MONDAY, March 9 (HealthDay News) -- A new technique that more accurately determines the stage of bladder cancer could help reduce the number of bladder removals, a new study says.

U.S. researchers studied 70 bladder cancer specimens and found that the technique was about 95 percent accurate in identifying bladder cancer that can be treated without removing the bladder. The findings were expected to be presented in Boston Monday at the annual meeting of the United States and Canadian Academy of Pathology.

"The results are very encouraging. However, we still need to be cautious. The technique needs to be studied further," Dr. Gladell Paner, assistant professor in the pathology department at the Stritch School of Medicine, Loyola University Chicago, said in a university news release.

In the early stages (0 and 1) of bladder cancer, the tumor is confined to the surface or just below the surface of the bladder. These stages generally don't require removal of the bladder. In stage 2 and later stages, the cancer has penetrated to a deep muscle layer, typically requiring partial or total removal of the bladder.

In some cases, stage 2 cancer can resemble stage 1, because a layer of muscle near the surface can look like the deep-layer muscle. In as many as 4 percent of biopsies, it's extremely difficult to distinguish between stages 1 and 2, Paner said, but confusing these stages can lead to unnecessary removal of the bladder.

Paner developed the new technique, in which bladder cancer samples are exposed to an antibody called smoothelin. The antibody reacts strongly with deep muscle but does not react with muscle taken from near the surface of the bladder.

In the study, Paner found that this method was 97.9 percent accurate in identifying specimens with deep muscle and 95.2 percent accurate in identifying specimens without deep muscle.

About 69,000 people were diagnosed with bladder cancer in the United States last year, and about 14,000 died of the disease, according to the American Cancer Society.

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