evaluate whether disease limited to sentinel lymph nodes (SLNs) represents different clinical significance than disease spread into NSLNs.

DESIGN, SETTING, AND PARTICIPANTS

The database of the John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, California, was queried for all patients with SLNs positive for cutaneous melanoma who subsequently underwent completion lymph node dissection.

MAIN OUTCOMES AND MEASURES

Disease-free survival, melanoma-specific survival (MSS), and overall survival.

RESULTS

A total of 4223 patients underwent SLN biopsy from 1986 to 2012. Of these patients, 329 had a tumor-positive SLN. Of the 329, 250 patients (76.0%) had no additional positive nodes and 79 (24.0%) had a tumor-positive NSLN. Factors predictive of NSLN positivity included older age (P = .04), greater Breslow thickness (P < .001), and ulceration (P < .02). Median overall survival was 178 months for the SLN-only positive group and 42.2 months for the NSLN positive group (5-year overall survival, 72.3% and 46.4%, respectively). Median MSS was not reached for the SLN-only positive group and was 60 months for the NSLN positive group (5-year MSS, 77.8% and 49.5%, respectively). On multivariate analysis, NSLN positivity had a strong association with recurrence (hazard ratio [HR], 1.75; 95% CI, 1.23-2.50; P = .002), shorter overall survival (HR, 2.24; 95% CI, 1.48-3.40; P < .001), and shorter MSS (HR, 2.23; 95% CI, 1.46-3.07; P < .001). To further control for the effects of total positive lymph nodes, comparison was done for patients with only N2 disease (2-3 total positive lymph nodes); the results of this comparison confirmed the independent effect of NSLN status (MSS; P = .04).

CONCLUSIONS AND RELEVANCE

Nonsentinel lymph node positivity is one of the most significant prognostic factors in patients with stage III melanoma. Subclassification of melanoma by NSLN tumor status should be considered for the American Joint Committee on Cancer staging system.

Age as a prognostic factor in patients with localized melanoma and regional metastases

BACKGROUND

We postulated that the worse prognosis of melanoma with advancing age reflected more aggressive tumor biology and that in younger patients the prognosis would be more favorable.

MATERIALS AND METHODS

The expanded AJCC melanoma staging database contained 11,088 patients with complete data for analysis, including mitotic rate.

RESULTS

With increasing age by decade, primary melanomas were thicker, exhibited higher mitotic rates, and were more likely to be ulcerated. In a multivariate analysis of patients with localized melanoma, thickness and ulceration were highly significant predictors of outcome at all decades of life (except for patients younger than 20 years). Mitotic rate was significantly predictive in all age groups except patients <20 and >80 years. For patients with stage III melanoma, there were four independent variables associated with patient survival: number of nodal metastases, patient age, ulceration, and mitotic rate. Patients younger than 20 years of age had primary tumors with slightly more aggressive features, a higher incidence of sentinel lymph node metastasis, but, paradoxically, more favorable survival than all other age groups. In contrast, patients >70 years old had primary melanomas with the most aggressive prognostic features, were more likely to be head and neck primaries, and were associated with a higher mortality rate than the other age groups. Surprisingly, however, these patients had a lower rate of sentinel lymph node metastasis per T stage. Among patients between the two age extremes, clinicopathologic features and survival tended to be more homogeneous.

CONCLUSIONS

Melanomas in patients at the extremes of age have a distinct natural history.

Identification of functional DNA methylation aberrations associated with outcome in melanoma patients with brain metastasis

9095

Background: Brain metastasis (MBM) represents one of the most significant causes of death in melanoma patients. Identification of clinically relevant markers is necessary to recognize patients with high risk of MBM development. Alterations in DNA methylation patterns have been recognized as a major epigenetic hallmark of metastasis initiation and progression. Methods: To generate a comprehensive genomic DNA methylation landscape of MBM, we performed genome-wide data integrative analyses examining the DNA methylation (Illumina HumanMethylation 450K), gene expression (Affymetrix HumanExon 1.0), and genotype (Affymetrix SNP 6.0) of specimens related to melanoma progression from normal to MBM (n=65). Results: We observed significant genome-wide hypomethylation and CpG island hypermethylation according to melanoma progression to the brain. To identify significant differentially methylated CpG sites between lymph node metastasis and MBM, we applied a strict statistical threshold (β-value difference >0.3 and FDR-corrected p <0.005). We identified the homeobox D (HOXD) gene family members amongst the most significantly affected genes. The influence on gene expression and the frequency of HOXD hypermethylation were verified using integrative analysis of publicly available data generated from 168 melanoma specimens. In a cohort of clinically annotated melanoma patients (n = 159), we demonstrated that hypermethylation of a genomic region in the HOXD gene cluster was significantly associated with shorter disease-free survival (p = 0.004) and overall survival (p = 0.002).Multivariate analysis confirmed the association with poorer survival (p = 0.01 and HR = 2.8; CI95%: 1.3-6.1). Conclusions: The use of genome-wide DNA methylation, gene expression, and genotyping integrative analyses allowed the identification of novel markers with functional and clinical implications for melanoma patients with brain metastasis.

Late recurrence in melanoma: clinical implications of lost dormancy

BACKGROUND

For patients with melanoma, if there has been no recurrence of disease 10 years after initial treatment, additional disease is believed to be very unlikely. However, such late recurrences are known to occur. The frequency of this phenomenon and its clinical significance are not well characterized due to the difficulty in obtaining relevant data. We examined a large, mature, institutional database to evaluate late recurrence.

STUDY DESIGN

The late recurrence cohort was defined as having a disease-free interval of 10 or more years after potentially curative treatment and was compared with an early recurrence cohort recurring within 3 years. Actuarial late recurrence frequency and factors associated with late recurrence were examined. Post-recurrence overall and melanoma-specific survival and prognostic variables were analyzed.

