Pharmacology of Alkylating Agents (Anticancer Drugs Part 2) [ENGLISH] by Dr. Shikha Parmar
Excessive, abnormal and uncontrolled growth of body cell is called cancer. Cancer is the name given to a collection of related diseases. In all types of cancer, some of the body’s cells begin to divide without stopping and spread into surrounding tissues. Many cancers form solid tumours, which are masses of tissue. Cancers of the blood, such as leukaemias, generally do not form solid tumours. Cancerous tumours are malignant, which means they can spread into, or invade nearby tissues. In addition, as these tumours grow, some cancer cells can break off and travel to distant places in the body through the blood or the lymph system and form new tumours far from the original tumour.
Unlike malignant tumours, benign tumours do not spread into, or invade nearby tissues. Benign tumours can sometimes be quite large, however, when removed, they usually don’t grow back, whereas malignant tumours sometimes do. Unlike most benign tumours elsewhere in the body, benign brain tumours can be life-threatening.
Metastatic cancer has the same name and the same type of cancer cells as the original, or primary, cancer. For example, breast cancer that spreads to and forms a metastatic tumour in the lung is metastatic breast cancer, not lung cancer.
Symptoms of cancer may be following found in patients with different cancers: fatigue, weight loss, pain, skin changes, change in bowel or bladder function, unusual bleeding, persistent cough or voice change, fever, lumps, or tissue masses.
Alkylating agents are compounds that work by adding an alkyl group to the guanine base of the DNA molecule, preventing the strands of the double helix from linking as they should. This causes breakage of the DNA strands, affecting the ability of the cancer cell to multiply. Eventually, the cancer cell dies. Alkylating agents were one of the first classes of drugs to be used against cancer. There are five traditional categories of alkylating agents:
(1) Nitrogen mustards (eg, bendamustine, chlorambucil, cyclophosphamide, ifosfamide, mechlorethamine, melphalan)
(2) Nitrosoureas (eg, carmustine, lomustine, streptozocin)
(3) Alkyl sulfonates (eg, busulfan)
(4) Triazines (eg, dacarbazine, temozolomide)
(5) Ethylenimines (eg, altretamine, thiotepa)
