The current state of molecular testing in the treatment of patients with solid tumors, 2019.

The world of molecular profiling has undergone revolutionary changes over the last few years as knowledge, technology, and even standard clinical practice have evolved. Broad molecular profiling is now nearly essential for all patients with metastatic solid tumors. New agents have been approved based on molecular testing instead of tumor site of origin. Molecular profiling methodologies have likewise changed such that tests that were performed on patients a few years ago are no longer complete and possibly inaccurate today. As with all rapid change, medical providers can quickly fall behind or struggle to find up-to-date sources to ensure he or she provides optimum care. In this review, the authors provide the current state of the art for molecular profiling/precision medicine, practice standards, and a view into the future ahead.

Predictive Biomarkers for Immunotherapy Response Beyond PD-1/PD-L1.

Advances in immuno-oncology over the last several years have led to FDA approvals of novel agents. As our understanding of immune response and its checkpoints has evolved, further advances have been made in treatment for several cancer types. To predict a response to immunotherapy, the initial biomarkers used were expression of the PD-1 receptor and PD-L1, as assessed by immunohistochemistry. More recently, predictive biomarkers have included microsatellite instability, DNA mismatch repair, and tumor mutational burden. Although these markers may be clinically relevant in predicting an immunotherapy response, cancer immunotherapy fails some patients. Improved understanding of the human immune system is necessary, as is a careful evaluation of the methods used to predict and assess response to immuno-oncology treatments. With the application of therapeutic immune-modulating agents, more comprehensive assays, and associated bioinformatics tools to accurately assess the tumor microenvironment, we may better predict responses to immuno-oncology agents and the ever-increasing complexity of their clinical use.

The role of margins in extremity soft tissue sarcoma.

For extremity soft tissue sarcomas, limb salvage is now standard of care. The extent of surgical margins is balanced with functionality of the resected limb. Although negative margins are the goal, the necessary width is unclear. Additional considerations for margin adequacy include presence of anatomic barriers such as fascia and periosteum, proximity of critical structures, receipt of adjuvant and neoadjuvant therapies, and histologic subtype. Multidisciplinary team discussion is critical for treatment planning.

Mice null for the deubiquitinase USP18 spontaneously develop leiomyosarcomas.

BACKGROUND: USP18 (ubiquitin-specific protease 18) removes ubiquitin-like modifier interferon stimulated gene 15 (ISG15) from conjugated proteins. USP18 null mice in a FVB/N background develop tumors as early as 2 months of age. These tumors are leiomyosarcomas and thus represent a new murine model for this disease. METHODS: Heterozygous USP18 +/- FVB/N mice were bred to generate wild-type, heterozygous and homozygous cohorts. Tumors were characterized immunohistochemically and two cell lines were derived from independent tumors. Cell lines were karyotyped and their responses to restoration of USP18 activity assessed. Drug testing and tumorigenic assays were also performed. USP18 immunohistochemical staining in a large series of human leiomyosacomas was examined. RESULTS: USP18 -/- FVB/N mice spontaneously develop tumors predominantly on the back of the neck with most tumors evident between 6-12 months (80 % penetrance). Immunohistochemical characterization of the tumors confirmed they were leiomyosarcomas, which originate from smooth muscle. Restoration of USP18 activity in sarcoma-derived cell lines did not reduce anchorage dependent or independent growth or xenograft tumor formation demonstrating that these cells no longer require USP18 suppression for tumorigenesis. Karyotyping revealed that both tumor-derived cell lines were aneuploid with extra copies of chromosomes 3 and 15. Chromosome 15 contains the Myc locus and MYC is also amplified in human leiomyosarcomas. MYC protein levels were elevated in both murine leiomyosarcoma cell lines. Stabilized P53 protein was detected in a subset of these murine tumors, another feature of human leiomyosarcomas. Immunohistochemical analyses of USP18 in human leiomyosarcomas revealed a range of staining intensities with the highest USP18 expression in normal vascular smooth muscle. USP18 tissue array analysis of primary leiomyosarcomas from 89 patients with a clinical database revealed cases with reduced USP18 levels had a significantly decreased time to metastasis (P = 0.0441). CONCLUSIONS: USP18 null mice develop leiomyosarcoma recapitulating key features of clinical leiomyosarcomas and patients with reduced-USP18 tumor levels have an unfavorable outcome. USP18 null mice and the derived cell lines represent clinically-relevant models of leiomyosarcoma and can provide insights into both leiomyosarcoma biology and therapy.

