(RxWiki News) Treating most cancers takes a multi-pronged approach. Surgery is often followed by radiation and/or chemotherapy. But one type of radiation may encourage the development of another cancer.
The study revealed that women who had received pelvic radiation had twice the risk of having bladder cancer as did patients who weren’t treated with radiation.
What’s important to point out though, is that the risk of bladder cancer was less than 1 percent for both groups.
"If you have trouble emptying your bladder, visit your doctor."
This study involving thousands of women who had been diagnosed with uterine cancer was directed by Guan Wu, MD, PhD, of the University of Rochester Medical Center.
Uterine cancer is the most common gynecologic cancer in the United States, affecting nearly 50,000 women annually. The standard of care involves surgery to remove the diseased uterus. In about 40 percent of cases, surgery is followed by radiation to kill any lingering cancer cells and to help keep the cancer from returning.
The radiation — high-powered x-ray energy — is delivered with an external beam that’s directed at the patient’s pelvis. Some women may also have radiotherapy that’s delivered with radioactive beads that are implanted internally — a process known as brachytherapy.
To investigate the possible link between uterine cancer radiation and the development of bladder cancer, Dr. Wu and team analyzed the medical records of 56,681 women who had been treated for uterine cancer between 1980 and 2005. The researchers gathered the data from the Surveillance, Epidemiology and End-Results (SEER) database.
Study participants had been treated with external beam radiation, and some of the women had also had brachytherapy.
After an average follow-up of 15 years, the researchers discovered that bladder cancer was diagnosed in 146 (0.93 percent) of 15,726 uterine cancer patients who received radiation treatment, compared to 197 (0.48 percent) of 40,955 of uterine cancer patients who did not receive radiotherapy.
Additionally, women with radiation-treated uterine cancer had a three times higher risk of developing a fatal form of bladder cancer than uterine cancer patients who didn’t have radiation treatment. But again, the percentages were quite small — 0.25 percent versus 0.09 percent.
The team also learned that the bladder cancers that developed in uterine cancer survivors were not significantly different than bladder cancers seen in women who never received radiation. In other words, they were no more aggressive or more advanced than bladder cancers in women who never had radiation.
These findings could help physicians be watchful, the authors suggested.
"Physicians who care for patients with a history of uterine cancer and pelvic radiation treatment should keep in mind the increased risk of bladder cancer," Dr. Wu said in a statement. "Proper clinical evaluation should be performed to avoid delayed diagnosis, which may improve the quality of care for this group of patients."
Signs of bladder cancer include painful or incomplete voiding and/or blood in the urine. The authors said such symptoms in women who have undergone pelvic radiation should be thoroughly evaluated.
This study was published in the December issue of BJU International.
Funding sources were not reported, and there were no conflicts of interest disclosed.