Beads to Treat Cancer

Scientists have an exciting new treatment approach to cure advanced-stage ovarian and colorectal cancer. The bad news is that it has only been tested in mice. The good news is that testing it in humans is the next step and clinical trials could begin soon.

Ovaries are almond-sized organs on each side of the uterus in females. The ovaries release eggs and the hormones estrogen and progesterone that are important for sexual and reproductive development. Ovarian cancer affects 1 in 70 women. Age is a major risk factor, with two-thirds of all ovarian cancers being diagnosed in women between 50 and 75. Early symptoms of ovarian cancer are often not noticeable or non-specific. About 80% of women with ovarian cancer have advanced cancer by the time they are diagnosed. Survival rates depend on the specific type of ovarian cancer and how far it has spread.

Colorectal cancers arise in the cells that line either the colon or the rectum. These cancers usually start as a growth or polyp that over time progresses into cancer. Again, age is a risk factor in developing colorectal cancer along with having a direct relative with the disease. If the polyps are not found and removed, cancers can form. Eventually the cancer cells penetrate the wall of the colon and travel to other parts of the body through the blood or lymph vessels. As is the case for most cancers, early diagnosis leads to more successful treatment outcomes.

The new cancer treatment uses cells that have been engineered to produce natural cytokines such as interleukin-2 (IL-2) encased in a protective bead made of hydrogel. Cytokines are tiny molecular messengers that can activate the immune system. IL-2 in particular plays a critical role in regulating immune cells such as T cells, some of which can kill tumor cells.

The tiny beads holding the IL-2 producing cells are implanted into the abdomen so they are close to the affected organ. This allows the levels of IL-2 around the tumor to be much higher than would be tolerated if administered by IV injection. The beads can deliver IL-2 directly to the tumors in amounts about 30 times higher than in other parts of the body, targeting the cancer while reducing issues that result from IL-2 elsewhere in the body.

The hydrogel beads are recognized as foreign but not as immediate threats, so the cells inside are able to produce IL-2 for about 30 days before the body destroys them. These beads were tested in animal models of advanced ovarian and colorectal cancers. After 30 days, there was a significant reduction in tumors across all groups that received the beads when compared to control mice. The treatment eradicated tumors in all the animals with ovarian cancer and in seven of eight animals with colorectal cancer. The treatment did not result in significant side effects or toxicity.

Hopefully, these encouraging results in mice will translate into successful treatments of people with similar cancers.