Contemporary Management of Retroperitoneal Soft Tissue Sarcomas.

Management of retroperitoneal soft tissue sarcomas (RP STS) can be very challenging. In contrast to the more common extremity STS, the two predominant histologic subtypes encountered in the retroperitoneum are well-differentiated/dedifferentiated liposarcoma and leiomyosarcoma. Surgery remains the mainstay of treatment for RP STS. Preoperative planning and anticipation of the need for resection of adjacent organs/structures are critical. The extent of surgery, including the role of compartmental resection, is still controversial. Radiation therapy may be an important adjunct to surgery to provide locoregional disease control; this is currently being evaluated in the preoperative setting in the EORTC STRASS trial. Systemic therapy, tailored to the specific histologic subtype, may also be of benefit for the management of RP STS. Further investigation of novel therapies (e.g., targeted therapies, immunotherapy) is needed. Overall, multi-institutional collaboration is important moving forward, to continue to better understand and optimize management of this disease.

Estrogen receptor alpha and androgen receptor are commonly expressed in well-differentiated liposarcoma.

BACKGROUND: Liposarcoma (LS) is the second-most common type of soft-tissue sarcoma. Despite advances in knowledge and treatment of this disease, there remains a need for more effective LS therapy. Steroid hormone receptors regulate metabolism in adipocytes. Estrogen receptor alpha (ER), progesterone receptor (PR), and androgen receptor (AR) have been implicated in the pathophysiology of other cancer types. We sought to comprehensively determine temporal expression patterns of these receptors in LS. METHODS: We analyzed 561 histologically subtyped LS specimens from 354 patients for expression of ER, PR, and AR by immunohistochemistry (IHC) using diagnostic-grade reagents and protocols. The fractions of positively stained tumor cells were scored within each specimen. IHC scores were compared across LS subtypes using the Kruskal-Wallis test, and subtypes were compared using Dunn's post-hoc test. Ages of patients with receptor-positive vs. -negative LS were compared by t-test. Genders and races were compared for hormone receptor positivity using Fisher's exact test and Chi-square analysis, respectively. Recurrence-free survival was compared between receptor-positive and negative patients by log-rank test. p< 0.05 was considered significant. RESULTS: ER and AR were frequently expressed in LS, while few tumors expressed PR. Most of the ER + and AR + samples were of the well-differentiated LS subtype. A smaller fraction of de-differentiated LS expressed ER or AR, but expression was common within well-differentiated regions of tumors histologically classified as de-differentiated LS. In LS specimens from patients who underwent multiple surgeries over time, receptor expression frequently changed over time, which may be attributable in part to intratumor heterogeneity, varying degrees of de-differentiation, and biopsy bias. ER and AR were frequently co-expressed. Receptor status was not significantly associated with gender or race, but AR and PR expression were associated with earlier age at diagnosis. Receptor expression was not associated with altered recurrence-free survival. CONCLUSIONS: ER and AR are commonly expressed in LS, particularly in well-differentiated tumors. These data warrant further functional study to determine receptor function in LS, and the potential efficacy of anti-hormone therapies for the treatment of patients with LS.

A proof of principle clinical trial to determine whether conjugated linoleic acid modulates the lipogenic pathway in human breast cancer tissue.

