With surprising accuracy saliva can point to head and neck cancer. Researchers from the Johns Hopkins University School of Medicine identified tumor DNA in the saliva. The DNA contains distinctive mutations associated with cancer and makes it easy to identify. As a tumor sheds parts of its genetic code into its surroundings, some of the DNA will be incorporated into the saliva allowing for detecting. Currently, there are no screenings for head and neck cancer because it does not improve the mortality rate of those types of cancer patients; so the saliva test could possibly increase survival chance through earlier treatments.
However, this study has one major flaw. The results obtained were not compared to healthy individuals, so the effectiveness of the spit test is still unclear. More research needs to be conducted to determine if this test is worthwhile, but at its current stage, it seems to be very promising.