A group of Harvard and MIT students have created a lung cancer breathalyzer system

“… Earlier this week at MIT’s 27th annual Entrepreneurship Competition, Astraeus Technologies won a $100,000 grand prize for its L CARD (Chemically Actuated Resonate Device), a postage stamp-sized device capable of detecting certain gases that could indicate the presence lung cancer.
The device works just like a traditional breathalyzer, requiring users to blow on its sensor. But what happens after is very different indeed: A companion mobile app will turn a smartphone screen red should the device detect suspicious gases, and green in their absence.” …

http://www.digitaltrends.com/cool-tech/lcard-breathalyzer-lung-cancer-detection/