Cancer detection method using sense of smell of nematode

A method for detecting cancer in a subject, comprising the steps of:

• (a) exposing a transgenic nematode whose genome comprises a Ca indicator gene operably linked to a promoter expressed in an AWC neuron to a sample from the subject, and
• (b) testing a calcium response of the AWC neurons of the transgenic nematode to the diluted sample,
• wherein a change in the calcium response indicates that the subject is determined to have cancer, or to have cancer risk, when the change in the calcium response is increased in comparison to a control as a healthy subject,
• wherein the Ca indicator gene is selected from the group consisting of YC and GCaMP,
• wherein the sample is a body fluid, cells, tissues, a culture of the cells or tissues, or a preservative solution of the cells or tissues;
• and
• wherein when sample is urine it is diluted to 1.5 to 1000 times or when the sample is a cell culture medium it is diluted to 106 to 107 times, or when the sample is a preservative solution of the cells or a preservative solution of tissues it is diluted to 102 to 104 times.