X-rays – Lacto Bacto

A recent study found that there is an increased risk of blood cancers occurring in children who receive X-rays and CT scans. And as the number of X-rays and CT scans go up (thus an increase in total cumulative dose of radiation), the risk of a blood cancer also increases.

The researchers refer to these increased number of cancers as "radiation-induced hematologic cancers". These include such cancers as lymphoid cancers, leukemia, and histiocytic- or dendritic-cell cancers. They estimated that the number of these radiation-induced cancers is 1 in 10 blood cancers in children.

They advise only getting X-rays and CT scans if necessary, and consider getting an MRI or ultrasound instead (if possible).

From Medical Xpress: Study finds 10% of pediatric blood cancers may stem from medical imaging radiation

A study led by UC San Francisco and UC Davis has concluded that radiation from medical imaging is associated with a higher risk of blood cancers in children.

The researchers examined data from nearly 4 million children and estimated that one in 10 blood cancers—some 3,000 cancers in all—may be attributable to radiation exposure from medical imaging. The risk increased proportionally based on the cumulative amount of radiation the children received. ...continue reading "Medical Imaging Radiation and Increased Risk Of Blood Cancers In Children"

Mammography image Credit: National Cancer Institute

Women have been advised by their doctors to get frequent mammograms for decades. However, what if frequent (e.g., annual) mammograms result in an increased risk for breast cancer due to exposure to X-rays? After all, there is a cumulative dose from the mammograms - year after year you get exposed to a little ionizing radiation, but it builds up over time.

Dr. Seth Hardy (radiologist and Associate Professor at Penn State Univ.) discusses this issue, while referencing research by Dr. Daniel Corcos about the possibility of some breast cancers occurring from the cumulative radiation from previous mammograms. This is because radiation is a carcinogen (can cause cancer). [NOTE: studies find that over the years breast cancer treatments have so improved that any benefits of mammography screening are diminished.]

From Dr. Seth Hardy, writing at Sensible Medicine: The Ethics of Screening Mammography

The value of breast cancer screening with mammography is increasingly being questioned. Women are trying to decide what is right for them and the USPSTF is trying to decide what is worthy of reimbursement. Currently, the medical literature is at a stalemate.[1]1 ...

Screening mammography uses ionizing radiation, a known carcinogen. The dose of radiation in each exam is very low, but exposure is cumulative. Also, the absorbed dose varies with the density of the breast. Women with more glandular tissue receive a higher exposure. Thus, over decades of screening, radiation exposure may not be trivial, particularly in women with extremely dense breasts.

Across a population there is some percentage of breast cancers which are caused by screening mammography. The exact number is the subject of debate and not well studied. One article from 2011 approximates 86 cancers and 11 deaths per 100,000 women due to breast cancer screening. Another paper estimates 20-25 fatalities for 100,000 women screened starting at age 40. Due to lack of data, and ethical limitations in obtaining more data, we do not know how many breast cancers are caused by screening. ...continue reading "Can Mammograms Increase Risk of Breast Cancer?"