Jill Stein

May 10, 2010

May 10, 2010 (Barcelona, Spain) — Researchers report a "worrisome" increase in metastatic bladder cancer at the time of initial presentation.

The new data, released here at the European Association of Urology 25th Annual Congress, show that the overall incidence of metastatic disease at the time the patient is initially diagnosed with bladder cancer increased by approximately 1.7% per year from 1988 to 2006. The increase was statistically significant.

The findings come from an analysis of trends observed in a large American population-based cancer registry, known as the Surveillance, Epidemiology, and End Results (SEER) database.

"The results can be troublesome, and may reflect changes in the bio-psycho-social patterns of bladder cancer," Daniel Liberman, MD, a urology resident at the University of Montreal Health Center, in Quebec, told Medscape Urology in an interview. Dr. Liberman works with study coauthor Pierre Karakiewicz, MD, who is director of the Cancer Prognostics and Health Outcomes Unit at the University of Montreal Health Center.

Another possibility is that the findings don't represent a true increase in the frequency of metastatic bladder cancer at diagnosis, but rather improved diagnostic methods, he added. "Nowadays, with more sensitive imaging available, we are more likely to pick up metastases that weren't detectable 20 years ago using only computerized tomography."

A mortality study is probably the best way to determine the reasons for the increased incidence of metastatic bladder cancer, Dr. Liberman noted.

Information on Temporal Patterns in Bladder Cancer is Lacking

Although bladder cancer is the fourth most common cancer in men and the ninth most common cancer in women, and 20% to 40% of cases are muscle-invasive at diagnosis, there is a paucity of data on temporal trends in the stage at diagnosis in community-based populations," Dr. Liberman pointed out.

The Canadian group reviewed data from 22,327 patients with a diagnosis of bladder cancer across all stages who were included in the National Cancer Institute's SEER 17 registry, conducted between 1988 and 2006. The SEER 17 registry comprises about 25% of the American population. All SEER registries routinely collect data on patient demographics, cancer type and site, stage, first course of treatment, and follow-up vital status.

"Importantly, although the SEER registries include only cancer patients in the United States, the information gleaned from the various analyses is 'translatable' worldwide," Dr. Liberman said.

Trend is "Disturbing"

The overall results showed an increase in the yearly incidence of metastatic bladder cancer at diagnosis of 1.7%.

The analysis also showed that being female, being single, divorced, or widowed, and having a high tumor grade predicted advanced stage at diagnosis.

Dr. Liberman pointed out that population-based registries like the SEER database provide an accurate gauge of metastatic bladder cancer in the community, where the majority of patients are treated. "Normally, when you read a paper in the New England Journal of Medicine, JAMA, and so on, the information comes from tertiary care centers, which employ world-famous uro-oncologists and have a very biased kind of population," he said. "The SEER database, by contrast, has information that is largely derived from community-based institutions. While it's important to know what's going on at Harvard, it's also important to know what's going on in rural Louisiana."

Regardless of the reasons for the increase in metastatic bladder cancer rates, the findings are a cause for concern, Dr. Liberman pointed out. Primary care physicians and patients should be better sensitized to the warning signs of bladder cancer, so that patients can present to their primary care physician for an earlier evaluation.

"This is an important study because it suggests that the biology of the disease is changing and is potentially becoming more aggressive," Daniel Petrylak, MD, professor of medicine (oncology) at Columbia University Medical Center in New York City, told Medscape Urology. "It would be important to understand why, biologically, there appears to be a higher rate of metastatic bladder cancer. Moreover, although a small but significant fraction of metastatic patients are cured with systemic therapy, it would also be important to note whether the patients are behaving the same clinically."

"The observed increase in the rate of metastasis at the time of bladder cancer is extremely concerning, given the broad decline in metastatic disease seem among other cancers within the same time period," Samir Taneja, MD, the James M. Neissa and Janet Riha Neissa Associate Professor of Urologic Oncology and director of the Division of Urologic Oncology at NYU Langone Medical Center in New York City, told Medscape Urology.

"As bladder cancer is not a malignancy for which routine screening has proven beneficial or feasible, early aggressive treatment at the time of diagnosis of invasive disease is critical in maintaining maximal oncologic efficacy for bladder cancer."

Dr. Taneja also noted that given the desire to preserve the bladder through conservative therapies, a delay in referral for bladder removal, as the authors suggested, might be a major factor in the observed increase in metastatic disease.

Although an exact cause for delays in treatment cannot be determined from this study, a number of other factors — including absence of published clinical management guidelines, concern regarding the complexity of bladder removal/reconstruction, and financial disincentives towards bladder removal — may all add, in part, to the delay in treatment, Dr. Taneja said.

Dr. Liberman, Dr. Petrylak, and Dr. Taneja have disclosed no relevant financial relationships.

European Association of Urology (EAU) 25th Annual Congress: Abstract 41. Presented April 17, 2010.

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