Prognostic implications of p53 overexpression in cutaneous melanoma from sun-exposed and nonexposed sites

p53 Promotes Cytokine Expression in Melanoma to Regulate Drug Resistance and Migration

The transcription factor p53 is frequently lost during tumor development in solid tumors; however, most melanomas retain a wild type p53 protein. The presence of wild type p53 in melanoma has fueled speculation that p53 may play a neutral or pro-tumorigenic role in this disease. Here we show that p53 is functional in human melanoma cell lines, and that loss of p53 results in a general reduction in basal NF-kB regulated cytokine production. The reduced cytokine expression triggered by p53 loss is broad and includes key inflammatory chemokines, such as CXCL1, CXCL8, and the IL6 class cytokine LIF, resulting in a reduced ability to induce chemotactic-dependent migration of tumor cells and immune cells and increased sensitivity to BRAF inhibition. Taken together, this result indicates that wild type p53 regulates cytokine expression and induces cytokine-dependent phenotype on melanoma.

Clinicopathological features and clinical outcomes associated with TP53 and BRAFNon-V600 mutations in cutaneous melanoma patients

BACKGROUND

BRAFV600 , NRAS, TP53, and BRAFNon-V600 are among the most common mutations detected in non-acral cutaneous melanoma patients. Although several studies have identified clinical and pathological features associated with BRAFV600 and NRAS mutations, limited data are available regarding the correlates and significance of TP53 and BRAFNon-V600 mutations.

METHODS

This study analyzed the patient demographics, primary tumor features, and clinical outcomes of a large cohort of non-acral cutaneous melanoma patients who had undergone clinically indicated molecular testing (n = 926).

RESULTS

The prevalence of BRAFV600 , NRAS, TP53, and BRAFNon-V600 mutations was 43%, 21%, 19%, and 7%, respectively. The presence of a TP53 mutation was associated with older age (P = .019), a head and neck primary tumor site (P = .0001), and longer overall survival (OS) from the diagnosis of stage IV disease in univariate (P = .039) and multivariate analyses (P = .015). BRAFNon-V600 mutations were associated with older age (P = .005) but not with primary tumor features or OS from stage IV. Neither TP53 nor BRAFNon-V600 mutations correlated significantly with OS with frontline ipilimumab treatment, and the TP53 status was not significantly associated with outcomes with frontline BRAF inhibitor therapy. Eleven patients with BRAFNon-V600 mutations were treated with a BRAF inhibitor. Three patients were not evaluable for a response because of treatment cessation for toxicities; the remaining patients had disease progression as the best response to therapy.

CONCLUSIONS

These results add to the understanding of the clinical features associated with TP53 and BRAFNon-V600 mutations in advanced cutaneous melanoma patients, and they support the rationale for evaluating the prognostic significance of TP53 in other cohorts of melanoma patients. Cancer 2017;123:1372-1381. © 2016 American Cancer Society.

Melanoma: Advances in Targeted Therapy and Molecular Markers

PURPOSE AND DESIGN

In recent years, there have been dramatic improvements in the diagnosis and treatment of patients with melanoma. The development of molecular markers and associated targeted therapies have given new hope to subsets of patients with advanced disease. Here we discuss the most important advances in molecular targeted therapy and how these developments are likely to affect the practice of the clinical surgeon.

RESULTS AND CONCLUSIONS

Germ-line and somatic mutations are common in melanoma and provide prognostic information that can now be harnessed to provide a more personalized approach to cancer treatment. BRAF mutation at the V600 position is the most commonly identified mutation in patients with melanoma. Treatment with targeted inhibitors in patients with BRAF-mutant melanoma has afforded dramatic responses in about half of selected patients. Unfortunately, disease control is not durable and recurrences are common. We predict an increasing role for the surgeon in the multidisciplinary treatment of patients with metastatic disease, as well as a role for molecular profiling in patients with high-risk early stage disease. Further, we are only beginning to understand the prognostic significance of various gene mutations in patients with melanoma.

