Study finds how obesity, weight loss, hematopoietic cancer are linked

The corresponding number in the control group was 51 haematological cancers, with the group remaining at the level of severe obesity.

Goteborg: Previous studies found that having a weight problem increases your risk of developing certain types of cancer. It is also well-known that women who are obese have higher cancer risk than males do, and that risk declines with deliberate weight loss. However, there is little proof that obesity, weight loss, and hematopoietic cancer are related.

Data from the National Board of Health and Welfare’s Cancer Registry and the Swedish Obese Subjects (SOS) study at the University of Gothenburg were both used into the most recent study, which was written up in the journal Lancet Healthy Longevity.

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The researchers analysed 2,007 people who had bariatric surgery and compared them to a control group of 2,040 obese adults who did not have surgery.

During the follow-up period, 34 individuals in the surgery group developed haematological cancer, in parallel with a significant weight loss.

The corresponding number in the control group was 51 haematological cancers, with the group remaining at the level of severe obesity.

Most of the blood cancers were lymphomas, and when these were studied separately, there was a 55 per cent reduction in the risk of lymphoma in the group that had undergone bariatric surgery. The corresponding risk reduction for all blood cancers was 40 per cent.

In particular, women with high blood sugar at the start of the study seemed to benefit from bariatric surgery. This is according to Magdalena Taube, Associate Professor of Molecular and Clinical Medicine at Sahlgrenska Academy, University of Gothenburg, and corresponding author of the study.

“The benefit of the surgery is linked to baseline blood glucose levels. The reduced risk of haematological cancer was much more pronounced if the women’s blood sugar levels were high at the beginning, which clearly shows that blood sugar is an important factor in cancer development,” she said.

The researchers in the study point out that the mechanisms behind the link between obesity and blood cancers are complex and involve multiple factors, such as chronic inflammation and so-called clonal hematopoiesis, a type of genetically related risk factor for blood cancer. They suggest that the metabolic improvements that take place after bariatric surgery, including reduced inflammation, may reduce the risk of cancer.

“The results provide further support of considering obesity a risk factor for haematological cancer, and that bariatric surgery can reduce the risk of blood cancer in obese women,” said Magdalena Taube, Associate Professor of Molecular and Clinical Medicine at the Sahlgrenska Academy, University of Gothenburg and corresponding author of the study.