Brain metastasis: Incidence, trend analysis, and impact on survival using SEER database (2010-2020).

2021 Background: Brain metastasis has a poor prognosis in cancer patients with high morbidity and mortality rates. An updated comprehensive analysis of patients with brain metastasis across all primary cancer sites is lacking. So, the study aims to provide the literature with updated evidence about recent trends and survival analysis of brain metastasis. Methods: Data of 75,797 patients with brain metastasis, diagnosed in 2010-2020, were extracted using the Surveillance, Epidemiology, and End Results (SEER) software. We used a rate session to calculate the incidence, percent change (PC), and annual percentage change (APC). Rates are per 100,000 and age-adjusted to the 2000 US Std population. Confidence intervals (CI) are 95% per rate with statistical significance at P > 0.05. We used SPSS version 23 for data analysis and Kaplan Meier Curve and log-rank test for survival analysis. Results: Brain metastasis represented 1.9% of all cancer cases with a mean age of 64.4 (Sd = 11.2). The age-adjusted incidence rate of brain metastasis was 7.1 with a PC of -9.6 from 2010 to 2020 (APC = -0.60; 95% CI: -1.2-0.001, P < 0.05). The APC was significantly declining in Caucasians (-0.70; P > 0.05) and African Americans (-1.2; P < 0.05) with a significant decrease in males (-1, P < 0.05) while the Asian or Pacific islanders (API) race had PC of 11.7 and APC of 1.30 (P < 0.05). Lung, breast, skin melanoma, and kidneys were the most common primary sites for brain metastasis (78.5%, 3.8%, 3.7%, and 3.2%). The 5-year relative survival of patients with brain metastasis was 6.1% compared to the non-metastatic group 71.5%. The 5-year age standardized relative survival was 5.7% for the metastatic group. The 5-year relative survival of brain metastasis was higher in the API race compared to Caucasians and African Americans (10.1%, 5.9%, and 5.3%). Conclusions: The results of this study show a very poor survival outcome for brain metastasis. However, there was a significant decline in brain metastasis trends over the years, which highlights promising improvements in the early detection of primary cancers. Further stratifications showed disparities according to race and primary cancer site. These data may have clinical-directed variations in screening and counseling for subpopulations with cancer.