CT Scans boost risk of cancer, heart disease

A study published recently in JAMA suggests a calcium score may help researchers to reclassify patients into high a risk category or low risk category.

Calcium score is based on an examination by CT scans of calcium deposits on the walls of arteries, part of the process of accumulating plaque called atherosclerosis.

The study of 5,878 patients aged 45 to 84 participating in the Multi-Ethnic Study of Atherosclerosis showed that 77 percent of patients were able to be reclassified into high or low risk categories based on calcium scores compared to 69 percent when calcium scores were not used.

For the study, researchers checked calcium in the walls of patients' coronary arteries, followed the participants by phone every nine to 12 months for a period of six years and found 209 participants experienced a heart disease event such as heart attack, death from heart disease or cardiac arrest.

The researchers acknowledged that it is not clear whether calcium scores obtained by using CT scores provide any value in predicting patients' outcome.  Additionally, CT scans are not recommended for a routine screening test because x-ray by itself can raise risk for cancer and heart disease.

"We have uncovered powerful evidence that customary x-ray practices became and remain one of the necessary causal co-actors in over half of the fatal cases of cancer and over half of the fatal cases of ischemic heart disease (coronary artery disease) in the USA," John Gofman, a distinguished nuclear physician says in one of his publications.

Dr. Gofman explains "Our Unified Model of Atherogenesis and Acute IHD Death proposes that a lipid-containing arterial plaque arises where atherogenic mutations (acquired after conception) produce a clone of dysfunctional cells (mini-tumors) which do an incomplete job of clearing the lipids out of that patch of dysfunctional arterial tissue and of protecting the arterial lumen from the accumulated thrombogenic lipids within the plaque."

In response to reports on the study, Andrew Einstein of Columbia University was cited by USA Today as saying that "scanning 20 million people is likely to produce an additional 4,200 cancers in men and 6,200 cancers in women over their lifetimes, depending on how often they're scanned."

Rita Redberg, a cardiologist at the University of California-San Francisco was quoted as saying that the CT scan-based calcium scores  did not appear to help people.  

"There's no known benefit," Redberg said. "Any risk isn't worth it."

Dr. Colin T Campbell, a world-famous nutrition professor from Cornell University, says in his book China Study that a study of hundreds of young soldiers who died in Korea War found about 70 percent of the young men got more or less deposits on the walls of their arteries.

Dr. Campell attributed the problem to the Western diet.

Jimmy Downs and editing by Rachel Stockton