Tuesday, July 18, 2006

An important health advisory for women

Ladies, an important study has found that women with a family history of Breast or Ovarian cancer who may have mutations to the BRCA 1 or BRCA 2 genes should NOT undergo earlier or more frequent mammograms or other X-Rays. The study has found that these women are more susceptible to genetic damage due to ionizing radiation. The risk of developing cancer for those women, which is already very high in relation to women without the genetic defect, who report undergoing an x-ray more than doubled. The two genes involved, named BRCA 1 and BRCA 2, are part of the body’s genetic repair machinery. Damage to these genes means that mutations to other parts of your DNA due to ionizing radiation can lead to cancer. Instead of more frequent mammograms, the researchers suggest that women with these genetic defects should instead have MRI’s with Gadolinium contrast in order to show new vascularization of the tumor. This is possible because solid tumors excrete protiens that encourage new blood vessel growth to feed the tumor. These new blood vessels are what would appear on the MRI. MRI’s do NOT use ionizing radiation, but instead very strong magnetic fields to stimulate the hydrogen atoms to emit very weak radio waves which the machine can interpret. Gadolinium, which is very magnetic, allows the blood to radiate stronger radio waves than the surrounding tissue thereby highlighting the blood vessels.

2 Comments:

Blogger TxGoodie said...

Damned if you do, damned if you don't.

July 25, 2006 11:58 AM  
Blogger Rorschach said...

TXGoodie, not exactly. There are two other testing procedures that can be run instead of a mammogram, one is less sensitive (ultrasound) and won't pick up the smallest of tumors, the other is more expensive than mammograms (MRI with Gadolinium Contrast), but neither use ionizing radiation which is the issue. BRCA-1 and BRCA-2 make you extremely sensitive to DNA damage. conventional wisdom was to test you more often if you had a family history (and therefore likely to have one or both of these genetic defects) to catch incipient cancers before they got too far along, but they did not take into account the extra damage that the x-rays themselves might do. This study has tried to quantify the risks of the extra testing.

This really underscores the need to have genetic testing done if there is a family history of these cancers and to take into account the risks of the extra testing that may be required and consider any alternatives that may exist to that testing.

July 25, 2006 12:18 PM  

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