Distant Melanoma Research Articles

Rural–Urban Disparities in Stage of Diagnosis Among Cancers With Preventive Opportunities

Despite having lower overall incidence rates, rural populations tend to have higher cancer mortality rates. Rural populations often have higher rates of cancers with primary and secondary prevention modalities. However, there is limited research on rural-urban differences in incidence by stage. Therefore, the objective was to assess rural-urban differences in cancer rates by stage. The North American Association of Central Cancer Registries public use data set (2009-2013) was used to calculate age-adjusted incidence rates and rate ratios (rural versus urban) for all stageable cancers, tobacco-associated cancers, human papillomavirus-associated cancers, and individual cancers with screening modalities. Analyses were performed in summer 2017 for all populations and stratified by race/ethnicity and region for localized and distant stages. For all cancers, rural populations had lower rates of localized stage cancers (rate ratio=0.95, 95% CI=0.95, 0.95) and higher rates of distant stage cancer (rate ratio=1.05, 95% CI=1.05, 1.06). Higher rates of distant stage human papillomavirus-associated, tobacco-associated, colorectal, oropharyngeal, lung, cervical cancers, and melanoma were identified in rural populations. Racial/ethnic stratifications identified higher rates of distant stage cancers in rural non-Hispanic whites, but not non-Hispanic blacks and Hispanics. Distant stage lung cancer rates were higher in all rural groups, whereas rural whites had higher distant rates of tobacco-associated, colorectal, and cervical cancers, and rural blacks had higher distant rates for human papillomavirus-associated and oral cancers. Regional stratifications showed the greatest disparity in stage at diagnosis in the South. These findings might help explain the higher rural cancer mortality rates and provide additional evidence to support targeted interventions.

Systemic treatments for metastatic cutaneous melanoma.

Systemic treatments for metastatic cutaneous melanoma.

Relationship between Melanoma Stage at the Diagnosis and Survival During a period of 30 Years (1982-2011)

Melanoma is a malignant tumor of melanocytes, and is a potentially aggressive cancer. The incidence of melanoma is rising at a greater rate than any other cancer in the U.S. The aim of this study was to examine the association between melanoma stage at the time of diagnosis and survival among U.S. adult melanoma patients during 1982-2011. This was a secondary analysis of a non-concurrent cohort study conducted on 185219 U.S. adult patients who were diagnosed with primary cutaneous melanoma between 1982-2011. Chi-square, Kaplan-Meier, and Cox proportional hazards regression were used to analyze the data. Significance was assessed using p-value and 95% confidence interval. Men had more cutaneous melanoma. Black non-Hispanic patients were diagnosed less frequently. Patients who were married or in a domestic partnership were most likely to be diagnosed. The adjusted HR for distant melanoma was 141-fold that of in situ (95% CI 126.38-157.19). The adjusted HR was the highest in the first decade of diagnosis (1.7; 95% CI 1.6 1.75). In conclusion, survival is highly affected by melanoma stage at diagnosis. Black non-Hispanic patients had the lowest hazard ratio of all races. The sample size was large, which enhances the generalizability to the U.S. population.

Melanoma Sequentially Suppresses Different DC Subsets in the Sentinel Lymph Node, Affecting Disease Spread and Recurrence.

Melanoma exerts immune-suppressive effects to facilitate tumor progression and metastatic spread. We studied these effects on dendritic cell (DC) and T-cell subsets in 36 melanoma sentinel lymph node (SLN) from 28 stage I-III melanoma patients and determined their clinical significance. Four conventional DC subsets, plasmacytoid DCs, and CD4+, CD8+, and regulatory T cells (Tregs), were analyzed by flow cytometry. We correlated these data to clinical parameters and determined their effect on local and distant melanoma recurrence, with a median follow-up of 75 months. In stage I and II melanoma, increased Breslow thickness (i.e., invasion depth of the primary melanoma) was associated with progressive suppression of skin-derived migratory CD1a+ DC subsets. In contrast, LN-resident DC subsets and T cells were only affected once metastasis to the SLN had occurred. In stage III patients, increased CD4:CD8 ratios in concert with the accumulation of Tregs resulted in decreased CD8:Treg ratios. On follow-up, lower frequencies of migratory DC subsets proved related to local melanoma recurrence, whereas reduced maturation of LN-resident DC subsets was associated with distant recurrence and melanoma-specific survival. In conclusion, melanoma-mediated suppression of migratory DC subsets in the SLN precedes local spread, whereas suppression of LN-resident DC subsets follows regional spread and precedes further melanoma dissemination to distant sites. This study offers a rationale to target migratory as well as LN-resident DC subsets for early immunotherapeutic interventions to prevent melanoma recurrence and spread. Cancer Immunol Res; 5(11); 969-77. ©2017 AACR.

