BARCELONA—Researchers have documented a small but significant stage migration in metastatic bladder cancer between 1988 and 2006.
Their findings revealed a roughly 1.7% annual increase over the study period in the incidence of metastatic disease at the time the patient is diagnosed with bladder cancer. Female gender, single/divorced/widowed status and high tumor grade predicted metastatic disease at diagnosis.
“We are not sure why there a trend towards increased metastatic disease at the time of bladder cancer diagnosis, but we think it may be due to the availability of more sensitive diagnostic imaging methods for patients presenting with some sort of urological symptom,” Daniel Liberman, MD, a urology resident at the University of Montreal Health Center, said at the 25th Anniversary European Association of Urology Congress.
“Diagnostic technology is improving and expanding exponentially,” he said. “We are catching smaller lesions and smaller advanced cancers than we did before. We used to have computed tomography (CT) scans that provided slices that were 4 mm in depth but the resolution is better nowadays so that we can see CT slices that are 1 mm in depth.”
Dr. Liberman and his collaborators reviewed data from 22,327 patients with a diagnosis of bladder cancer across all stages who were being tracked in the database of the National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) 17 registry, which was conducted between 1988 and 2006 and includes about 25% of the American population.
Bladder cancer is the fourth most common cancer in men and the ninth most common cancer in women, Dr. Liberman pointed out. From 20% to 40% of cases are muscle-invasive at diagnosis.
There is a lack of information on temporal trends in the stage at diagnosis in community-based populations, he said.
Prior to their analysis, the researchers hypothesized that “contemporary” patients will present with more advanced disease stage due to the evolution in metastasis assessment and patient selection.
Most reports on metastatic bladder cancer in the medical literature to date have been drawn from the tertiary care setting while the SEER database provides information obtained in the community setting, Dr. Liberman observed. “This is important because most patients are seen in the community and not at tertiary care institutions,” he said. “At tertiary care centers, patients are managed with state-of-the art technology and procedures which may not be available at community hospitals. I am not saying that a study done at a community hospital is any more valuable than one done at a tertiary center, but rather that it’s just as important to know what the regular urologist is doing in a community-based hospital as it is to know what an academic urologist is doing at a tertiary center in a large metropolis.”