Cancer, treatment using agents

Dronabinol is indicated for the treatment of the nausea and vomiting produced by cancer chemotherapy in patients who have failed to respond adequately to other conventional treatments. This agent may be habit forming and can be expected to produce disturbing psychomimetic reactions. It should only be used under close supervision. 

Cancer treatment is a multimodality treatment, i.e., surgery is combined with radiotherapy and antineoplastic chemotherapy. The latter treatment mode is used mainly for cancers which have disseminated. Different forms of cancer differ in their sensitivity to chemotherapy with antineoplastic agents. The most responsive include lymphomas, leukemias, choriocarcinoma and testicular carcinoma, while solid tumors such as colorectal, pancreatic and squamous cell bronchial carcinomas generally show a poor response. The clinical use of antineoplastic agents is characterized by the following principles. 

Erythropoietin (Eprex ) is physiologically produced in the kidney and regulates proliferation of committed progenitors of red blood cells. It is used to substitute erythropoietin in severe anemias due to end stage renal disease or treatment of cancer with cytostatic agents. Side effects include hypertension and increased risk of thrombosis. 

Why Do We Need to Know This Material The d-block metals are the workhorse elements of the periodic table. Iron and copper helped civilization rise from the Stone Age and are still our most important industrial metals. Other members of the block include the metals of new technologies, such as titanium for the aerospace industry and vanadium for catalysts in the petrochemical industry. The precious metals—silver, platinum, and gold—are prized as much for their appearance, rarity, and durability as for their usefulness. Compounds of d-block metals give color to paint, turn sunlight into electricity, serve as powerful oxidizing agents, and form the basis of some cancer treatments. 

Despite the evidence for the cytotoxicity of CNTs, there are an increasing number of published studies that support the potential development of CNT-based biomaterials for tissue regeneration (e.g., neuronal substrates [143] and orthopedic materials [154—156]), cancer treatment [157], and drug/vaccine delivery systems [158, 159]. Most of these applications will involve the implantation and/or administration of such materials into patients as for any therapeutic or diagnostic agent used, the toxic potential of the CNTs must be evaluated in relation to their potential benefits [160]. For this reason, detailed investigations of the interactions between CNTs/CNT-based implants and various cell types have been carried out [154, 155, 161]. A comprehensive description of such results, however, is beyond the scope of this chapter. Extensive reviews on the biocompatibility of implantable CNT composite materials [21, 143, 162] and of CNT drug-delivery systems [162] are available. 

The control of cell numbers is regulated by cell proliferation, differentiation and apoptosis. Increased proliferation and/or decreased apoptosis result in neoplasia. In addition to inhibition of proliferation or induction of differentiation, the modulation of apoptosis can be employed for treatment for cancer. Several anticancer agents in use are potent inducers of apoptosis (Dive and Hickman, 1991 Fisher, 1994). Tumor promotion may result in decreased apoptosis. Because PKC activation by TPA induces carcinogenesis, it seems that PKC may be involved in apoptosis. There are many reports on the effects of PKC on apoptosis. However, the results are very controversial. Here an overview of these data is presented. 

A large variety of agents used in cancer treatments has been examined on reversed phase. The alkylating agent melphalan was determined in acidic methanol-water (1 1) at the 50 ng/ml plasma level (J27). ACNU. a... 

Additionally, MMPIs are not expected to replace currently used, proven-effective modalities of cancer treatment such as radiotherapy, hormonal/chemotherapy, or surgery. It is predicted that they will be clinically developed for use in combination with these agents. As expected, given nonoverlapping toxicities and differing mechanisms of action, MMPIs have been combined preclinically with radiation therapy (4), cytotoxic (5-9), resultant additive or supraadditive efficacy. With these data in mind, the ability to combine an MMPI with radiation therapy, chemotherapy, and hormonal therapy may become an important feature in the ultimate clinical success of these agents. 

Platinum complexes (e.g., di-platinum, 8.100) are used as antineoplastic agents in the treatment of cancer. Their use is described in chapter 7. 

Investigators found that human breast cancer cell lines with BRCAl mutations showed a twofold to fourfold increase in apoptosis after treatment with ionizing radiation, cisplatin, or doxorubicin, compared with cells free of mutations. They also found that BRCAl tumor cell lines were resistant to other agents, such as paclitaxel (Taxol) and docetaxel (Taxotere), treatments used commonly in ovarian cancer and advanced-stage breast cancers. 

FU remains the most widely used agent in the treatment of colorectal cancer, both as adjuvant therapy and for advanced disease. It also has activity against a wide variety of solid tumors, including cancers of the breast, stomach, pancreas, esophagus, liver, head and neck, and anus. Major toxicities include myelosuppression, gastrointestinal toxicity in the form of mucositis and diarrhea, skin toxicity manifested by the hand-foot syndrome, and neurotoxicity. 

Other organoarsenicals, most notably lewisite (dichloro[2-chlorovinyl]arsine), were developed in the early twentieth century as chemical warfare agents. Arsenic trioxide was reintroduced into the United States Pharmacopeia in 2000 as an orphan drug for the treatment of relapsed acute promyelocytic leukemia and is finding expanded use in experimental cancer treatment protocols (see Chapter 54). Melarsoprol, another trivalent arsenical, is used in the treatment of advanced African trypanosomiasis (see Chapter 52). 

Among these are intercalating agents such as dauno-mycin (Figs. 5-22, 5-23), neocarzinostatin, and bleomycin (Box 5-B). These are alkylating reagents800 or attack DNA in other ways. The fact that such compounds are in use for chemotherapy emphasizes the need for new approaches to cancer treatment. 

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