Diffuse melanosis cutis related to dermal micrometastases as the first clinical symptom of distant metastatic malignant melanoma

Rationale:Diffuse melanosis cutis (DMC) is a very rare sign of malignant melanoma progression. The condition usually develops after approximately one year from melanoma diagnosis in a patient with metastatic tumors and after anticancer treatment with cytostatic medications.Patient concerns:A 72-year old Caucasian man was admitted to the Department of Dermatology with DMC for 4 months and the history of two melanomas treated surgically 30 years and 9 months before present hospitalization.Diagnosis:Histological and immunohistochemical examinations of DMC biopsy indicated melanoma metastatic cells as well as free deposits of melanin and melanophage presence in the dermis.Interventions:The patient refused to the treatment.Outcomes:The patient died eight months after DMC appeared.Lessons:DMC is a rare presentation of advanced MM and is a bad prognostic factor. The pathomechanisms of the discoloration of the skin are not fully explained. The role of micrometastases, as well as melanin precursors, released during lysis of MM metastases, and growth factors may play a role in the development of the symptom.

Abstract B022: Intratumoral CD40 activation and checkpoint blockade induces systemic anti-melanoma immunity that eradicates disseminated tumors

Abstract Although surgical resection is a reliable treatment for localized melanoma, treatment options for metastatic melanoma are limited. Melanoma Brain metastasis (MBM) is a major clinical problem in patients with advanced melanoma, and the incidence of brain metastasis is increasing every year. Thus, there is a significant unmet need for effective therapies for metastatic melanoma and MBM patients. Agonistic CD40 antibodies generate strong tumor specific CD8 T cell response and anti-tumor activity; however systemic anti-CD40 therapy has been associated with cytokine release syndrome and liver toxicity. We studied the anti-melanoma activity and mechanism of action of a non-replicating adenovirus encoding a CD40-targeting chimeric immunostimulatory protein (ISF35) by local intratumoral delivery approach to treat local and distant melanoma. Mice bearing established B16 melanomas on both right and left flanks or on right flank and in brain were treated intratumorally with ISF35 or rAd.empty to the right flank tumor and received anti-PD1 plus anti-CTLA-4 systemically. Anti-tumor effects of mono or combination therapies were determined by mice survival and tumor growth measurement. The mechanistic contribution of immune cells to this therapy was determined by using antibody blockades. Immune cell infiltrates in tumor and expression of activation markers on these cells were analyzed by flow cytometry. Intratumoral administration of ISF35 generates systemic anti-tumor immunity mediates by CD8 T cells and suppress both injected and distant uninjected wild-type B16.F10 melanomas. However, tumors did not completely regress after therapy. When combined with checkpoint inhibitors, ISF35 generates synergistic systemic anti-melanoma immunity that eradicates both injected and uninjected distant subcutaneous melanoma and uninjected brain melanoma with 40% of mice cured. The systemic anti-tumor activity of ISF35/anti-PD-1/anti-CTLA-4 was associated with greater production of melanoma-specific CD8 T cells with an activated phenotype. Immunotherapy based on intratumoral CD40 activation is potentiated by PD-1 and CTLA-4 blockade and this combination generates functional and long-lasting anti-tumor CD8 T cell immunity that systemically suppresses melanoma metastases. This approach will be a better option for treatment of patients with metastatic melanoma that does not respond to checkpoint blockage monotherapy. Citation Format: Manisha Singh, Christina Vianden, Adi Diab, Patrick Hwu, Willem W. Overwijk. Intratumoral CD40 activation and checkpoint blockade induces systemic anti-melanoma immunity that eradicates disseminated tumors [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B022.

Cutaneous Complications of Targeted Melanoma Therapy.

