Stacy Erholtz, a 50-year-old mother with advanced multiple myeloma, is cancer-free after receiving a massive injection of measles virus. The news comes from a research study that was published Tuesday in the Mayo Clinic Proceedings journal. But don't jump to the conclusion that measles is the cure for cancer. It's more complex than that.
What did researchers give Stacy Erholtz that sent her cancer into remission?
The researchers, led by Dr. Stephen Russell, injected a specially engineered oncolytic measles virus into a vein in Ms. Erholtz's left arm – it was a virus specifically designed to kill cancer cells.
Is this a new kind of cancer treatment?
No. Oncolytic virotherapy has been around for decades. The concept is simple: Many years ago doctors noticed that cancer patients sometimes experience an improvement when they contract a viral infection like measles. This is because the body's natural response to a viral infection is to release two types of proteins: interferon triggers the immune response, and tumor necrosis factor kill cells. Today researchers are manipulating this naturally occurring response to target and kill cancer cells. Thousands of people with cancer have received oncolytic therapy, but it's usually a last resort. And the results have never been so impressive. Ms. Erholtz is the first patient with such progressive cancer to go into complete remission after receiving an oncolytic virotherapy.
How does this treatment compare to a routine measles vaccination?
The injection contained the live measles virus, but isn't the same thing as the routine measles vaccination. The researchers gave Ms. Erholtz enough live virus to vaccinate 10 million people – that's way more than a simple shot.
Why did the treatment work?
Ms. Erholtz had a very weak immune system due to the severity of her cancer, which made her susceptible to infection. After the injection, she had a fever and experienced severe nausea and vomiting. These side effects subsided with treatment and the many tumours throughout her body completely disappeared. (A small tumour appeared nine months later and was treated with radiation.) The study suggests that the treatment worked because there were no measles antibodies in Ms. Erholtz's blood. This means it is likely she was not previously exposed to the virus.
What does this mean for cancer treatment?
It's important to remember that Dr. Russell and his team only reported results for two patients in the study – and that only one of these patients went into remission after treatment. It's still too soon to apply the results of the study to a general population and there is still a lot more research to be done before oncolytic virotherapy becomes a widespread, first-line treatment for cancer.