High expression of Wee1 is associated with poor disease-free survival in malignant melanoma: potential for targeted therapy

Notoriously resistant malignant melanoma is one of the most increasing forms of cancer worldwide; there is thus a precarious need for new treatment options. The Wee1 kinase is a major regulator of the G₂/M checkpoint, and halts the cell cycle by adding a negative phosphorylation on CDK1 (Tyr15). Additionally, Wee1 has a function in safeguarding the genome integrity during DNA synthesis. To assess the role of Wee1 in development and progression of malignant melanoma we examined its expression in a panel of paraffin-embedded patient derived tissue of benign nevi and primary- and metastatic melanomas, as well as in agarose-embedded cultured melanocytes. We found that Wee1 expression increased in the direction of malignancy, and showed a strong, positive correlation with known biomarkers involved in cell cycle regulation: Cyclin A (p<0.0001), Ki67 (p<0.0001), Cyclin D3 (p = 0.001), p21^Cip1/WAF1 (p = 0.003), p53 (p = 0.025). Furthermore, high Wee1 expression was associated with thicker primary tumors (p = 0.001), ulceration (p = 0.005) and poor disease-free survival (p = 0.008). Transfections using siWee1 in metastatic melanoma cell lines; WM239^WTp53, WM45.1^MUTp53 and LOX^WTp53, further support our hypothesis of a tumor promoting role of Wee1 in melanomas. Whereas no effect was observed in LOX cells, transfection with siWee1 led to accumulation of cells in G₁/S and S phase of the cell cycle in WM239 and WM45.1 cells, respectively. Both latter cell lines displayed DNA damage and induction of apoptosis, in the absence of Wee1, indicating that the effect of silencing Wee1 may not be solely dependent of the p53 status of the cells. Together these results reveal the importance of Wee1 as a prognostic biomarker in melanomas, and indicate a potential role for targeted therapy, alone or in combination with other agents.

Prognostic significance of regulators of cell cycle and apoptosis, p16(INK4a), p53, and bcl-2 in primary mucosal melanomas of the head and neck

Abnormalities in cell cycle regulation, tumor suppressor gene functions and apoptosis are frequent events in tumorigenesis. Their role in the pathogenesis and prognosis of primary mucosal melanomas (MM) of the upper aerodigestive tract remains unknown. Sixty-four patients (40 men, 24 women, median age 64 years) with MM were included in this study; 32 had tumors in the nasal/paranasal cavities, 28 in the oral cavity and 4 in the pharynx. Archival tissues from 47 initial mucosal tumors, 17 mucosal recurrences, and 13 nodal/distant metastases were subjected to immunohistochemistry using antibodies against p16, p53, and bcl-2. The results were correlated with histological features and survival data. Expressions of p16, p53, and bcl-2 proteins were seen in 25% (N=19/76), 21% (N=16/76), and 74% (N=56/76) of all tumors, respectively. bcl-2 expression in the initial tumors was associated with significantly longer overall and disease specific survival (3.3 vs. 1.5 years, P ≤ 0.05). Expression of p16 was increasingly lost, from 32% in initial tumors to 12% in recurrent and 15% in metastatic tumors (P=0.06). Tumors comprised of undifferentiated cells were significantly more p53 positive than epithelioid or spindle cells (80% vs. 33%, P=0.02). Expression of these markers did not correlate with necrosis, or vascular and/or deep tissue invasion. Expression of bcl-2 is associated with better survival in MM. Loss of p16 was seen with tumor progression whereas aberrant p53 expression was frequent in undifferentiated tumor cells.

