People who have a high body mass index (BMI), excess weight circumference, and Type 2 diabetes have a greater risk of developing liver cancer, a large new study finds. [1]
One expert in the United Kingdom (U.K.) is even calling for a shift in attitude so that obesity is seen as a red flag for having an increased risk of liver cancer.
The Study
In the study, BMI and waist measurement were used as 2 markers for excess belly fat. Type 2 diabetes was also used as a marker, due to its close association with obesity.
Researchers compared the rates of liver cancer, which have more than tripled in the U.K. since the 1970’s, against 1.57 million adults who were cancer-free when they enrolled in 14 different studies.
Liver cancer rates were compared among patients with and without obesity and diabetes to determine how much of a role these factors play in developing the disease.
Researchers controlled for age, sex, alcohol use, smoking, and race. [2]
An Increased Risk
The team found that for every 5-point increase in BMI, there was a 38% increase in the risk of liver cancer among men and a 25% increase among women. [1]
For every 2-inch increase in waist circumference, the risk of liver cancer increased by 8% – even after controlling for BMI.
In all, they found that being overweight increased the relative risk for liver cancer by between 21% and 142% as BMI increased. [2]
Participants who also had Type 2 diabetes were 2.61 times more likely to be diagnosed with liver cancer. The risk also increased in higher BMI. [3]
No association between BMI and cancer was found if the participant had hepatitis, a cause of liver cancer so strong that it overwhelms every other cause. However, among those without hepatitis, the increased risk was significant. [2]
Association Does Not Equal Causation
Peter Campbell, a director at the American Cancer Society, which participated in the research, says:
“We found that each of these three factors was associated, robustly, with liver cancer risk. All three relate to metabolic dysfunction. This adds substantial support to liver cancer being on the list of obesity-associated cancers.” [3]
Like the U.K., the incidence of liver cancer has tripled in the United States, where it is the 6th most common type of cancer.
According to the World Health Organization (WHO), obesity sparks about 500,000 cancer cases annually.
In May, a review of more than 1,000 studies by the WHO’s International Agency for Research on Cancer showed that being overweight or obese increased the risk for at least 13 types of cancer. Those 13 types are:
- Esophageal
- Colorectal
- Breast
- Uterine
- Kidney
- Gallbladder
- Pancreatic
- Thyroid
- Ovarian
- Brain
- Multiple myeloma
- Blood
- Stomach
Researchers said that the only risk factor that seemed to be more significant was smoking.
Obesity can cause metabolic and hormonal abnormalities, as well as chronic inflammation, which are all contributors to cancer.
Sources:
[1] WebMD
[2] The New York Times
[2] Daily Mail