RESULTS

Among all patients, 408 exhibited late recurrence (mean disease-free interval 15.7 years). For patients who received primary treatment at our institution with 10 or more years follow-up, 327 of 4,731 (6.9%) showed late recurrence. On an actuarial basis, late recurrence rates were 6.8% and 11.3% at 15 and 20 years, respectively, for those with no recurrence at 10 years. Late recurrence was associated with both tumor (thin, non-ulcerated, non-head/neck, node negative) and patient (younger age, less male predominant) characteristics. Multivariate analysis confirmed younger age, thinner and node negative tumors in the late recurrence group. Late recurrences were more likely to be distant, but were associated with better post-recurrence survival on univariate and multivariate analyses.

CONCLUSIONS

Late melanoma recurrence is not rare. It occurs more frequently in certain clinical groups and is associated with improved post-recurrence survival.

B7-H3 associated with tumor progression and epigenetic regulatory activity in cutaneous melanoma

B7-H3, a cell surface transmembrane glycoprotein, was assessed for its functional and prognostic role in cutaneous melanoma progression. B7-H3 expression in melanoma cells was shown to be related to specific downstream signal transduction events as well as associated with functional epigenetic activity. B7-H3 expression and prognostic utility was shown by RT-qPCR and IHC analysis on individual melanoma specimens and then verified in clinically annotated melanoma stage III and stage IV metastasis tissue microarrays in a double blind study. B7-H3 mRNA expression was shown to be significantly increased with stage of melanoma(P<0.0001) and significantly associated with melanoma-specific survival(MSS) in both stage III(P<0.0001) and stage IV(P<0.012) melanoma patients. B7-H3 expression was related to migration and invasion; overexpression B7-H3 increased migration and invasion while knockdown of B7-H3 reduced cell migration and invasion. MiR-29c expression was shown to inversely regulate B7-H3 expression. Furthermore, we demonstrated that melanoma B7-H3 expression was correlated to p-STAT3 activity level in melanoma tissues and cell lines. These studies demonstrate that B7-H3 is a significant factor in melanoma progression, and events of metastasis.

Preoperative imaging of pulmonary metastases in patients with melanoma: implications for minimally invasive techniques

HYPOTHESIS

Preoperative imaging underestimates the number of pulmonary melanoma metastases. Although thoracoscopic resection is less invasive than resection via thoracotomy, it does not allow manual palpation of the lung to identify any metastases not visible on the preoperative scan or at the time of resection.

DESIGN

Retrospective review of a prospectively maintained database.

SETTING

Tertiary referral center.

PATIENTS

A total of 170 patients who underwent preoperative computed tomography of the chest, followed within 30 days by thoracotomy for resection of pulmonary metastatic melanoma.

MAIN OUTCOME MEASURES

Number of pathology-confirmed pulmonary metastases detected by preoperative chest computed tomography vs intraoperative manual palpation.

RESULTS

The mean age of the patients was 49.5 years at initial diagnosis of melanoma and 57.1 years at diagnosis of pulmonary metastases; 69% of patients were male. A total of 334 pulmonary metastases were resected; the mean lesion size was 2.0 cm (range, 0.1-14.0 cm). In 49 of 190 pulmonary resections (26%), manual palpation of the subpleural parenchyma revealed lesions not identified during preoperative imaging. The rate of 5-year overall survival was 33%.

CONCLUSIONS

Preoperative imaging underestimates the number of pulmonary lesions in patients with metastatic melanoma. Because incomplete resection of metastatic disease is associated with worse outcomes, we recommend caution when considering a minimally invasive approach for the resection of pulmonary metastatic melanoma.

Association between circulating tumor cells and prognosis in patients with stage III melanoma with sentinel lymph node metastasis in a phase III international multicenter trial

PURPOSE

The outcomes of patients with melanoma who have sentinel lymph node (SLN) metastases can be highly variable, which has precluded establishment of consensus regarding treatment of the group. The detection of high-risk patients from this clinical setting may be helpful for determination of both prognosis and management. We report the utility of multimarker reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) detection of circulating tumor cells (CTCs) in patients with melanoma diagnosed with SLN metastases in a phase III, international, multicenter clinical trial.

PATIENTS AND METHODS

Blood specimens were collected from patients with melanoma (n = 331) who were clinically disease-free after complete lymphadenectomy (CLND) before entering onto a randomized adjuvant melanoma vaccine plus bacillus Calmette-Guérin (BCG) versus BCG placebo trial from 30 melanoma centers (United States and international). Blood was assessed using a verified multimarker RT-qPCR assay (MART-1, MAGE-A3, and GalNAc-T) of melanoma-associated proteins. Cox regression analyses were used to evaluate the prognostic significance of CTC status for disease recurrence and melanoma-specific survival (MSS).

RESULTS

Individual CTC biomarker detection ranged from 13.4% to 17.5%. There was no association of CTC status (zero to one positive biomarkers v two or more positive biomarkers) with known clinical or pathologic prognostic variables. However, two or more positive biomarkers was significantly associated with worse distant metastasis disease-free survival (hazard ratio [HR] = 2.13, P = .009) and reduced recurrence-free survival (HR = 1.70, P = .046) and MSS (HR = 1.88, P = .043) in a multivariable analysis.

CONCLUSION

CTC biomarker status is a prognostic factor for recurrence-free survival, distant metastasis disease-free survival, and MSS after CLND in patients with SLN metastasis. This multimarker RT-qPCR analysis may therefore be useful in discriminating patients who may benefit from aggressive adjuvant therapy or stratifying patients for adjuvant clinical trials.