p53 prevents progression of nevi to melanoma predominantly through cell cycle regulation

p53 is the central member of a critical tumor suppressor pathway in virtually all tumor types, where it is silenced mainly by missense mutations. In melanoma, p53 predominantly remains wild type, thus its role has been neglected. To study the effect of p53 on melanocyte function and melanomagenesis, we crossed the ‘high-p53’Mdm4+/− mouse to the well-established TP-ras0/+ murine melanoma progression model. After treatment with the carcinogen dimethylbenzanthracene (DMBA), TP-ras0/+ mice on the Mdm4+/− background developed fewer tumors with a delay in the age of onset of melanomas compared to TP-ras0/+ mice. Furthermore, we observed a dramatic decrease in tumor growth, lack of metastasis with increased survival of TP-ras0/+: Mdm4+/− mice. Thus, p53 effectively prevented the conversion of small benign tumors to malignant and metastatic melanoma. p53 activation in cultured primary melanocyte and melanoma cell lines using Nutlin-3, a specific Mdm2 antagonist, supported these findings. Moreover, global gene expression and network analysis of Nutlin-3-treated primary human melanocytes indicated that cell cycle regulation through the p21WAF1/CIP1 signaling network may be the key anti-melanomagenic activity of p53.

Nucleotide excision repair gene expression after Cisplatin treatment in melanoma

Two of the hallmark features of melanoma are its development as a result of chronic UV radiation exposure and the limited efficacy of cisplatin in the disease treatment. Both of these DNA-damaging agents result in large helix-distorting DNA damage that is recognized and repaired by nucleotide excision repair (NER). The aim of this study was to examine the expression of NER gene transcripts, p53, and p21 in melanoma cell lines treated with cisplatin compared with melanocytes. Basal expression of all genes was greater in the melanoma cell lines compared with melanocytes. Global genome repair (GGR) transcripts showed significantly decreased relative expression (RE) in melanoma cell lines 24 hours after cisplatin treatment. The basal RE of p53 was significantly higher in the melanoma cell lines compared with the melanocytes. However, induction of p53 was only significant in the melanocytes at 6 and 24 hours after cisplatin treatment. Inhibition of p53 expression significantly decreased the expression of all the GGR transcripts in melanocytes at 6 and 24 hours after cisplatin treatment. Although the RE levels were lower with p53 inhibition, the induction of the GGR genes was very similar to that in the control melanocytes and increased significantly across the time points. The findings from this study revealed reduced GGR transcript levels in melanoma cells 24 hours after cisplatin treatment. Our findings suggest a possible mechanistic explanation for the limited efficacy of cisplatin treatment and the possible role of UV light in melanoma.

Tissue biomarkers for prognosis in cutaneous melanoma: a systematic review and meta-analysis

In the clinical management of early-stage cutaneous melanoma, it is critical to determine which patients are cured by surgery alone and which should be treated with adjuvant therapy. To assist in this decision, many groups have made an effort to use molecular information. However, although there are hundreds of studies that have sought to assess the potential prognostic value of molecular markers in predicting the course of cutaneous melanoma, at this time, no molecular method to improve risk stratification is part of recommended clinical practice. To help understand this disconnect, we conducted a systematic review and meta-analysis of the published literature that reported immunohistochemistry-based protein biomarkers of melanoma outcome. Three parallel search strategies were applied to the PubMed database through January 15, 2008, to identify cohort studies that reported associations between immunohistochemical expression and survival outcomes in melanoma that conformed to the REMARK criteria. Of the 102 cohort studies, we identified only 37 manuscripts, collectively describing 87 assays on 62 distinct proteins, which met all inclusion criteria. Promising markers that emerged included melanoma cell adhesion molecule (MCAM)/MUC18 (all-cause mortality [ACM] hazard ratio [HR] = 16.34; 95% confidence interval [CI] = 3.80 to 70.28), matrix metalloproteinase-2 (melanoma-specific mortality [MSM] HR = 2.6; 95% CI = 1.32 to 5.07), Ki-67 (combined ACM HR = 2.66; 95% CI = 1.41 to 5.01), proliferating cell nuclear antigen (ACM HR = 2.27; 95% CI = 1.56 to 3.31), and p16/INK4A (ACM HR = 0.29; 95% CI = 0.10 to 0.83, MSM HR = 0.4; 95% CI = 0.24 to 0.67). We further noted incomplete adherence to the REMARK guidelines: 14 of 27 cohort studies that failed to adequately report their methods and nine studies that failed to either perform multivariable analyses or report their risk estimates were published since 2005.

