It's a tedious hobby, but David Rose doesn't mind. Building miniature ships keeps his hands occupied - something cigarettes did for the last 40 years. Between his 3-Pack a day habit and his job working with asbestos, Rose was living a risky life. 

"I got down in the pit with a broom and swept all this stuff up to the end and shoveled it out with a shovel. I lived in a cloud of asbestos for a year and a half." 

Eventually he developed lung cancer, but because he caught it early, doctors were able to remove it. To keep it from coming back, scientists are trying a new approach - they're giving patients high doses of vitamin D. 

According to Dr. Alex Adjei of Roswell Park Cancer Institute, "In cancer cells grown in the lab, as well as in animal models, that it can actually stop cells from dividing, and growing and spreading." 

This is crucial for lung cancer patients. By the time many are diagnosed, the disease is already advanced and treatment options are limited. 

"With an agent that's shown as much activity as vitamin D, that, in this population, we have an opportunity to slow the progression to lung cancer and maybe reverse it,” says Dr. Mary Ellen Reid. 

Rose signed up for the study in an effort to keep his lung cancer in check and to help doctors build new defenses against this deadly disease.