The FISH test can be used to detect bladder cancer, according to WebMD. In some cases, the test can identify bladder cancer almost six months before other tests. However, the FISH test is more expensive than cystoscopy and other testing methods, reports the MD Anderson Cancer Center.
The FISH test name is an acronym, standing for "fluorescence in situ hybridization." The test helps doctors to map a cell's genetic material and is useful for diagnosing cancer cells, explains WebMD. The FISH test can also provide doctors with an idea of a specific patient's likely response to certain chemotherapy drugs.
Unlike some diagnostic tests, the FISH test does not need to be performed on live cells and can identify minuscule genetic changes that other tests might miss, notes WebMD. In some cases, the FISH test may be performed along with cystoscopy, although this can lead to false positives and more emotional anxiety for the patient, according to the MD Anderson Cancer Center.
Doctors perform a FISH test by first taking a tissue sample from the patient and then attaching dyes to certain chromosomes in the tissue cells, notes WebMD. The dyes allow doctors to see any chromosome abnormalities common in cancer cells, including translocation, inversion, deletion and duplication.