Secondary tumors of the brain are very common in the terminal phases of patients with an incurable metastasized cancer; the most common types of cancers that bring about secondary tumors of the brain are lung cancer, breast cancer, malignant melanoma, kidney cancer, and colon cancer (in decreasing order of frequency).Secondary brain tumors are more common than primary ones; in the United States, there are about 170,000 new cases every year. Secondary brain tumors are the most common cause of tumors in the intracranial cavity. The skull bone structure can also be subject to a neoplasm that by its very nature reduces the volume of the intracranial cavity, and can damage the brain. By behavior
Brain tumors or intracranial neoplasms can be cancerous (malignant) or non-cancerous (benign). However, the definitions of malignant or benign neoplasms differ from those commonly used in other types of cancerous or non-cancerous neoplasms in the body. In cancers elsewhere in the body, three malignant properties differentiate benign tumors from malignant forms of cancer: benign tumors are self-limited and do not invade or metastasize. Characteristics of malignant tumors include:
uncontrolled mitosis (growth by division beyond the normal limits)
anaplasia: the cells in the neoplasm have an obviously different form (in size and shape). Anaplastic cells display marked pleomorphism. The cell nuclei are characteristically extremely hyperchromatic (darkly stained) and enlarged; the nucleus might have the same size as the cytoplasm of the cell (nuclear-cytoplasmic ratio may approach 1:1, instead of the normal 1:4 or 1:6 ratio).
Public Citizen Health Research Group, another patient advocacy group, opposed the reintroduction.On June 7, 2002, the FDA announced the approval of a supplemental New Drug Application (sNDA) that allows restricted marketing of Lotronex (alosetron hydrochloride), to treat only women with severe diarrhea-predominant irritable bowel syndrome (IBS). The strict prescribing guidelines initially introduced in 2002 were relaxed slightly in 2016, enabling electronic prescriptions among other benefits. It is not known whether alosetron has been filed for registration in the EU. GSK sold Lotronex to the Californian corporation Prometheus in late 2007.Since 2015, generic versions of alosetron have been available in the US, sold by a number of different companies including Actavis Pharma Company, Prometheus Laboratories and Sebela Pharmaceuticals Inc

Criticism of the FDA
In 2001, the editor of the renowned medical journal The Lancet, Richard Horton, criticized the FDAs handling of alosetron in an unusually sharp language. Horton argued that the treatment of a non-fatal condition did not justify the use of a drug with potentially lethal side effects, and that the FDA should have revoked the approval for alosetron sooner when postmarketing surveillance revealed that many patients had suffered constipation necessitating surgical intervention and ischaemic colitis. He asserted that FDA officials were improperly motivated to maintain and reinstate the approval for alosetron because of the extent to which the FDAs Center for Drug Evaluation and Research is funded by user fees paid by pharmaceutical manufacturers, and that the reinstatement of alosetron was negotiated in confidential meetings with representatives of GlaxoSmithKline.