77>how these drugs can provide anti-cancer activity
Reply:Here is some info to get you started.
Chemotherapy
The ideal chemotherapeutic drug would target and destroy only cancer cells. Unfortunately, few such drugs exist. Common chemotherapeutic drugs and their adverse effects are described in Table 2: Principles of Cancer Therapy: Commonly Used Antineoplastic Drugs .
Table 2
Commonly Used Antineoplastic Drugs
This table is presented as a PDF and requires the free Adobe PDF reader. Get Adobe Reader
The most common routes of administration are IV and oral. Frequent dosing for extended periods may necessitate subcutaneously implanted venous access devices (central or peripheral), multilumen external catheters, or peripherally inserted central catheters.
Drug resistance can occur to chemotherapy. Identified mechanisms include overexpression of target genes, drug inactivation by tumor cells, defective apoptosis in tumor cells, and loss of receptors for hormonal agents. One of the best characterized mechanisms is overexpression of the MDR-1 gene, a cell membrane transporter that causes efflux of certain drugs (eg, vinca alkaloids, taxanes, anthracyclines). Attempts to alter MDR-1 function and thus prevent drug resistance have been unsuccessful.
Cytotoxic drugs: Traditional cytotoxic chemotherapy, which damages cell DNA, kills many normal cells in addition to cancer cells. Antimetabolites, such as 5-fluorouracilSome Trade Names
ADRUCIL
Drug Information
and methotrexateSome Trade Names
RHEUMATREX
Drug Information
, are cell cycle鈥搒pecific and have no linear dose-response relationship. In contrast, other chemotherapeutic drugs (eg, DNA cross-linkers, also known as alkylating agents) have a linear dose-response relationship, producing more tumor killing as well as more toxicity at higher doses. At their highest doses, DNA cross-linkers may produce bone marrow aplasia, necessitating bone marrow transplantation to restore bone marrow function.
Single-drug therapy may cure selected cancers (eg, choriocarcinoma, hairy cell leukemia). More commonly, multidrug regimens incorporating drugs with different mechanisms of action and different toxicities are used to increase the tumor cell kill, reduce dose-related toxicity, and decrease the probability of drug resistance. These regimens can provide significant cure rates (eg, in acute leukemia, testicular cancer, Hodgkin lymphoma, non-Hodgkin lymphoma, and, less commonly, solid tumors such as small cell lung cancer and nasopharyngeal cancer). Multidrug regimens typically are given as repetitive cycles of a fixed combination of drugs. The interval between cycles should be the shortest one that allows for recovery of normal tissue. Continuous infusion may increase cell kill with some cell cycle-specific drugs (eg, 5-fluorouracilSome Trade Names
ADRUCIL
Drug Information
).
For each patient, the probability of significant toxicities should be weighed against the likelihood of benefit. End-organ function should be assessed before chemotherapeutic drugs with organ-specific toxicities are used (eg, echocardiography before doxorubicinSome Trade Names
ADRIAMYCIN
Drug Information
use). Dose modification or exclusion of certain drugs may be necessary in patients with chronic lung disease (eg, bleomycinSome Trade Names
BLENOXANE
Drug Information
), renal failure (eg, methotrexateSome Trade Names
RHEUMATREX
Drug Information
), or hepatic dysfunction (eg, taxanes).
Despite these precautions, adverse effects commonly result from cytotoxic chemotherapy. The normal tissues most commonly affected are those with the highest intrinsic turnover rate: bone marrow, hair follicles, and the GI epithelium.
Imaging (eg, CT, MRI, PET) is frequently performed after 2 to 3 cycles of therapy to evaluate response to treatment. Therapy continues if a clear response is seen. If the tumor progresses despite therapy, the regimen is often amended or stopped. If the disease remains stable with treatment and the patient can tolerate therapy, then a decision to continue is reasonable with the understanding that the disease will eventually progress.
Hormonal therapy: Hormonal therapy uses hormone agonists or antagonists to influence the course of cancer. It may be used alone or in combination with other treatment modalities.
Hormonal therapy is particularly useful in prostate cancer, which grows in response to testosteroneSome Trade Names
DELATESTRYL
Drug Information
. Other cancers with hormone receptors on their cells (eg, breast, endometrium) can often be palliated by hormone antagonist therapy or hormone ablation.
