Residents in a small town in Japan with high rates of stomach cancer are part of a research program to see whether dogs can screen cancer by detecting odors from cancer cells. So far, they've found dogs were able to detect signs of cancer at nearly 100%. While dogs are expensive to train and use for this purpose, many groups are trying to automate the dog's nose for early detection.
Smithsonian Magazine reviews the accuracy of cancer-sniffing dogs and what we mere humans can learn for improved screening and detection.