A new study from Australia suggests B cells, a type of white blood cell, undergo spontaneous changes that could lead to cancer if the immune system does not carry out regular checks and kill them before they form tumors.
In the journal Nature Medicine, Dr. Axel Kallies, of the Walter and Eliza Hall Institute in Parkville, Victoria, and colleagues report that the immune system removes errant B cells before they become cancerous."Each and every one of us has spontaneous mutations in our immune B cells that occur as a result of their normal function," Dr. Kallies says.
If cancerous B cells go on to form tumors they develop into B cell lymphomas, also known as non-Hodgkin's lymphomas.
The researchers found T cells of the immune system carry out regular checks to find cancerous and pre-cancerous B cells.
They made the discovery while investigating how B cell lymphomas arise, and they believe this regular surveillance by the immune system is probably why there are not as many cases of B cell lymphomas in the population, given how often the spontaneous changes occur.
They suggest the discovery offers the prospect of an early-warning test that could find patients at higher risk for developing B cell lymphomas. This could lead to treatments that prevent the tumors growing in the first place.
Disabling T cells led to faster-growing lymphomas
In their study, the team showed how disabling T cells in mice led to lymphomas growing within weeks, instead of the years that they normally take to develop.
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."
He says treatments that could remove the errant B cells already exist, so once a test is developed it should not take long to move toward clinical use.
According to estimates from the National Cancer Institute, nearly 70,000 Americans were diagnosed with B cell or non-Hodgkin's lymphoma in 2013, and just over 19,000 died of the disease.
In Australia, where it is the most common blood cancer, about 2,800 cases are diagnosed each year. Patients with weakened immune systems are most at risk.
Funds from the Victorian Government, Cancer Council Victoria, the Australian National Health and Medical Research Council, Australian Research Council, and the Leukaemia Foundation of Australia financed the study.
In October 2013, Medical News Today reported on another study that suggested activating aging in tumor cells may help lymphoma treatment. A team of US researchers found that in the case of large B cell lymphoma, reactivating a gene that controls normal aging prevented tumor cells dividing.