PSA may be used to detect breast cancer

The prostate-specific antigen blood test for prostate cancer in men may get a second life as a much-needed new test for breast cancer, U.S. researchers say. Chien Chou of Chang Gung University in Taoyuan, Taiwan, and colleagues say the PSA also is a potential biomarker of breast cancer in women. However, levels of PSA in healthy women are usually so small that only ultrasensitive tests can measure them. To improve PSA detection in women, the researchers built a tiny fiber-optic biosensor using gold nanoparticles and PSA antibodies to detect and report PSA levels via a fluorescent signal. The biosensor's sensitivity its ability to detect elevated PSA levels in cases of breast cancer and its specificity, or how well it avoids false predictions of breast cancer, are comparable to those found in using PSA as a biomarker for prostate cancer. "Furthermore, these values may compare favorably with the sensitivity and specificity of the current screening methods for breast cancer such as clinical examination … and mammogram," the researchers say in a statement. The findings are published in the journal Analytical Chemistry.