Conjugated linoleic acid (CLA) is widely used as a "nutraceutical" for weight loss. CLA has anticancer effects in preclinical models, and we demonstrated in vitro that this can be attributed to the suppression of fatty acid (FA) synthesis. We tested the hypothesis that administration of CLA to breast cancer patients would inhibit expression of markers related to FA synthesis in tumor tissue, and that this would suppress tumor proliferation. Women with Stage I-III breast cancer were enrolled into an open label study and treated with CLA (1:1 mix of 9c,11t- and 10t,12c-CLA isomers, 7.5 g/d) for ≥ 10 days before surgery. Fasting plasma CLA concentrations measured pre- and post-CLA administration, and pre/post CLA tumor samples were examined by immunohistochemistry for Spot 14 (S14), a regulator of FA synthesis, FA synthase (FASN), an enzyme of FA synthesis, and lipoprotein lipase (LPL), the enzyme that allows FA uptake. Tumors were also analyzed for expression of Ki-67 and cleaved caspase 3. 24 women completed study treatment, and 23 tumors were evaluable for the primary endpoint. The median duration of CLA therapy was 12 days, and no significant toxicity was observed. S14 expression scores decreased (p = 0.003) after CLA administration. No significant change in FASN or LPL expression was observed. Ki-67 scores declined (p = 0.029), while cleaved caspase 3 staining was unaffected. Decrements in S14 or Ki-67 did not correlate with fasting plasma CLA concentrations at surgery. Breast tumor tissue expression of S14, but not FASN or LPL, was decreased after a short course of treatment with 7.5 g/day CLA. This was accompanied by reductions in the proliferation index. CLA consumption was well-tolerated and safe at this dose for up to 20 days. Overall, CLA may be a prototype compound to target fatty acid synthesis in breast cancers with a "lipogenic phenotype".

Kinase Mutations and Imatinib Response in Patients With Metastatic Gastrointestinal Stromal Tumor.

PURPOSE: Most gastrointestinal stromal tumors (GISTs) express constitutively activated mutant isoforms of KIT or kinase platelet-derived growth factor receptor alpha (PDGFRA) that are potential therapeutic targets for imatinib mesylate. The relationship between mutations in these kinases and clinical response to imatinib was examined in a group of patients with advanced GIST. PATIENTS AND METHODS: GISTs from 127 patients enrolled onto a phase II clinical study of imatinib were examined for mutations of KIT or PDGFRA. Mutation types were correlated with clinical outcome. RESULTS: Activating mutations of KIT or PDGFRA were found in 112 (88.2%) and six (4.7%) GISTs, respectively. Most KIT mutations involved exon 9 (n = 23) or exon 11 (n = 85). All KIT mutant isoforms, but only a subset of PDGFRA mutant isoforms, were sensitive to imatinib, in vitro. In patients with GISTs harboring exon 11 KIT mutations, the partial response rate (PR) was 83.5%, whereas patients with tumors containing an exon 9 KIT mutation or no detectable mutation of KIT or PDGFRA had PR rates of 47.8% (P = .0006) and 0.0% (P < .0001), respectively. Patients whose tumors contained exon 11 KIT mutations had a longer event-free and overall survival than those whose tumors expressed either exon 9 KIT mutations or had no detectable kinase mutation. CONCLUSION: Activating mutations of KIT or PDGFRA are found in the vast majority of GISTs, and the mutational status of these oncoproteins is predictive of clinical response to imatinib. PDGFRA mutations can explain response and sensitivity to imatinib in some GISTs lacking KIT mutations.

Use of MRI in preoperative planning for women with newly diagnosed DCIS: risk or benefit?

BACKGROUND: The role of magnetic resonance imaging (MRI) in preoperative planning for women diagnosed with breast cancer remains controversial. The risks and benefits in women with newly diagnosed ductal carcinoma in situ (DCIS) are largely unknown. PATIENTS AND METHODS: Retrospective chart review comparing women treated for DCIS who did and did not undergo MRI for preoperative planning. End points included number of additional biopsies prompted by MRI, surgical reexcision rates, weight of excisions, mastectomy rates, and conversion to mastectomy after attempted breast conservation. RESULTS: 218 patients met study criteria. Sixty-four patients did not undergo preoperative MRI, and 154 patients did. There was no statistically significant difference (P = not significant, NS) in reexcision rates between the 34.1 % (42/123) of women who did and 20/51 (39.2 %) women who did not undergo MRI. Despite use of preoperative MRI, 11/123 women (8.9 %) were converted to mastectomy due to positive margins compared with 4/51 (7.8 %) in the women who did not undergo MRI (P = NS). In women undergoing MRI, average weight of excision at definitive surgery was 49.5 g, while in women who did not undergo MRI, average weight of excision at definitive surgery was 48.7 g. CONCLUSIONS: Our data show that MRI does not significantly decrease reexcision rates or conversion to mastectomy after attempted breast-conservation surgery. Based on our findings, we do not believe preoperative MRI adds benefit to the care of this patient population. Prospective trials are necessary to further investigate the risks and benefits of preoperative MRI in women with DCIS.