The landscape of advanced and metastatic melanoma therapy has shifted dramatically in recent years. Since 2011, eight drugs (ipilimumab, vemurafenib, dabrafenib, trametinib, cometinib, pembrolizumab, nivolumab, and talimogene laherparepvec) have received FDA approval for the treatment of advanced or metastatic melanoma, including combination regimens of both small molecule kinase and immune checkpoint inhibitors. These therapies have revolutionized the management of unresectable regional nodal and distant melanoma, providing hope of extended survival to patients. As the use of novel agents has increased, so have the cutaneous toxicities associated with these medications. While most skin reactions are low-grade and can be managed conservatively with topical therapies, malignant lesions and more serious or life-threatening drug reactions can arise during therapy, requiring prompt dermatologic recognition and treatment in order to improve patient outcome. Given the survival benefit attributed to these new agents, treating skin toxicity and maintaining patient quality of life is of paramount importance. Oncologists should be aware of the common cutaneous toxicities associated with these medications and should be encouraged to involve dermatologists in the collaborative care of advanced melanoma patients. Close communication between oncologists and dermatologists can help to avoid unnecessary dose reduction or treatment discontinuation and identify situations when treatment cessation is truly warranted.

Abstract LB-096: Induction of systemic immunity through single-site intratumoral CD40 activation and checkpoint blockade eradicates melanoma in the brain

Abstract Background: Melanoma brain metastases (MBM) are a rapidly growing clinical problem with up to 60% of melanoma patients developing MBM over the course of their disease. Locoregional treatment with surgery, radiotherapy, radiosurgery, and newer drug classes such as checkpoint inhibitors and targeted agents against BRAF-mutation melanoma have shown limited effectiveness against MBM (Lancet 2015; 16: e486-97). MBM patients continue to have poor clinical outcomes and life expectancies of only 3-7 months. Thus, there is a significant unmet need for effective therapies for MBM patients. Direct intratumoral administration of a non-replicating adenovirus encoding a CD40-targeting chimeric immunostimulatory protein (ISF35) leads to generation of potent melanoma-specific T cells. When combined with checkpoint inhibitors, ISF35 generates synergistic systemic anti-melanoma immunity that eradicates both injected and uninjected distant melanoma with 40% of mice cured using a B16 model. Based on this evidence of systemic activity, we hypothesized that ISF35/checkpoint inhibitors combination treatment may have systemic activity against MBM. Methods: A MBM mouse model was developed using luciferase-expressing B16 (B16-Luc). B16-Luc cells were subcutaneously (s.c.) implanted in the right flank of C57BL/6 mice 12 days prior to treatment. B16-Luc cells were then injected into the brain four days prior to treatment. Following tumor establishment at both sites, ISF35 was injected intratumorally in the right flank tumor on days 0, 4, 9, and 14. Simultaneously, anti-PD1 and anti-CTLA-4 antibodies were systemically administered. Results: Intratumoral administration of ISF35 in combination with anti-PD-1 and anti-CTLA-4 significantly increased (p<0.01) mouse survival compared to untreated mice. Median survival was not reached for the ISF35 plus checkpoint combination, was 10 days for untreated mice, 26 days for ISF35 monotherapy, and 17 days for anti-PD-1/anti-CTLA-4 combination therapy. ISF35/anti-PD-1/anti-CTLA-4 combination treatment of s.c. tumors resulted in complete and durable abscopal regression of brain tumors as assessed by bioluminescent imaging 30 days following initiation of treatment. In contrast, brain melanoma tumors continued to grow in the ISF35 monotherapy or anti-PD-1/anti-CTLA-4 treatment groups. The systemic anti-tumor activity of ISF35/anti-PD-1/anti-CTLA-4 was associated with greater production of melanoma-specific CD8 T cells with an activated phenotype, including upregulated PD-1 surface expression. Conclusions: These results suggest ISF35 may improve the effectiveness of checkpoint inhibitors therapy for metastatic melanoma, including in the brain. Citation Format: Manisha Singh, Christina Vianden, Adi Diab, Patrick Hwu, Willem W. Overwijk. Induction of systemic immunity through single-site intratumoral CD40 activation and checkpoint blockade eradicates melanoma in the brain. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-096.

Analysis of melanoma recurrence following a negative sentinel lymph node biopsy.

