Background: Brain Metastasis (BM) is the commonest intracranial neoplasm in adults. There are different treatment approaches for BM including Whole Brain Radiotherapy (WBRT) which is used mainly for patients with multiple lesions and those unfit for Stereotactic Radiotherapy (SRS) or surgery (S). Multiple prognostic indices have been developed for better patient selection for treatment and to identify patients with very short survival. We analyzed the survival for patients with brain metastasis and investigated some predictive factors for survival and we studied a small subset of patients with lung cancer without BM to look into some predictive factors for development of BM.
Material and Methods: We retrospectively analyzed data of patients with radiologic diagnosis of brain metastasis who underwent whole brain radiotherapy either alone or with other local treatment modalities (SRS or Surgery) at our institution, looking into Overall Survival (OS) and any predictive models for prognosis and we identified a subset of lung cancer patients without brain metastasis to try to find factors associated with development of brain metastasis.
Results: The median overall survival in our study was 2.7 months and it was better for breast cancer (5.6 months) than lung cancer (3.5 months). In multivariate analysis, we found that the following factors remain the significant predictive factors for survival; use of local treatment modality (SRS or surgery), primary breast cancer, higher Radiotherapy (RT) dose (30 Gy), controlled primary, age less than 65 years, female and 2 weeks or more interval from diagnosis of BM to the start of RT. In univariate analysis, we found from our study that, age>65 years, female, smoking, weight loss, poor performance status, advanced stage at presentation and adenocarcinoma subtype were all factors associated with a higher incidence of BM in lung cancer patients. While in multivariate analysis, only age, smoking and weight loss remain risk factors for development of BM in lung cancer patients.
Conclusion: The survival after whole brain radiotherapy for BM is still poor. Our predictive models and other scoring systems have failed to identify the most important factors which can play the major role in treatment decision. We think it is worthwhile to do more studies that focus on predictive models and to develop nomograms to predict BM in asymptomatic patients, when the disease burden is low and effective local treatment whether SRS or resection could be used.