Phase II trial of neoadjuvant/adjuvant imatinib mesylate for advanced primary and metastatic/recurrent operable gastrointestinal stromal tumors: long-term follow-up results of Radiation Therapy Oncology Group 0132.

BACKGROUND: Imatinib inhibits the KIT and PDGFR tyrosine kinases, resulting in its notable antitumor activity in gastrointestinal stromal tumor (GIST). We previously reported the early results of a multi-institutional prospective trial (RTOG 0132) using neoadjuvant/adjuvant imatinib either in primary resectable GIST or as a planned preoperative cytoreduction agent for metastatic/recurrent GIST. METHODS.: Patients with primary GIST (≥5 cm, group A) or resectable metastatic/recurrent GIST (≥2 cm, group B) received neoadjuvant imatinib (600 mg/day) for approximately 2 months and maintenance postoperative imatinib for 2 years. We have now updated the clinical outcomes including progression-free survival, disease-specific survival, and overall survival at a median follow-up of 5.1 years, and we correlate these end points with duration of imatinib therapy. RESULTS: Sixty-three patients were originally entered (53 analyzable: 31 in group A and 22 in group B). Estimated 5-year progression-free survival and overall survival were 57% in group A, 30% in group B; and 77% in group A, 68% in group B, respectively. Median time to progression has not been reached for group A and was 4.4 years for group B. In group A, in 7 of 11 patients, disease progressed >2 years from registration; 6 of 7 patients with progression had stopped imatinib before progression. In group B, disease progressed in 10 of 13 patients>2 years from registration; 6 of 10 patients with progressing disease had stopped imatinib before progression. There was no significant increase in toxicity compared with our previous short-term analysis. CONCLUSIONS: This long-term analysis suggests a high percentage of patients experienced disease progression after discontinuation of 2-year maintenance imatinib therapy after surgery. Consideration should be given to studying longer treatment durations in intermediate- to high-risk GIST patients.

Programmatic Efforts Increase Adoption of Genomic Precision Medicine in Cancer Care in a Community Cancer Center.

PURPOSE: The adoption of precision medicine (PMed) depends on the critical curation of data and interpretation of genomic results. Herein, we sought to study the effect of a coordinated multidisciplinary program to assess results in a community cancer center clinic. METHODS: In a retrospective review from July 2018 to July 2021, we analyzed the implementation of a multidisciplinary PMed program in a tertiary referral community cancer center. Germline genetics test results have been reviewed since 2017. RESULTS: A total of 3,131 tumor samples were analyzed by large panel somatic genomic testing through commercial laboratories during the study period. The number of reviewed cases rose from 661 in the first year to 1,532 in year 3. Additional recommendations beyond what was reported by the commercial laboratory were made in 42.9% of cases. Referrals to the hereditary cancer program for germline testing increased by 32% from the 2017 baseline. Process improvement efforts reduced the rate of DNA quantity nonsufficient for testing to 3.3% compared with a national average of 4.89%. The average time from receipt of orders to issuing of a report of the somatic panel was 15.5 days, compared with 19.1 days for other institutions using the same laboratory. The PMed team has been critical in support of clinical research by assisting in trial procurement and feasibility assessment to the identification of patients for clinical trials. CONCLUSION: The use of somatic genomic testing is increasing at our cancer center. Education and in-depth analysis of the data are valued by cancer physicians. The development and implementation of a PMed program has demonstrated improved physicians' understanding of molecular testing, resulting in improved outcomes for patients.

Transcriptional Profiling of Malignant Melanoma Reveals Novel and Potentially Targetable Gene Fusions.

