Evaluation of GPA, molGPA and prognostic factors in melanoma brain metastases: a single-center study

Background Malignant melanoma ranks among the leading causes of brain metastases (BM). The Graded Prognostic Assessment (GPA) and the melanoma-specific molecular GPA (molGPA) are well-established prognostic tools that help estimate survival and guide therapeutic decisions. This single-center, retrospective clinical study aimed to evaluate prognostic factors for overall survival (OS), intracranial tumor control (IC), and intracranial progression-free survival (IPFS), as well as GPA and molGPA within a real-world clinical setting. Methods Patients with melanoma-associated BM who underwent radiotherapy (RT) between January 2016 and December 2023 were included. Study endpoints included OS, IC, and IPFS, with OS and IPFS analyzed across the entire cohort ( n = 59) and IC was evaluated in cases with follow-up imaging ( n = 47). Results The median survival of all patients was 6.9 months (IQR 2.2; 23.6). Regarding OS, three predictive factors were significantly associated with the survival probability: a Karnofsky performance status index (KPS) <70 ( p = 0.003), a GPA score of 0–1.0 versus 1.5–4.0 ( p = 0.002) and a molGPA score of 0–1.0 versus 1.5–4.0 ( p = 0.034). Intracranial progression-free survival was significantly decreased in patients with KPS <70 ( p = 0.01), multiple brain metastases ( p = 0.036), and GPA scores of 0–1.0 ( p = 0.011). Conclusions Both GPA and molGPA were validated as significant predictors of OS in patients with melanoma-associated BM. However, GPA emerged as the sole score significantly associated with both OS and IPFS, suggesting a potential advantage in its clinical utility. The validation of GPA and molGPA as significant predictors for OS in a real clinical setting support their use in guiding treatment recommendations.