Baseball All-Star Darren Daulton has been diagnosed with brain cancer. (Credit: Hunter Martin/Getty Images)

Darren Daulton, 51, who rose to fame when he led the Philadelphia Phillies to the World Series in 1993, has been diagnosed with brain cancer.

The All-Star player, nicknamed Dutch by Philadelphia fans, had "not been feeling well" during the last two weeks of June, prompting doctors to discover two brain tumors, according to 97.5 FM, where he hosted a nightly radio show after retiring from baseball. He underwent brain surgery last week and was diagnosed with glioblastoma, an aggressive brain cancer.

"It's actually one of the most rapidly growing cancers in people," said Dr. Reid Thompson, a neurosurgeon who directs the Vanderbilt Brain Tumor Center in Tennessee, who has not treated Daulton. "Glioblastoma can double in six weeks if not treated. I've seen situations where people had an MRI scan three or four months ago and then found a six centimeter tumor."

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Daulton returned to his home in Clearwater, Fla., and will start chemotherapy once he recovers from surgery, according to the radio station. Thompson said this is typical treatment.

It's rare for someone with glioblastoma to live more than two years after diagnosis because the tumors are apt to return after surgery and chemotherapy, Thompson said.

According to the South Jersey Times, Daulton is the fifth Phillies player to be diagnosed with a brain tumor. Tug McGraw died of the disease in 2004.

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When the station first announced news of Daulton's brain tumors on June 27, it included an email address for fans to write to and wish Daulton well. According to the station, the email address has received thousands of messages from supportive fans.

Researchers still have a lot to learn about these tumors, but they know they tend to be more common in certain geographic areas, Thompson said. The South, for instance, is considered a "hot spot," he said.

"Maybe it's something in the environment in the South or something in the Southern diet," he said. "It's taking some smart epidemiologists to figure that out."

Thompson said brain tumors present themselves differently for different patients depending on where they are located in the brain. He's had one patient whose only symptom was a numb spot on his arm, and another one who experienced pressure headaches and difficulty walking.

"We know so much more than we did even five years ago," Thompson said. "The pace of research is picking up, but it's truly not fast enough for patients right now … but one thing is for sure: we're learning more."