Invasive melanoma is the deadliest type of skin cancer, with 101,110 expected cases to be diagnosed in 2021. Recurrent BRAF and NRAS mutations are well documented in melanoma. Biologic implications of gene fusions and the efficacy of therapeutically targeting them remains unknown. Retrospective review of patient samples that underwent next-generation sequencing of the exons of 592 cancer-relevant genes and whole transcriptome sequencing for the detection of gene fusion events and gene expression profiling. Expression of PDL1 and ERK1/2 was assessed by immunohistochemistry (IHC). There were 33 (2.6%) cases with oncogenic fusions (14 novel), involving BRAF, RAF1, PRKCA, TERT, AXL, and FGFR3. MAPK pathway-associated genes were over-expressed in BRAF and RAF1 fusion-positive tumors in absence of other driver alterations. Increased expression in tumors with PRKCA and TERT fusions was concurrent with MAPK pathway alterations. For a subset of samples with available tissue, increased phosphorylation of ERK1/2 was observed in BRAF, RAF1, and PRKCA fusion-positive tumors. Oncogenic gene fusions are associated with transcriptional activation of the MAPK pathway, suggesting they could be therapeutic targets with available inhibitors. Additional analyses to fully characterize the oncogenic effects of these fusions may support biomarker driven clinical trials.

Adjuvant and neoadjuvant imatinib therapy: current role in the management of gastrointestinal stromal tumors.

Although surgery remains the mainstay for the treatment of primary gastrointestinal stromal tumors (GIST), a significant number of patients experience disease recurrence within 5 years of surgery. The emergence of imatinib therapy for the treatment of patients with advanced GIST has offered unprecedented improvements in clinical outcomes for these patients. Prospective clinical trials have supported the efficacy and safety of imatinib before and after surgical resection of GIST. The American College of Surgeons Oncology Group Z9001 pivotal trial revealed that 1 year of adjuvant imatinib therapy provides significantly superior recurrence-free survival in patients with GIST after surgical resection, when compared to placebo. Additional trials and case studies have also begun to define the potential clinical benefit of imatinib in the neoadjuvant setting. Optimized risk stratification paradigms will be required to ensure the appropriate selection of patients to undergo treatment with imatinib in these settings. Risk stratification schemes are evolving that potentially will include mutation status and tumor rupture, and predictive nomograms have recently been proposed. The recent European Society of Medical Oncology and National Comprehensive Cancer Network guidelines mention use of adjuvant imatinib for ≥ 1 year in patients with KIT(+) , resectable GIST at high risk of recurrence. Moreover, the guidelines support the use of neoadjuvant imatinib in cases of limited disease if it would facilitate less extensive surgery and organ sparing. This article reviews pivotal efficacy and safety data for adjuvant imatinib and explores the potential clinical benefit of neoadjuvant imatinib in patients with GIST.

Insulin-like growth factor 1 receptor is a potential therapeutic target for gastrointestinal stromal tumors.

A subset of gastrointestinal stromal tumors (GISTs) lack gain-of-function mutations in c-KIT and PDGFRalpha. These so-called wild-type (WT) GISTs tend to be less responsive to imatinib-based therapies and have a poor prognosis. We identified amplification of IGF1R in a SNP analysis of GIST and thus studied its potential as a therapeutic target in WT and mutant GIST. Expression of IGF1R and downstream effectors in clinical GIST samples was examined by using immunoblots and immunohistochemistry. The roles of IGF1R signaling in GIST and viability were analyzed by using NVP-AEW541, an inhibitor of IGF1R, alone and in combination with imatinib, or via siRNA silencing of IGF1R. IGF1R was strongly overexpressed, and IGF1R amplification was detected at a significantly higher frequency in WT GISTs, including a pediatric WT GIST, compared with mutant GISTs (P = 0.0173 and P = 0.0163, respectively). Inhibition of IGF1R activity in vitro with NVP-AEW541 or down-regulation of expression with siIGF1R led to cytotoxicity and induced apoptosis in GIST cell lines via AKT and MAPK signaling. Combination of NVP-AEW541 and imatinib in GIST cell lines induced a strong cytotoxicity response. Our results reveal that IGF1R is amplified and the protein is overexpressed in WT and pediatric GISTs. We also demonstrate that the aberrant expression of IGF1R may be associated with oncogenesis in WT GISTs and suggest an alternative and/or complementary therapeutic regimen in the clinical management of all GISTs, especially in a subset of tumors that respond less favorably to imatinib-based therapy.

