A STUDY OF LABORATORY-BASED FECAL OCCULT BLOOD TESTING IN MELBOURNE, AUSTRALIA

Faecal occult blood tests (FOBT) are widely used in clinical practice and are under increasing scrutiny as a tool for colorectal cancer scre ening. However, there is little information regarding the quality of t esting performed in pathology laboratories. Therefore, we asked 13 pat hology laboratories in Melbourne, Australia, to test coded contrived f aecal samples prepared from a composite stool specimen which had been spiked to various concentrations of haemoglobin. The samples were prov ided to the laboratories in mio forms: (i) on/in the sample collection device appropriate for the faecal occult blood test they normally use d; and (ii) as a moist faecal sample. Some variation in threshold anal ytical sensitivity between laboratories for the same FOBT was observed for Hemoccult(R) SENSA(R), ColoRectal(R), Hematest(R), MonoHaem(R) an d Hemolex(R) suggesting that, at least for those tests, technician tra ining could be improved. Two tests, Hematest(R) and an in-house FOBT d id not perform as well as the other FOBT. When samples were sent in mo ist form, Hemoccult(R) SENSA(R) (P = 0.0002), ColoRectal (P = 0.02) an d MonoHaem(R) (P = 0.04) had significantly lower overall positivity ra tes; for Hemolex(R) the decrease was not significant (P = 0.3). The lo wer positivity rate with moist samples is important, given that 11 of the 13 laboratories in the study stated that they receive at least som e samples in moist form. Thus, technician training and laboratory proc edure need to be reviewed to maximize the benefits of faecal occult bl ood testing in clinical practice, especially with its expanding role i n colorectal cancer screening.