Prostate-specific antigen (PSA) as a possible biomarker in non-prostatic cancer: A review

•PSA is expressed in non-prostatic tissues, not only in men but also in women.•PSA is expressed at a 1000-times lower concentration in women than men.•PSA could have a role as a tumor biomarker for breast and colon cancer in women.•PSA as a biomarker for early detection, diagnosis and prognosis of cancer in women.