New prognostic factors of cutaneous melanoma: a review of the literature

The involvement of a chemokine receptor antagonist CTCE-9908 and kynurenine metabolites in cancer development

Cancer is the second leading cause of mortality worldwide. Skin cancer is the most common cancer in South Africa with nearly 20,000 reported cases every year and 700 deaths. If diagnosed early, the 5-year survival rate is about 90%, however, when diagnosed late, the 5-year survival rate decreases to about 20%. Melanoma is a type of skin cancer with an estimated 5-year survival rate of approximately 90%. Neuroblastoma is a paediatric cancer with a low survival rate. Sixty percent of patients with metastatic disease do not survive 5 years after diagnosis. Despite recent advances in targeted therapies, there is a crucial need to identify reliable prognostic biomarkers which will be able to contribute to the development of more precision-based chemotherapeutic strategies to prevent tumour migration and metastasis. The compound, CTCE-9908 inhibits the binding of CXC chemokine ligand 12 (CXCL12) to the CXC chemokine receptor 4 (CXCR4) receptor leading to reduced metastasis. Kynurenine metabolites are derived tryptophan, which is an essential amino acid. Kynurenine metabolites inhibit T-cell proliferation resulting in cell growth arrest. For this reason, chemokines receptors represent potential targets for the treatment of cancer growth and metastasis. In this review paper, the role of the CXCL12/CXCR4 signalling pathway in the development of cancer is highlighted together with the current available treatments involving the CTCE-9908 compound in combination with microtubule inhibitors like paclitaxel and docetaxel.

Eosinophil-cationic protein - a novel liquid prognostic biomarker in melanoma

BACKGROUND

The role of eosinophils in cancer is not yet completely understood, but patients with eosinophilia show a trend towards longer survival in several types of cancer, including melanoma. However, eosinophil count at initial diagnosis of metastatic melanoma does not predict survival. Since eosinophil cationic protein (ECP) mediates anticancer effects, such as tissue remodelling and cytotoxic activity, we investigated this marker as an early prognostic marker in metastatic melanoma.

METHODS

Serum of 56 melanoma patients was collected at the time of diagnosis of metastatic disease. ECP levels as measured by ELISA were correlated with overall survival (OS) in patients before systemic therapy with immunotherapy or chemotherapy. Statistical analyses were performed using the Log-Rank (Mantel-Cox) test.

RESULTS

The median OS for patients with high serum ECP above 12.2 ng/ml was 12 months (n = 39), compared to 28 months for patients with ECP below this threshold (n = 17; p = 0.0642). In patients with cutaneous melanoma, excluding patients with uveal and mucosal melanoma, the survival difference was even more striking (p = 0.0393). ECP's effect size on OS was observed independently of the consecutive therapy. ECP levels were not correlated with LDH levels.

CONCLUSION

ECP seems to be a novel prognostic serum marker for the outcome of melanoma patients, which is independent of LDH and easy to perform in clinical practice. The striking negative prognostic value of high ECP level is unanticipated and can guide patient management.

Microvessel Density in Patients with Cutaneous Melanoma: An Up-to-Date Systematic Review and Meta-Analysis

Background

We conducted a meta-analysis, in order to appraise the effect of microvessel density (MVD) on the survival of patients with cutaneous melanoma.

Methods

This study was conducted according to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. A systematic literature search in electronic databases (MEDLINE, Web of Science, and Cochrane Central Register of Controlled Clinical Trials) was performed. Fixed Effects or Random Effects model was used, based on the Cochran Q test.

Results

In total 9 studies (903 patients) were included. Pooled HR for overall survival (OS) and disease-free survival (DFS) were 2.62 (95% CI: 0.71–9.60, p = 0.15) and 2.64 (95% CI: 0.82–8.47, p = 0.10), respectively. Odds ratios of overall survival between high and low MVD groups, at 12 (1.45, 95% CI: 0.16–13.24), 36 (2.93, 95% CI: 0.63–13.59), and 60 (4.09, 95% CI: 0.85–19.77) months did not reach statistical significance. Significant superiority of low MVD group, in terms of DFS, at all time intervals (OR: 4.69, p < 0.0001; OR: 2.18, p = 0.004; OR: 7.46, p = 0.01, resp.) was documented.

Discussion

MVD does not affect the HR of OS and DFS. A strong correlation with DFS rates at 12, 36, and 60 months was recorded.

Longitudinal study using voxel-based relaxometry: Association between cartilage T1ρ and T2 and patient reported outcome changes in hip osteoarthritis

PURPOSE

To study the local distribution of hip cartilage T_1ρ and T₂ relaxation times and their association with changes in patient reported outcome measures (PROMs) using a fully automatic, local, and unbiased method in subjects with and without hip osteoarthritis (OA).

