Hormonal agents

HPI BB is a 76-year ld man with metKtatic prostate cancer. He was diagnosed 4 years ago and underwent a radical prostatectomy but ejected to delay other treatment because he was asymptomatic. Today he presents to evaluate treatment options because he is experiencing bone pain from hb metastases. He b very opposed to orchiectomy, but b willing to try hormonal therapy to control hb disease. He b in otherwise good health. 

Side effects include sexual dysfunction (loss of libido, impotence), hot flashes, gynecomastia, and rare but potentially serious hepatotoxicHy. 

Estrogenic agents (diethylstilbestrol [DES] and estramustine) can be effective in the treatment of metastatic prostate cancer however, concerns about potential thromboembolic events and other side effects (painful gynecomastia) have limited their use. 

Most hormone-sensitive cancers will express hormone receptors that can be assayed on biopsy specimens. This allows the clinician to predict whether an individual patient is likely to benefit from hormonal therapy. For example, it is now standard to measure estrogen receptor (ER) and progesterone receptor (PR) content in breast cancer tissue. Patients with ER- or PR-positive tumors are more likely to respond to antiestrogen therapy compared with patients who lack these hormone receptors. 

Aminoglutethimide is a nonsteroidal inhibitor of corticosteroid biosynthesis. It results in decreased production of endogenous estrogens, androgens, and cortisol. It has been used to treat patients with breast cancer, and off-label uses include treatment of prostate cancer. Because this is a rela- 

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Most hormonal agents are used for other indications. It is not possible to estimate usage for antitumor purposes. 

Tumors derived from hormone sensitive tissues may remain hormone dependent and are then amenable to therapeutic approaches with hormonal agents. These include hormones with opposing (apoptotic) action, hormone antagonists, and agents that inhibit hormone synthesis. 

The specific function of many phytochemicals is still unclear however, a considerable number of studies have shown that they are involved in the interaction of plants/pests/diseases. Most plants produce phytochemicals as anti-microbial, antibiotic, insecticidal and hormonal agents either as part of... 

Finally, therapeutic sequencing of different hormonal agents is fast becoming a common clinical practice, and fulvestrant is a good treatment choice to extend the opportunity for using endocrine therapies before reliance upon cytotoxic chemotherapy is necessary. Further research is required in order to evaluate the optimal sequence, both in clinical practice as well as in the laboratory, to choose the correct treatment of breast cancer in each person after the appearance of tamoxifen-induced drug resistance (Robertson 2004 Osipo et al. 2004 Johnston 2004 Robertson et al. 2005). 

In addition to antineoplastic, cytotoxic agents, there are cancer therapeutic or preventative drugs that are intended to be given on a chronic basis. This includes chemopreventatives, hormonal agents, immunomodulators, and so on. The toxicity assessment studies on these will more closely resemble those of more traditional pharmaceutical agents. Chronic toxicity, carcinogenicity, and Ml developmental toxicity (ICH A-B, C-D, E-F) assessments will be required. For a more complete review, the reader is referred to DeGeorge et al. (1998). 

Hormonal agents that inhibit the production or action of angiotensin reduce peripheral vascular resistance and possibly blood volume (e.g., ACE inhibitors such as enalapril (5.137), ATj antagonists) other hormones that influence blood pressure could also be targeted... 

Various hormonal agents (eg, glucocorticoids) lower the affinity of insulin receptors for insulin growth hormone in excess increases this affinity slightly. Aberrant serine and threonine phosphorylation of the insulin receptor subunits or IRS molecules may result in insulin resistance and functional receptor down-regulation. 

Glucocorticoids (corticosteroids) were the first hormonal agents recognized as having lympholytic properties. Administration of any glucocorticoid reduces the size and lymphoid content of the lymph nodes and spleen, although it has no toxic effect on proliferating myeloid or erythroid stem cells in the bone marrow. 

CHEMOTHERAPEUTICS. ANTICANCER. Cancer is second only to cardiovascular disease as the principal cause of human mortality. As the median age of populations has risen, total deaths from cancer have increased. Treatment of cancer includes surgery, radiation, and chemotherapy, die last encompassing the use of both cytotoxic agents and relatively nnntoxic hormonal agents for the control of tumor growth. 

It is unclear which of the hormonal agents used was responsible for this complication in the last case. 

Two of the better known "anti-juvenile "Hormone" agents, preco-cenes (9) and fluoromevalonate (10) are inhibitors of JH biosynthesis. The mode of action of fluoromevalonate at the molecular level is unknown. Elucidation of the mode of action of precocenes indicates that these plant chromene derivatives reach the site of JH biosynthesis, the corpora allata (CA), where they undergo a lethal epoxidation leading to extensive macromolecular alkylation and ultimately cause cell death (11, 12). Bioactivation of precocenes to the highly reactive precocene epoxide (13) in the corpora allata is almost certainly catalyzed by methyl farnesoate (MF) epoxidase (14), a cytochrome P-450 sonooxygenase (15) tdtich is the last enzyme of the JH biosynthetic pathway (at least in locusts and cockroaches). 

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