Molecular genomic profiling of adrenocortical cancers in clinical practice.

BACKGROUND: At presentation, 21% to 49% of patients with adrenocortical cancer have metastases. Standard chemotherapy has a 23% response rate. We assessed whether next generation sequencing could elucidate additional treatment options in refractory adrenocortical cancer. METHODS: Retrospective analysis using a commercial, 592-gene DNA-based panel was performed of next generation sequencing data from 94 adrenocortical cancer tumors profiled for clinical care. We compared our data to the adrenocortical cancer database of The Cancer Genome Atlas containing survival data. We evaluated mutations, indels, amplifications, tumor mutation burden, microsatellite instability, and programmed death-ligand 1 protein expression. RESULTS: Our cohort included 54 primary neoplasms and 40 metastatic lesions. The most frequently mutated genes were TP53 (36%) and CTNNB1 (19%). Low prevalence mutations were noted in 37 genes including DNA damage repair genes in 15 samples. High tumor mutation burden was seen in 3 patients, and programmed death-ligand 1 was positive in 12. Potential targets to Food and Drug Administration-approved drugs were seen in 16% of cases. CONCLUSION: DNA sequencing panel tests may identify therapeutic options for some patients with adrenocortical cancer. TP53 and mutations were associated with an adverse outcome. An expanded repertoire of drugs and, perhaps, more expansive multi-omic sequencing are needed to advance the treatment of adrenocortical cancer.

Role of surgery combined with kinase inhibition in the management of gastrointestinal stromal tumor (GIST).

BACKGROUND: Surgery is the standard treatment for primary, gastrointestinal stromal tumor (GIST); however, surgical resection often is not curative, particularly in large GIST. Five years after complete removal of their tumor, approximately half of treated patients relapse. Imatinib, an oral tyrosine kinase inhibitor (TKI), is first-line treatment in patients with metastatic or unresectable GIST. It has resulted in durable objective responses or stable disease in 84% of patients and is well tolerated. The efficacy of imatinib in advanced GIST has created interest in a variety of potential multimodal approaches to management that combine surgery with systemic therapy. RESULTS: Recently, a large, randomized, Phase III, US cooperative group trial that compared adjuvant imatinib, for 1 year after primary complete surgical resection, with placebo in primary GIST, reported a significantly shorter time to relapse for those in the placebo group. This led to the approval of imatinib for this new indication in the US and Europe. Several studies evaluating the efficacy of adjuvant imatinib in patients with primary GIST who are at high risk for postoperative relapse are ongoing; in particular two large European studies are expected to yield preliminary results in the near future. Neoadjuvant therapy with imatinib is also being investigated for its effect on surgical outcomes, with first trial results reported. CONCLUSION: This article provides an update on the rapidly evolving role of surgery, treatment with TKI therapy, and their combination in the management of GIST as well as further reviews pertinent to current clinical research findings.

High density DNA array analysis reveals distinct genomic profiles in a subset of gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) generally harbor activating mutations in KIT or platelet-derived growth facter receptor (PDGFRA). Mutations in these receptor tyrosine kinases lead to dysregulation of downstream signaling pathways that contribute to GIST pathogenesis. GISTs with KIT or PDGFRA mutations also undergo secondary cytogenetic alterations that may indicate the involvement of additional genes important in tumor progression. Approximately 10-15% of adult and 85% of pediatric GISTs do not have mutations in KIT or in PDGFRA. Most mutant adult GISTs display large-scale genomic alterations, but little is known about the mutation-negative tumors. Using genome-wide DNA arrays, we investigated genomic imbalances in a set of 31 GISTs, including 10 KIT/PDGFRA mutation-negative tumors from nine adults and one pediatric case and 21 mutant tumors. Although all 21 mutant GISTs exhibited multiple copy number aberrations, notably losses, eight of the 10 KIT/PDGFRA mutation-negative GISTs exhibited few or no genomic alterations. One KIT/PDGFRA mutation-negative tumor exhibiting numerous genomic changes was found to harbor an alternate activating mutation, in the serine-threonine kinase BRAF. The only other mutation-negative GIST with significant chromosomal imbalances was a recurrent metastatic tumor found to harbor a homozygous deletion in chromosome arm 9p. Similar findings in several KIT-mutant GISTs identified a minimal overlapping region of deletion of approximately 0.28 Mbp in 9p21.3 that includes only the CDKN2A/2B genes, which encode inhibitors of cell-cycle kinases. These results suggest that GISTs without activating kinase mutations, whether pediatric or adult, generally exhibit a much lower level of cytogenetic progression than that observed in mutant GISTs.