Use of prednisoneSome Trade Names
DELTASONE
Drug Information
, a glucocorticosteroid, is also considered hormonal therapy. It is frequently used to treat tumors derived from the immune system (lymphomas, lymphocytic leukemias, multiple myeloma).
Biologic response modifiers: Interferons are proteins synthesized by cells of the immune system as a physiologic immune protective response to foreign antigens (viruses, bacteria, other foreign cells). In pharmacologic amounts, they can palliate some cancers, including hairy cell leukemia, chronic myelocytic leukemia, locally advanced melanoma, metastatic renal cell cancer, and Kaposi's sarcoma. Significant toxic effects of interferon include fatigue, depression, nausea, leukopenia, chills and fever, and myalgias.
Interleukins, primarily the lymphokine IL-2 produced by activated T cells, can be used in metastatic melanomas and can provide modest palliation in renal cell cancer.
Differentiating drugs: These drugs induce differentiation in cancer cells. All-trans-retinoic acid has been highly effective in treating acute promyelocytic leukemia. Other drugs in this class, including phenylbutyrate, phenylacetate, arsenic compounds, vitamin D analogs, and the hypomethylating agent de-oxyazacytidine, are under study. When used alone, these drugs have only transient effects, but their role in prevention and in combination with cytotoxic drugs is promising.
Antiangiogenesis drugs: Solid tumors produce growth factors that form new blood vessels necessary to support ongoing tumor growth. Several drugs that inhibit this process are available. Thalidomide is antiangiogenic, among its many effects. Avastin, a monoclonal antibody to vascular endothelial growth factor (VEGF), is effective against renal cancers and colon cancer.
Signal transduction inhibitors: Many epithelial tumors possess mutations that activate signaling pathways that contribute to their continuous proliferation and failure to differentiate. These mutated pathways include growth factors and the downstream proteins that transmit messages from growth factor receptors on the cell surface. Two such drugs, imatinibSome Trade Names
GLEEVEC
Drug Information
(an inhibitor of the Bcr-Abl tyrosine kinase in chronic myelocytic leukemia) and erlotinib (an inhibitor of the epidermal growth factor receptor), are now in routine clinical use. Other inhibitors of these signaling pathways are under study.
Monoclonal antibodies: Monoclonal antibodies directed against unique tumor antigens have some efficacy against neoplastic tissue (see also Tumor Immunology: Passive Humoral Immunotherapy). TrastuzumabSome Trade Names
HERCEPTIN
Drug Information
, an antibody directed against a protein called Her-2 or Erb-B2, plus chemotherapy has shown benefit in metastatic breast cancer. Antibodies against CD antigens expressed on neoplastic cells, such as CD20 and CD33, are used to treat patients with non-Hodgkin lymphoma (rituximabSome Trade Names
RITUXAN
Drug Information
, anti-CD20 antibody) and acute myelocytic leukemia (gemtuzumab, an antibody linked to a potent toxin).
The effectiveness of monoclonal antibodies may be increased by linking them to radioactive nuclide. One such drug, ibritumomab, is used to treat non-Hodgkin lymphoma.
Reply:there r many cancer drugs available. keemo therapy is the best option for cancer. this treatement kills the bads cells but it has many side effects.
Reply:Cancer
By Dr.Rangadhar Satpathy
Cancer is a cellular malfunction.
Noni鈥檚 effect to cure cancer work in cellular level.
The sooner a cancer is detected, the greater the chance of remission.
Noni helps to fight the cancer in the following way
(A) By its anti carcinogenic agent
Noni juice contains 150 neutraceuticals. Among them six have been shown to fight cancer.
(1) Polysaccharides
Polysaccharides are found abundant in Noni. Polysaccharides block the adhesion of mutated cells to other cells, so stopping metastasis. Blocking the adhesion of mutated cells to new cell depends on the density of the polysaccharides sulphate groups, their mol.wt and their carbohydrate structure.
(2) Anthraquinones
鈥amnacanthal, an anthraquinone inhibits the growth of malignant cells.
鈥lizarin, another antraquinone block the blood circulation to the malignant tumors, hence prevents its growth.
