Does brain radiotherapy and lactate dehydrogenase (LDH) levels affect the prognosis of melanoma with brain metastases?

Objective: The prognosis of patients with advanced melanoma is poor, especially for those with brain metastases. Currently, there is no standard treatment regimen for patients with brain metastases in the later lines of therapy. The purpose of this study was to explore the prognostic factors for patients with advanced melanoma and brain metastases, focusing on the prognostic value of baseline lactate dehydrogenase (LDH) levels and brain radiotherapy in these patients. Materials and Methods: A total of 145 patients with melanoma and brain metastases who were admitted between December 2015 and August 2024 were consecutively enrolled. LDH levels before the treatment of brain metastases were retrospectively collected. Patients with LDH > 250 U/L (upper limit of normal) were defined as the High LDH group, and those with LDH ≤ 250 U/L were defined as the Normal LDH group. Clinical information such as whether the patients received local intensity-modulated radiotherapy (IMRT) for the brain, immunotherapy, chemotherapy, targeted therapy, MET inhibitor targeted therapy, the number of treatment lines received at the time of brain metastases, and the presence of symptoms were collected. Regression models were used to examine the prognostic factors affecting overall survival (OS) and progression-free survival (PFS). The analyses were performed using SPSS software version 21.0. Results: The median OS was 6.7 months (range: 0.4 to 101 months). Ninety-two patients (63.4%) received local brain IMRT, and 53 patients (46.6%) did not. The multivariate Cox regression model showed that receiving local brain IMRT (P=0.010, P=0.019), having normal LDH levels (LDH < 250 U/L) before the treatment of brain metastases (P < 0.001, P = 0.037), and receiving ≤3 lines of treatment for brain metastases (P = 0.004, P = 0.015) were factors that improved OS and PFS. Additionally, the absence of central nervous system symptoms at the time of brain metastases was a factor that improved OS (P = 0.001), but its impact on PFS did not reach statistical significance. Patients with LDH < 250 U/L before the treatment of brain metastases and who received local brain IMRT had better OS and PFS (P < 0.001). Conclusion: LDH levels before the treatment of brain metastases can predict OS and PFS in patients with melanoma and brain metastases. Local brain radiotherapy seems to improve OS and PFS in these patients. Receiving more than 3 lines of treatment for brain metastases affects OS. The presence of central nervous system symptoms before treatment affects OS in these patients.