A new study from the Walter and Eliza Hall Institute in Parkville, Victoria suggests that B cells, a type of white blood cell involved in defending the body against both infectious disease and foreign materials, undergoes spontaneous changes that could lead to cancer, if the immune system does not regularly check and destroy them before becoming tumors.

"Each and every one of us has spontaneous mutations in our immune B cells that occur as a result of their normal function," Dr. Axel Kallies says. If cancerous B cells are not attacked, then the cells can develop into B cell lymphomas – also known as non-Hodgkin’s lymphomas. The T cells of the immune system regularly check and find cancerous and pre-cancerous B cells.

They believe that this regular surveillance made by the immune system is why there are not as many cases of B cell lymphomas in the population, despite how often spontaneous changes occur.

Published in Nature Medicine, their study showed how disabling T cells in mice can lead to lymphomas growing within weeks, rather than years.

Co-author David Tarlinton, an associate professor at the Walter and Eliza Hall Institute, says, “In the majority of patients, the first sign that something is wrong is finding an established tumor, which in many cases is difficult to treat. Now that we know B cell lymphoma is suppressed by the immune system, we could use this information to develop a diagnostic test that identifies people in early stages of this disease, before tumors develop and they progress to cancer.”

According to the National Cancer Institute, nearly 70,000 Americans were diagnosed with B cell or non-Hodgkin’s lymphoma in 2013. Also, more than 19,000 died from the disease.

The authors believe the discovery of B cells destroying cancer cells offer a direction to find which patients are at higher risk for developing B-cell lymphomas. This could lead to treatments that prevent the tumors growing in the first place.