Hemoccult's long recognized use for colon cancer screening (1, 2) has recently been challenged by newer fecal occult blood tests with reputed advantages in sensitivity and specificity.
The HemoQuant quantitatively measures the concentration of heme-derived porphyrins (3, 4). The Hemoccult SENSA, a modified guaiac-based test, reportedly detects lower levels of hemoglobin, thereby increasing sensitivity (5). The HemeSelect, using an antihuman hemoglobin antibody, is reported to be highly sensitive and specific (6, 7). Although dietary constituents, especially red meat, can increase the false-positive rate of the Hemoccult (1, 2, 8, 9), Hemoccult SENSA (5), and HemoQuant (4) tests, the comparative duration