Therapy Analysis - Anticancer drugs
History of cancer treatment
Along with surgical intervention and radiotherapy, chemotherapy is a mainstay of cancer treatment. Modern day chemotherapy has its roots in the First World War. Soldiers exposed to mustard gas, an alkylating agent, were noted to die due to the destruction of their bone marrow. In 1942, US doctors further investigated this effect by intravenously dosing lymphoma patients with 'nitrogen mustard'. This had limited success, primarily due to the toxic side-effects.
In the 1950s more alkylating agents were developed, and with better success. To this day, chlorambucil, melphalan and busulphan are still the major players in treating haematological cancers. The subsequent discovery and use of nitrosoureas and antimetabolites such as 5-fluorouracil quickly followed. Other classes that have also been developed include anthracyclines, antitumour antibiotics that interfere with DNA replication enzymes, topoisomerase inhibitors that also target enzymes critical for DNA replication, as well as plant alkaloid-based mitotic inhibitors.
A further key discovery came in 1965, when platinum derivatives were discovered in experiments investigating whether bacteria can grow in electric fields. The electrodes used in these experiments were coated with platinum, and while electricity alone did not impact cell division, the platinum and buffer liquid reacted together to form a highly toxic compound that halted bacterial cell division. The first platinum salt that was approved for use as an anticancer was cisplatin. Side-effect issues from platinum derivatives include nephrotoxicity and emesis, for which many drugs have been developed as adjuncts to allow patients to maintain a quality of life during and after treatment. The question now is what is the future for powerful anticancers such as platinum salts? Will they go the way of other metal-based therapeutics such as arsenic and mercury-based drugs, to be replaced by safer alternatives or used only in severely limited, controlled circumstances? Or will they continue to remain a crucial part of oncology treatment?
