Researchers are hoping they’ve found a new weapon in the war on breast cancer — freezing tumors.
A new study carried out by researchers from the University of Michigan Comprehensive Cancer Center found that freezing breast tumors helps stop the spread of cancer in mice.
A new clinical trial is underway to evaluate this technique for human patients and could potentially lead to improved survival rates over surgery for breast cancer.
Breast cancer is the third leading cause of death for women in the U.S. The University of Michigan study, which appears in the “Annals of Surgical Oncology,” looked at two different cryoablation [freezing] techniques. Both involved applying a cold probe to a tumor to freeze it. One entailed the rapid freezing of the tumor (in about 30 seconds) and the other involved freezing the tumor more slowly.
The results: the benefit from the rapid freezing is more effective and is likely due to changes in the immune system that help to kill the tumor. Freezing with the slower technique appeared to make the immune system not as able to kill the tumor. Both tests were compared to results from mice that underwent surgery to remove the tumors.
Researchers found that the mice treated with the rapid freeze had fewer tumors that spread to the lungs and improved survival compared to mice treated with surgery alone or mice treated with the slower freezing.
The good news for breast cancer patients is that this freezing technique has the potential to be a powerful treatment tool for the treatment of breast cancer, says lead study author Michael Sabel M.D., associate professor of surgery at the U-M Medical School. An estimated 192,280 Americans will be diagnosed with breast cancer this year and 40,610 who will die from the disease, according to the American Cancer Society.
“Cryoablation has strong potential as a treatment for breast cancer,” says Dr. Sabel. “Not only does it appear effective in treating the primary tumor with little cosmetic concerns, but it also may stimulate an immune response capable of eradicating any cells that have traveled throughout the body, reducing both local and distant recurrence, similar to giving a breast cancer vaccine.”
But what researchers also learned is that much of the success relies on the technique used to freeze the tumors, which can have “a significant impact on how the immune system responds,” says Dr. Sabel. “The system we use today appears to be ideal for both destroying the tumor within the breast and generating an anti-cancer immune response.”
Cryoablation has also recently reported improved treatment of prostate cancer, and it has been reported to show promise for kidney patients who are not good candidates for surgery, as well as treatment for a variety of cancers that have spread to the liver and bone.
Laurence Wagman, M.D., medical director of the Center for Cancer Treatment and Prevention at St. Joseph Hospital in Orange, California, has used cryoablation for his prostate cancer patients. He found that the freezing of the prostate gland can destroy cancerous cells.
“It has been well-known to physicians that extreme temperatures, either hot or cold, can destroy biological tissues,” says Dr. Wagman.
The University of Michigan researchers are participating in a national clinical trial to evaluate using cryoablation for early stage breast cancer. Participants will undergo rapid freezing of their tumor, and their blood samples will be analyzed to assess changes in their immune system. All participants will be treated three to four weeks later with standard surgery to remove their tumor.