Years ago, I recall seeing a movie in which Woody Allen obsesses over unexplained headaches, convinced that he has an undiagnosed brain tumor.
After endless tests, he still struggles with ruminating fear and anxiety. Sadly, brain tumors do occur with some regularity in clinical medical practice. Recently, I encountered two cases of brain tumors. One was benign and the other was malignant. In both cases, I became involved due to concerns about causation. Specifically, the issue at hand was possible industrial causation of brain cancer.
In California, cancers are generally presumed to be industrially caused in certain employees, including firefighters and police officers. These Labor Code statutes typically are applicable if an evaluating physician finds a malignant tumor in a setting of occupational exposure to carcinogens. A benign brain tumor, although clearly a “growth” and a “neoplasm,” might not necessarily be considered work-related. There is something a bit arbitrary in this process.
For example, a pituitary adenoma is a “benign” lesion, but it may cause blindness by compressing the nerves that transmit vision within the brain. Some “malignant” tumors, such as a squamous cell carcinoma of the skin, might represent far less serious health challenges.
With respect to malignant brain tumors, they may arise within the brain’s supporting tissues, or as a result of spread from distant organs, such as the lung. The most common primary brain tumor, glioblastoma multiforme, often comes to the attention of medical personnel after a person suffers a headache, seizure or problem with speech. Most such lesions are fairly advanced, with grave implications.
Brain cancers strike two to three people per hundred thousand per year. That may not seem impressive, but consider the impact on a city with 10 million people, like New York, in which this translates into 300 cases annually. Nationally, 19,500 brain tumors are diagnosed annually, resulting in 13,000 annual deaths.
Among people with glioblastoma, astrocytoma and other malignant tumors, prognoses may be guarded. Some localized benign tumors, as adenomas or meningiomas, may have a very positive outlook for survival and recovery. Moreover, treatments are improving. Surgery, chemotherapy and radiation therapy are among the modalities employed by oncologists.
With respect to causation, researchers historically noted that certain occupations seemed to suffer higher levels of brain cancer. This observation led to a theory that certain chemicals, or radiation exposures, might play a role in brain cancer. Further research also showed an association of brain cancer with specific industries, including agriculture and petrochemical processing. Links have been postulated between brain tumors and food preservatives, rubber products, plastic residues and toxic fumes. Magnetic fields, such as those around high-voltage wires, were thought by some to cause some brain tumors.
Further research, however, has failed to definitively prove this hypothesis. Recently, cellphone use has attracted attention in a similar manner, as these devices generate magnetic fields and local temperature change. In evaluating the recent literature, I was surprised to learn that head injuries may be linked to some brain tumors. About 5 percent of brain cancers may be linked to hereditary factors, including rare diseases such as Li-Frauman syndrome. Viruses have also garnered some attention among researchers.
Most brain tumors, however, are deemed idiopathic, or of unknown specific cause.
On a practical basis, it would seem prudent to minimize any unnecessary exposure to cancer-causing chemicals, and to prevent unnecessary head injuries, in an effort to ward off brain cancer. Moreover, such precautions are generally conducive to good health for other reasons, as well. Severe headaches, difficulty speaking or new-onset seizures should prompt a visit to one’s health care provider. The earlier a brain tumor is detected, the better the prognosis.
Scott T. Anderson, M.D., Ph.D. ([email protected]) is clinical professor of medicine, UC Davis. This column is informational, and does not constitute medical advice.