According to a story from Science Daily, researchers at the University of Michigan have discovered why it is possible for basal cell carcinomas, a common form of skin cancer, to regrow. Basal cell carcinomas are common in people with Gorlin syndrome, a genetically linked condition that dramatically increases the likelihood of an affected person to have cancer and other tumors throughout the body.
People with Gorlin syndrome normally have basal cell carcinomas present in multiple areas on the skin. Another common sign is the development of keratocystic odontogenic tumors on the jaw. Other signs and symptoms include intercranial calcification, skelatal abnormalities like those of the ribs and vertebrae, and distinct facial features. Women may develop tumors in the ovaries, and about ten percent of affected people develop cardiac fibromas. Cardiac fibromas may then cause irregular heartbeats. To learn more about Gorlin syndrome, click here.
While there is no cure for Gorlin syndrome, the common and numerous basal cell carcinomas are typically treated, often via surgery. However, this may not always be practical when there are a large number of carcinomas present or if there are located in areas where surgery would be impossible. A common and effective alternative is the targeted cancer treatment vismodegib. This therapy blocks a key pathway for basal cell carcinomas called Hedgehog, which kills the cancer cells.
While vismodegib is highly effective in killing basal cell carcinomas, it does have a noticeable weakness. When patients stop taking, the cancer often returns in the exact same location where it had been growing previously. Therefore, patients have to take the treatment for life if they want to remain cancer free. This not always ideal because of drug side effects, such as muscle cramps, fatigue, weight loss, and loss of taste.
In basal cell carcinomas, the cells on the outer edge of the tumor are not identical to the cells at the center. Outer cells are often able to persist under vismodegib treatment in a dormant state. The disparity in ability to survive vismodegib treatment came down to a pathway called Notch and the manner in which cells activated it. When the Notch pathway was expressed, cancer cells died much more easily.