DURHAM, N.C. — Could pancreatic cancer be a thing of the past? A study by a team at Duke University could soon make this a reality. Their latest research on pancreatic cancer found a gel-like, radioactive treatment that not only slowed down cancer growth, but also obliterated 80 percent of tumors in mice. The treatment worked even on mice with hard-to-treat tumors.
“We did a deep dive through over 1,100 treatments across preclinical models and never found results where the tumors shrank away and disappeared like ours did,” says Jeff Schaal, who conducted the research during his PhD study at Duke, in a university release. “When the rest of the literature is saying that what we’re seeing doesn’t happen, that’s when we knew we had something extremely interesting.”
Pancreatic cancer makes up 3.2 percent of all cancer cases. Despite the low case rate, it is difficult to treat and is currently the third leading cause of cancer-related death. The reason for this is because pancreatic tumors often form aggressive genetic mutations that current cancer drugs cannot defeat. Moreover, doctors often find pancreatic cancer in its late stages, when the disease has already spread to other parts of the body.
Current pancreatic treatments use chemotherapy to stop cells from reproducing with a beam of radiation targeted at the tumor. However, this is not a guaranteed cure-all, as a certain amount of radiation needs to reach the tumor for it to take effect. That threshold is hard to achieve without producing severe side-effects for the patient.
Another proposed method involved implanting a radioactive sample covered in titanium directly into the tumor. However, titanium can cause extensive damage to the body if doctors leave it in for a long period of time.
“There’s just no good way to treat pancreatic cancer right now,” says Schaal.
Gel provides a better cancer drug vessel
The study’s experimental approach involves using chemotherapy drugs already in use with a new method for exposing the tumor to radiation. Instead of an external beam that travels across healthy tissue to get to the tumor, the treatment adds radioactive iodine-131 directly into the tumor. Scientists insert the radioactive iodine-131 into a gel-like substance, avoiding interaction with healthy and non-cancerous tissue. When the iodine-131 is absorbed by the body, the radiation fades away.
The study authors tested the new treatment in combination with the chemotherapy drug paclitaxel on several mouse models of pancreatic cancer. The cancers in mice occurred under the skin through several genetic mutations known to cause the disease. They also had another group of mice with tumors within the pancreas, which is much more difficult to treat.
The approach had a 100-percent response rate in all mouse models and was successful in getting rid of 80 percent of tumors. Additionally, the test did not produce any additional side-effects beyond the ones resulting from chemotherapy.
“We think the constant radiation allows the drugs to interact with its effects more strongly than external beam therapy allows,” explains Schaal. “That makes us think that this approach might actually work better than external beam therapy for many other cancers, too.”
Since researchers tested the new approach on mice, it will take a while before scientists consider it safe to try on humans. The next step researchers are taking is conducting large animal trials to show the technique is doable using existing clinical tools and endoscopy techniques doctors already use. If it works, there’s hope for getting the green light on a phase 1 clinical trial in humans.
The study is published in the journal Nature Biomedical Engineering.