鈥nthraquinone reduces the cytochrome c (a hem protein whose main function is electron transport using the hem prosthetic group. It act as a cancer causing agent in the body) inside the body without causing the formation of any new free radicals. (Source 鈥?from the research study conducted by group of scientist in Japan 1990)
(3) Epigollocatechin gallate (EGCg)
鈥GCg is a polyphenolic flavonoid antioxidant found in abundant in Noni.
鈥GCg prevent the growth of malignant cells and so induce apoptosis.
鈥n cancer cell the enzyme NOX is active all time. In normal cell the NOX is only active during cell division in response to Growth hormone signal. The EGCg interferes the tumor associated activity of NOX. (Source 鈥?From the research study on Noni juice)
(3) Terpenes compound :
鈥t helps in preventing the proliferation of malignant cells and induces apoptosis.
鈥imonene one terpens has been shown to prevent mammary, liver, lungs carcinoma and also may be effective in treating leukemia.
鈥eta carotene, other terpenes helps to stimulate thymus gland to secrete more T- cells that destroys the carcinoma cells.
鈥rsolic acid, one terpen compound has anti carcinogenic effect both externally and internally to prevent the growth of cancerous cell and inducing apoptosis. (Source- research conducted by the National Cancer Institute, Finland)
(4) Proxeronine
Dr.Heinicke鈥檚 theory suggests that xeronine (conversion from proxeronine by the enzyme proxeroninase) combines with various biochemical鈥檚 and building blocks i.e. hormones, proteins, enzymes, serotonins, vitamins, minerals and antioxidants in intracellular level. The Golgi apparatus and reticuloendothelium then assemble the necessary compounds into a specific 鈥榩ackage鈥?鈥?that 鈥榩ackage鈥?is sent from healthy cells to deranged cells to help in regeneration or rebuild the damaged cells.
Sqamous cell carcinoma
Noni helps to prevents proliferation of cancer cell %26amp; Hence prevents cell mitosis
(B) Modulating the body Immune process.
Noni helps to modulate the production, activity and effectiveness of some immune system agent. That are 鈥?br>
鈥?Nitric Oxide:
Nitric Oxide is produced by activated macrophages plays a role in the host protection against pathogen as well as malignant tumor. Noni increases the body鈥檚 biosynthesis of nitric oxide
鈥?Interleukin:
Noni modulate the production, activity and effectiveness of interleukin-2 that enhances the production of B-cell antibodies and also the cytotoxicity character of Natural Killer (NK) cells.
鈥?Interleukins:
Noni modulate the production %26amp; activity of interferon-y that helps in the activation of macrophages and the over all process of cell mediated immunity. (Source- Dr.Hirajumi report)
鈥?Tumor necrosis factor (TNF):
Tumor necrosis factor from various macrophages destroys the malignant cells. Noni modulate the production, activity of TNF from the macrophages
鈥?Lipopolysachrides (LPS):
The LPS in serum stimulate the body鈥檚 immune process to eliminate any pathogens. Noni help to modulate the production of LPS in serum thus increases the immune process of the body.
鈥?Natural killer cells (NK cells):
Noni helps to modulate the production of NK cells that destroys the malignant cells.
Thus Noni juice is multifaceted in its approach to fight cancer.
Reply:Often Cancer is suffered by those who donot believe in the concept of self present within each of us and are instead often rational or very religious. once they start believing in their self and allow the self to take over their problem through meditation, internal repair starts and cancer vanishes from their system without any trace in a short period.
Reply:Try Vitamin C therapy. A few years ago a cancer researcher came out with a paper saying that the best cancer and infection fighter as yet found was Interferon, but, at the time, it cost $15,000 a gram. The good part was that Interferon was a product of the natural breakdown of Vitamin C in your system. Shortly after that paper came out the FDA tried to make Vit C by prescription only. Guess why? The FDA says that the RDA for Vit C is 64 mg a day, just enough to prevent scurvy. Linus Pauling, who got a Nobel Prize for his work with Vit C and a second Nobel Prize for organic chemistry, said 1000 mg a day as a minimum and 2000 mg a day if you are sick. On a personal note, I was sick twice a year, for 2 weeks at a time, for 20 years, and was flat on my back for at least a week each time. To this day the doctors have no idea what the problem was. After I gave up on the doctors I tried Vit C. I took enough to keep from being sick and just below too much to get diarrhea. It followed a bell curve over 2 weeks with a peak at 40,000 mg a day 鈥?about 300,000 over the 2 weeks. I was not sick for those 2 weeks and after a couple of years of that I have not been sick since. I did not dissolve my kidneys, as some doctors said would happen. I did not get any calcium build up or stones and did not dissolve my cones or solidify my joints. Try it, but drink a lot of water 鈥?Vit C is a natural diuretic.
