Turmeric, a yellow spice used widely in Indian cooking, may help stop the spread of cancer, U.S. researchers reported on Thursday.Tests in mice showed that curcumin, an active compound found in turmeric, helped stop the spread of breast cancer tumor cells to the lungs.Tests have already started in people, too, said Bharat Aggarwal of the Department of Experimental Therapeutics at the University of Texas M.D. Anderson Cancer Center in Houston, who led the study.