Survival by radiation therapy oncology group recursive partitioning analysis class and treatment modality in patients with brain metastases from malignant melanoma: a retrospective study

Abstract

Background: In a population of patients with brain metastases from melanoma, the authors sought to determine whether various therapies provided any benefit at all, whether local therapy was better than whole brain radiotherapy (WBRT), and whether combined local therapy and WBRT provided any advantage over local therapy alone. They also analyzed survival according to a Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) to determine how well the RTOG RPA classes predicted survival in this patient population and whether treatments varied in effectiveness from category to category.

Methods: A total of 74 patients with brain metastases from melanoma were treated at The Cleveland Clinic Foundation between 1984 and 1998. For this study, the authors reviewed patient charts and confirmed survival status. Survival was compared by treatment modality (surgical resection, WBRT, stereotactic radiosurgery, or WBRT combined with local therapy). Survival also was compared according to the RTOG RPA prognostic classes (Class 1, Class 2, or Class 3), which has not been validated previously in patients with malignant melanoma.

Results: The median survival was 5.5 months for all patients. Survival varied significantly by RTOG prognostic class; The median survival was 10.5 months (range, 2.2-99.2 months) for patients in Class 1, 5.9 months (range, 0.2-43.9 months) for patients in Class 2, and 1.8 months (range, 0.1-6.9 months) for patients in Class 3 (P < 0.0001). Survival analysis showed that combined treatment offered significantly better survival (P < 0.0001; combined vs. other). The median survival was 8.8 months (range, 1.8-99.2 months) for the combined therapy group, 4.8 months (range, 1.2-27.8 months) for the local therapy alone group, 2.3 months (range, 0.2-9.6 months) for the WBRT alone group, and 1.1 months (0.1-3.0 months) for the group that received no therapy.

Conclusions: Adding WBRT to local therapy may improve survival in this group of patients: Combined therapy was superior to WBRT alone. The RPA classification scheme likely has prognostic value for patients with brain metastases from malignant melanoma. Prospective studies are required to overcome selection bias and confirm these results.