New nuclear imaging technology causes breast cancer

Wednesday, September 15, 2010 by: S. L. Baker, features writer

(NaturalNews) Over and over, women are pushed to have mammograms in order to detect breast cancer. But you rarely hear about the research that shows these tests, which expose breast tissue to radiation, may actually cause breast cancer. For example, as NaturalNews has covered previously, a study presented at the annual meeting of the Radiological Society of North America (RSNA) last winter conclusively showed that low-dose radiation from annual mammography screening significantly increases breast cancer risk in women with a genetic or familial predisposition to the disease (http://www.naturalnews.com/027641_m...). But, thankfully, the newest technology such as nuclear-based breast imaging exams must be designed to be safer, right?

Unfortunately, the answer is no. In fact, according to a report just published in the journal Radiology, some nuclear-based breast imaging exams increase a woman's risk of developing radiation-induced cancer. And not just a little. If you thought the risk from mammograms was worrisome, wait until you hear how dangerous breast-specific gamma imaging (BSGI) or positron emission mammography (PEM) examinations are: one single BSGI or PEM carries a lifetime risk of inducing fatal cancer that is far greater than the cancer risk associated with having annual screening mammograms starting at age 40.

Specifically, a single BSGI exam is estimated to cause the lifetime risk of terminal cancer to soar 20 to 30 time over that of digital mammography in women aged 40 and up, while the lifetime fatal risk of cancer caused by only one PEM is 23 times greater than that of digital mammography. What's more, BSGI and PEM may increase the risk of not only breast cancer but also malignancies in other organs, too -- including the intestines, kidneys, bladder, gallbladder, uterus, ovaries and colon.

That's the conclusion of the study's author, R. Edward Hendrick, Ph.D., who is clinical professor of radiology at the University of Colorado-Denver School of Medicine in Aurora, Colorado. In order to estimate the lifetime risk of radiation-induced cancer incidence and death from breast imaging exams using ionizing radiation, Dr. Hendrick used recent studies on radiation doses from radiologic procedures and organ doses from nuclear medicine procedures and Biologic Effects of Ionizing Radiation (BEIR) VII age-dependent risk data. 

He found that two-view digital mammography and screen-film mammography have an average lifetime risk of causing fatal breast cancer of 1.3 and 1.7 cases, respectively, per 100,000 women aged 40 years at exposure and less than one case per one million in women who are 80 or older at exposure. However, he found that mammography, either digital or screen-film, performed annually in women from age 40 to age 80, is associated with causing fatal breast cancer in 20 to 25 cases out of 100,000 women.

While the risks and benefits of screening mammography are finally coming under the scrutiny of researchers, newer breast imaging technologies, such as BSGI and PEM, have been approved by the U.S. Food and Drug Administration (FDA) and are now being used in clinical practice as if they were safe. According to a media statement, preliminary studies have shown these tests to be promising at detecting cancer. However, they both involve injecting potentially cancer-causing radioactive substances into women's bodies.

BSGI uses an injection of a nuclear radiotracer, which is absorbed at a higher rate by cancerous cells so a malignancy can be spotted and photographed with a gamma camera. For PEM, a radioactive substance is injected into the body to measure metabolic activity that supposedly detects the presence of cancer. 

Other technologies, not yet approved by the FDA, seem destined to be used on women's breasts in upcoming years, too -- including dedicated breast CT and digital breast tomosynthesis. So far, studies have found these newer tests also cause breast cancer in some women. They have an average lifetime risk of fatal breast cancer of 1.3 to 2.6 cases, respectively, per 100,000 women 40 years of age at exposure.

Dr. Hendrick, like most physicians involved in mainstream medicine, remains a proponent of screening mammography. But he points out that women can reduce their risk from the tests by making sure they have digital mammograms which, on average, expose patients to a lower radiation dose than the screen-film type mammograms. He also pointed out in a statement to the media that women under 40 who are known to be at higher risk of breast cancer should consider being screened with breast ultrasound or breast MRI -- both of these tests involve no ionizing radiation exposure and have sensitivities to breast cancer that are unaffected by higher breast density.

For more information:
http://www.ncbi.nlm.nih.gov/pubmed/...