A Kinder, Gentler Bladder Cancer Test
The results indicate a high degree of test sensitivity, Altieri says, meaning the presence of the molecule is a strong signal a tumor is present. At the same time, however, he notes that three of the patients with noncancerous urinary tract disease, and one patient with increased prostate specific-antigen, also tested positive for survivin.
This indicates the test may not be perfectly specific for bladder cancer and could therefore lead to false-positive results.
"Clearly, this study needs to be expanded in a much larger population," Altieri cautions. "We are following the three individuals who had a false-positive test and have found after six months had elapsed, that one of them did develop bladder cancer."
While more research is necessary, and approval by the FDA is required before the test can become routinely available, Altieri says the technology for performing the test already is available and could be performed by doctors at low cost.
Ultimately, if proven successful in future research, the test may be best used in combination with other diagnostic tests.
The survivin study is particularly promising because of the invasive and uncomfortable nature of cystoscopy, says Sudhir Srivastava, PhD, MPH, chief of the cancer biomarkers research group at the National Cancer Institute.
The effort to use survivin to detect bladder cancer recurrence is part of a broad scientific effort to develop biomarkers for a variety of diseases, Srivastava tells WebMD. But the problem of false-positives is one that plagues many of these efforts, some of which have been highly touted by commercial companies without appropriate scientific validation, he says.
"For many years, we have been discovering biomarkers and leaving it there, without taking it further along to prove whether they are clinically applicable," he says. "Validation studies are not very glamorous and do not get the same kind of funding and attention that discovery does."
For that reason, the NCI has developed an Early Detection Research Network to shepherd research on biomarkers from discovery to validation. And he says that the NCI is likely to instigate large-scale trials of survivin to validate the results found by Altieri and colleagues.