Circulating tumor DNA (ctDNA) in the blood plasma of cancer patients is an emerging biomarker used across oncology, facilitating noninvasive disease monitoring and genetic profiling at various ...disease milestones. Digital droplet PCR (ddPCR) technologies have demonstrated high sensitivity and specificity for robust ctDNA detection at relatively low costs. Yet, their value for ctDNA-based management of a broad population of cancer patients beyond clinical trials remains elusive.
We developed mutation-specific ddPCR assays that were optimized for their use in real-world cancer management, covering 12 genetic aberrations in common cancer genes, such as
,
,
,
, and
. We assessed the limit of detection (LOD) and the limit of blank (LOB) for each assay and validated their performance for ctDNA detection using matched tumor sequencing.
We applied our custom ddPCR assays to 352 plasma samples from 96 patients with solid tumors. Mutation detection in plasma was highly concordant with tumor sequencing, demonstrating high sensitivity and specificity across all assays. In 20 cases, radiographic cancer progression was mirrored by an increase of ctDNA concentrations or the occurrence of novel mutations in plasma. Moreover, ctDNA profiling at diagnosis and during disease progression reflected personalized treatment selection through the identification of actionable gene targets in 20 cases.
Collectively, our work highlights the potential of ctDNA assessment by sensitive ddPCR for accurate disease monitoring, robust identification of resistance mutations, and upfront treatment selection in patients with solid tumors. We envision an increasing future role for ctDNA profiling within personalized cancer management in daily clinical routine.
MicroRNAs (miR) are small noncoding RNAs that regulate gene expression, posttranscription, and manipulate immune responses in different types of cancers. In this study, we identify miR-146a as a ...negative regulator of immune activation, comparable to immune-checkpoint molecules. miR-146a levels were increased in melanoma microenvironmental tissue, and
mice survived longer and developed less metastases in comparison with wild-type melanoma-bearing mice. T cells isolated from
mice revealed higher expression levels of the miR-146a target gene Stat1 and the Stat1-regulated cytokine IFNγ. Neutralization of IFNγ in
mice decreased survival and increased melanoma metastasis patterns to those of wild-type mice.
, IFNγ reduced melanoma cell migration, cell-cycle activity, and basal metabolic rate. Conversely, IFNγ also increased PD-L1 levels on the melanoma cells, which may counterbalance some of the beneficial effects increasing immune escape
. Combined treatment with a miR-146a antagomiR and anti-PD-1 resulted in improved survival over isotype control or anti-PD-1 treatment alone. In summary, these data show that miR-146a plays a central role within the STAT1/IFNγ axis in the melanoma microenvironment, affecting melanoma migration, proliferation, and mitochondrial fitness as well as PD-L1 levels. Additionally, combined inhibition of PD-1 and miR-146a could be a novel strategy to enhance antitumor immune response elicited by checkpoint therapy. SIGNIFICANCE: These findings identify a microRNA-based mechanism by which melanoma cells escape the immune system, providing a new therapeutic strategy to improve the current management of patients with melanoma.
Systemic immunotherapy with PD-1 inhibitors is established in the treatment of metastatic melanoma. However, up to 60% of patients do not show long-term benefit from a PD-1 inhibitor monotherapy. ...Intralesional treatments with immunomodulatory agents such as the oncolytic herpes virus Talimogene Laherparepvec and interleukin-2 (IL-2) have been successfully used in patients with injectable metastases. Combination therapy of systemic and local immunotherapies is a promising treatment option in melanoma patients. We describe a case series of nine patients with metastatic melanoma and injectable lesions who developed progressive disease under a PD-1 inhibitor monotherapy. At the time of progressive disease, patients received intratumoral IL-2 treatment in addition to PD-1 inhibitor therapy. Three patients showed complete, three patients partial response and three patients progressive disease upon this combination therapy. IHC stainings were performed from metastases available at baseline (start of PD-1 inhibitor) and under combination therapy with IL-2. IHC results revealed a significant increase of CD4
+
and CD8
+
T cells and a higher PD-1 expression in the inflammatory infiltrate of the tumor microenvironment in metastases from patients with subsequent treatment response. All responding patients further showed a profound increase of the absolute eosinophil count (AEC) in the blood. Our case series supports the concept that patients with initial resistance to PD-1 inhibitor therapy and injectable lesions can profit from an additional intralesional IL-2 therapy which was well tolerated. Response to this therapy is accompanied by increase in AEC and a strong T cell-based inflammatory infiltrate.