Lymphatics, lymph nodes and the immune system: barriers and gateways for cancer spread

Metastasis to the regional lymph node is the most important prognostic indicator for the outcomes of patients with sold cancer. In general, it is well recognized that cancer development is genetically determined with progression from the microenvironment of the primary tumor site, oftentimes via the SLN gateway, to the distant sites. In about 20 % of the time, the cancer cells may spread directly through the blood vascular system to the distant sites. Thus, in general, cancer progression is consistent with Hellman's spectrum theory in that development of nodal and systemic metastasis from a localized cancer growth is a progressive process. Cancer proliferation within the tumor microenvironment may give rise to increased tumor heterogeneity, which is further complicated by its continuous change through its evolution within the host in a Darwinian sense. It is crucial to understand the molecular process of lymphangiogenesis and hemangiogenesis in the tumor microenvironment with respect to the initial steps of cancer cells entering into the lymphatic and vascular systems so that rational therapy can be developed to curb the process of specific routes of metastasis. This chapter elucidates the role of lymphatics, nodal metastasis and antitumor immunity. We present novel immune targets in nodal metastases, the importance of the lymph node as a pre-metastatic niche, and immune-related proteins as biomarkers of metastasis.

A landscape of driver mutations in melanoma

Despite recent insights into melanoma genetics, systematic surveys for driver mutations are challenged by an abundance of passenger mutations caused by carcinogenic UV light exposure. We developed a permutation-based framework to address this challenge, employing mutation data from intronic sequences to control for passenger mutational load on a per gene basis. Analysis of large-scale melanoma exome data by this approach discovered six novel melanoma genes (PPP6C, RAC1, SNX31, TACC1, STK19, and ARID2), three of which-RAC1, PPP6C, and STK19-harbored recurrent and potentially targetable mutations. Integration with chromosomal copy number data contextualized the landscape of driver mutations, providing oncogenic insights in BRAF- and NRAS-driven melanoma as well as those without known NRAS/BRAF mutations. The landscape also clarified a mutational basis for RB and p53 pathway deregulation in this malignancy. Finally, the spectrum of driver mutations provided unequivocal genomic evidence for a direct mutagenic role of UV light in melanoma pathogenesis.

Future perspectives in melanoma research. Meeting report from the "Melanoma research: a bridge from Naples to the World. Napoli, December 5th-6th 2011"

After more than 30 years, landmark progress has been made in the treatment of cancer, and melanoma in particular, with the success of new molecules such as ipilimumab, vemurafenib and active specific immunization.

After the first congress in December 2010, the second edition of “Melanoma Research: a bridge from Naples to the World” meeting, organized by Paolo A. Ascierto (INT, Naples, Italy), Francesco M. Marincola (NIH, Bethesda, USA), and Nicola Mozzillo (INT, Naples, Italy) took place in Naples, on 5–6 December 2011. We have identified four new topics of discussion: Innovative Approaches in Prevention, Diagnosis and Surgical Treatment, New Pathways and Targets in Melanoma: An Update about Immunotherapy, and Combination Strategies.

This international congress gathered more than 30 international faculty members and was focused on recent advances in melanoma molecular biology, immunology and therapy, and created an interactive atmosphere which stimulated discussion of new approaches and strategies in the field of melanoma.

Epitrochlear Sentinel Lymph Nodes in Melanoma: Interval or Independent?

Most primary melanomas on the distal upper extremity metastasize to a sentinel lymph node (SLN) in the axillary basin, but occasionally a primary melanoma will drain to the epitrochlear basin. The relationship between tumor-draining axillary and epitrochlear SLNs is unclear. We hypothesize that the epitrochlear SLN functions in an interval manner with the axillary lymph node basin. We queried our melanoma database to identify patients who underwent SLN biopsy for a distal upper-extremity melanoma. Patient demographics, tumor characteristics, patterns of nodal drainage, and incidence of SLN metastasis were analyzed. Of 255 patients identified, 38 (14.9%) had an epitrochlear SLN. Mean Breslow thickness was 2.26 mm. All patients with epitrochlear drainage had concurrent axillary drainage and underwent axillary and epitrochlear SLN biopsies. Of these 38 patients, two (5.2%) had epitrochlear and axillary SLN metastasis, four (10.5%) had epitrochlear metastasis only, four (10.5%) had axillary metastasis only, and the remaining 28 (73.7%) had tumor-free SLNs. The invariable association of epitrochlear and axillary drainage in this study suggests that epitrochlear nodes function in an interval role with the axillary lymph node basin. Therefore we recommend that all patients with a positive epitrochlear SLN undergo completion axillary dissection.

Epitrochlear sentinel lymph nodes in melanoma: interval or independent?

Most primary melanomas on the distal upper extremity metastasize to a sentinel lymph node (SLN) in the axillary basin, but occasionally a primary melanoma will drain to the epitrochlear basin. The relationship between tumor-draining axillary and epitrochlear SLNs is unclear. We hypothesize that the epitrochlear SLN functions in an interval manner with the axillary lymph node basin. We queried our melanoma database to identify patients who underwent SLN biopsy for a distal upper-extremity melanoma. Patient demographics, tumor characteristics, patterns of nodal drainage, and incidence of SLN metastasis were analyzed. Of 255 patients identified, 38 (14.9%) had an epitrochlear SLN. Mean Breslow thickness was 2.26 mm. All patients with epitrochlear drainage had concurrent axillary drainage and underwent axillary and epitrochlear SLN biopsies. Of these 38 patients, two (5.2%) had epitrochlear and axillary SLN metastasis, four (10.5%) had epitrochlear metastasis only, four (10.5%) had axillary metastasis only, and the remaining 28 (73.7%) had tumor-free SLNs. The invariable association of epitrochlear and axillary drainage in this study suggests that epitrochlear nodes function in an interval role with the axillary lymph node basin. Therefore we recommend that all patients with a positive epitrochlear SLN undergo completion axillary dissection.

