Sally Ride's death: Why is pancreatic cancer so deadly?

Sally Ride in a 2009 file photo. (AP/Houston Chronicle)

Astronaut Sally Ride, the first U.S. woman in space, died today from pancreatic cancer at the age of 61, according to news reports.

As a group, pancreatic cancers come with a very low survival rate — 75 percent of patients die less than a year after diagnosis, and 94 percent die within five years, according to the Pancreatic Cancer Action Network (PCAN), an organization in Manhattan Beach, Calif., that champions research and patient and family support.

What is it about pancreatic cancer that makes it so lethal?

One reason is that the cancer is usually not found until its late stages, Michelle Duff, director of research and scientific affairs at PCAN, told MyHealthNewsDaily in an interview last year. "By the time most patients are diagnosed, the disease has already spread," Duff said.

The cancer often escapes early detection because patients display few warning signs that anything is wrong. When patients do experience symptoms, they are often vague aches and pains, such as indigestion or back pain, that can be attributed to other ailments. And unlike for breast cancer or prostate cancer, there are no screening tools available for pancreatic cancer, she said.

Only 8 percent of cases are diagnosed before the cancer has spread beyond the pancreas, according to the National Cancer Institute.

On top of being hard to detect, pancreatic cancer is very resistant to chemotherapy treatments, Duff said. And there are only three chemotherapy drugs approved by the Food and Drug Administration to treat it.

The best treatment option is surgery to remove the tumor, Duff said, but only 15 percent of patients have their pancreatic cancer detected in time for surgery. In the other cases, the cancer has already spread beyond the pancreas to other organs.

For this reason, the PCAN recommends that patients with pancreatic cancer consider participating in clinical trials testing new treatments.

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