The Bacillus Calmette-Guérin (BCG) vaccine for tuberculosis prevents TB--but it also works in superficial bladder cancer, treating early-stage disease and cutting recurrences. Vitamin D is linked with boosting the immune system, and historically, tuberculosis patients have been given vitamin D-boosting sunlight therapy. So a team of researchers from University of Rochester Medical Center is looking at mice with bladder cancer to see what happens when you combine the two.
Mice with bladder cancer were given vitamin D alone, BCG alone, BCG with vitamin D, or no treatment. The combination group was the only group in which all of the mice survived. While it's not quite clear how BCG boosts the immune system to clear the cancer cells in bladder cancer, or why 30% to 40% of people do not respond to it, it's known that one of the actions of the vaccine is to increase the number of vitamin D receptors and boost the enzyme that converts vitamin D to a more potent form. Yi-Fen Lee, Ph.D. and associate professor of Urology at URMC, suspects that a lack of vitamin D might be behind the poor response.
"Vitamin D appears to be critical to the success of BCG immunotherapy," Lee said.
The researchers are planning an early clinical trial in patients to see if what they observed in mice also works in people, and are looking at whether vitamin D could be useful as a biomarker picking out the patients that won't respond, as well as a route to improving treatment.
- read the press release
- see the abstract