Many experts, cancer patients and medical care workers agree that cancer can smell like decay or very bad breath. According to WebMD.com, researchers are trying to pinpoint the different scents that suggest particular cancers may be present, as of 2015.
Dr. George Preti at the Monell Chemical Senses Center states that cancer cells metabolize differently than regular cells, which causes them to emit chemicals that cause odor. Dr. Preti and his team are working to develop an electronic nose that enables detection of cancer cells by smelling blood samples, as of 2015. The idea to formulate such a device is based on evidence that dogs have been able to detect cancer in humans through scent.