Metastasectomy for distant metastatic melanoma: analysis of data from the first Multicenter Selective Lymphadenectomy Trial (MSLT-I)

BACKGROUND

For stage IV melanoma, systemic medical therapy (SMT) is used most frequently; surgery is considered an adjunct in selected patients. We retrospectively compared survival after surgery with or without SMT versus SMT alone for melanoma patients developing distant metastases while enrolled in the first Multicenter Selective Lymphadenectomy Trial.

METHODS

Patients were randomized to wide excision and sentinel node biopsy, or wide excision and nodal observation. We evaluated recurrence site, therapy (selected by treating clinician), and survival after stage IV diagnosis.

RESULTS

Of 291 patients with complete data for stage IV recurrence, 161 (55 %) underwent surgery with or without SMT. Median survival was 15.8 versus 6.9 months, and 4-year survival was 20.8 versus 7.0 % for patients receiving surgery with or without SMT versus SMT alone (p < 0.0001; hazard ratio 0.406). Surgery with or without SMT conferred a survival advantage for patients with M1a (median > 60 months vs. 12.4 months; 4-year survival 69.3 % vs. 0; p = 0.0106), M1b (median 17.9 vs. 9.1 months; 4-year survival 24.1 vs. 14.3 %; p = 0.1143), and M1c (median 15.0 vs. 6.3 months; 4-year survival 10.5 vs. 4.6 %; p = 0.0001) disease. Patients with multiple metastases treated surgically had a survival advantage, and number of operations did not reduce survival in the 67 patients (42 %) who had multiple surgeries for distant melanoma.

CONCLUSIONS

Our findings suggest that over half of stage IV patients are candidates for resection and exhibit improved survival over patients receiving SMT alone, regardless of site and number of metastases. We have begun a multicenter randomized phase III trial comparing surgery versus SMT as initial treatment for resectable distant melanoma.

Assessment of a novel immunological biomarker SNP panel from a phase III trial of Bacillus Calmette-Guérin (BCG) adjuvant treatment in stage III melanoma patients

2519

Background: Melanoma is an immunogenic cancer, whereby immunotherapy in stage III patients has shown some success. However, there are no effective immune biomarker tests to identify patients most likely to benefit from immunotherapy. BCG (Bacillus Calmette-Guérin) therapy is a form of immunomodulation. The objective was to assess the predictive clinical effect of a single nucleotide polymorphism(SNP) immune biomarker panel in stage III resected melanoma patients treated with BCG. Methods: MMAIT-III was a phase III prospective randomized international multicenter trial of BCG+melanoma vaccine vs BCG+placebo after complete resection of stage III melanoma patients (NIH #NCT00052130). 120/292 patients with palpable disease treated with resection and BCG+placebo had lymphocytes(PBL) from USA sites available for analysis. Endpoints were overall survival(OS) and disease-free survival(DFS), with a 10-yr follow-up. PBL DNA was assessed by MassARRAY MALDI-TOF for 28 SNPs associated with macrophage/monocyte-related immune response pathways to BCG/tuberculosis. A pilot study(n=34) from phase II BCG trial confirmed presence of the SNPs. A logistic regression determined a SNP score, and a cutoff was identified by ROC and used as a predictor in a Cox proportional hazard model in a verification study(n=120). Results: 9 SNPs in 6 genes had prognostic value: NRAMP1 and CD14, 18, 195, 209, 282. The 9-SNP panel distinguished patients in 2 survival groups(OS median 4.9-yrs vs 1.5-yrs, p=0.0008), AUC=0.77. SNP biomarker positivity demonstrates significant association with 10-yr OS (59.7% vs 15.7%; HR 1.97, CI 1.11-3.50, p=0.018) and DFS (47.2% vs 12.3%; HR 2.35, CI 1.43-3.92, p=0.0007). In Cox model, the SNP panel was a significant predictor of OS(HR 2.69, CI 1.56-9.00, p=0.0052) and DFS(HR 2.33, CI 1.49-5.16, p=0.0003) independent of known melanoma prognostic factors. Conclusions: The 9-SNP panel identified patients with an exceptionally favourable disease outcome, and may represent a stratifying predictive SNP panel for identifying patients that are inherently responsive to BCG therapy and potentially other immunomodulating agents in melanoma.

Prognostic significance of metastatic cascade in melanoma

e19029

Background: The ability of metastases to spawn subsequent generations of metastatic lesions is controversial, and its prognostic significance is unknown. We hypothesize that melanoma metastases that have spread to draining lymph nodes will have a worse prognosis than those that have not. Methods: One hundred consecutive patients who had undergone pulmonary resection for metastatic melanoma and who had concomitant hilar and/or mediastinal lymph node evaluation available were identified. Patient demographics, tumor characteristics, mediastinal lymph node status, and overall survival were analyzed. Results: 100 patients (71%) were male and the mean age at metastasectomy was 55 years (mean age at diagnosis 47 years.) The average Breslow thickness was 2.43mm (range 0.46 – 20.55). Twenty-one (21%) of the patients had evidence of metastatic disease present in regional lymph nodes during pulmonary resection. The 5-year overall survival for patients with positive mediastinal lymph nodes was 16% versus 36% with node negative disease (p=0.0005). On multivariate analysis, age at pulmonary resection (HR 1.018, 95% CI 1.002-1.035) and regional lymph nodes status (HR 3.203, 95% CI 1.774-5.781) were found to be independent prognostic indicators of 5-year overall survival. Conclusions: Regional lymph node status is an important prognostic factor in patients with pulmonary metastatic melanoma, and regional nodal assessment should be considered during metastasectomy. The metastatic cascade appears to be a strong prognostic factor in melanoma.