Reply:Here's an answer in simpler terms:
There are several categories of anti-cancer drugs. Chemotherapy, moncolonal antibodies and, immunotherapy work by killing cancer cells. Differentiation agents, hormone therapy and, targeted therapies work by addressing cancer specific proteins. I will briefly supply a description of each and the mechanism they use.
Chemotherapy drugs can usely be classified as alkylating agents or anti-metabolites. These drugs are taken in by cells that are actively dividing. Both healthy and cancerous cells divide. While some healthy cells (hair, digestive tract lining, blood cells) divide rapidly, most cancerous cells divide much more often. So, they are impacted greater. For anti-metabolites, these drugs are chemically similar to nutrients used by cells. So, cells are fooled to taking in the chemotherapy. Alkylating agents are believed to cross-link DNA. When the cancer cell tries to divide, it cannot overcome the damage and commits suicide (apoptosis). Cancer cells tend to mutate and develop resistance to chemotherapy. This is usually though little pumps called gycloproteins which prevent the chemotherapy drugs from making it to the nucleus. Chemotherapy is used for all types of cancer. Side effects vary and can be harsh.
Monoclonal antibodies are antibodies that were derived from a single line (hence "mono"). Like normal antibodies, these antibodies recognize a specific antigen on the surface of cancer. These monclonal antibodies are linked to either a cytotoxin (cell poison) or a radioactive isotope to kill the cancer cells. Since normal cells do not possess the targeted antigen, they do not bind with the monoclonal antibodies. As mentioned, cancer cells mutate. They may develop a mechanism to fight off the antibodies or lose the antigen signature. Monoclonal antibodies are often used for lymphomas. Because they do not attack healthy cell, the side effects are often mild.
Immunotherapy involves vaccines and/or interferon. The idea is to remove a part of the tumor and some white blood cells. Train the white blood cells to recognize and attack the cancer cells as foreign. Interferon enhances the immune response. As noted, cancers mutate and may lose no longer be recognized by the vaccine. Immunotherapy is used for melamona, kidney cancer and, some sarcomas but, is mostly experimental in other cancers. Side effects can be like a severe flu.
Differentiation agents are drugs used to cause a cancer cell to become mature and functional. Cancer cells start as stem cells that do not differentiate into mature cells. Because of this, they are often not functional (unable to perform the normal function like fight infection for immature white blood cells). Only in AML type 3 (APL), are differentiation agents used as first line therapy. All Trans-Retinoic Acid (ATRA) causes the myeloid to mature. As mature cells, they are fully function to normal cells. Because they do not attack healthy cell, the side effects are often mild.
Hormone therapy is used to block production and/or binding of certain hormones normally produced by the body. These hormones are growth factors signalling cancer cells to divide. Hormone therapy is usually used adjuvant to chemotherapy or as prevention of recurrence if the patient has the gene that indicates the their tumor is hormone receptive. Hormone therapy is used mainly in breast cancer and prostate cancer. It is being tried experimentally in other cancers such as gliomas. Side effects can include menopause which can be severe.
Targeted therapies are drugs which bind to proteins produced by the cancerous cells. These oncoproteins are signals for the cell to divide or other function like recruit blood vessels (angiogenesis). These targeted therapies bind to growth factors with a much greater affinity than the tumor produced growth factors. The side effects of targeted therapies are typically mild. Unfortunately, identifying an oncoprotein and developing a binding agent can be difficult. Some of the more successful targeted therapies (Gleevec, Sprycel and, Tasigna) have produced excellent remission rates for Ph+ CML and ALL and GIST. Other targeted therapies target blood supply recruitment like Avastin, Erbitux, Iressa and, Tarceva have produced survival benefit for some to most patients.
Reply:http://www.webmd.com/cancer/default.htm
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Reply:Are you suffering with cancer if not why you want to know about the drugs stop thinking about any think which is not related to you to have knowledge is good but any thing too much is too bad for you ok
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