Patients with prostate cancer that has metastasized, or spread, to other parts of the body face a significantly higher risk of dying when visiting a hospital emergency department on the weekend instead of on a weekday, according to researchers at Henry Ford Hospital in Detroit.
The new study focused on metastatic prostate cancer in examining the so-called “weekend effect” of higher patient mortality, subject of numerous studies for about a decade.
Results from the study will be presented May 5 at the annual meeting of the American Urological Association in San Diego.
Khurshid R. Ghani, M.D., of Henry Ford’s Vattikuti Urology Institute and lead author of the study, said he and his colleagues can only speculate on the reasons why this phenomenon appears to affect metastatic prostate cancer patients.
“Our data clearly show they have higher mortality rates after weekend visits to emergency departments,” Dr. Ghani says. “But as to why, there is only a suggestion that they’re more likely being treated at hospitals outside of metropolitan areas, places that may have limited access to advanced care.”
The researchers identified their study group – metastatic prostate cancer patients who visited emergency rooms from the beginning of 2006 through the end of 2009 – in the Nationwide Emergency Department Sample, the largest such database in the U.S., approximating about 20 percent of hospital-based emergency departments across the country.
The prostate is a glandular organ of the male reproductive system. It is often described as the same size of a walnut, normally about 3 cm long (slightly more than 1 inch); it weighs about 30 g (1 ounce) and is located at the neck of the bladder and in front of the rectum. The prostate surrounds the urethra, which is a tubular structure that carries the urine (produced by the kidney and stored in the bladder) out of the penis during voiding, and the sperm (produced in the testicle) during ejaculation. In addition, during ejaculation a thin, milky fluid produced by the prostate is added to the mix. This ejaculate that also includes fluid from the seminal vesicles, constitutes the male semen.
In prostate cancer, normal cells undergo a transformation in which they not only grow and multiply without normal controls, but they also differentiate and can invade adjacent tissues. Tumors overwhelm surrounding tissues by invading their space and taking vital oxygen and nutrients. Tumors can eventually invade remote organs via the bloodstream and the lymphatic system.
This process of invading and spreading to other organs is called metastasis. Common metastatic locations include pelvic lymph nodes, bones, lung, and the liver.
Almost all prostate cancers arise from the secretory glandular cells in the prostate. Cancer arising from a glandular cell is known as adenocarcinoma. Therefore, the most common type of prostate cancer is an adenocarcinoma and accounts for more than 95% of all prostate cancer. The most common nonadenocarcinoma is transitional cell carcinoma. Other rare types include small cell carcinoma and sarcoma.
Of the 15,365 men in this group, 3,943 made weekend visits to emergency departments and 11,422 went on weekdays. A total of 9.3 percent in the weekend group died after their visit, compared to 7.7 percent after a weekday visit.
In theory, prostate cancer cells can spread anywhere in the body. In practice, though, most cases of prostate cancer metastasis occur in the lymph nodes and the bones.
Prostate cancer metastasis occurs when cells break away from the tumor in the prostate. The cancer cells can travel through the lymphatic system or the bloodstream to other areas of the body.
More commonly prostate cancer metastasis can occur in the:
Rare locations of prostate cancer metastasis include:
The data also showed that patients seen on the weekend were:
Older, with a mean age of 75.1 versus 74.1.
Healthier, having fewer additional diseases or disorders.
More likely to visit a non-metropolitan hospital, 19.5 percent versus 14.1 percent.
Less likely to be suffering acute renal failure, 14.7 percent versus 16.6 percent.
More likely to have blood in their urine, 18.8 percent versus 17.2 percent.
“After adjusting for age and the presence of disease or disorders other than metastatic prostate cancer, weekend visits were associated with a 23 percent increased likelihood of death,” Dr. Ghani says.
Henry Ford Health System