Episode 42. Bop Shaplen’s thyroid cancer did not cause his death but a high dose of radiation killed him. “Radiation-induced thyroid cancer”

Chapter 11. Bop Shaplen’s thyroid cancer did not cause his death but a high dose of radiation killed him.

Episode 42. Bop Shaplen’s thyroid cancer did not cause his death but a high dose of radiation killed him. “Radiation-induced thyroid cancer”

1. Evidence and analysis.

1. “The youngest children are most sensitive to radiation-induced carcinogenesis, and the minimal latent period for thyroid cancer development after exposure is as short as 4 yr.” (Text 1).

2. “For terrorist or accidental events involving exposure to radioiodines, prophylaxis against malignant disease of the thyroid is also recommended, particularly for children and adolescents. ” (Text 2).
3. Radiation-induced thyroid cancer.

                “It is not clear whether radiation-induced thyroid cancers (usually papillary cancers) are intrinsically different from those that arise because of other causes. Certainly, it was thought that they were not different until the thyroid cancers that were caused by the Chernobyl radiatioactive fallout were analyzed. In those cases, there seemed to be a large number of diffuse-sclerosing variant of papillary carcinoma; a variant that otherwise was quite unusual and not previously common in children. The thyroid cancers seen in the Chernobyl children were also unusual in that the latency period, the time between the radiation exposure and the time that the cancer was discovered, was unusually short, at least a decade shorter than seen previously.” (Text 3).

1. Documents used for research.

(Text 1).

1. Radiation-induced thyroid cancer: what we have learned from chernobyl.

Endocr Pathol. 2006 Winter;17(4):307-17.

Nikiforov YE¹.

Author information

Abstract

http://www.ncbi.nlm.nih.gov/pubmed/17525478

An increased incidence of thyroid cancer in the exposed children remains the most well-documented long-term effect of radioactive contamination after the Chernobyl nuclear accident in April, 1986. Multiple studies on approx 4000 children and adolescents with thyroid cancer have provided important new information about the epidemiological, clinical, pathological, and molecular aspects of radiation-induced carcinogenesis in the thyroid gland. They revealed that environmental exposure to 131I during childhood carries an increased risk of thyroid cancer and the risk is radiation dose dependent. The youngest children are most sensitive to radiation-induced carcinogenesis, and the minimal latent period for thyroid cancer development after exposure is as short as 4 yr. The vast majority of these cancers are papillary carcinomas, many of which have characteristic solid or solid-follicular microscopic appearance. On the molecular level, post-Chernobyl tumors are characterized by frequent occurrence of chromosomal rearrangements, such as RET/PTC, whereas point mutations of BRAF and other genes are much less common in this population.

(Text 2).

PubMed

TI

http://www.uptodate.com/contents/biology-and-clinical-features-of-radiation-injury-in-adults/abstract/1?utdPopup=true

Medical management of the acute radiation syndrome: recommendations of the Strategic National Stockpile Radiation Working Group.

AU

Waselenko JK, MacVittie TJ, Blakely WF, Pesik N, Wiley AL, Dickerson WE, Tsu H, Confer DL, Coleman CN, Seed T, Lowry P, Armitage JO, Dainiak N, Strategic National Stockpile Radiation Working Group

SO

Ann Intern Med. 2004;140(12):1037.

Physicians, hospitals, and other health care facilities will assume the responsibility for aiding individuals injured by a terrorist act involving radioactive material. Scenarios have been developed for such acts that include a range of exposures resulting in few to many casualties. This consensus document was developed by the Strategic National Stockpile Radiation Working Group to provide a framework for physicians in internal medicine and the medical subspecialties to evaluate and manage large-scale radiation injuries. Individual radiation dose is assessed by determining the time to onset and severity of nausea and vomiting, decline in absolute lymphocyte count over several hours or days after exposure, and appearance of chromosome aberrations (including dicentrics and ring forms) in peripheral blood lymphocytes. Documentation of clinical signs and symptoms (affecting the hematopoietic, gastrointestinal, cerebrovascular, and cutaneous systems) over time is essential for triage of victims, selection of therapy, and assignment of prognosis. Recommendations based on radiation dose and physiologic response are made for treatment of the hematopoietic syndrome. Therapy includes treatment with hematopoietic cytokines; blood transfusion; and, in selected cases, stem-cell transplantation. Additional medical management based on the evolution of clinical signs and symptoms includes the use of antimicrobial agents (quinolones, antiviral therapy, and antifungal agents), antiemetic agents, and analgesic agents. Because of the strong psychological impact of a possible radiation exposure, psychosocial support will be required for those exposed, regardless of the dose, as well as for family and friends. Treatment of pregnant women must account for risk to the fetus. For terrorist or accidental events involving exposure to radioiodines, prophylaxis against malignant disease of the thyroid is also recommended, particularly for children and adolescents.

AD

Walter Reed Army Medical Center and Catholic University of America, Washington, DC 20307, USA.

(Text 3).

http://www.thyroidcancerdoctor.com/help.html

http://www.thyroidcancerdoctor.com/help.html#letterr

R
Radiation exposure causing thyroid cancer

Not every exposure to radiation, even as a fetus, is sufficient to increase the risk for thyroid cancer. Typical exposures used for diagnostic radiology tests do not add to risk of this disease. Radioactive fallout, such as seen with Chernobyl in 1986, does enhance the risk. External beam radiation therapy that hits the thyroid gland of a fetus or child does enhance the risk.

There is great variability in whether such a cancer will develop, even in people with identical radiation exposures. This is because the radiation enhances the chance of random genetic mutations or, more likely, gene translocations. All of these are still probabilistic events and are not guaranteed to occur.
—ThyroidCancerHelp, July, 2007

Radiation-induced thyroid cancer

It is not clear whether radiation-induced thyroid cancers (usually papillary cancers) are intrinsically different from those that arise because of other causes. Certainly, it was thought that they were not different until the thyroid cancers that were caused by the Chernobyl radiatioactive fallout were analyzed. In those cases, there seemed to be a large number of diffuse-sclerosing variant of papillary carcinoma; a variant that otherwise was quite unusual and not previously common in children. The thyroid cancers seen in the Chernobyl children were also unusual in that the latency period, the time between the radiation exposure and the time that the cancer was discovered, was unusually short, at least a decade shorter than seen previously.

Considering that there appears to be a world-wide increase in new thyroid cancer cases, exceeding the rate of increase of any other cancer type, and most of these are clearly not associated with previous radiation exposure, it would be very difficult to assign a specific causation to any particular case of thyroid cancer.

Generally, if a person has been born and raised in a region of the country (and time period) that has been known to have been exposed to nuclear testing fallout and they were in a high-risk category (for example, drinking fresh milk from a family farm), then there is an assumption that the cancer could have been caused by radiation. Likewise, if a small child has been treated with mantle external beam radiation for Hodgkin’s disease and 12 years later develops thyroid cancer, it is a reasonable presumption that the radiation caused the thyroid cancer; however, it remains a presumption that cannot (as of yet) be proven.

Some researchers have identified specific gene translocations that appear to be associated with ionizing radiation exposure, following a pattern suggested by the three-dimensional nuclear chromosome arrangement; however, this is not yet sufficiently verified as specific for radiation-induced cancers and certainly does not include all possible genetic changes.

As far as therapy, there is no difference in the approach to such patients, compared to any other similar type or extent of disease presentation. The appropriate surgery is the same and the need for lymph node resection is the same. Follow-up care with radioactive iodine and scanning is not any different. Like thyroid cancers from any other cause, known or unknown, some tumors are responsive to conventional treatments and some are not.
—ThyroidCancerHelp, September, 2007