Brain tumor
Glioblastoma multiforme (GBM) is the most aggressive (grade IV) and most common form of a malignant brain tumor. Even when aggressive multimodality therapy consisting of radiotherapy, chemotherapy, and surgical excision is used, median survival is only 12–17 months. Standard therapy for glioblastoma multiforme consists of maximal surgical resection of the tumor, followed by radiotherapy between two and four weeks after the surgical procedure to remove the cancer, then by chemotherapy, such as temozolomide. Most patients with glioblastoma take a corticosteroid, typically dexamethasone, during their illness to relieve symptoms. Experimental treatments include targeted therapy, gamma knife radiosurgery, boron neutron capture therapy and gene therapy.
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.