Long-term cure after complete resection and adjuvant immunotherapy for distant melanoma metastases

8534

Background: In phase II trials, postoperative therapy with Canvaxin allogeneic melanoma cell vaccine plus Bacillus Calmette-Guerin (BCG) improved the survival of patients with stage IV melanoma. A multicenter, phase III placebo-controlled study was undertaken to investigate the vaccine’s efficacy. Methods: After complete resection of melanoma involving up to 5 distant sites, patients were randomized to treatment with BCG plus Canvaxin (BCG-Canvaxin) or BCG plus placebo (BCG-placebo). The primary endpoint was overall survival (OS); secondary endpoints were disease-free survival (DFS) and skin test responsiveness to the study agent. Results: Between May 1998 and April 2005, 496 patients were randomized. In April 2005, entry to the study was terminated due to low probability of demonstrating treatment differences. However, 256 patients from sites enrolled in a follow-up study were monitored until March 2010. Median OS and 5-year and 10-year rates of OS were 39.1 months, 43.3% and 33.3%, respectively, in the BCG-placebo group, versus 34.9 months, 42.5% and 36.4%, respectively, in the BCG-Canvaxin group (hazard ratio, 1.053; 95% confidence interval, 0.81 to 1.36; p=0.6964). Median DFS, 5-year DFS, and 10-year DFS were 7.6 months, 23.8% and 21.7%, respectively, for the BCG-placebo group, versus 8.5 months, 30.0%, and 30.0%, respectively, for the BCG-Canvaxin group (hazard ratio, 0.882; 95% confidence interval, 0.708 to 1.097; p=0.2595). Positive skin test results correlated with improved survival. Conclusions: BCG-Canvaxin was not superior to BCG-placebo, but the highly favorable long-term survival for combined groups indicates that complete metastasectomy should be considered as initial therapy for patients with resectable stage IV melanoma (ClinicalTrials.gov identifier: NCT00052156).

Aberrant hypermethylation in primary tumours and sentinel lymph node metastases in paediatric patients with cutaneous melanoma

BACKGROUND

Debate on how to manage paediatric patients with cutaneous melanoma continues, particularly in those with sentinel lymph node (SLN) metastases who are at higher risk of poor outcomes. Management is often based on adult algorithms, although differences in clinical outcomes between paediatric and adult patients suggest that melanoma in paediatric patients differs biologically. Yet, there are no molecular prognostic studies identifying these differences.

OBJECTIVES

We investigated the epigenetic (methylation) regulation of several tumour-related genes (TRGs) known to be significant in adult melanoma progression in histopathology(+) SLN metastases (n = 17) and primary tumours (n = 20) of paediatric patients with melanoma to determine their clinical relevance.

METHODS

Paediatric patients (n = 37; ≤ 21 years at diagnosis) with American Joint Committee on Cancer stage I-III cutaneous melanoma were analysed. Gene promoter methylation of the TRGs RASSF1A, RARβ2, WIF1 and APC was evaluated.

RESULTS

Hypermethylation of RASSF1A, RARβ2, WIF1 and APC was found in 29% (5/17), 25% (4/16), 25% (4/16) and 19% (3/16) of histopathology(+) SLNs, respectively. When matched to adult cutaneous melanomas by Breslow thickness and ulceration, hypermethylation of all four TRGs in SLN(+) paediatric patients with melanoma was equivalent to or less than in adults. With a median follow-up of 55 months, SLN(+) paediatric patients with melanoma with hypermethylation of > 1 TRG vs. ≤ 1 TRG had worse disease-free (P = 0·02) and overall survival (P = 0·02).

CONCLUSIONS

Differences in the methylation status of these TRGs in SLN(+) paediatric and adult patients with melanoma may account for why SLN(+) paediatric patients have different clinical outcomes. SLN biopsy should continue to be performed; within SLN(+) paediatric patients with melanoma, hypermethylation of TRGs can be used to identify a subpopulation at highest risk for poor outcomes who warrant vigilant clinical follow-up.

AIM1 and LINE-1 epigenetic aberrations in tumor and serum relate to melanoma progression and disease outcome

Aberrations in the methylation status of non-coding genomic repeat DNA sequences and specific gene promoter region are important epigenetic events in melanoma progression. Promoter methylation status in LINE-1 and Absent in melanoma-1(AIM1;6q21) associated with melanoma progression and disease outcome was assessed. LINE-1 and AIM1 methylation status was assessed in paraffin-embedded archival tissues(PEAT)(n=133) and melanoma patients’ serum(n=56). LINE-1 U-Index(hypomethylation) and AIM1 were analyzed in microdissected melanoma PEAT sections. The LINE-1 U-Index of melanoma(n=100) was significantly higher than that of normal skin(n=14) and nevi(n=12)(P=0.0004). LINE-1 U-Index level was elevated with increasing AJCC stage(P<0.0001). AIM1 promoter hypermethylation was found in higher frequency(P=0.005) in metastatic melanoma(65%) than in primary melanomas(38%). When analyzed, high LINE-1 U-Index and/or AIM1 methylation in melanomas were associated with disease-free survival(DFS) and overall survival(OS) in Stage I/II patients (P=0.017, 0.027; respectively). In multivariate analysis, melanoma AIM1 methylation status was a significant prognostic factor of OS(P=0.032). Furthermore, serum unmethylated LINE-1 was at higher levels in both stage III(n=20) and stage IV(n=36) patients compared to healthy donors(n=14)(P=0.022). Circulating methylated AIM1 was detected in patients’ serum and was predictive of OS in Stage IV patients (P=0.009). LINE-1 hypomethylation and AIM1 hypermethylation have prognostic utility in both melanoma patients’ tumors and serum.

