Local experts target stress hormones in fight against cancer
The treatment method will now be tested on patients at Sheba Medical Center, Tel Hashomer, starting with individuals suffering from colon-cancer.
A method developed by Tel Aviv University researchers to treat cancer by targeting stress hormones will now be tested on humans, starting with colon-cancer patients at Sheba Medical Center, Tel Hashomer.
The study, partly supported by the U.S. National Institutes of Health, is being led by Prof. Shamgar Ben-Eliyahu, head of the university's psychology department and an expert on neuropsychoimmunology - the influence of the nervous system on the immune system.
Over the past 10 years, the researchers managed to bring down by a double-digit percentage the chances of metastasis in animals in which a primary malignant tumor had been removed. The animals' chances for long-term survival significantly increased.
By the time a cancer patient undergoes an operation to remove a primary tumor, the tumor may have already metastasized throughout his body, a process that might continue during the operation itself. As a result, new tumors may appear in the months and years after the operation.
Although surgery is still seen as as the mainstay of cancer treatment, chances of postoperative metastases are estimated at 40 percent to 50 percent among colon-cancer patients, 25 percent among breast-cancer patients, and up to 90 percent among lung-cancer patients.
Ben-Eliyahu noted that certain hormones "are released in great quantities when the body is in a state of stress and when it is exposed to invasive surgery that damages tissue." This increases the chance for metastasis.
The researchers found that these hormones suppress lymphocytes in a manner that may provoke metastasis and help cancer cells that remain in the body after an operation develop into dangerous tumors.
Medicine that delays the release of the hormones or disables them has lowered the chances for metastasis among rats and mice in experiments. When the animals were exposed to breast or colon cancer, the treatment brought down chances of metastasis by more than half.
Similar results were obtained with rats exposed to blood cancer. In mice in which a primary lung or skin tumor was removed, only half experienced metastasis. These results were published in the Journal of Immunology last year.
The medicines propranorol and etodolac are now being tested on colon-cancer patients, in cooperation with Dr. Oded Zmora of Sheba's surgery department. The patients receive pills twice a day, from five days before an operation and up to two weeks after it, with gradually lower dosage.
The research aims to include 400 patients, and if more funding is secured, it will be expanded to other kinds of cancer such as pancreatic and breast cancer.
The initial phase is supported by the International Monetary Fund.
"Moving from successful testing on animals to clinical testing on cancer patients is complicated and expensive; it's also the moment of truth for any new treatment," said Ben-Eliyahu. "We're hoping for further significant donations to allow that to happen."
He said the product could also have added value psychologically. "The treatment may also reduce anxiety common before an operation, but this is secondary," he said. "Our efforts are directed mainly at finding out whether the treatment can prevent immunological suppression and prevent the development of metastases."