Brain Cancer: Causes, Effects and Treatment Options

 The medical diagnosis that will be discussed in this assessment is brain cancer, inclusive to all types of brain tumors and ones that also affect the central nervous system (CNS), that stem from the brain.  Brain cancer and brain tumors will be used interchangeably as well.  The presenting features or symptoms of brain cancer present can vary.  Some signs to look out for are: headaches, seizures, personality or memory changes, changes in the ability to do daily activities, nausea, changes in any of the senses like vision changes, changes in speech, and many others depending on the location of the brain tumor/cancer (Brain Tumor ASCO 2019).  The most common symptom of a brain tumor is called a focal neurological sign, which are impairments that affect specific parts of the body like paralysis (Comelli, Lippi Campana, Servadei, and Cervellin, 2017).  Unfortunately, most brain tumors are not diagnosed until after symptoms appear.

 According to Cancercenter.org, the way brain tumors can be detected and diagnosed are through several types of tests.  Some of the tests are taking a biopsy of the tissue to determine the type of cancer, genomic testing, nuclear medicine bone scans to see if the cancer has spread to the bones, an angiography to see how the blood vessels flow and are affected in the brain, and imaging tests such as MRI’s, CT’s and PET scans. 

 The brain is the primary organ of brain cancer/tumors.  The most common primary brain tumor is glioblastoma which is one out of 120 different types of brain tumors.  The brain can be affected as a secondary organ and develop tumors when cancer metastasizes which means it started somewhere else in the body and then spread to the brain.   The most common type of brain cancer that develops is secondary, and fortunately, a tumor/cancer that starts in the brain rarely metastasizes to other parts of the body. The treatment options for brain cancer depends on the type of tumor, grade, and location.  Surgery is an option for some types and locations of tumors.  There may be some of the residual tumor left after surgery depending on the complications of the cancer’s location and affected areas of the brain.  A person may also receive chemotherapy, radiation, or targeted therapy after surgery.

 According to Global Health Data Exchange tool, when looking at the frequency of all types of brain cancers globally, we have seen a steady increase and diagnosis since 1990.  In 1990, the number of brain cancers globally for both sexes were about 630,000 and in 2017 it was over 1,700,000.  The occurrence of brain cancer between the sexes is fairly equal; roughly 881,000 cases in 2017 for males, and about 823,000 cases for females in 2017.

 Looking at the distribution of brain cancer for 2017 by age, the highest occurrence of brain tumors is 1-4-year-old children at around 151,000.  The second-highest occurrence is in 30-34-year-old adults at about 129,000, followed by 45-49 and 50-55-year-old averaging about 125,000.  Other interesting occurrences are that between the ages of 10-24, the prevalence of brain cancer averages 55,000, and after the age of 75, the number of brain cancer decreases as well from about 58,000 cases to 6,000 at age 90 and over. 

When comparing the Socio-demographic Index (SDI), a summary indicator of income per capita, years of schooling, and total fertility rate for 2017, the number of brain cancer occurrences in high SDI is about 622,000, middle SDI 381,000, and low was about 75,000.  On a global scale, China, the United States, Central Europe, and North Africa all had the highest number of prevalence of brain cancer, between 100,000-128,000, except China which had over 600,000. 

In the United States, Massachusetts, Minnesota, New Hampshire, Wisconsin, North Dakota, and Oregon, were the top states that had the most cases of brain cancer, which is 5% compared to their total population.  A factor to any regional difference in tumor incidence could be access to health care, higher health care costs, and variations in diagnostic practices. Throughout the research, there has not been named one single cause or determining factor for developing brain cancer.  Only through genetic studies and testing has there been a more qualifying factor as scientists are able to identify where on the human genome glioma tumors are located.  In the United States, ethnic/race variations are likely to contribute to observed differences such as Black, Asian and Hispanic patients had a significantly lower risk of mortality and improved survival compared to non-Hispanic Caucasian patients and several studies have identified race-specific genetic anomalies (Xu, H., Chen, J., Xu, H., & Qin, Z. 2017).

