A blood test taken years before cancer appears may hold a warning sign for men’s long-term health. The link was broad, but it came with an important exception: prostate cancer did not follow the same pattern. Low Testosterone May Be a Health Warning SignThat does not mean testosterone is necessarily causing cancer, and it does not mean testosterone therapy would prevent it. Why Prostate Cancer Was DifferentThe prostate cancer result may be the most surprising part of the study. Instead, prostate cancer risk was higher among men with lower levels of SHBG and luteinizing hormone.