Glioblastoma
Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive cancer that begins within the brain. Initially, signs and symptoms of glioblastoma are non-specific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Worsening of symptoms often is rapid. This may progress to unconsciousness.
The cause of most cases is unclear. Uncommon risk factors include genetic disorders such as neurofibromatosis and Li–Fraumeni syndrome, and previous radiation therapy. Glioblastomas represent 15% of brain tumors. They can either start from normal brain cells or develop from an existing low-grade astrocytoma. The diagnosis typically is made by a combination of CT scan, MRI scan, and tissue biopsy.
There is no clear way to prevent the disease. Typically, treatment involves surgery, after which chemotherapy and radiation therapy are used. The medication temozolomide is used frequently as part of chemotherapy. High dose steroids may be used to help reduce swelling and decrease symptoms. It is unclear whether trying to remove all or simply most of the cancer is better.
Despite maximum treatment, the cancer usually recurs. The most common length of survival following diagnosis is 12 to 15 months, with fewer than 3% to 5% of people surviving longer than five years. Without treatment, survival is typically three months. It is the most common cancer that begins within the brain and the second most common brain tumor, after meningioma. About 3 per 100,000 people develop the disease a year. It most often begins around 64 years of age and occurs more commonly in males than females. Immunotherapy is being studied.
Common symptoms include seizure, headaches, nausea and vomiting, memory loss, changes to personality, mood or concentration, and localized neurological problems.
Gongylonema neoplasticum
Experimental evidence later refuted Fibiger's Nobel Prize discovery. In 1918, there was a critical comment from F. D. Bullock and G. L. Rohdenburg that Fibiger could have confused cancer-like (neoplastic) tumour from true (metastatic) cancer, and that he had not induced actual cancer. But Fibiger responded "That these tumors are true carcinomata cannot, thus, be doubted, and the fact that they may occur in younger animals does not diminish our right to range them among the true malignant neoplasms." After his death in 1928, there was a better understanding of the nature of cancer—on the differences of neoplastic tumour and malignant tumours (cancer), challenging the claims of Fibiger. The most important criticism was by Richard Douglas Passey, with his colleagues A. Léese, and J.C. Knox. Their experimental conclusions were that the nematode could not cause cancer, and that experimentally-induced cancer was due to other factors such as vitamin A deficiency. Fibiger used a vitamin A-less diet for his experimental rats, and it was by then established that vitamin A deprivation alone could induce cancer. An elaborate experiment by W. Cramer in 1937 came to the conclusion that Fibiger's tumour could not be a true cancer. A more rigorous study was done by Claude R. Hitchcock and E. T. Bell in 1952. They repeated Fibiger's experiments using advanced techniques, and concluded that the tumours induced by the nematode in rats were metaplasia, not cancer. All tumours were due to vitamin A deficiency. Systematic reanalysis of Fibiger's data also gave the same conclusion that "G. neoplasticum" can cause tumour, but is not carcinogenic by itself.