Unique patterns of metastases in common and rare types of malignancy

This review on the unique patterns of metastases by common and rare types of cancer addresses regional lymphatic metastases but also demonstrates general principles by consideration of vital organ metastases. These general features of successfully treated metastases are relationships to basic biological behavior as illustrated by disease-free interval, organ-specific behavior, oligo-metastatic presentation, genetic control of the metastatic pattern, careful selection of patients for surgical resection, and the necessity of complete resection of the few patients eligible for long-term survival after resection of vital organ metastasis. Lymph node metastases, while illustrating these general features, are not related to overall survival because lymph node metastases themselves do not destroy a vital organ function, and therefore have no causal relationship to overall survival. When a cancer cell spreads to a regional lymph node, does it also simultaneously spread to the systemic site or sites? Alternatively, does the cancer spread to the regional lymph node first and then it subsequently spreads to the distant site(s) after an incubation period of growth in the lymph node? Of course, if the cancer is in its incubation stage in the lymph node, then removal of the lymph node in the majority of cases with cancer cells may be curative. The data from the sentinel lymph node era, particularly in melanoma and breast cancer, is consistent with the spectrum theory of cancer progression to the sentinel lymph node in the majority of cases prior to distant metastasis. Perhaps, different subsets of cancer may be better defined with relevant biomarkers so that mechanisms of metastasis can be more accurately defined on a molecular and genomic level.

Prognostic significance of mitotic rate in localized primary cutaneous melanoma: an analysis of patients in the multi-institutional American Joint Committee on Cancer melanoma staging database

PURPOSE

The aim of this study was to assess the independent prognostic value of primary tumor mitotic rate compared with other clinical and pathologic features of stages I and II melanoma.

METHODS

From the American Joint Committee on Cancer (AJCC) melanoma staging database, information was extracted for 13,296 patients with stages I and II disease who had mitotic rate data available.

RESULTS

Survival times declined as mitotic rate increased. Ten-year survival ranged from 93% for patients whose tumors had 0 mitosis/mm(2) to 48% for those with ≥ 20/mm(2) (P < .001). Mean number of mitoses/mm(2) increased as the primary melanomas became thicker (1.0 for melanomas ≤ 1 mm, 3.5 for 1.01 to 2.0 mm, 7.3 for 3.01 to 4.0 mm, and 9.6 for > 8 mm). Ulceration was also associated with a higher mitotic rate; 59% of ulcerated melanomas had ≥ 5 mitoses/mm(2) compared with 16% of nonulcerated melanomas (P < .001). In a multivariate analysis of 10,233 patients, the independent predictive factors for survival in order of statistical significance were as follows: tumor thickness (χ(2) = 104.9; P < .001), mitotic rate (χ(2) = 67.0; P < .001), patient age (χ(2) = 48.2; P < .001), ulceration (χ(2) = 46.4; P < .001), anatomic site (χ(2) = 34.6; P < .001), and patient sex (χ(2) = 33.9; P < .001). Clark level of invasion was not an independent predictor of survival (χ(2) = 3.2; P = .37).

CONCLUSION

A high mitotic rate in a primary melanoma is associated with a lower survival probability. Among the independent predictors of melanoma-specific survival, mitotic rate was the strongest prognostic factor after tumor thickness.

Management of popliteal sentinel nodes in melanoma

BACKGROUND

Although most melanomas on the distal lower extremity drain exclusively to inguinal lymph nodes, a small percentage (<5%) drain to interval nodes in the popliteal basin. We investigated a possible relationship between tumor-draining popliteal and inguinal nodes in patients with lower-extremity melanoma.

STUDY DESIGN

We queried our melanoma database to identify patients who underwent sentinel node biopsy (SNB) for an infrapopliteal melanoma. Patterns of nodal drainage and nodal metastasis were analyzed.

RESULTS

Of 461 patients who underwent SNB for a primary infrapopliteal melanoma, 15 (3.2%) had drainage to the popliteal basin. Thirteen melanomas were on the posterior leg and foot, and 2 were on the anterior lower leg. Mean Breslow thickness was 2.4 mm. All 15 patients with popliteal drainage also had inguinal drainage and therefore underwent concurrent inguinal and popliteal SNB. The average number of popliteal sentinel nodes was 1.4 (range 1 to 3). Eight patients (53%) had a tumor-positive popliteal sentinel node, and 6 of the 8 underwent completion popliteal lymphadenectomy. Four of the 8 patients (50%) also had tumor-positive inguinal sentinel nodes; all underwent complete inguinal lymphadenectomy. We also identified 9 additional patients who underwent SNB for locoregional recurrent melanomas of the infrapopliteal leg. Three (33%) of these patients had concurrent inguinal and popliteal SNB, with 1 isolated tumor-positive popliteal node found.

CONCLUSIONS

In our series, a high percentage of popliteal sentinel lymph nodes contained metastases, and these patients frequently also had inguinal metastases. In our patients, all inguinal metastases were associated with concomitant popliteal metastases. Although it is anatomically separate, the inguinal basin appears to be a functional extension of the popliteal basin.

Does metastasectomy improve survival in patients with Stage IV melanoma? A cancer registry analysis of outcomes

INTRODUCTION

Patients with Stage IV melanoma have limited therapeutic options with few long-term survivors. Our goal was to study the impact of metastasectomy on survival in these patients.

METHODS

Patients with Stage IV melanoma were identified from the Surveillance, Epidemiology, and End Results (SEER) database (1988-2006). Those who had metastasectomy performed were compared with patients that did not.

RESULTS

The median age of the study population (n = 4,229) was 63 years and median survival was 7 months. Patients who underwent metastasectomy (33.6%) had an improved median and 5-year overall survival as compared to patients who did not; 12 months versus 5 months and 16% versus 7% (P < 0.001). In patients with M1a disease (n = 1,994), this improvement of survival following metastasectomy was enhanced; median survival of 14 months versus 6 months and 5-year overall survival of 20% versus 9% (P < 0.001). Younger age and diagnosis from 2001 to 2006 were predictors of metastasectomy. Metastasectomy was an independent and significant predictor of survival for the entire cohort (HR 0.59, 95% CI 0.55-0.63).

CONCLUSIONS

Metastasectomy in patients with Stage IV melanoma may improve long-term survival. The true therapeutic benefit, if any, of metastatectomy needs to be determined by a randomized trial.