MATERIALS AND METHODS

The 3 Tesla MRI studies of the hip were obtained for 37 healthy controls and 16 subjects with radiographic hip OA. The imaging protocol included a three-dimensional (3D) SPGR sequence and a combined 3D T_1ρ and T₂ sequence. Quantitative cartilage analysis was compared between a traditional region of interest (ROI)-based method and a fully automatic voxel-based relaxometry (VBR) method. Additionally, VBR was used to assess local T_1ρ and T₂ differences between subjects with and without OA, and to evaluate the association between T_1ρ and T₂ and 18-month changes PROMs.

RESULTS

Results for the two methods were consistent in the acetabular (R = 0.79; coefficients of variation [CV] = 2.9%) and femoral cartilage (R = 0.90; CV = 2.6%). VBR revealed local patterns of T_1ρ and T₂ elevation in OA subjects, particularly in the posterosuperior acetabular cartilage (T_1ρ : P = 0.02; T₂ : P = 0.038). Overall, higher T_1ρ and T₂ values at baseline, particularly in the anterosuperior acetabular cartilage (T_1ρ : Rho = -0.42; P = 0.002; T₂ : Rho = -0.44; P = 0.002), were associated with worsening PROMS at 18-month follow-up.

CONCLUSION

VBR is an accurate and robust method for quantitative MRI analysis in hip cartilage. VBR showed the capability to detect local variations in T_1ρ and T₂ values in subjects with and without osteoarthritis, and voxel based correlations demonstrated a regional dependence between baseline T_1ρ and T₂ values and changes in PROMs.

LEVEL OF EVIDENCE

1 J. MAGN. RESON. IMAGING 2017;45:1523-1533.

Serum miR-16: A Potential Biomarker for Predicting Melanoma Prognosis

Melanoma is among the most malignant cancers with notorious aggressiveness, and its prognosis is greatly influenced by progression status. Serum microRNAs are small noncoding RNAs with high stability and easy accessibility in human blood. Their expression profiles are frequently dysregulated in cancers; hence, levels of serum microRNAs may reflect progression status and thus predict melanoma prognosis. In a hospital based case-control study, we found a significant reduction of serum miR-16 level in melanoma patients compared with cancer-free controls (P < 0.001). In addition, serum miR-16 level markedly decreased in melanoma patients with increased tumor thickness, occurrence of ulceration, and advanced American Joint Committee on Cancer stages, and was highly correlated with tissue Ki-67 expression (r = -0.521, P < 0.0001). Kaplan-Meier analysis and Cox proportional hazards regression analysis revealed a prognostic role of serum miR-16 (hazard ratio 2.49, 95% confidence interval 1.10-5.63, P = 0.028), which independently evaluated patients' survival outcome. Finally, the suppressive role of miR-16 in melanoma growth was validated both in vitro and in vivo. In conclusion, we demonstrated that serum miR-16 is a potential biomarker for predicting melanoma prognosis.

Modifying effect of gender on the prognostic value of clinicopathological factors and Ki67 expression in melanoma: a population-based cohort study

Background

Malignant melanoma is the most deadly form of skin cancer. Female sex is known to have a protective effect on incidence, tumour characteristics, and mortality from melanoma. However, the potentially modifying effect of sex on the prognostic significance of clinicopathological and investigative factors is generally not taken into consideration in biomarker studies. In this study, we compared the sex-specific distribution and prognostic value of established tumour characteristics and Ki67 expression in 255 cases of incident primary melanoma in a prospective, population-based cohort study.

Methods

The study included 255 incident cases of melanoma, 132 females and 123 males, in the Malmö Diet and Cancer Study. Tumours from 226 (88.6%) cases had been assembled in tissue microarrays. Clinicopathological factors and immunohistochemical Ki67 expression were assessed and correlated with disease-free survival (DFS) and overall survival (OS) using Kaplan-Meier analysis, log rank test and univariable and multivariable Cox regression analyses, stratified for gender. Effect of gender on melanoma-specific survival (MSS) after first recurrence was also analysed.

Results

Women were significantly younger at diagnosis than men (p = 0.012). The most common tumour sites were the legs in women (37.5%) and the dorsal trunk in men (37.8%). Kaplan-Meier analysis revealed that tumour location had no prognostic impact in women, but in men, location to the frontal trunk was significantly associated with a reduced DFS compared with all other locations combined and location to the dorsal trunk was significantly associated with a prolonged OS. High Ki67 expression was significantly associated with a reduced DFS and OS in men but not in women, also when adjusted for other factors. In men, but not in women, ulceration was an independent prognostic factor for both DFS and OS. MSS after first local, regional or distant recurrence was significantly shorter for men than for women.