Little attention has been paid to the characteristics and outcomes of patients who experience distant, local or regional recurrence of melanoma following a negative sentinel lymph node biopsy. This article aims to review the published literature on the topic and presents some general summaries regarding this patient population. Patients who experience a disease recurrence following a negative sentinel lymph node biopsy have a worse overall survival compared with patients with a positive sentinel lymph node biopsy. The implications and possible explanations for these findings are discussed in order to both underscore the need for in-depth investigation of local, regional or distant melanoma recurrence among patients following a true negative sentinel lymph node biopsy, as well as increased efforts to minimize the rate of false negative sentinel lymph node biopsies.

Survival of SLNB-positive melanoma patients with and without complete lymph node dissection: A multicenter, randomized DECOG trial.

LBA9002 Background: Complete lymph node dissection (CLND) following positive sentinel node biopsy (SLNB) was evaluated in a randomized phase III trial. Methods: 1,258 patients with cutaneous melanoma of the trunk and extremities and with positive SLNB were evaluated. Of these, 483 (39%) agreed to randomization into the clinical trial. 241 patients underwent observation only, 242 received CLND. Both groups had a subsequent 3-years follow-up. Recurrence-free (RFS), distant metastases free (DMFS) and melanoma specific (MSS) survival were analyzed as endpoints. Results: Patient enrolment was performedfrom January 2006 to December 2014. In the intent to treat analysis, both groups did not differ significantly in distribution of age, gender, localization, ulceration, tumor thickness (median 2,4 mm in both groups), number of positive nodes, or tumor burden in the SN. The mean follow-up time was 34 months (SD ± 22.1). No significant treatment-related difference was seen in the 5-years RFS (P = 0.72), DMFS (P= 0 .76) and MSS (P = 0.86) in the overall study population. Conclusions: In this early analysis of trial results, no survival benefit was achieved by CLND in melanoma patients with positive SLNB. A subsequent analysis three years after inclusion of the last patient is planned.

Induction vemurafenib followed by consolidative radiation therapy for surgically incurable melanoma.

Approximately half of melanomas are driven by a point mutation in the BRAF kinase gene, targetable with vemurafenib. However, the chief limitation of continuous BRAF inhibition is that the majority of patients develop resistance within 8 months, including those with surgically unresectable stage III melanoma. Researchers retrospectively reviewed medical records of all patients at our institution with surgically incurable BRAF V600E mutated stage III or limited stage IV melanoma treated with induction vemurafenib, stopped electively during ongoing response, followed by consolidative radiation therapy with or without intervening surgery to debulk nodal metastases. In our six-patient cohort, the median duration of vemurafenib was 5.8 months and the median radiation dose was 57 Gy using conventional fractionation. This algorithm produced 100% locoregional control at 29+ months following radiation and a median progression-free survival of 32.5+ months. Three of six patients remained progression free, and three relapsed in a single organ and achieved ongoing complete response to subsequent therapy. Outcomes greatly exceeding those reported with either BRAF inhibition or radiation alone suggest unanticipated synergies with this therapeutic sequence for both in-field and distant melanoma control, which may be mediated by radiosensitization and immune activation, respectively. In patients with surgically incurable melanoma encompassed within a radiation field, induction vemurafenib and consolidative radiation therapy, rather than continuing vemurafenib until progression, also limit the duration of vemurafenib toxicity and preserve sensitivity to future BRAF inhibition.

Shaggy Photoreceptors with Subfoveal Fluid Associated with a Distant Choroidal Melanoma

Purpose. To describe the enhanced depth imaging optical coherence tomography (EDI-OCT) findings in a patient with an extra macula choroidal melanoma before and after treatment. Methods. Observational case report. Results. A 45 year-old Caucasian male patient was referred to retina clinic for management of choroidal melanoma. Examination revealed a nasal choroidal melanoma while EDI-OCT illustrated subfoveal fluid pocket with elongated shaggy photoreceptors distant and separate from the tumor. The patient was treated with plaque brachytherapy and intravitreal bevacizumab. One week after plaque removal, there was a dramatic reduction in the shaggy photoreceptors. Conclusion. Choroidal melanomas have effects that are not localized to the area of the tumor. This loculated pocket of subretinal fluid and coinciding changes to photoreceptor morphology may be related to global changes in choroidal function or release of tumor related cytokines.

