Survival Analysis of Patients with Brain Metastsis by Weighting According to the Primary Tumor Oncotype

Gwak, Hee Keun; Kim, Woo Chul; Kim, Hun Jung; Park, Jung Hoon; Song, Chang Hoon

Abstract

PURPOSE
This study was performed to retrospectively analyze patient survival by weighting according to the primary tumor oncotype in 160 patients with brain metastasis and who underwent whole brain radiotherapy.
MATERIALS AND METHODS
A total of 160 metastatic brain cancer patients who were treated with whole brain radiotherapy of 30 Gy between 2002 and 2008 were retrospectively analyzed. The primary tumor oncotype of 20 patients was breast cancer, and that of 103 patients was lung cancer. Except for 18 patients with leptomeningeal seeding, a total of 142 patients were analyzed according to the prognostic factors and the Recursive Partitioning Analysis (RPA) class. Weighted Partitioning Analysis (WPA), with the weighting being done according to the primary tumor oncotype, was performed and the results were correlated with survival and then compared with the RPA Class.
RESULTS
The median survival of the patients in RPA Class I (8 patients) was 20.0 months, that for Class II (76 patients) was 10.0 months and that for Class III (58 patients) was 3.0 months (p<0.003). The median survival of patients in WPA Class I (3 patients) was 36 months, that for the patients in Class II (9 patients) was 23.7 months, that for the patients in Class III (70 patients) was 10.9 months and that for the patients in Class IV (60 patients) was 8.6 months (p<0.001). The WPA Class might have more accuracy in assessing survival, and it may be superior to the RPA Class for assessing survival.
CONCLUSION
A new prognostic index, the WPA Class, has more prognostic value than the RPA Class for the treatment of patients with metastatic brain cancer. This WPA Class may be useful to guide the appropriate treatment of metastatic brain lesions.