Survival in melanoma brain metastases in the era of novel systemic therapies

Anti-tumor treatment and healthcare consumption near death in the era of novel treatment options for patients with melanoma brain metastases

Background

Effective systemic treatments have revolutionized the management of patients with metastatic melanoma, including those with brain metastases. The extent to which these treatments influence disease trajectories close to death is unknown. Therefore, this study aimed to gain insight into provided treatments and healthcare consumption during the last 3 months of life in patients with melanoma brain metastases.

Methods

Retrospective, single-center study, including consecutive patients with melanoma brain metastases diagnosed between June-2015 and June-2018, referred to the medical oncologist, and died before November-2019. Patient and tumor characteristics, anti-tumor treatments, healthcare consumption, presence of neurological symptoms, and do-not-resuscitate status were extracted from medical charts.

Results

100 patients were included. A BRAF-mutation was present in 66 patients. Systemic anti-tumor therapy was given to 72% of patients during the last 3 months of life, 34% in the last month, and 6% in the last week. Patients with a BRAF-mutation more frequently received systemic treatment during the last 3 (85% vs. 47%) and last month (42% vs. 18%) of life than patients without a BRAF-mutation. Furthermore, patients receiving systemic treatment were more likely to visit the emergency room (ER, 75% vs. 36%) and be hospitalized (75% vs. 36%) than those who did not.

Conclusion

The majority of patients with melanoma brain metastases received anti-tumor treatment during the last 3 months of life. ER visits and hospitalizations occurred more often in patients on anti-tumor treatment. Further research is warranted to examine the impact of anti-tumor treatments close to death on symptom burden and care satisfaction.

In Vivo Visualized Tracking of Tumor-Derived Extracellular Vesicles Using CRISPR-Cas9 System

Introduction: Tumor extracellular vesicles (EVs) and their relevance to various processes of tumor growth have been vigorously investigated over the past decade. However, obtaining direct evidence of spontaneous EV transfer in vivo remains challenging. In our previous study, a single-guide RNA (sgRNA): Cas9 ribonucleoprotein complex, which can efficiently delete target genes, was delivered into recipient cells using an engineered EV. Aim: Applying this newly discovered exosomal bio-cargo to track the uptake and distribution of tumor EVs. Methods: Tumor cells of interest were engineered to express and release the sgRNA:Cas9 complex, and a reporter cell/system containing STOP-fluorescent protein (FP) elements was also generated. EV-delivered Cas9 proteins from donor cells were programmed by a pair of sgRNAs to completely delete a blockade sequence and, in turn, recuperated the expression of FP in recipient reporter cells. Thus, fluorescently illuminated cells indicate the uptake of EVs. To improve the efficiency and sensitivity of this tracking system in vivo, we optimized the sgRNA design, which could more efficiently trigger the expression of reporter proteins. Results: We demonstrated the EV-mediated crosstalk between tumor cells, and between tumor cells and normal cells in vitro. In vivo, we showed that intravenously administered EVs can be taken up by the liver. Moreover, we showed that EVs derived from melanoma xenografts in vivo preferentially target the brain and liver. This distribution resembles the manifestation of organotrophic metastasis of melanoma. Conclusion: This study provides an alternative tool to study the distribution and uptake of tumor EVs.