Downregulation of microRNA-29c is associated with hypermethylation of tumor-related genes and disease outcome in cutaneous melanoma

Hypermethylation of the promoter region of tumor-related genes (TRGs) has been shown to silence gene expression during melanoma progression, whereas microRNA-29(miR-29) has been found to downregulate DNA methyltransferases DNMT3A and DNMT3B which were shown as essential to the methylation of TRGs. We hypothesized that the expression level of miR-29 is associated to TRG methylation status and may have prognostic utility in melanoma. AJCC stage I-IV cutaneous melanoma paraffin-embedded archival tissue (PEAT) specimens (n=149) were assessed. Expression of miR-29 isoforms a, b, and c were analyzed by reverse-transcription quantitative real-time polymerase chain reaction(RT-qPCR). Expression of DNMT3A and DNMT3B was assessed by immunohistochemistry(IHC) on defined clinically annotated tissue microarrays (TMA) of AJCC stage III melanoma lymph node metastases. Promoter region CpG island methylation status of RASSF1A, TFPI-2, RAR-β, SOCS, GATA4 and genomic repeat sequence MINT17 and MINT31 were previously evaluated in melanoma tissues. Only miR-29c isoform expression was correlated to advancing AJCC stages in melanoma. miR-29c expression was significantly downregulated in AJCC stage IV melanoma tumors compared to primary melanomas. Hypermethylation status of TRGs and non-coding MINT loci in different stages of melanoma showed an inverse association with miR-29c expression. Overall, an increase in miR-29c expression inversely correlated to both DNMT3A and DNMT3B protein expression in melanomas. Expression of DNMT3B and miR-29c were significantly (p=0.004 and p=0.002, respectively) associated with overall survival(OS) in AJCC stage III melanoma patients by multivariate analysis. The studies demonstrated that both miR-29c and DNMT3B have significant roles in melanoma progression, and may be useful epigenetic biomarkers for disease outcome.

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.

The role of lymphatic mapping and sentinel node biopsy in the management of atypical and anomalous melanocytic lesions

Atypical and anomalous melanocytic lesions are tumors that cannot be determined by microscopy to be certainly benign or fully malignant. The malignant potential of these borderline lesions is unknown and logical determination of best therapy is challenging, in particular whether lymphatic mapping and sentinel node biopsy have a place in their management. Lesions that fall into this category include atypical Spitzoid lesions, atypical cellular blue nevi, combined nevi, deep penetrating nevi, ancient nevi, desmoplastic nevi, balloon cell nevi and proliferation nodules of congenital nevi. We report our experience managing patients with these problematic tumors and discuss our approaches to determining the true location of lesional cells in sentinel nodes.

The impact on morbidity and length of stay of early versus delayed complete lymphadenectomy in melanoma: results of the Multicenter Selective Lymphadenectomy Trial (I)

BACKGROUND

Complete lymph node dissection, the current standard treatment for nodal metastasis in melanoma, carries the risk of significant morbidity. Clinically apparent nodal tumor is likely to impact both preoperative lymphatic function and extent of soft tissue dissection required to clear the basin. We hypothesized that early dissection would be associated with less morbidity than delayed dissection at the time of clinical recurrence.

MATERIALS AND METHODS

The Multicenter Selective Lymphadenectomy Trial I randomized patients to wide excision of a primary melanoma with or without sentinel lymph node biopsy. Immediate completion lymph node dissection (early CLND) was performed when indicated in the SLN arm, while therapeutic dissection (delayed CLND) was performed at the time of clinical recurrence in the wide excision-alone arm. Acute and chronic morbidities were prospectively monitored.

RESULTS

Early CLND was performed in 225 patients, and in the wide excision-alone arm 132 have undergone delayed CLND. The 2 groups were similar for primary tumor features, body mass index, basin location, and demographics except age, which were higher for delayed CLND. The number of nodes evaluated and the number of positive nodes was greater for delayed CLND. There was no significant difference in acute morbidity, but lymphedema was significantly higher in the delayed CLND group (20.4% vs. 12.4%, P = .04). Length of inpatient hospitalization was also longer for delayed CLND.

CONCLUSION

Immediate nodal treatment provides critical prognostic information and a likely therapeutic effect for those patients with nodal involvement. These data show that early CLND is also less likely to result in lymphedema.

Sentinel node biopsy in melanoma: technical considerations of the procedure as performed at the John Wayne Cancer Institute

Since its first description in 1990, sentinel node (SN) biopsy has become the standard for accurate staging of a melanoma-draining regional lymphatic basin. This minimally invasive, multidisciplinary technique can detect occult metastases by selective sampling and focused pathologic analysis of the first nodes on the afferent lymphatic pathway from a primary cutaneous melanoma. An understanding of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and the definition of SN are critical for surgical expertise with SN biopsy.

Multivariate analysis of prognostic factors among 2,313 patients with stage III melanoma: comparison of nodal micrometastases versus macrometastases

PURPOSE

To determine the survival rates and independent predictors of survival using a contemporary international cohort of patients with stage III melanoma.

PATIENTS AND METHODS

Complete clinicopathologic and follow-up data were available for 2,313 patients with stage III disease in an updated and expanded American Joint Committee on Cancer (AJCC) melanoma staging database. Kaplan-Meier and Cox multivariate survival analyses were performed.

RESULTS

Among all 2,313 patients with stage III disease, 81% had micrometastases, and 19% had clinically detectable macrometastases. The 5-year overall survival was 63%; it was 67% for patients with nodal micrometastases, and it was 43% for those with nodal macrometastases (P < .001). Tremendous heterogeneity in survival was observed, particularly in the microscopically detected nodal metastasis subset (from 23% to 87% for 5-year survival). Multivariate analysis demonstrated that in patients with nodal micrometastases, number of tumor-containing lymph nodes, primary tumor thickness, patient age, ulceration, and anatomic site of the primary independently predicted survival (all P < .01). When added to the model, primary tumor mitotic rate was the second-most powerful predictor of survival after the number of tumor-containing nodes. In contrast, for patients with nodal macrometastases, the number of tumor-containing nodes, primary ulceration, and patient age independently predicted survival (P < .01).