According to the American Cancer Society, the ages where the highest amount of five-year survival rates of the most common types of brain cancer are during ages 20-44, and the lowest amount of survival is between 55-64 years of age, yet the median age at diagnosis for all primary brain tumors is 59 years old.   For example, an anaplastic astrocytoma has a 54% survival rate in the lower age group and a 14% in the upper age group.  Glioblastomas, the most aggressive type of brain cancer only has a 19% five-year survival rate for the lower age group, and a 5% rate in the upper age group.  The prognosis for most individuals with that specific cancer is a life expectancy of 12-18 months upon diagnosis.   Unfortunately, though brain tumors are the most common cancer and the leading cause of cancer-related deaths for children age 0-14.  The survival rate for infants is the lowest, around 30%, this increases with age to upwards of 80% depending on the type of cancer (cancer.net 2019).  If a child develops a Glioblastoma, the survival rate drops to 20%.  Over their lifetime, children treated for low-grade gliomas, the most common non-aggressive type pediatric brain tumor, finds that almost 90 percent are alive 20 years later and that few die from the tumor as adults. However, children who received radiation as part of their treatment had significantly lower long-term survival rates than children who were not radiated (Manley, 2014).  There are not a lot of findings on adults past the 5-year survival rate due to the amount of brain tumor types, different locations and circumstances for each one and how it affects the brain, but for non-malignant tumors, about 15% of adults survive past the 5-year mark.

In conclusion, brain cancer/tumors are very complex.  There are many factors that affect the development of brain cancer which affects all ethnicities and genders across the globe.  There are many treatment options and more on the way to being developed.

References

• Bohn, A., Braley, A., Rodriguez de la Vega, P., Zevallos, J. C., & Barengo, N. C. (2018). The association between race and survival in glioblastoma patients in the US: A retrospective cohort study. PloS one, 13(6), e0198581. doi:10.1371/journal.pone.0198581
• Brain Cancer: Causes, Symptoms & Treatments. (2019, July 18).  Retrieved from https://www.cancercenter.com/cancer-types/brain-cancer
• Brain Tumor (ASCO). (2019).  Retrieved from https://www.cancer.net/cancer-types/brain-tumor
• Brain tumor. (2019, April 27). Retrieved from https://www.mayoclinic.org/diseases-conditions/brain-tumor/symptoms-causes/syc-20350084
• Cancer of the Brain and Other Nervous System – Cancer Stat Facts. (n.d.).  Retrieved from https://seer.cancer.gov/statfacts/html/brain.html
• Comelli, I., Lippi, G., Campana, V., Servadei, F., & Cervellin, G. (2017). Clinical presentation and epidemiology of brain tumors firstly diagnosed in adults in the Emergency Department: a 10-year, single center retrospective study. Annals of translational medicine, 5(13), 269. doi:10.21037/atm.2017.06.12
• Cousino, M. K., Hazen, R., Josie, K. L., Laschinger, K., Blank, P. D., & Taylor, H. G. (2017). Childhood Cancer and Brain Tumor Late Effects: Relationships with Family Burden and Survivor Psychological Outcomes. Journal of Clinical Psychology in Medical Settings, 24(3-4), 279–288. doi: 10.1007/s10880-017-9519-6
• GBD 2016 Brain and Other CNS Cancer Collaborators. (2019). Global, regional, and national burden of brain and other CNS cancer, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurology , 18, 376–393. doi: https://doi.org/10.1016/S1474-4422(18)30468-X
• Global Health Data Exchange. (2019). Retrieved from http://ghdx.healthdata.org/gbd-results-tool
• Manley, P. (2014, February). Long-term survival among patients with most common childhood brain tumor is high; radiation treatment linked with lower long-term survival rate. Retrieved from https://www.dana-farber.org/newsroom/news-releases/2014/long-term-survival-among-patients-with-most-common-childhood-brain-tumor-is-high–radiation-treatment-linked-with-lower-long-term-survival-rate/
• Nilsson, M., Englund, E., Szczepankiewicz, F., Westen, D. V., & Sundgren, P. C. (2018). Imaging brain tumour microstructure. NeuroImage, 182, 232–250. doi: 10.1016/j.neuroimage.2018.04.075
• Schmidt-Hansen, M., Berendse, S., & Hamilton, W. (2015). Symptomatic diagnosis of cancer of the brain and central nervous system in primary care: a systematic review. Family Practice, 32(6), 618–623. doi: 10.1093/fampra/cmv075
• Xu, H., Chen, J., Xu, H., & Qin, Z. (2017). Geographic Variations in the Incidence of Glioblastoma and Prognostic Factors Predictive of Overall Survival in US Adults from 2004-2013. Frontiers in aging neuroscience, 9, 352. doi:10.3389/fnagi.2017.00352