CEACAM5 and breast cancer: Table 1 shows a sensitivity of CEA and CA 15–3 as 12.5 and 29.2%, so the urinary nucleosides had higher diagnostic sensitivity than serum CEA and CA 15–3. In another study on women with breast cancer, the modified nucleosides had a higher diagnostic sensitivity than CEA and CA 15–3 (Rasmuson et al, 1987; Xu et al, 2000; Zheng et al, 2005).