SATURDAY, June 2, 2007 (HealthDay News) -- Researchers are discovering glimmers of hope in alternative therapies for various cancers.
Two studies being presented Saturday at the American Society of Clinical Oncology annual meeting in Chicago found some promise in ginseng in easing cancer-linked fatigue and flaxseed for the treatment of prostate cancer. A third study, however, seems to shut the door on shark cartilage as an antidote for lung cancer.
Flaxseed, when taken daily for 30 days, seemed to slow the growth of prostate tumors, researchers say.
In this study, 161 men scheduled to undergo prostatectomy were divided into four groups: one maintaining their regular diet; one taking 30 grams of flaxseed daily for a month prior to surgery; one in which men restricted their dietary fat; and one in which men took flaxseed and restricted their dietary fat.
Men who were taking flaxseed, in either the low-fat or normal diet group, had the slowest rate of tumor growth, reported researchers at Duke University.
The seed, which is high in omega-3 fatty acids and in lignans (an estrogen-like chemical), is thought to intervene in the processes that cause cells to multiply irregularly. It may also interrupt blood supply to a tumor.
Flaxseed is indigestible in its whole form but can be ground up and mixed in drinks or sprinkled on food.
The findings, said experts, were hopeful but still preliminary. Ultimately, though, flaxseed could have a significant benefit with little downside.
"I would buy flaxseed futures," said Dr. Richard Greenberg, chief of urologic oncology at Fox Chase Cancer Center in Philadelphia. "I wouldn't, at this point, tell everyone to go out and start doing this, but I think this is a very promising early start."
Scientists still need to determine how much flaxseed a person should take and what the long-term effects might be.
In another promising early study, researchers at the Mayo Clinic found that the herb ginseng may help alleviate fatigue in cancer patients.
Close to 300 patients were randomized to receive 750 milligrams, 1,000 milligrams or 2,000 milligrams of ginseng a day or a placebo. Participants had different types of cancer and were either in treatment or had completed treatment and had a life expectancy of at least six months. All had a history of fatigue. The herb used in the study was Wisconsin ginseng.
About a quarter of patients in the 1,000-milligram and 2,000-milligram groups reported "moderately better" or "much better" fatigue levels compared with just 10 percent in both the 750-milligram and placebo groups, the researchers found.
"We believe that Wisconsin ginseng deserves to be studied in a larger trial, and we are planning to do so in our research group," said researcher Debra L. Barton, an associate professor of oncology at Mayo Clinic.
On a more negative note, shark cartilage appeared to have no benefit on advanced non-small cell lung cancer.
Lung cancer, the leading cancer killer in both men and women, is notoriously difficult to treat.
This trial, the first of its kind, looked at an actual drug in development, AE-941 (Neovastat), not an over-the-counter supplement. The drug was developed by Aeterna Zentaris, which funded the trial in concert with the U.S. National Cancer Institute (NCI).
Cartilage does not have blood vessels, indicating that it may have properties that impede a tumor's blood supply. The public has also long believed that shark cartilage may have healing properties, because sharks have a low incidence of cancer.
For this Phase III study, initiated at the request of the NCI, almost 400 newly diagnosed lung cancer patients underwent chemotherapy and chemo-radiation and were then randomized to receive either shark cartilage or a placebo, both in the form of a liquid taken twice daily.
After a follow-up of almost four years, researchers could find no statistically significant difference in survival between patients taking shark cartilage (14.4 months) and those receiving a placebo (15.6 months).
"This is the first large, rigorous, scientifically done clinical trial of shark cartilage," said study author Dr. Charles Lu, an associate professor in the department of thoracic, head and neck medical oncology at M.D. Anderson Cancer Center in Texas. "For the first time, oncologists will have something to discuss with their patients. When the patient asks whether he or she should spend his money on shark cartilage, the oncologist can at least say there has been one large trial funded by the National Cancer Institute and, unfortunately, it was negative."
The company has stopped development of the product.
There's more on complementary and alternative cancer treatments at the U.S. National Cancer Institute.