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Thyroid Cancer Causes: Nuclear Bombs and Radioiodine?

Does Radiation and Radioactivity Exposure Cause Thyroid Cancer?

This page is an excerpt from the AACE home page.

In early August 1997, the National Cancer Institute acknowledged radiation exposure to millions of children during above ground nuclear tests in the early 1950s. The media blitz that followed this report heightened interest and concern among the public about thyroid cancer.

The American Association of Clinical Endocrinologists (AACE), which published "AACE Clinical Practice Guidelines for the Management of Thyroid Carcinoma" in January 1997, and conducted the "Stick Your Neck Out, America" campaign to assist patients in recognizing and detecting thyroid cancer, believes clarification needs to be made about the link between radiation exposure and thyroid cancer.

There is no doubt radioactive fallout could lead to an increased incidence of thyroid cancer in the children (now middle-aged adults) who were exposed. However, the link between I-131 (iodine) and thyroid cancer has never been proven.

The AACE President at the time, H. Jack Baskin, MD, FACE, issued the following statement: "Many of the news reports erroneously stated that I-131 contaminated grass, which was consumed by cows, excreted in milk, and fed to children, had concentrated in the thyroid and caused cancer. While this made an interesting story for the media, this hypothesis has never been proven. Dozens of studies involving even much larger doses of I-131 given to adults and children have shown no correlation between I-131 and thyroid cancer. Over the past 50 years, hundreds of thousands of patients have received I-131 for medical purposes, and there is no increase of thyroid cancer in these patients."

Fallout from a nuclear test involves many types of radiation including other isotopes of iodine (I-133 and I-132) as well as other forms of radiation such as radioactive cesium, which may have been inhaled and caused cancer. People who lived in fallout area, "hot spots" (over 25 counties in Montana, Utah, Idaho, Colorado, and South Dakota) as a child, should be aware of the increased risk of developing thyroid cancer and learn to perform a self-exam of their thyroid. This can be done using a simple technique know as the AACE Neck Check. Additional information on this self-examination can be found online at the American Association of Clinical Endocrinologists.

Whenever a physical examination is done, always ask the physician to examine the thyroid. If a nodule or protrusion is seen or felt, a needle biopsy should be done. Although a thyroid scan, ultrasound, or blood test may also be required, the thyroid needle biopsy is the best test to determine if a nodule is benign or is cancerous and requires surgery.