However, researchers from Baylor College of Medicine in Houston are hoping to change that with the help of thalidomide, a drug that became infamous for causing birth defects.
"Kidney cancer patients with metastatic cancer at the time of diagnosis have an average survival of about 11 months," says Dr. Robert Amato, lead researcher and an associate professor of urology at Baylor. "We are looking at the merits of combining thalidomide with interleukin 2. There is some promising data unfolding with this combination."
Every year, 30,000 Americans are diagnosed with kidney cancer. It is twice as common in males as it is in females, according to the Kidney Cancer Association. Symptoms of the disease include blood in the urine and back pain. Since back pain is a common symptom, people often ignore it until the cancer has spread. The association estimates the cancer has metastasized to other parts of the body in 15 percent to 25 percent of kidney cancer patients by the time they are diagnosed with the disease.
Amato and his colleagues recruited 15 people with metastatic kidney cancer to test whether combining the commonly used interleukin 2 with thalidomide would work.
Interleukin 2 helps the immune system recognize the presence of cancer cells. Studies of interleukin 2 treatment alone show a partial positive response in 30 percent to 40 percent of the cases, says Dr. Samir Taneja, a urologist at New York University Medical Center. Taneja says there's no real cure for metastatic kidney cancer, although about 5 percent of patients respond to current treatments.
Thalidomide, first marketed as a sleeping pill, is now used as a treatment for leprosy, some autoimmune diseases and some cancers because of its anti-inflammatory properties. The drug was taken off the shelves in the 1960s because it caused severe birth defects in the children of women who took the drug early in pregnancy. In recent years, doctors discovered it was an effective treatment for leprosy. Even with its newfound uses, people taking the drug must take many precautions -- most importantly, making sure they either don't get pregnant or don't impregnate anyone.
Thalidomide may work against cancer by limiting the development of new blood vessels, Taneja says. Without a constant blood supply, the cancer is starved and cannot thrive.
"Eight of the 15 patients in this Phase I study have had a benefit [from this drug combination]," says Amato. "That's a very small patient number, but quite interesting data."
Amato says the treatment was fairly well tolerated, and the most common side effects were sedation, fluid retention, skin rash and constipation.
The researchers are currently conducting the next phase of research on the combination with 33 patients.
Results of the study were presented today at the American Society of Clinical Oncologists meeting in Orlando, Fla.
"This is a promising study," Taneja says, but he cautions it was a very small study, designed to test for toxicity and side effects, so the results need to be replicated in larger studies.
What To Do
To learn more about thalidomide, check out the National Institutes of Health National Toxicology Program.