CONCLUSION

In this multi-institutional analysis, we demonstrated remarkable heterogeneity of prognosis among patients with stage III melanoma, especially among those with nodal micrometastases. These results should be incorporated into the design and interpretation of future clinical trials involving patients with stage III melanoma.

Abstract 5626: Single-chain bispecific BiTE antibody specific for CD3 and melanoma-associated chondroitin sulfate proteoglycan: In vitro and in vivo anti-melanoma activity

Introduction: Bispecific T-cell engager (BiTE) antibodies redirect cytotoxic T cells to malignant cells and are in clinical trials for treatment of various cancers. A recently developed BiTE antibody targets CD3 on T cells and melanoma-associated chondroitin sulfate proteoglycan (MCSP) on human melanoma cells. We examined 1) cytotoxic activity of MCSP-BiTE against a human melanoma cell line cocultured with peripheral blood mononuclear cells (PBMC) from melanoma patients, 2) T cell activation by MCSP-BiTE, and 3) anti-tumor effect of MCSP-BiTE in a human melanoma xenograft model.

Methods: 1) Strongly MCSP-positive metastatic human melanoma cell line M27-HI was cultured alone or at a 3:1 effector: target (E: T) ratio with PBMC from 12 melanoma patients. Cocultures were treated for 6-7 days with MCSP-BiTE antibody or a control BiTE antibody that binds CD3 but not MCSP. Cytotoxicity was assessed by a FACS-based assay. 2) PBMC from a healthy donor were incubated with MCSP-BiTE antibody and M27-HI cells, stained with antibody to CD4, CD8, CD69 and granzyme B followed by FACS analysis (Student's t-test). 3) 2 million M27-HI cells, which produce moderately aggressive tumor growth in NOD/SCID mice, were mixed with nonstimulated healthy donor PBMC at an E: T ratio of 1:1 and injected subcutaneously into NOD/SCID mice. MCSP-BiTE antibody was continuously infused intraperitoneally for 4 weeks. Tumor growth in each treatment group of 3 mice was measured in two dimensions twice weekly for 10 weeks; the time for tumors to reach 0.2 cm3 was compared between the treatment and control groups (log-rank test).

Results: PBMC of melanoma patients contained 25.93 ± 9.27% CD3+ T cells. 1) The percentage of dead cells was significantly higher when M27-HI cells were cocultured with PBMC and 100 ng/ml MCSP-BiTE (36.07 ± 21.38%; range 2.05-71.17%) versus PBMC and 100 ng/ml control antibody (10.67 ± 6.4%; range 3.05-25.9%; p=0.002) or PBMC alone (12.21 ± 4.18%; range 3.71-19.94%; p=0.003). The percentage of dead cells was lower when PBMC were from patients with clinical evidence of melanoma. 2) A 48-h coculture of healthy donor PBMC, MCSP-BiTE and M27-HI cells showed dose-dependent increases of CD69+ (both on CD4+ and CD8+ cells) and granzyme B (CD8+ cells). 3) Four μg/day MCSP-BITE significantly inhibited tumor growth (p=0.03) compared to a bispecific control antibody.

Conclusions: In our previous experiments, CD3+ T cells comprised approximately 60% of healthy donor PBMC and melanoma cell killing was 46-55% (AACR 2009). Here, CD3+ T cells comprised approximately 26% of melanoma patients’ PBMC and melanoma cell killing was 36%; decreased killing could be due to a lower percentage of CD3+ T cells in patients’ PBMC. MCSP-BiTE not only mediated redirected lysis but also T-cell activation as was evident from upregulation of CD69 and granzyme B. MCSP-BiTE shows anti-tumor activity in vivo.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5626.

Predictors of occult nodal metastasis in patients with thin melanoma

HYPOTHESIS

Thin primary lesions are largely responsible for the rapid increase in melanoma incidence, making identification of appropriate candidates for nodal staging in this group critically important. We hypothesized that common clinical variables may accurately estimate the risk of nodal metastasis after wide excision and determine the need for sentinel node biopsy.

DESIGN

Review of prospectively acquired data in a large melanoma database.

SETTING

A tertiary referral center.

PATIENTS

A total of 2211 patients with thin melanoma treated by wide local excision alone were identified in the database between January 1, 1971, and December 31, 2005. Of those, 1732 met entry criteria.

MAIN OUTCOME MEASURES

We examined the rate of regional nodal recurrence and the impact of clinical and demographic variables by univariate and multivariate analyses.

RESULTS

The overall nodal recurrence rate was 2.9%; median time to recurrence was 38.3 months. Univariate analysis of 1732 patients identified male sex (P < .001), increased Breslow thickness (P < .001), and increased Clark level (P < .001) as significant for nodal recurrence. Multivariate analysis identified male sex (hazard ratio, 3.5; 95% confidence interval, 1.8-7.0; P < .001), younger age (0.45; 0.24-0.86; P = .001), and increased Breslow thickness (2.5; 1.6-3.7; categorical P < .001) as significant for nodal recurrence. The Clark level was no longer significant (P = .63). Breslow thickness, age, and sex were used to develop a scoring system and nomogram for the risk of nodal involvement. Predictions ranged from 0.1% in the lowest-risk group to 17.4% in the highest-risk group.

CONCLUSIONS

Many patients with thin melanoma will have nodal recurrence after wide excision alone. Three simple clinical variables may be used to estimate recurrence risk and select patients for sentinel node biopsy.