Métastases cutanées d’un mélanome sur un territoire de radiothérapie au niveau du sein : traitement par vémurafénib et chirurgie d’exérèse large

This article describes the unique case of a female patient who presented distant melanoma metastasis on the breast while having irradiation therapy for breast cancer. This happened eight months after the initial treatment for a melanoma of the back (under the right scapula). Furthermore, this case report demonstrates the efficiency of Vemurafenib® as a treatment for late stage melanomas. The patient was a 47-year-old female that had a superficial spreading melanoma under the right scapula (Breslow 1.02mm) that was treated with 2cm skin excision and sentinel lymph node sampling that was negative. The melanoma was positive for the BRAF600E mutation. One month after this incident, the patient developed breast cancer that was treated with conservative surgery and radiotherapy. Three months after the end of the irradiation treatment, she developed multiple melanoma metastasis on the skin of the breast. Our multidisciplinary team decided to initiate a treatment with vemurafenib. The patient showed an excellent response, so the surgical team completed the treatment with a radical mastectomy and immediate reconstruction with a pedicled latissimus dorsi flap. The histologic report of the mastectomy specimen showed no sign of melanocytic proliferation, that demonstrates the efficacy of vemurafenib. The patient showed no relapse after two years of follow-up. The speed of development and location of cutaneous metastases in this case brought us to think about the effects of radiation therapy on the skin. Radiation therapy causes acute complications (radiodermatitis) by cellular and molecular mechanisms. Moreover, depressed immunity is found after irradiation. Association of these mecanisms could explain the appearance of these metastases in irradiation field. The efficiency of vemurafenib found in our case is consistent with what is described in literature, especially with the improvement in median overall survival. This case demonstrates a unique case of distant melanoma metastasis on the irradiation field of a breast cancer. It also demonstrates the efficacy of vemurafenib as well as the efficacy of a radical complementary surgical treatment in these patients.

Conditional survival in melanoma and thyroid cancer patients.

6599 Background: Melanoma and thyroid cancer are two increasingly common malignancies. Although likelihood of survival from both cancers can vary by disease severity, it isn't known how patients' life expectancy changes the further they are from time of diagnosis. Methods: Using Surveillance, Epidemiology, End Results (SEER) data we selected patients diagnosed with melanoma (N=95,041) or well-differentiated thyroid cancer (N=43,392) between 1998 - 2005. Patients were followed for up to 12 years. Cox regression provided estimates of disease-specific survival by SEER stage and age, which we then transformed to estimate conditional five year survival. Results: Patients with localized melanoma and thyroid cancer have an excellent five year survival at time of diagnosis and for subsequent years. For both regional melanoma and thyroid cancer there is an age gradient with improved conditional survival in melanoma patients over time. For distant melanoma, the initial five year survival is poor but improves rapidl...

Predictors of Neighborhood Risk for Late-Stage Melanoma: Addressing Disparities through Spatial Analysis and Area-Based Measures

Minority populations have disproportionately more advanced stage melanoma and worse survival. To clarify the impact of race and ethnicity on late-stage melanoma diagnosis, we performed spatial analysis of geocoded melanoma cases diagnosed in Florida, 1999-2008, to identify geographic clusters of higher-than-expected incidence of late-stage melanoma and developed predictive models for melanoma cases in high-risk neighborhoods accounting for area-based poverty, race/ethnicity, patient insurance status, age, and gender. In the adjusted model, Hispanic ethnicity and census tract-level poverty are the strongest predictors for clustering of late-stage melanoma. Hispanic whites were 43% more likely to live in neighborhoods with excessive late-stage melanoma (P<0.001) compared with non-Hispanic whites (NHW). For every 1% increase in population living in poverty, there is a 2% increase in late-stage melanoma clustering (P<0.001). Census tract-level poverty predicted late-stage melanoma similarly among NHW and Hispanic whites. The impact of insurance coverage varied among populations; the most consistent trend was that Medicaid coverage is associated with higher odds for late-stage melanoma. The finding that Hispanics are most likely to reside in high-risk neighborhoods, independent of poverty and insurance status, underscores the importance of addressing, and overcoming community-level barriers to melanoma care.

A single institution retrospective analysis of malignant melanoma.