Genetics of melanoma tumorigenesis

Melanoma therapy is moving away from combinatorial approaches and towards newer targeted strategies. With the identification of mutations in various RAS pathway genes, there are now tremendous opportunities to bring inhibitors of RAS signalling to the clinical arena.

The role of p53 in pigmentation, tanning and melanoma

p53 has a central role in skin pigmentation and may impact on melanoma at all stages, however, as it's mutation frequency in melanoma is low, it's role has been somewhat under-appreciated. During normal skin function, p53 in the keratinocyte is a transducer of the skin tanning signal and an essential component of what is effectively a keratinocyte-melanocyte signaling cycle that regulates skin pigmentation. It is clear that this cycle functions optimally in skin of dark pigmentation. When melanin biosynthesis is genetically disrupted in skin of white complexion, we propose that this cycle operates as a promoter of melanocyte proliferation. The cell autonomous function of p53 in melanocytes is not well described, however, the balance of the evidence suggests that p53 is an effective tumor suppressor and the myriad of mechanisms by which the p53 pathway may be dysregulated in tumors attests to it importance as a tumor suppressor. In this review, we outline the known mechanisms that impair p53 itself and its immediate regulators or target genes during melanomagenesis. Due to the importance of this pathway, it is clear that p53 disruptions may relate directly to a patient's prognosis. This pathway will continue to be a focus of investigation, particularly with respect to targeted experimental chemotherapeutics.

New thymidylate synthase inhibitors induce apoptosis in melanoma cell lines

Malignant melanoma is particularly resistant to conventional chemotherapy and radiotherapy. For this reason in the past years a huge variety of new compounds has been developed with potential chemotherapeutic activity which needs to be tested in vitro and in vivo. We investigated the in vitro action of three new experimental antifolate substances (MR7, MR21 and MR36) with a critical target for thymidylate synthase (TS), an essential enzyme for DNA synthesis. The response of two melanoma cell lines (SK-MEL-2 derived from malignant melanoma metastasis and SK-MEL-28 derived from primary malignant melanoma) was examined after treatment with these substances. The antifolate agents induced apoptosis in SK-MEL-2 and SK-MEL-28 cells as confirmed by the TUNEL technique and Comet Assay. Western-blot analysis showed a down-regulation of Bcl-2 protein level and PARP cleavage, otherwise p53 and Bax expressions were not modulated. Moreover, these antifolate-induced apoptosis was accompanied by both pro-caspase-9 and -8 activations. These results were supported by the use of the pan-caspases inhibitor Z-VAD-FMK that almost completely decreased the amount of apoptosis in both the melanoma cell lines treated with antifolate. In conclusion our results show that TS inhibitors are able to induce apoptosis through a caspase-mediated pathway, but without the involvement of the p53/Bax signalling.

Long term follow-up of c-myc, p53 and proliferation measurements in malignant melanoma

AIMS

We report a prospective study examining the prognostic significance of the c-myc oncoprotein, p53 tumour suppressor gene and proliferation rate measurements in malignant melanoma.

METHODS

Flow cytometry (FCM) was used to measure the expression of c-myc, p53 and proliferation parameters in patients who had received an injection of the thymidine analogue bromodeoxyuridine prior to surgery.

RESULTS

Sixty-seven patients had successful FCM measurements of the three parameters. c-myc was detected in 97% of patients with a median cell positivity of 62%. The median p53 positivity was 13%. The median potential doubling time (T(pot)) of the tumours wasf 9.4 days. In univariate analysis, each of the parameters showed an association with survival in metatstatic disease with rapid proliferation (p=0.006) or overexpression of c-myc (p=0.038) related to poor survival whereas increased positivity for p53 predicted better survival (p=0.013).

CONCLUSIONS

These data indicate that laser cytometric technology can be used to obtain quantitative data on oncoproteins expression and cell proliferation rates in clinical samples of malignant melanoma.