Background
Ipilimumab and programmed death (PD) 1-antibodies are effective treatment options in metastatic melanoma. The safety and efficacy of ipilimumab in patients with pre-existing autoimmune ...disorders (AD) has only been evaluated in a selected number of patients.
Methods
We performed a retrospective analysis in 14 German skin cancer centers for patients with metastatic melanoma and pre-existing AD treated with ipilimumab.
Results
41 patients with 44 pre-existing AD were treated with ipilimumab (thyroiditis
n
= 15, rheumatoid
n
= 11, dermatologic
n
= 10, Crohn’s disease/ulcerative colitis
n
= 3, neurological
n
= 2, sarcoidosis
n
= 2, pancreatitis
n
= 1). 3 out of 41 patients had two AD, 11 patients required immunosuppressants at the time of induction of ipilimumab. 12 patients (29.2%) experienced a flare of their pre-existing AD, mainly patients with rheumatoid or dermatologic diseases. Additional immune-related adverse events (irAEs) occurred in 12 patients (29.2%). In 23 patients (56%) neither a change of their AD nor additional irAEs were observed. Objective responses were seen in five patients (one complete remission, four partial remissions, 12.1%).
Conclusion
This is the largest series of patients with pre-existing AD and treatment with ipilimumab reported. Flares of pre-existing AD were observed but manageable. Response rates and occurrence of new irAEs were comparable to previous trials. Thus, in this patient subgroup, ipilimumab can be a treatment option after a thorough discussion of pros and cons and taking severity and activity of the preexisting AD into account.
Cobimetinib (GDC-0973, XL518) Andrlová, Hana; Zeiser, Robert; Meiss, Frank
Recent results in cancer research,
2018, Letnik:
211
Journal Article
Recenzirano
The mitogen-activated protein kinase cascade (MAPK/ERK pathway) is a signaling pathway activated as a cellular response to various stimuli and for regulating the proliferation and survival of several ...types of eukaryotic cells, among others a wide variety of tumor cells. Mutations of the proteins involved in this pathway have been discovered in several tumor entities, indicating their inhibition as a potential therapeutic target. BRAF inhibitors have been in the clinical use since 2011. Several MEK inhibitors have been studied for metastatic cancer treatment in the recent past. After trametinib, cobimetinib is another potent, selective oral MEK1/2 inhibitor that was approved by European Medicine Agency (EMA) and Food and Drug Administration (FDA) in 2015 for treatment of malignant melanoma in a combination with the BRAF inhibitor vemurafenib.
The enzyme indoleamine 2,3-dioxygenase (IDO) is emerging as a facilitator of cancer development through its effects on cancer-associated inflammation. Recent studies report a significant improvement ...of the response rates in melanoma patients to PD-1 antibodies when IDO inhibitors were added to the regimen. Data on IDO expression in primary human melanomas are, however, incomplete and conflicting. Here, we show that the level of IDO expression in primary human melanoma cells significantly correlates with Breslow thickness (P = 0.003), the presence of tumor-infiltrating lymphocytes (P = 0.029), and the intensity of the peritumoral inflammatory infiltrate (P = 0.001). The expression of IDO in melanoma cells predicted independently of Breslow thickness and tumor stage (P = 0.04). We further show that CD11c+ dendritic cells and CD68+ macrophages in the microenvironment of melanomas express IDO. The level of IDO expression in antigen-presenting cells correlated positively to peritumoral inflammation (P = 0.001) but not to tumor-infiltrating lymphocytes. Significant negative correlation with progression-free survival was found for patients for whom antigen-presenting cells were very strongly IDO positive. These results suggest that IDO induction within melanoma cells may directly reflect tumor progression, whereas IDO in antigen-presenting cells may determine immune surveillance with impact on local and systemic tolerance.
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