From Washington University School of Medicine
Bladder cancer returns sooner with each recurrence, study shows St. Louis, September 4, 2002 -- A study by researchers at Washington University School of Medicine in St. Louis has found that the number of months between recurrences of superficial bladder cancer progressively shortens with each recurrence. The study also identified two proteins in tumor cells that may help predict the risk of a first or second recurrence. The findings will be published online Sept. 5 in the journal Cancer and in the Sept. 15 print edition.
"Our findings may help improve the guidelines doctors use for follow-up care for superficial bladder cancer," says lead author Yan Yan, MD, Ph.D., assistant professor of surgery. "They also could lead to a better understanding of why these tumors recur."
Doctors will diagnose some 56,500 new cases of bladder cancer this year, according to the American Cancer Society. It is the fourth most common cancer in men and the ninth most common in women. About 80 percent of those cases are superficial bladder cancer, cancer that has not yet invaded the deeper layers of the bladder wall. The disease recurs in more than half of those patients and is fatal 20 percent of the time.
"Little is known about the biology of multiple sequential recurrent tumors or about which patients are most at risk for sequential recurrence," says Yan, who also is a member of the cancer prevention and control program at the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine.
The study involved 270 patients with superficial bladder cancer who were treated between January 1994 and April 1999; follow-up time ranged from one to 54 months. Of these patients, 47 percent had one or more recurrences, 14 percent had two or more recurrences, and 5 percent had three or more recurrences. The researchers found that the average time from initial treatment to first recurrence was 23 months, while the time to second and third recurrence averaged 15 and 13 months respectively.
The investigators also tested each patient's tumor tissue for several tumor markers, proteins that often are associated with cancer. Patients whose original tumor tested positive for the marker Ki-67 had a 49 percent higher risk for a first recurrence than did patients whose tumors lacked the marker.
Tumors that recurred and tested positive for the p53 protein were at 173 percent greater risk for an additional recurrence. The researchers found no statistically significant link between p53 and the risk of a first recurrence.
"The finding that Ki-67 is important for the first recurrence and p53 is important for a second recurrence came as a surprise," says Yan. "It raises questions that might lead to a better understanding of the mechanics of recurrence."
The study also confirmed that a tumor's stage and grade remain the most import factors in determining a patient's prognosis and probability of recurrence. Tumor stage refers to the degree to which a tumor has penetrated the organ; tumor grade classifies a tumor according to its microscopic appearance.
Yan now plans to examine the timing of follow-up visits for patients with superficial bladder cancer. In light of the current findings, doctors may need to see some patients more often to adjust for the progressively faster recurrence pattern. But, the procedures needed to spot a recurrence are inconvenient and sometimes painful.
"Would patients prefer fewer uncomfortable exams but later tumor detection, or more exams and earlier detection?" asks Yan. "Patients must decide for themselves, but we can provide them with information and help as they make the decision."
Yan Y, Andriole GL, Humphrey PA, Kibel AS. Patterns of multiple recurrences of superficial (Ta/T1) transitional cell carcinoma of bladder and effects of clinicopathologic and biochemical factors. Cancer, 95(6), 1239-1246, Sept. 15, 2002.
The full-time and volunteer faculty of Washington University School of Medicine are the physicians and surgeons of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.