Types and Classifications of Chemotherapy
interfere with DNA replication to prevent cancer cells from reproducing. Most
alkylating agents are cell cycle non-specific. Alkylating agents can produce
major toxicities affecting the hematopoietic system (the blood producing system
of the bone marrow), and the gastrointestinal, and reproductive systems. These
drugs are active against chronic leukemia, non-Hodgkins lymphoma, Hodgkins
lymphoma, multiple myeloma, and some cancers of the lung, breast, and ovary.
The following cytotoxic drugs are examples of alkylating agents: busulfan, carboplatin,
chlorambucil, cisplatin, cyclophosphamide, dacarbazine, ifosfamide, mechlorethamine
hydrochloride, melphalan, procarbazine, thiotepa, and uracil mustard.
with enzymes needed for DNA repair. The nitrosoureas are able to cross the blood-brain
barrier, so they are used to treat brain tumors as well as non-Hodgkins
lymphoma, multiple myeloma, and malignant melanoma. Most nitrosourea drugs are
cell cycle nonspecific. Major toxicities occur in the hematopoietic and gastrointestinal
systems. Carmustine, lumustine, and streptozocin are examples of nitrosoureas.
with DNA and RNA growth. Antimetabolites are used to treat chronic leukemias
as well as tumors of the breast, ovary, and the gastrointestinal tract. Most
antimetabolites are cell cycle specific and act in the S phase of the cell cycle.
Major toxicities occur in the hematopoietic and gastrointestinal systems. Antimetabolites
include drugs such as 5-fluorouracil, 6-mercaptopurine, capecitabine, cytosine
arabinoside, floxuridine, fludarabine, gemcitabine, methotrexate, and thioguanine.
Antitumor antibiotics interfere with DNA by stopping enzymes needed for cell division or by altering the membranes that surround cells. These agents are cell cycle non-specific.Major toxicities affect the hematopoietic, gastrointestinal, reproductive, and cardiovascular systems. Antitumor antibiotics include dactinomycin, daunorubicin, doxorubicin, idarubicin, mitomycin-C, and Mitoxantrone.
Plant alkaloids inhibit
or stop mitosis or inhibit enzymes that prevent cells from making proteins needed
for cell growth. Most plant alkaloids are cell cycle specific, acting in the
M phase. Major toxicities occur in the hematopoeitic, integumentary, neurologic,
and reproductive systems. Frequently used plant alkaloids include vinblastine,
vincristine, vindesine, and vinorelbine.
The taxanes include drugs such as paclitaxel and docetaxel. Taxanes have a unique way of preventing the growth of cancer cells they affect cell structures called microtubules that play an important role in cell functions. In normal cell growth, microtubules are formed when a cell starts dividing. Once the cell stops dividing, the microtubules are broken down or destroyed. Taxanes stop the microtubules from breaking down and cancer cells become so clogged with microtubules that they cannot grow and divide. Paclitaxel is used for advanced ovarian cancer and as an initial treatment for ovarian cancer in combination with cisplatin. The FDA has also approved paclitaxel for the treatment of breast cancer that recurs within 6 months after chemotherapy or that has spread to nearby lymph nodes or other parts of the body. Paclitaxel is also used for other cancers, such as AIDS-related Kaposis sarcoma and lung cancer.
Tamoxifen is an example
of a hormonal agent that interferes with the activity of estrogen. Estrogen
promotes the growth of breast cancer cells. Tamoxifen, which is often referred
to as an "anti-estrogen", works against the effects of estrogen on
these cells. While tamoxifen acts against the effects of estrogen in breast
tissue, it acts like estrogen in other tissues. Tamoxifen is used as adjuvant,
or additional therapy following primary treatment for early state breast cancer.
In women at high risk of developing breast cancer, tamoxifen reduces the chance
of developing the disease. Tamoxifen is also used to treat men with breast cancer.
include drugs such as bleomycin, hydroxyurea, L-asparaginase, and procarbazine.
Please visit the Clinical Trials site of the National Cancer Institute.
Click here and look for the answer to this question:
What is the name of the new class of drugs that is showing some promise for treatment of breast cancer?