Temozolomide is primarily used in the treatment of specific types of brain tumors, particularly glioblastoma multiforme, an aggressive form of brain cancer. It is often prescribed as part of a combination therapy, typically following surgery and radiation, to help slow the progression of the disease. The drug works by interfering with the DNA replication process in cancer cells, leading to their destruction. It is also used in treating anaplastic astrocytoma, another type of brain tumor, especially in cases where the cancer has recurred or progressed after initial treatment. Due to its ability to cross the blood-brain barrier, it is particularly effective in targeting tumors within the central nervous system. Additionally, temozolomide is sometimes employed in clinical trials for other types of cancers, exploring its potential efficacy in broader oncological applications.