Molecular markers in malignant cutaneous melanoma: Gift horse or one-trick pony?

The management of malignant cutaneous melanoma is problematic. Current clinical prognostic factors do not adequately predict disease recurrence and overall survival in a significant subset of patients. Adjuvant therapies for melanoma are notoriously toxic and associated with significant morbidity. Furthermore, it has been difficult to predict which patients will respond best to these treatments, if at all. DNA and RNA biomarkers have been developed to help overcome these problems. Biomarkers have been shown to upstage patients with melanoma, but are the assays sensitive and specific enough for clinical use as predictors of disease outcome or treatment response? We review our experience with DNA and RNA biomarkers in terms of their prognostic and predictive capabilities in malignant melanoma and outline their likely role in the future of melanoma staging, surveillance, and treatment.

Genetic progression of metastatic melanoma

Melanoma progression is well defined in its clinical, histopathological and biological aspects, but the molecular mechanism involved and the genetic markers associated to metastatic dissemination are only beginning to be defined. The recent development of high-throughput technologies aimed at global molecular profiling of cancer is switching on the spotlight at previously unknown candidate genes involved in melanoma, such as WNT5A and BRAF. In fact, several tumor suppressors and oncogenes have been shown to be involved in melanoma pathogenesis, including CDKN2A, PTEN, TP53, RAS and MYC, though they have not been related to melanoma subtypes or validated as prognostic markers. Here, we have reviewed the published data relative to the major genes involved in melanoma pathogenesis, which may represent important markers for the identification of genetic profiles of melanoma subtypes.

Pathology of malignant melanoma

Understanding the fundamental aspects of the pathology of melanoma is crucial for the surgeon to deliver optimal care to the patient with melanoma. Pathology provides diagnostic data, offers prognostic information, and, to a large extent, directs management. This article reviews several aspects of the pathology of melanoma, with special relevance to the surgeon, including benign clinicopathologic simulators of melanoma, fundamental concepts of the pathology of melanoma, histopathologic prognostic factors of melanoma, approach to lymph nodes, and implications of the revised staging system.

Prognostic implications of thick (>or=4-mm) melanoma in the era of intraoperative lymphatic mapping and sentinel lymphadenectomy

BACKGROUND

Lymphatic mapping/sentinel lymphadenectomy (LM/SL) has become a routine part of our treatment algorithm for primary melanoma, yet its role in the management of thick (>or=4-mm) lesions is unknown.

METHODS

One hundred twenty-one patients with thick primaries underwent LM/SL at our institute. Survival curves were constructed from Kaplan-Meier estimates and analyzed by Cox proportional hazards methods.

RESULTS

Sixty-three percent of patients were men, median age 54 years. The primary tumor sites were trunk (46%), extremities (32%), and head and neck (21%). Primary thickness ranged from 4 to 15 mm (median, 6.0 mm). Forty-five percent of primary tumors were ulcerated. Thirty-five percent of patients had tumor-positive dissections. Median follow-up was 31 months. The overall 5-year survival was no different (P =.726) for ulcerated and nonulcerated lesions. There was no difference (P =.159) in overall survival after tumor-negative (60% +/- 7%) and tumor-positive (50% +/- 10%) dissections. The 5-year disease-free survival was significantly (P =.012) lower in patients with tumor-positive (34% +/- 9%) than tumor-negative (47% +/- 7%) dissections.

CONCLUSIONS

Although LM/SL has become a popular technique for staging the regional lymph nodes in early-stage melanoma, our results suggest that sentinel node status is predictive of disease-free survival for thick primary tumors but is not yet reflective of overall survival. The role of LM/SL for patients with thick primary tumors is not clearly defined.