Conclusions

The results from this study demonstrate that the prognostic value of tumour location, Ki67 expression and ulceration in melanoma differs according to gender. These findings need to be validated in future studies, as they may help improve prognostication in patients with melanoma. Moreover, our findings demonstrate that sex-stratified analyses add valuable information to biomarker studies.

Treatment of primary melanoma of the lung monitored by 5-S-cysteinyldopa levels

Malignant melanoma originating outside the skin is very rare, whereas primary malignant melanoma of the lung is extremely rare. 5-S-Cysteinyldopa (5-S-CD), a melanin metabolite, has been reported to be a prognostic marker for cutaneous malignant melanoma. This is the first report in the English language literature dealing with primary malignant melanoma of the lung using serum 5-S-Cysteinyldopa levels to monitor the effects of surgery and chemotherapy.

Tumor necrosis factor receptor superfamily member TROY is a novel melanoma biomarker and potential therapeutic target

Incidence of melanoma continues to rise, and a better understanding of its genetics will be critical to improve diagnosis and develop new treatments. Here, we search for novel melanoma-specific genes that may serve as biomarkers and therapeutic targets by using an in vitro genetic screen. One identified cDNA encoded TROY, a member of the tumor necrosis factor receptor superfamily (TNFRSF). TROY is widely expressed during embryogenesis, but in adults expression is restricted to hair follicles and brain. However, TROY had never been associated with melanoma, and it was selected for further study. First we show that expression in melanoma is specific by semiquantitative RT-PCR analysis of a large panel of established tumor cell lines. Next, specificity of expression was evaluated by immunohistochemistry analysis of primary cell cultures and patient tissues. TROY is expressed in 2/2 primary melanoma cells and 45/45 melanoma tissue samples (p < 0.0001). With the exception of sebaceous glands, TROY is not expressed in normal skin biopsies (p < 0.0001) or primary skin cell cultures that contain keratinocytes and epidermal melanocytes, nor is it expressed in other skin tumor cells (p < 0.0001). Finally, we show that TROY regulates melanoma growth, because replication of melanoma cells with reduced TROY levels through treatment with short-interfering RNA was significantly decreased relative to control cells (p < 0.004). In summary, TROY is the first TNFRSF member that is a biomarker for melanoma. TROY also presents a potentially novel cell surface signaling target for inhibitors, cell and/or antibody-based immunotherapies.

Proliferating endothelial cells, but not microvessel density, are a prognostic parameter in human cutaneous melanoma

The induction of angiogenesis is crucial in the development of most human tumors. Angiogenesis is routinely assessed by the density of tumor microvessels. This technique reveals controversial results on the clinical and prognostic value of angiogenesis in melanoma. We investigated angiogenesis in tumor tissues of 58 cutaneous melanoma patients, of which a clinical follow-up of over 10 years was available, through assessment of microvessel density and by enumeration of the number of proliferating endothelial cells. To that end, vessels were immunohistochemically detected by CD31/CD34 staining, and proliferating endothelial cells were enumerated in a double staining with the proliferation marker Ki67. We found that microvessel density did not correlate with tumor stage or survival, neither in intratumoral nor in peritumoral areas. In contrast, proliferating endothelial cells were only observed in intratumoral areas and were correlated positively with tumor stage and the presence of distant metastases. In addition, a strong positive correlation was found with the number of proliferating tumor cells. Finally, high numbers of growing endothelial cells predicted short survival. Our results show that angiogenesis could best be measured by enumeration of proliferating endothelial cells and that this parameter has prognostic value in patients with cutaneous melanoma.

Molecular diagnostics in melanoma

Molecular pathology is rapidly evolving, featuring continuous technologic improvements that offer novel clinical opportunities for the recognition of disease predisposition, for identifying sub-clinical disease, for more accurate diagnosis, for selecting efficacious and non-toxic therapy, and for monitoring of disease outcome. Currently, the identification and prognosis of primary cutaneous melanoma is based on histologic factors (tumor depth and ulceration) and clinical factors (number of lymph node and/or distant metastases). However, metastasis can occur in patients with thin melanomas, and sentinel lymph node biopsy does not identify all patients at risk for distant metastasis. New markers exist that correlate with melanoma progression, which may aid in melanoma identification, prognostication, and detection of minimal residual disease/early recurrence. Moreover, not many therapeutic options exist for melanoma as no regimen prolongs survival. Emerging data with investigational therapies suggest that certain markers might play a crucial role in identifying patients who will respond to therapy or show utility in the monitoring the response to therapy. Herein, molecular diagnostics that can potentially benefit the individual melanoma patient will be discussed.

