Even When Diagnosed Early, Bladder Cancer Mortality Is Higher in Blacks

ANN ARBOR, Mich., Sept. 22 -- Bladder cancer is deadlier in blacks than whites, even when it is diagnosed early.

The 10-year mortality rate for blacks with bladder cancer was 24% versus a 15% mortality rate for whites, reported Cheryl T. Lee, M.D., of the University of Michigan, and colleagues, in the September issue of the Journal of Urology.

Blacks-especially black women--had significantly lower survival rates than whites for every stage of localized or regional bladder cancer, they wrote. Ten-year survival in black and white patients with similar tumor stage and grade was consistently worse in black patients, except those with metastasis. An adjusted multivariable model demonstrated a persistent survival disadvantage in black patients (HR 1.35, P <0.001).

And while bladder cancer is now diagnosed at an earlier stage than it was a decade ago, blacks were still diagnosed with a higher stage disease than were whites (P<0.001).

Data analyzed during the period 1993 to 1999 found that black women had a 15% higher rate of regional tumors than white men and women. During that period black women were consistently more likely to have distant metastases than black men or whites.

Dr. Lee and colleagues used the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) data to identify 93,093 patients with a new diagnosis of transitional cell carcinoma of the bladder from 1973 to 1999.

Disease-specific survival was defined as time from initial diagnosis to time of death related to bladder cancer. Tumors confined to the bladder were defined as localized, those with extravisecial extension and/or regional nodes were defined as regional, and patients with visceral metastases and/or nodal involvement above the pelvic brim.

They analyzed patient age, sex, race, marital status, treatment type, tumor grade and stage at diagnosis, and survival at five- and seven- year intervals.

Among the findings:

• Of the 93,093 bladder cancer patients in the SEER database, 89,481 were white and 3,612 were black.
• White patients were 15% to 20% more likely to be married than blacks (P<0.001).
• From 1973 to 1999 there was a small (1%) but significant increase in the number of white and black patients diagnosed with local disease (P<0.001) and (P=0.05).
• Surgery was the predominant treatment for both blacks and whites, but compared with white patients, black patients were less likely to be treated with transurethral resection of the bladder as definitive therapy and more likely to have total cystectomy (P<0.001).
• For same-grade disease, 10-year disease-specific survival was 10.5% less for blacks than whites in the analysis done from 1993 to 1999 (P<0.001).

The authors wrote that while it is encouraging that more blacks are now being diagnosed with localized disease, the 68% rate of localized disease in black patients in the 1993 to 1999 interval is still well below the 80% rate of localized tumors observed in white patients.

At every time interval analyzed, black patients were consistently diagnosed with higher grade tumors than white patients, they wrote.

The authors said the study was limited by the small number of black patients available for evaluation "which could offer a biased view of the black population as a whole."

Moreover, the SEER database does not include information on patient comorbidity, which could adversely affect survival.

In an editorial comment, Benjamin A. Spencer, M.D., and Mitchell G. Benson, M.D., both of Columbia University in New York, agreed that information missing from the SEER database-specifically information about access to care and quality of care-could also explain some of the survival differences reported by Dr. Lee and colleagues.