An organ earlier believed to be nonfunctional and often removed in adults during cardiac surgery has been found to have a protective role against cancer and autoimmune disease. A new study has revealed the unexpected importance of an often-forgotten gland tucked between the breast bone – the thymus gland.
The thymus gland makes white blood cells, called T lymphocytes or T cells, that are crucial for the body’s immune system. Most of the T cells are made before birth and the rest during childhood. As children grow, the gland becomes smaller and less active.
Researchers from Massachusetts General Hospital compared the data of 1,146 adults who had their thymus removed during cardiac surgeries with the same number of patients who did not undergo thymectomy – the surgery to remove the thymus gland. They found the thymus gland is critical for adult health in general and for preventing cancer and, perhaps, autoimmune disease.
“By studying people who had their thymus removed, we discovered that the thymus is absolutely required for health. If it isn’t there, people’s risk of dying and risk of cancer is at least double,” senior author Dr. David T. Scadden said in a press release.
During the study, 7.4% of patients who had thymectomy developed cancer compared to only 3.7% of patients in the control group. Five years after thymectomy, the mortality rate was 8.1%, while it was 2.8% in those who did not have their thymus removed.
The findings, published in the New England Journal of Medicine, suggest individuals who underwent thymectomy face around three times more risk of death within five years and two times higher cancer incidence during the period.
The removal of the organ also elevated the risk of developing autoimmune disease in adults who did not have a previous infection, cancer or autoimmune disease.
“In this study, all-cause mortality and the risk of cancer were higher among patients who had undergone thymectomy than among controls. Thymectomy also appeared to be associated with an increased risk of autoimmune disease when patients with preoperative infection, cancer, or autoimmune disease were excluded from the analysis,” the researchers wrote.
The team now plans to estimate how the levels of thymus functionality can affect the health of an individual.
“We can test the relative vigor of the thymus and define whether the level of thymus activity, rather than just whether it is present, is associated with better health,” Dr. Scadden said.
Published by Medicaldaily.com