Reuters Health Information (2014-04-04): Study identifies potential SNPs for personalized bladder cancer care

Clinical

Study identifies potential SNPs for personalized bladder cancer care

Last Updated: 2014-04-04 12:06:59 -0400 (Reuters Health)

NEW YORK (Reuters Health) - A new 563-patient study has identified single-nucleotide polymorphisms (SNPs) that could be candidates for use in personalized bladder cancer surveillance and treatment.

"Our present data suggest novel associations between SNPs and bladder cancer recurrence that merit future investigation," Dr. Angeline Andrew of the Geisel School of Medicine in Lebanon, New Hampshire and her colleagues write. "Prognostic variations will help identify sub-groups of bladder cancer cases at high risk of tumor recurrence and progression for more intensive tumor surveillance and targeted treatment regimens."

Dr. Andrew and her team looked at variants in about 400 genes associated with key processes in carcinogenesis, including apoptosis, proliferation, DNA repair, hormone regulation, immune surveillance, and cellular metabolism. They used data from the New Hampshire State Cancer Registry on 783 patients diagnosed with bladder cancer. Patients in the study were followed for a median of 5.4 years, during which time half had at least one recurrence and 40% died. A total of 563 patients had adequate DNA samples for analysis.

The investigators found a shorter time to recurrence in bladder cancer patients with aldehyde dehydrogenase 2 (ALDH2) variants, while patients with non-invasive tumors who were heterozygous for DNA repair X-ray repair cross-complementing protein 4 (XRCC4) had a longer survival than those with the wild-type variant. The investigators also found a shorter time to recurrence in patients with a variant allele in vascular cellular adhesion molecule 1 (VCAM1) who received immunotherapy.

The results, published in BJU International online March 26, were concordant when the investigators divided the patients into two groups based on date of cancer diagnosis and analyzed them separately.

Dr. Lambertus Kiemeney, a cancer epidemiologist at Radboud University Medical Center in Nijmegen, the Netherlands, reviewed the study for Reuters Health. "Although this is a nice study and corrections were made for multiple testing, an important disadvantage is that there is no external validation of the results," he said via email.

"We have seen many suggestions in the past for good prognosticators which all turned out to be false positive results," he added. "An external validation would have been great. There are data out there that could have been used and I don't understand why they weren't."

Before the information from the current study can be used clinically, Dr. Kiemeney added, "there should be replication and validation of the results. Even better, there should be hypothesis-free genome wide association studies on prognosis in bladder cancer."

Dr. Andrew did not respond to a request for comments.

SOURCE: http://bit.ly/1lBOlUP

BJU Int 2014.