Study assesses contemporary burden of brain and other CNS tumors in US
New study found that incidence rates of malignant brain tumors and other central nervous system (CNS) tumors declined 0.8% per year between 2008 and 2017 in the United States for all ages combined . The decline was driven by trends among adults, as rates rose slightly from 0.5% to 0.7% per year among children and adolescents over the same period. The report, published in CA: A Cancer Journal for Clinicians, assessed contemporary patterns of brain tumor occurrence in the context of incidence, mortality and survival trends in the United States
This collaborative study with researchers from the US Central Brain Tumor Registry, led by Kimberly D. Miller, MPH, American Cancer Society, also found that although malignant brain tumors and other CNS tumors are rare in United States, they represent a substantial cancer death burden due to their high death rate. In 2021, an estimated 83,570 people will be diagnosed with brain tumors and other CNS tumors in the United States (24,530 malignant tumors and 59,040 non-malignant tumors), and 18,000 people will die from the disease.
While incidence rates for malignant tumors are declining overall, survival remains low – only 36% of patients survive more than 5 years after diagnosis, compared to 26% for patients diagnosed in the mid-1970s. This progress largely reflects a lack of progress in the early detection and treatment of glioblastoma, for which 5-year survival has only increased by 4% to 7% during this period. Glioblastoma accounts for 49% of all malignant brain cancers in the United States
Incidence rates of non-malignant tumors, which disproportionately affect women and blacks, are slowly increasing, possibly due to improved case finding and increased awareness. For example, meningioma incidence rates, which account for 54% of all non-malignant cases in the United States, increased 0.9% per year in adults from 2008 to 2017. Although relative survival of 5 years for all non-malignant tumors remains high (92%), patients often experience long-term debilitating effects from their tumor and / or its treatment.
The report also found persistent disparities among children. For example, death rates are the same in white and black children despite a lower incidence in black children, reflecting a lower 5-year survival (70% vs. 79%, respectively). The greatest disparities between blacks and whites among children diagnosed between 2009 and 2015 were in diffuse astrocytomas (75% vs. 86%, respectively) and embryonic tumors (59% vs. 67%).
Although the molecular understanding of how brain cancers differ from each other is advancing rapidly, we continue to know little about why these tumors grow in the first place. To facilitate a better understanding, it is essential to have access to timely and complete data on the occurrence. This is particularly important for understanding the causes of gender, age, and racial / ethnic differences, especially for the rarer subtypes and among poorly studied populations. “
Kimberly D. Miller, MPH, American Cancer Society
The report also noted differences in incidence by gender:
- The incidence rates of malignant brain tumors were higher in men (8.3 cases per 100,000) than in women (6.0).
- Conversely, the incidence rates of non-malignant tumors were higher in women (20.3) than in men (12.8).
- For malignant tumors, the sex differences were greatest in people 45 years of age or older, among whom the rates in women were 30% lower than in men.
- For non-malignant tumors, gender differences peaked between 25 and 29 years of age, among which the rates in women were> 2 times higher than those in men (10.2 vs. 4.7 per 100,000), a trend due to high rates of pituitary adenoma in women in this age group.
Miller, KD, et al. (2021) Brain and other tumors of the central nervous system statistics, 2021. A cancer journal for clinicians. doi.org/10.3322.caac.21693.