According to the World Heath Organization (WHO), cancer is a leading cause of death worldwide, accounting for more than seven million deaths in 2003 worldwide. In the United States, the Centers for Disease Control and Prevention (CDC) name it the second leading cause of death at more than a half-million deaths in 2006.
Medical treatment continues to evolve in the fight against cancer as newer and more effective drugs are sought with fewer side effects. Chemotherapy, using effective and relatively safe medications, remains a vital part of cancer treatment.
Alkylating Agents
Alkylating agents affect all cells in any phase of development. According to the American Cancer Society, this group can be poisonous to the bone marrow. Drugs in this group include mustard gas derivatives (cyclophosphamide, chlorambucil, melphalan, ifosfamide and mechlorethamine), nitrosureas (lomustine, carmustine and streptozocin), hydrazines and triazines (procarbazine, dacarbazine and temozolomide), metal salts (cisplatin, carboplatin and oxaliplatin), alkylsulphonates (busulphan) and ethylenimines (thiotepa and hexamethylmelamine).
Plant Alkaloids
Plant alkaloids are extracts that suppress the growth and division of cancer cells in diverse ways. They specifically affect cells that are in the process of cell division (mitosis). They include vinca alkaloids ( vinblastine, vincristine and vinorelbine), taxanes (paclitaxel and docitaxel), podophyllotoxins (etoposide and tenisopide) and camptothecan analogues (irinotecan and topotecan).
Antitumor Antibiotics
Certain species of soil fungi produce substances that suppress tumor growth. One hallmark of drugs in this category, according to the American Cancer Society, is their ability to damage the heart. Drugs in this category include anthracyclines (daunorubicin, doxorubicin, epirubicin and idarubicin), chromomycins (dactinomycin and plicamycin), bleomycin and mitomycin.
Antimetabolites
Antimetabolites act by interfering with the body's use of certain nutrients, which they closely resemble in chemical structure. They include methotrexate, 6-mercaptopurine, 5-flourouracil, cytarabine, foxuridine, gemcitabine, fludarabine, 6-thioguanine and pentostatin and nelarabine.
Mitotic Inhibitors
Mitotic inhibitors interfere with the processes involved in cell division. The taxanes and vinca alkaloids also function in this group. Other drugs here are estramustine and ixabepilone.
Corticosteroids
Corticosteroids are used to suppress the growth of certain cancer cells, especially those arising from the immune system, leukemias and lymphomas. They also help to relieve the nausea that follows chemotherapy. Examples include prednisone, dexamethasone and methylprednisolone.
Targeted Therapies
Targeted therapies are drugs designed to specifically attack certain types of cancer cells based on some peculiar characteristics of the cancer cells. Medications in this class include imatinib, gefitinib, erlotinib, bortezomib and sunitinib.
Hormonal Therapy
Certain hormones encourage or discourage the growth of specific cancers. Drugs in this category are used to treat hormone-dependent cancers. They include anti-estrogens (tamoxifen and toremifene), estrogens, progestins, aromatase inhibitors (anastrozole, letrozole and exemestane), anti-androgens (flutamide, bicalutamide and nilutamide) and LHRH (Leuteinizing Hormone Releasing Hormone) agonists (leuprolide and goserelin).
Differentiating Agents
Differentiating agents here try to force the cancer cells to mature, reducing their tendency to divide and multiply. They include retinoids (tretinoin and bexarotene) and arsenic trioxide.
Miscellaneous Drugs
Certain medications like bortezomib and L-asparaginase work in ways that are not clearly understood to stop or slow the growth of cancer cells.
Other treatments are used to improve the patient's quality of life, by reducing discomfort and depression. Medications in this group are food supplements, multivitamins, pain killers (including narcotics) and medical marijuana.