The incidence of melanoma is rising at a rate greater than any other malignancy, although much of this increase is due to the more frequent diagnosis of patients with the earlier stages of melanoma. In this study, patient and tumor-related characteristics and their effects on survival were evaluated. The data was drawn from the patients' records with histologically proven primary cutaneous melanomas treated at the Ankara Oncology Hospital between January 2003 and December 2010. Sixty-nine patients (48 men and 21 women) were included in this study. 17 of the patients had already distant metastases at the time of diagnosis. While 45 of all patients had undergone surgery alone, 17 had received only palliative radiotherapy, and 7 had received primary radiotherapy. Survival curves were determined from the time of diagnosis. A total of 69 cutaneous melanoma cases were evaluated. While there was a predominance of males in all body sites, especially in the head and neck regions, the number of male patients was 5 times higher than females. Diseases located on the head tended to present a significantly higher rate in older patients (P = 0.009). Overall survival rates for 1 and 3 years were 79% and 44%, respectively. Distant metastatic melanoma was significantly related with poor prognosis (P < 0.001). Anatomic location showed a borderline significancy as a prognostic factor for overall survival (P = 0.053). Cutaneous melanomas developing at different body sites are associated with distinct patterns of survival outcomes. In this retrospective analysis, melanomas of the head and neck and limb, which are regional melanoma, appear to have better survival outcomes.

Serum S100B, Lactate Dehydrogenase and Brain Metastasis Are Prognostic Factors in Patients with Distant Melanoma Metastasis and Systemic Therapy

BackgroundPrognostic factors of melanoma with distant metastasis and systemic treatment are only poorly established. This study aimed to analyse the impact of S100B, lactate dehydrogenase (LDH) and the type of treatment on survival in advanced patients receiving systemic treatment.Patients and MethodsWe analysed overall survival of 499 patients from the university department of dermatology in Tuebingen, Germany, with unresectable melanoma at the time point of initiation of first-line systemic therapy. Only patients who started treatment between the years 2000 and 2010 were included. Disease-specific survival was calculated by bivariate Kaplan Meier survival probabilities and multivariate Cox hazard regression analysis.ResultsIn univariate analysis LDH, S100B, the site of distant metastasis (soft tissue vs. lung vs. other visceral), the presence of brain metastases and the type of treatment (monochemotherapy, polychemotherapy, immunotherapy or biochemotherapy) were associated with overall survival (all p<0.001). In multivariate analysis LDH (Hazard ratio [HR] 1.6 [1.3–2.1]; p<0.001), S100B (HR 1.6 [1.2–2.1]; p<0.001) and the presence of brain metastases (HR 1.5 [1.1–1.9]; p = 0.009), but not the type of treatment had significant independent impact. Among those factors normal S100B was the best indicator of long-term survival, which was 12.3% after 5 years for this subgroup.ConclusionSerum S100B is a prognostic marker predicting survival at the time of initiation of first-line treatment in unresectable melanoma patients. Compared to the other independent factors LDH and the presence of brain metastases it is most appropriate to predict long-term survival and requires further prospective investigation in patients treated with new and more potent drugs in metastatic melanoma.

The clinical significance ofBRAFandNRASmutations in a clinic-based metastatic melanoma cohort

BRAF and NRAS mutations are frequently found in melanoma tumours, and recently developed BRAF-targeted therapies demonstrate significant clinical benefit. We sought to investigate the clinical significance of BRAF and NRAS mutations in a clinic-based metastatic melanoma cohort. In total, 237 tumours, mostly metastatic lesions, from 203 patients were screened for mutations in exon 15 of BRAF and exon 2 of NRAS using Sanger sequencing. BRAF and NRAS mutation status was analysed in relation to clinical and histopathological characteristics, and outcome. Mutation in BRAF and NRAS was present in 43% (88% V600E, 10% V600K) and 30% (48% Q61K, 40% Q61R) of metastatic melanomas, respectively. We found consistent BRAF and NRAS mutation status in all but one of 27 patients with multiple metastases. BRAF mutation was associated with younger age at primary diagnosis (P = 0.02). Among patients with distant metastatic melanoma, patients with BRAF-mutant tumours without BRAF inhibitor treatment had inferior survival compared with patients with BRAF inhibitor treatment [hazard ratio (HR) 2.35, 95% confidence interval (CI) 1.10-5.01, P = 0.03]. We also observed a trend towards better prognosis for patients with wild-type and NRAS-mutant tumours compared with BRAF V600E-mutant tumours (HR 0.64, 95% CI 0.39-1.04, P = 0.07; and HR 0.76, 95% CI 0.48-1.21, P = 0.25, respectively). We were able to confirm the effect of BRAF inhibitor treatment in a single clinical institution. The results suggest further that BRAF mutation is a weak prognostic factor but a strong predictive factor and that BRAF-mutant melanoma might constitute one or more distinct subtypes of the disease with certain aetiology and clinical outcome.

