Researchers have shown for the first time that the quality of diagnostic staging using biopsy in patients with bladder cancer is directly linked with survival, meaning those whose biopsies are not optimal are more likely to die from their disease.
The 2-year study found that insufficient material was collected (ie, no bladder wall muscle was retrieved) from approximately half of the 1,865 patients with bladder cancer who underwent biopsy to accurately stage the cancer. In addition, suboptimal biopsy and incorrect tumor staging was found to be associated with a significant increase in death from bladder cancer, said study first author Karim Chamie, MD, an assistant professor of urology and surgical director of the bladder cancer program at the University of California Los Angeles.
“These findings are very important because while patients know about the stage of their cancer, they rarely question the quality of the biopsy,” said Chamie. “We hope these findings will help empower patients to ask about the quality of their biopsy and, if it is suboptimal, then urge their doctors to repeat the biopsy prior to deciding on what type of treatment to prescribe.”
Chamie said that many times, biopsies only take tissue from the inner lining of the bladder itself, ignoring the underlying muscle wall. If the cancer has started to invade, tissue from the muscle wall needs to be examined to determine the next course of treatment.
For the study, published in Cancer (2014; doi:10.1002/cncr.29071), the researchers reviewed the medical records of every patient with a diagnosis of noninvasive bladder cancer during 2004 and 2005 across medical institutes in Los Angeles County. Biopsy and surgery reports were reviewed.
The team found that about half the time, the surgeon either did not do an adequate biopsy or the pathologist did not clearly state the extent of the cancer invasion. When patients had aggressive tumors and their surgeons and pathologists appropriately staged them, the chance of dying of bladder cancer at 5 years was 8%.
If the staging was inadequate but the pathologist alerted the physician of it, the 5-year mortality rate was 12%. However, if the pathologist did not comment on the extent of the cancer invasion, then the 5-year mortality was 19%.
“Appropriately staging patients with bladder cancer is a skill set that every urologist and pathologist should have in his/her armamentarium,” Chamie said. “We believe the next step is to change the staging system for bladder cancer to incorporate the quality of staging. Not all stage I cancers are alike. Some patients may have stage II cancer, but because the biopsy was insufficient, these patients were inaccurately staged and may be undertreated. I really do believe that one reason why we have yet to see significant improvement in bladder cancer survival over the last two decades may, in part, be attributed to inadequate staging.”
The study states, “Because urologists cannot reliably discern between aggressive and indolent disease, we recommend that patients with bladder cancer should undergo adequate muscle sampling at the time of biopsy.”