Transcription factors and other dysregulated proteins in melanoma prognosis

Approximately one third of patients with cutaneous melanoma later develop a metastatic disease, having then an extremely poor rate of survival. Because of the highly unpredictable nature of melanomas, finding those patients who are likely to develop a metastatic disease and those patients who probably will survive is an ongoing challenge. The current "conventional" prognosticators, such as Breslow thickness, Clark level of invasion, and ulceration, cannot perfectly predict the clinical course of this disease at an individual level. Although the sentinel lymph node biopsy procedure and reverse transcription polymerase chain reaction techniques have significantly improved the staging of patients with melanoma, new molecular prognostic markers may help in selection of appropriate patients for strenuous adjuvant therapies and for randomized clinical trials. Furthermore, these markers also improve our basic understanding of the biology of cutaneous melanoma, potentially offering new targets for novel treatment strategies. This paper reviews the current literature on transcription factors and other dysregulated proteins involved in melanoma prognosis.

Genetic dissection of melanoma pathways in the mouse

The frequent loss of the INK4a/ARF locus, encoding for both p16(INK4a)and p19(ARF)in human melanoma, raises the question as to which INK4a/ARF gene product functions to suppress melanoma-genesis in vivo. Studies in the mouse have shown that activated RAS mutation can cooperate with INK4a(Delta 2/3)deficiency (null for both p16(INK4a)and p19(ARF)) to promote development of melanoma, and these melanomas retain wild-type p53. Given the functional link between p19(ARF)and p53, we have now shown that activated RAS can also cooperate with p53 deficiency to produce melanoma in the mouse. Moreover, genome-wide analysis of RAS-induced p53 mutant melanomas reveals alterations of key components governing RB-regulated G1/S transition, such as c-Myc. These experimental findings suggest that both RB and p53 pathways function to suppress melanocyte transformation in vivo in the mouse.

Dual inactivation of RB and p53 pathways in RAS-induced melanomas

The frequent loss of both INK4a and ARF in melanoma raises the question of which INK4a-ARF gene product functions to suppress melanoma genesis in vivo. Moreover, the high incidence of INK4a-ARF inactivation in transformed melanocytes, along with the lack of p53 mutation, implies a cell type-specific role for INK4a-ARF that may not be complemented by other lesions of the RB and p53 pathways. A mouse model of cutaneous melanoma has been generated previously through the combined effects of INK4a(Delta2/3) deficiency (null for INK4a and ARF) and melanocyte-specific expression of activated RAS (tyrosinase-driven H-RAS(V12G), Tyr-RAS). In this study, we made use of this Tyr-RAS allele to determine whether activated RAS can cooperate with p53 loss in melanoma genesis, whether such melanomas are biologically comparable to those arising in INK4a(Delta2/3-/-) mice, and whether tumor-associated mutations emerge in the p16(INK4a)-RB pathway in such melanomas. Here, we report that p53 inactivation can cooperate with activated RAS to promote the development of cutaneous melanomas that are clinically indistinguishable from those arisen on the INK4a(Delta2/3) null background. Genomewide analysis of RAS-induced p53 mutant melanomas by comparative genomic hybridization and candidate gene surveys revealed alterations of key components governing RB-regulated G(1)/S transition, including c-Myc, cyclin D1, cdc25a, and p21(CIP1). Consistent with the profile of c-Myc dysregulation, the reintroduction of p16(INK4a) profoundly reduced the growth of Tyr-RAS INK4a(Delta2/3-/-) tumor cells but had no effect on tumor cells derived from Tyr-RAS p53(-/-) melanomas. Together, these data validate a role for p53 inactivation in melanomagenesis and suggest that both the RB and p53 pathways function to suppress melanocyte transformation in vivo in the mouse.

Efficacy of lymphatic mapping, sentinel lymphadenectomy, and selective complete lymph node dissection as a therapeutic procedure for early-stage melanoma

BACKGROUND

Lymphatic mapping, sentinel lymphadenectomy, and selective complete lymph node dissection (LM/SL/SCLND) is an increasingly popular alternative to elective lymphadenectomy (ELND) for patients with early-stage melanoma. Although several reports have demonstrated the accuracy of the LM/SL technique, there are no data on its therapeutic value.