Abstract C11: Molecular mechanism driving BMI1-induced melanoma metastasis

Abstract Malignant melanoma is one of the most aggressive human cancers, with a high potential for lethal metastasis and therapeutic resistance. The epigenetic chromatin regulator Bmi1 acts as a key component of the Polycomb Repressor Complex 1 (PRC1) and is a known oncogene. Various studies shown that BMI1 is highly expressed in many human hematopoietic malignancies and in different solid tumor types including prostate, breast, ovarian, colon, brain and lung cancer. Importantly, high Bmi1 expression is an excellent predictor of both metastatic progression and poor therapeutic response. Bmi1's role in tumor onset has been assessed using germline mutant mice showing that Bmi1 ablation efficiently suppress tumor development. This impaired tumorigenicity correlates with an impairment of the self-renewal and proliferative properties of tumor initiating cells, mainly due to Bmi1's repressive activity on the Ink4a/Arf tumor suppressor locus. Nevertheless, this function does not explain why Bmi1 is frequently upregulated in tumors nor Bmi1's role in tumor progression. To evaluate Bmi1's contribution to melanoma progression, we upregulated Bmi1 in two different melanoma cell lines, a murine metastatic cell line and a poorly metastatic human cell line. We found that Bmi1 overexpression activates or increases invasive behavior of both cell lines, without enhancing their proliferative capacity. This finding allowed us to dissect Bmi1's oncogenic activity at later stages of tumorigenesis, in the absence of Bmi1's deregulation of cell proliferation. Our data show that Bmi1 significantly enhances in vitro cell movement and modulates adhesion. Bmi1 also protects cells from apoptosis induced by different stimuli and increases lung metastasis formation in vivo. To characterize Bmi1-induced changes in gene expression, we have performed comparative deep sequencing of total RNA libraries generated from Bmi1 or GFP overexpressing cells. Gene ontology analysis revealed enrichment in cancer-relevant pathways that seem to be controlled by Bmi1, including cell movement, cell death and survival, tissue development and cell morphology. In particular, Bmi1 expression modulates the gene regulatory programs associated with EMT, TGFβ and the non-canonical Wnt pathways. We have identified a new Bmi1 target gene, poorly characterized, that seems to be responsible for Bmi1-induced melanoma progression. These data determine a causal role for Bmi1 in melanoma cell migration and establishment of distant melanoma metastasis. Citation Format: Roberta Ferretti, Jacqueline A. Lees. Molecular mechanism driving BMI1-induced melanoma metastasis. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C11.

Intralesional Injection of Rose Bengal Induces a Systemic Tumor-Specific Immune Response in Murine Models of Melanoma and Breast Cancer

Intralesional (IL) injection of PV-10 has shown to induce regression of both injected and non-injected lesions in patients with melanoma. To determine an underlying immune mechanism, the murine B16 melanoma model and the MT-901 breast cancer model were utilized. In BALB/c mice bearing MT-901 breast cancer, injection of PV-10 led to regression of injected and untreated contralateral subcutaneous lesions. In a murine model of melanoma, B16 cells were injected into C57BL/6 mice to establish one subcutaneous tumor and multiple lung lesions. Treatment of the subcutaneous lesion with a single injection of IL PV-10 led to regression of the injected lesion as well as the distant B16 melanoma lung metastases. Anti-tumor immune responses were measured in splenocytes collected from mice treated with IL PBS or PV-10. Splenocytes isolated from tumor bearing mice treated with IL PV-10 demonstrated enhanced tumor-specific IFN-gamma production compared to splenocytes from PBS-treated mice in both models. In addition, a significant increase in lysis of B16 cells by T cells isolated after PV-10 treatment was observed. Transfer of T cells isolated from tumor-bearing mice treated with IL PV-10 led to tumor regression in mice bearing B16 melanoma. These studies establish that IL PV-10 therapy induces tumor-specific T cell-mediated immunity in multiple histologic subtypes and support the concept of combining IL PV10 with immunotherapy for advanced malignancies.