Complete response with talimogene laherparepvec in recurrent melanoma of the ear: A case report.

The current standard of care for cutaneous melanoma of the ear is surgical excision. This approach may result in unfavorable functional and cosmetic outcomes. We report here a case of recurrent melanoma of the ear that achieved complete response with talimogene laherparepvec treatment after the patient declined surgical resection.

Molecular profiling of melanoma brain metastases compared to primary cutaneous melanoma and to extracranial metastases.

BACKGROUND: Brain metastases are a significant cause of mortality and morbidity for patients with melanoma. We hypothesize that the development of brain metastases may be explained by molecular heterogeneity between primary cutaneous melanoma (PCM) or extracranial (ECM) and brain (MBM) melanoma metastases. MATERIALS AND METHODS: We compared next-generation sequencing, tumor mutational burden (TMB), and immunohistochemical staining for PD-L1 expression, among 132 MBM, 745 PCM, and 1190 ECM. RESULTS: The most common genetic alterations among MBM included: BRAF (52.4%), NRAS (26.6%), CDKN2A (23.3%), NF1 (18.9%), TP53 (18%), ARID2 (13.8%), SETD2 (11.9%), and PBRM1 (7.5%). Four genes were found with higher frequency among MBM compared to PCM or ECM: BRAF (52.4% v 40.4% v 40.9%), SETD2 (11.9% v 1.9% v 3.9%), PBRM1 (7.5% v 1.6% v 2.6%), and DICER1 (4.4% v 0.6% v 0.4%). MBM showed higher TMB (p = .04) and higher PD-L1 expression (p = .002), compared to PCM. PD-L1 expression was slightly higher among MBM compared to ECM (p = .042), but there was no difference between TMB (p = .21). CONCLUSIONS: Our findings suggest a unique molecular profile for MBM, including higher rates of BRAF mutations, higher TMB and higher PD-L1 expression, and also implicate chromatin remodeling in the pathogenesis of MBM.

Conjugated linoleic acid (CLA) inhibits expression of the Spot 14 (THRSP) and fatty acid synthase genes and impairs the growth of human breast cancer and liposarcoma cells.

Spot 14 (THRSP, S14) is a nuclear protein involved in the regulation of genes required for fatty acid synthesis in normal and malignant mammary epithelial and adipose cells. Harvatine and Bauman (1) reported that conjugated linoleic acid (CLA) inhibits S14 gene expression in bovine mammary and mouse adipose tissues and reduces milk fat production in cows. We hypothesized that CLA inhibits S14 gene expression in human breast cancer and liposarcoma cells and that this will retard their growth. Exposure of T47D breast cancer cells to a mixture of CLA isomers reduced the expression of the S14 and fatty acid synthase (FAS) genes. The mixture caused a dose-related inhibition of T47D cell growth, as did pure c9, t11 and t10, c12-CLA, but not linoleic acid. Similar effects were observed in MDA-MB-231 breast cancer cells. Provision of 8 mircoM palmitate fully (CLA mix, t10, c12-CLA) or partially (c9, t11-CLA) reversed the antiproliferative effect in T47D cells. CLA likewise suppressed levels of S14 and FAS mRNAs in liposarcoma cells and caused growth inhibition that was prevented by palmitic acid. CLA did not affect the growth of nonlipogenic HeLa cells or human fibroblasts. We conclude that as in bovine mammary and mouse adipose cells, CLA suppresses S14 and FAS gene expression in human breast cancer and liposarcoma cells. Rescue from the antiproliferative effect of CLA by palmitic acid indicates that reduced tumor lipogenesis is a major mechanism for the anticancer effects of CLA.