Biologic and prognostic significance of dermal Ki67 expression, mitoses, and tumorigenicity in thin invasive cutaneous melanoma

PURPOSE

Tumor cell proliferation is a central feature of melanoma progression. In this study, we characterized three biomarkers of proliferation (Ki67 expression, dermal mitotic rate [MR], and tumorigenicity) in thin (< or = 1.00 mm) primary cutaneous melanomas and examined their association with prognosis.

PATIENTS AND METHODS

We used immunohistochemistry to determine Ki67 expression using the monoclonal antibody MIB-1 in lesions from a prospective cohort that included 396 patients with thin invasive primary melanomas seen between 1972 and 1991. A multivariate Cox proportional hazards model was used to define independent prognostic factors, and recursive partitioning was used to develop a prognostic tree identifying risk groups.

RESULTS

Dermal Ki67 expression was lower than epidermal Ki67 expression in radial growth phase (RGP) melanomas (n = 171), and dermal Ki67 expression and MR were higher in tumorigenic vertical growth phase (VGP) melanomas (n = 193) compared with RGP and nontumorigenic VGP melanomas (n = 42). Dermal Ki67 expression, MR greater than 0, growth phase, thickness, ulceration, tumor-infiltrating lymphocytes, and sex were associated with metastasis at 10 years, however, only dermal Ki67 expression, MR greater than 0, and sex were independent prognostic factors. Two high-risk groups were identified: men and women with dermal MR greater than 0 and dermal Ki67 expression > or = 20% in tumor cells and men with MR greater than 0 and Ki67 expression less than 20%, with 10-year metastasis rates of 39% and 20%, respectively.

CONCLUSION

Proliferation slows as melanoma cells enter the dermis and then increases with the onset of tumorigenic VGP. Ki67 expression and dermal MR provide independent prognostic information that can potentially be used in risk-based management of patients.

Microtubule-associated protein 2, a marker of neuronal differentiation, induces mitotic defects, inhibits growth of melanoma cells, and predicts metastatic potential of cutaneous melanoma

Dynamic instability of microtubules is critical for mitotic spindle assembly and disassembly during cell division, especially in rapidly dividing tumor cells. Microtubule-associated proteins (MAPs) are a family of proteins that influence this property. We showed previously that MAP2, a neuron-specific protein that stabilizes microtubules in the dendrites of postmitotic neurons, is induced in primary cutaneous melanoma but is absent in metastatic melanomas. We proposed that induction of a microtubule-stabilizing protein in primary melanoma could disrupt the dynamic instability of microtubules, inhibit cell division and prevent or delay tumor progression. Here we show, by Kaplan-Meier survival and multivariate Cox regression analysis, that patients diagnosed with MAP2+ primary melanomas have significantly better metastatic disease-free survival than those with MAP2- disease. Investigation of the mechanisms that underlie the effect of MAP2 on melanoma progression showed that MAP2 expression in metastatic melanoma cell lines leads to microtubule stabilization, cell cycle arrest in G2-M phase and growth inhibition. Disruption of microtubule dynamics by MAP2 resulted in multipolar mitotic spindles, defects in cytokinesis and accumulation of cells with large nuclei, similar to those seen in vivo in MAP2+ primary melanomas cells. These data suggest that ectopic activation of a neuronal differentiation gene in melanoma during early tumor progression inhibits cell division and correlates with inhibition or delay of metastasis.

Ezrin in primary cutaneous melanoma

Ezrin is a member of the ezrin-radixin-moesin family of proteins that link the actin-containing cytoskeleton to the plasma membrane. Ezrin is also connected to signaling molecules involved in the regulation of cell survival, proliferation and migration. Here, we examined the expression of ezrin in 95 primary cutaneous melanomas and correlated ezrin expression with conventional prognostic factors and biomarkers. From 12 patients metastatic tissue samples were also examined. In addition to ezrin staining, Mib-1 proliferation antigen, p53 and Bcl-2 were evaluated. Ezrin immunoreactivity was seen in most tumors; only 19 (20%) melanomas were negative. A total of 48 (51%) tumors had weak immunoreactivity and 28 (29%) strong immunoreactivity. The intensity of ezrin immunoreactivity was associated with tumor thickness (Breslow, P=0.0008) and with tumor invasion level (Clark, P=0.004), thicker tumors having stronger immunoreactivity. Also, there was a correlation between higher Mib-1 index in tumors and strong ezrin expression. All metastatic samples (n=12) showed positive ezrin immunoreactivity. In univariate analysis of survival, patients (n=76) with positive ezrin immunoreactivity had worse clinical disease behavior than those (n=19) without ezrin immunoreactivity, but the difference was not significant (P=0.19). In multivariate analysis of survival, the ezrin immunoreactivity was not a significant marker. The results indicate that ezrin is expressed in most primary melanomas of the skin and in all metastatic tumors. Ezrin expression correlates with tumor thickness and level of invasion suggesting an association between ezrin expression and tumor progression.