Thinking out of the box, a new concept to fight cancer, including prostate cancer, has been developed. The strategy is simple, fight cancer with cancer!
In a very small phase one trial researchers at the Rogosin Institute have taken encapsulated tumor cells from mice and made a bead from a seaweed-derived sugar called agarose. Then, they implanted them into the abdomen of cancer patients. These beads secreted proteins that the researchers believe signaled a patient’s cancer to stop growing, shrink or die.
Will this concept work in humans? It’s too early to know, but in studies involving laboratory mice, dogs and cats the beads have substantially reduced the size of tumors. In some cases, it has also extended the survival time in the test animals; this is according to two peer reviewed articles being published today in the journal Cancer Research.
The good news is that there has slready been a small 30 patient human study using the cancer beads and there is a new phase two trial being launched to test this technique in patients with advanced colon, pancreatic and prostate cancers.
As I have mentioned many times, treatment strategies that work on the bench in the lab, in animals and even phase one and phase two trials don’t necessarily work in humans. If the cancer beads work in people, it would challenge long-standing conventional views about the nature of cancer, that cancer is just the wild and uncontrolled regeneration of cells. If successful, this approach to cancer treatment could open up a whole new approach for attacking cancer.
Howard L. Parnes, a researcher in the division of cancer prevention at the National Cancer Institute (NCI) who is familiar with the work but wasn’t involved with it said, “This is a completely novel way of thinking about cancer biology…. We talk about thinking outside the box. It’s hard to think of a better example.”
Barry Smith, director of the Rogosin Institute, which is an independent treatment and research center affiliated with Weill Cornell Medical College and New York Presbyterian Hospital, has stated that in animal and human studies so far, there has been no evidence that putting mouse tumors into humans or other species causes any harm or serious side effects. Moreover, when they put human cancer cells in the beads and implanted them in mice, they saw the mouse cancer recede.
Dr. Parnes also said, “They demonstrate a remarkable proof of principle that tumor cells from one animal can be manipulated to produce factors that can inhibit the growth of cancers in other animals.”
This novel concept underlying this strategy is that even tumor cells reach a point where when they’re surrounded by enough similar cells that growth regulators kick in and instruct them to stop proliferating. Dr. Smith and his colleagues believe the proteins secreted by the encapsulated tumor cells (the beads) trick the patient’s actual tumor cells into sensing similar cells are nearby, thus slowing down their proliferation.
When manufactured, the beads initially contain about 150,000 mouse kidney cancer cells which are mixed with agarose and then wrapped with a layer of agarose to creates a shell. The beads are then incubated in a culture where within days, 99% of the tumor cells die. The remaining cells have characteristics of cancer stem cells. The cells then produce inhibitory factors that seem to regulate cancer tumor growth.
The beads that will be used in the upcoming human study are about the size of a pea. They will be implanted in the abdominal cavity with the number of beads to be determined by body weight, but typically it involves 550 and 750 beads per treatment. The hypothesis is that in the body, the inhibitory factors are secreted by the beads, picked up by the bloodstream and detected by tumor cells outside the bead. Researchers believe the treatment effect begins to wane after about four months, but they also believe that re-treatment will be possible.
In the research being published today, Dr. Smith and his colleagues reported that in mice implanted with tumors, treatment with the cancer beads resulted 30 days later in tumors that were 30% to 60% smaller than tumors in untreated mice. Among 54 dogs and cats, whose cancers occurred naturally, treatment with the beads was associated with longer-than-expected survival and in some cases, near-eradication of tumors. There wasn’t a control group in the treatments involving dogs and cats, pets that had failed conventional treatment and whose owners agreed to try the experimental technique.
In one group of 11 dogs with prostate cancer that were treated with the beads, the median survival from diagnosis was 177 days, or nearly six months, compared to an expected survival of less than 50 days. One of the dogs lived for more than two years. A cat with breast cancer who received four treatments with the beads lived eight years after the initial diagnosis before dying of the disease.
“The lab data looks very compelling,” says Daniel P. Petrylak, director of the prostate-cancer program at Columbia University Medical Center. Dr. Petrylak was not involved in the basic research and says he was initially skeptical of the approach, but he now plans on enrolling prostate cancer patients in the phase-two study.
Dr. Smith says research so far indicates more than 700 different proteins or small proteins called peptides are secreted by the beads, including 25 to 30 that are known to have anti-tumor effects. Among those are factors that turn up processes that promote cell death and reduce a cell’s ability to induce formation of blood vessels needed to survive.
This “out of the box” strategy bears serious monitoring and might be a new “On The Horizon” treatment modality for not only the treatment of prostate cancer, but for many other cancers.
Joel T Nowak, M.A., M.S.W.