CANCER TREATMENT – CHEMOTHERAPY AND RADIOTHERAPY
The aim of this treatment is to lessen the tumour mass in the shortest possible period and to kill whatever cells that remain thus preventing their spread and multiplication.
This, however, can only be achieved in only a few of the cancer cases and is not possible in the majority of the other cases because:
It was diagnosed late
Early secondaries are present in the disease
There is medical risk, and
There are poisonous radiation effects and chemotherapeutic agents. To lessen the early tumour load, radiotherapy and surgery are best to use. They are the major modalities of cure in solid tumours. In the case of distributed neoplasms such as myeloma, leukaemia and certain fast developing tumours such as trophoblastic tumours, the first line of treatment has to be chemotherapy.
For choriocarcinoma, advanced lymphomas, leukaemia and other broadly distributed malignancies, chemotherapy is the sheet anchor of treatment. It is joined by way of surgery in embryonal tumours and is the primary treatment for advanced cancers that are not responsive to radiation or surgery. The efficacy of cytotoxic drugs is proportional to the inverse proportionate to a number of cancer cells. Before the decrease of tumour mass by chemotherapy Veness, cytotoxic medications are nonselective and affect every cell that is in some stages of its proliferative activity.
Tumor cells are more proliferating than normal cells and thus are more radiosensitive. Radiotherapy can be a sole treatment mode or can be used in conjunction with chemotherapy or surgery. With the use of very advanced equipment like the linear accelerator, 5000-6000 rads, which is a large dose, it can concentrate on tumours that are deep-seated. It will only leave the adjacent tissues with a marginal injury. The effectiveness of radiotherapy is improved by metronidazole, a radiosensitizing medication, and a hyperbaric oxygen exposure.
Regularly Used Anticancer Medications
Medicine Direct has some of these medications:
They make alkylation (covalent bonds) from formed electrophilic ions alongside guanine residues that result to cross-linking of interference in DNA replication and DNA strands.
Some of them are:
0.1 mg/kg/daily of Chlorambucil Leukeran. 4 to12 mg/daily of Busulfan Myeleran (oral), with fibrosis as the primary side effect. 6 mg/m2 infusion/intravenous of Mustargen, Nitrogen Mustard, with local inflammation as the side effect. 6 mg/m2/d oral for 5 to 10 days, every 4 to 6 weeks (intravenous or oral) of Alkeran Melphalan, Phenylalanine mustard. 10 to 150 mg oral/day or 1g/m2 every 3 weeks for Cyclophosphamide, Endoxan, Cytoxan, with marrow suppression and cystitis as side effects.
They hinder dihydrofolate reductase; tetrahydrofolate cannot form; one carbon unit is unavailable for DNA production. Amethopterin Methotrexate is an example of such medications. It is a 5 mg/day oral or 30 mg/ m2 intravenous two times a week dose, with renal and hepatic, and Marrow suppression as side effects.
They hinder thymidylate synthetase and hence DNA production. 5-fluorouracil is an example. Dosage is 15 to 20 mg/kg/ week intravenous. 1g is the maximum dosage, with marrow suppression and gastrointestinal disorder as side effects. They also hinder deoxycytidine and DNA creation. Cytosar Ara-C cytarabine and Cytosine arabinoside is a good example. The dosage is 100 mg/day intravenously.
Inhibit interconversions and purine biosynthesis.
Hypoxanthine analogue (6-Mercaptopurine Purinethol) with a dosage of 2.5 mg/kg/day oral and marrow suppression and Hepatoxicity as side effects.Guanine analogue (6-Thioguanine): 2 mg/kg/day/oral.
Originating from periwinkle, vinca rosea plant, they hinder microtubule gathering in mitotic spindle development.
Vinblastine Velban: 5 to 15 mg/m2 every 1 to 2 weeks intravenous, with marrow suppression, local inflammation and mental depression as side effects. Vincristine Oncovin: 0.5 to 2 mg/m2 every 1 to 2 weeks intravenous with local inflammation and alopecia, autonomic and peripheral neuropathy as side effects.
Hindering DNA directed RNA creation and DNA synthesis.
Actinomycin Dactinomycin Cosmegan: 12 to 15g/kg/day for 5 days for 2 to 4 weeks intravenously, with local inflammation and marrow suppression as side effects. Bleomycin: 1-5 mg/day intravenous or intramuscular with 300 mg/m2 as maximum and pulmonary fibrosis with marginal myelosuppression as side effects. Adriamycin and Daunomycin, Daunorubicin, Rubidomycin: 60 mg/m2 intravenous, 3 to 4 weeks, with Cardiotoxicity as a side effect. Mutamycin and Mitomycin-C: 20 mg/m2 intravenous every 4 to 6 weeks with marrow suppression and local inflammation as side effects.
L-asparaginase reduces asparagine obtainability; hinders protein creation. The prescription is 1000 IU/kg/day intravenous, with Allergy-coagulation defects as side effects.
Hinder nucleic acid synthesis. Cyclohexyl Chloroethyl nitrosourea (CCNU) is an example. The prescription is 100 mg/m2 oral every 4 to 6 weeks. Delayed marrow suppression is the side effect. Another prescription
is 200 mg/m2/intravenous of Bis chloroethyl nitrosourea (BCNU) every 4 to 6 weeks.
They ravage DNA via peroxide formation. Procarbazine methylhydrazine is an example. Dosage is 50 to 100 mg/m2/day, oral for 10 to14 days, with CNS depression and Myelosuppression as side effects.
The Mechanism is indeterminate, perhaps alkylation. Dacarpazine and Dimethyl triazenoimidazole carbodamide (DTIC) is an example. The prescription is 150 to 250 mg/m2 intravenous for 5 days. Myelosuppression is the side effect.
Hinder DNA creation through crosslinking. Cis-platinum and Cis-diamino dichloroplatinum are examples. The prescription is 100 mg intravenous, once in 3 to 4 weeks. Ototoxicity and renal toxicity are side effects
Androgens like Testosterone: 300 mg/weekly/intramuscular and virilization as a side effect. Estrogen, like Diethyl stilbesterol: 5 to15 mg/Oral/daily and Feminisation as side effect Progestogens like Provera (Medroxyprogesterone acetate): 300 mg/daily/orally and withdrawal bleeding as a side effect. Anti-estrogens like Nolvadex (Tamoxifen): 20 to 30 mg /daily/oral. Adrenocorticoids like Prednisone: 40 to 60 mg/m2 oral/daily and Cushingoid features as side effects. Thyroxine like Eltroxin: 0.1 to 0.3 mg daily/oral and Hyperthyroidism as a side effect.