METHODS

We performed a matched-pair statistical analysis of 534 patients with clinical stage I melanoma; one half of the patients were treated with LM/SL and the other half were treated with ELND. Patients in the two treatment groups were matched for age (54% were < or =50 years of age), gender (63% were male patients), site of the primary melanoma (49% were on the extremities, 36% on the trunk, and 15% on the head and neck), and thickness of the primary melanoma (7% were < 0.75 mm, 42% between 0.75 and 1.5 mm, 43% between 1.51 and 4.0 mm, and 8% > 4 mm). Patients in the LM/SL group underwent complete regional lymphadenectomy (SCLND) only if the LM/SL specimen contained metastatic melanoma.

RESULTS

The overall incidences of nodal metastases were no different (P = .18) between LM/SL (15.7%) and ELND (12%) groups, but the incidence of occult nodal disease was significantly (P = .025) higher among patients with intermediate-thickness (1.51-4.0-mm) primary tumors who underwent LM/SL (23.7%) instead of ELND (12.2%). Survival data were compared by the log-rank score test. LM/SL/SCLND and ELND resulted in equivalent 5-year rates of disease-free survival (79 +/- 3.3% and 84 +/- 2.2%, respectively; P = .25) and overall survival (88 +/- 3.0% and 86 +/- 2.1%, respectively; P = .98). The LM/SL and ELND groups also exhibited similar incidences of same-basin recurrences (4.8% vs. 2.1%, P = .10, respectively) and in-transit metastases (2.6% vs. 3.8%, P = .48) after tumor-negative dissections. Patients who underwent ELND showed a higher incidence of distant recurrences (8.9% vs. 4.0%, P = .03), but this may be related to the longer follow-up period for these patients (median, 169 months), compared with the LM/SL-treated patients (45 months). Among patients with tumor-positive nodal dissections, the 5-year overall survival rates were higher, and approached significance (P = .077) for patients treated by LM/SL/SCLND (64 +/- 12%) compared with ELND (45 +/- 10%).

CONCLUSIONS

These findings suggest that LM/SL/SCLND is therapeutically equivalent to ELND but may be more effective for identifying nodal metastases in patients with intermediate-thickness primary tumors.

Can immunohistochemical markers and mitotic rate improve prognostic precision in patients with primary melanoma?

BACKGROUND

In addition to tumor thickness, several other prognostic parameters have been identified in primary human melanomas. Some are available readily (localization, gender, age, and ulceration). Others must be evaluated with a moderate or even substantial amount of work (mitoses and immunohistochemical markers). This study was undertaken to determine whether this extra effort is justified because it actually improves the precision of prognostic statements.

METHODS

Immunohistologic markers were determined on frozen sections from 691 biopsies of human melanomas with the immunoperoxidase method. Univariate and multivariate Cox regression analyses were performed with metastases and with death as endpoints.

RESULTS

Fifteen parameters were related to disease free survival in univariate Cox regression analysis: tumor thickness, ulceration, localization, gender, age, mitoses, and the immunohistochemical markers very late antigen (VLA)-2, human leukocyte antigen (HLA)-ABC, HLA-DR, NKI-beteb, Mel 14, intercellular adhesion molecule (ICAM-1), K-1-2, G-7-E2, and H-2-4-7. Three of the easily available parameters exhibited independent significance in multivariate Cox regression analysis: tumor thickness, ulceration, and localization. If mitotic rate was included in this model, then it had independent prognostic significance but ulceration was no longer significant. However, the model that included tumor thickness, localization, and ulceration had a slightly higher overall chi-square test score, indicating a better performance compared with thickness, localization, and mitoses. The model that included tumor thickness, localization, and mitoses could not be improved by any of the immunohistochemical markers in this study.

CONCLUSIONS

Nine immunohistochemical markers with established prognostic significance for primary human melanoma were not found to improve a prognostic model that included tumor thickness, localization, and mitoses. If mitoses was replaced by ulceration, then the model performed slightly better, although ulceration was not significant in the presence of mitoses.