Thyroid function cancer

Iodine-131 131 j 8 days Thyroid function, cancer therapy, liver function... 

Zidan J, Rubenstein W (1999) Effect of adjuvant tamoxifen therapy on thyroid function in postmenopausal women with breast cancer. Oncology 56 43-45... 

In recent years, concern that chemicals might inadvertently be disrupting the endocrine system of humans and wildlife has increased. The concerns regarding exposure to these endocrine disrupters are based on adverse effects observed in certain wildlife, fish, and ecosystems increased incidences of certain endocrine-related human diseases and adverse effects observed in laboratory animals exposed to certain chemicals. The main effects reported in both wildlife and humans concern reproductive and sexual development and function altered immune system, nervous system, and thyroid function and hormone-related cancers. Endocrine dismption is not considered a toxicological endpoint in its own right, but a functional change or toxicological mode(s) of action that may lead to adverse effects. Endocrine dismpters are addressed further in Section 4.11. 

Other effects of oral PBB exposure include decreased thyroid function, body weight loss, and liver cancer. Adverse hepatic as well as dermal and ocular effects have been observed in a limited number of dermal studies in animals. No significant adverse effects were observed in animal inhalation studies of PBBs, but only two studies have been conducted (one with octabromobiphenyl and one w ith decabromobiphenyl). 

Morote J, Esquena S, Orsola A, Salvador C, Trilla E, Cecchini L, Raventos CX, Planas J, Catalan R, Reventos J. Effect of androgen deprivation therapy in the thyroid function test of patients with prostate cancer Anti-Cancer Drugs 2005 16 863-6. 

Thyroid function and thyroid antibodies were not modified in 20 breast cancer patients (451), and only one case of hypothyroidism with increased thyroid antibodies has been reported (SEDA-20, 337). G-CSF had no effect on thyroid function in 33 patients with cancer, even in patients with pre-existing antibodies (452). Subclinical and spontaneously reversible hyperthyroidism occurred in eight patients without thyroid antibodies and with normal thyroid function before treatment, but this was felt to be related to stressful procedures. 

PBDEs are estrogen disruptors and neurotoxins. They are believed to cause thyroid and neurodevelopmental effects. Short-term exposure to PBDEs interferes with thyroid function and disrupts hormonal balance. 18 Additive thyrotoxic effects were observed when PBDEs were administered to laboratory animals with PCBs or chlorinated hydrocarbons. 19 PBDE exposure has been linked to neurodevelopmental dysfunctions in children and young adults. 20 21 Administration of PBDE to 10-day-old laboratory animals resulted in impaired spontaneous motor behavior, affected learning and memory, and permanent behavioral effects. 21 ln vitro exposure of PBDE to human breast cancer cells demonstrated estrogenic potencies. 22 ... 

Marginal Deficiencies, Marginal selenium deficiencies are thought to be involved in thyroid function, immune function, reproductive disorders, mood disorders, inflammatory conditions, cardiovascular disease, viral virulence, and cancer chemoprevention. 

Growth of mammary breast cancer cells, which also express the same NIS as thyroid cells, is inhibited by iodine and also 6-iodolactone. Thus, a sufficient iodine supply has an important role, not only for thyroid function and growth, but also for the mammary gland. 2-IHDA, inhibits nicotinamide adenine dinucleotide hydride (NADH)-dependent H2O2 generation in vitro, as well as in vivo. It also inhibits adenylate-cyclase activity, and therefore is supposed to mediate the well-known Wolff—Chaikoff effect. 

An 80-year-old patient with advanced thyroid cancer taking levothyroxine 125 micrograms daily required treatment with oral ciprofloxacin 750 mg twice daily and intravenous dicloxacillin for osteomyelitis complicating a fracture. After 4 weeks of treatment she complained of increasing tiredness, and was found to have a markedly raised TSH level (10 times of the upper limit of normal). Increasing the levothyroxine dose to 200 micrograms daily did not have any effect on TSH, so the dose was returned to 125 micrograms. The ciprofloxacin was then stopped, and the thyroid function tests rapidly normalised. ... 

Retrospective analysis of 11 patients taking levothyroxine and with thyroid cancer found that 8 patients who had previously undergone a total thyroidectomy developed markedly elevated TSH levels and were clinically hypothyroid after receiving treatment with imatinib. Despite a mean increase in the dose of levothyroxine of about 200%, hypothyroidism was reversed in only 3 patients. Thyroid function tests normalised on discontinuing imatinib. Conversely, no effect on thyroid status was seen in the 3 patients who had not had their thyroid gland removed. ... 

With the production of artificial radioactive substances in 1934. the field of nuclear medicine was established. In 1937, the first radioactive isotope was used to treat a person with leukemia at the University of California at Berkeley. Major strides in the use of radioactivity in medicine occurred in 1946, when a radioactive iodine isotope was successfully used to diagnose thyroid function and to treat hyperthyroidism and thyroid cancer. Radioactive substances are now used to produce images of organs, such as liver, spleen, thyroid gland, kidneys, and the brain, and to detect heart disease. Today, procedures in nuclear medicine provide information about the function and structure of every organ in the body, which allows the nuclear physician to diagnose and treat diseases early. 

The radioactive form of iodine (1). It has a half-life of 8 days. Since its presence can be detected by a Geiger counter or similar instrument, iodine 131 has numerous uses in biology and medicine. Substances can be tagged with iodine 131 and then their metabolism, movement, or disappearance can be followed in the body. Medical diagnostic and therapeutic uses include thyroid function, blood volume, location of brain tumors, cancer treatment, and hyperthyroid treatment. 

Corticotropin is used for diagnostic testing of adrenocortical function. This drug may also be used for the management of acute exacerbations of multiple sclerosis, nonsuppurative thyroiditis, and hypercalcemia associated with cancer. It is also used as an anti-inflammatory and immunosuppressant drug when conventional glucocorticoid therapy lias not been effective (see Display 50-1). 

The first environmental physician I went to see listened to my story, sat back in her chair and said, It s obvious that you don t want to get well. I was devastated. I later learned that she had cancer and her friends were angry with her because she put off getting help for it, so I believe she was projecting some of her issues onto me because I was also a physician. Later, we did have a more satisfying telephone conversation, after my blood tests showed that my thyroid was not functioning properly. 

This is an unusual drug in that it contains a metal atom, platinum (Pt) in this case. Cisplatin reacts with DNA to cross-link bases, disrupting normal DNA structure and function. This agent has found broad use in cancer chemotherapy, including efficacy in tumors of the testis, ovary, bladder, head and neck, thyroid, cervix, and endometrium. It is also active against neuroblastoma and osteogenic sarcoma. 

---