INDIANAPOLIS — Veteran motorsports announcer Bob Jenkins, known by millions for his role behind the microphone during the Indianapolis 500 and other motorsports events, announced Tuesday that he is battling brain cancer.

Jenkins is set to scale back his role on the Indianapolis Motor Speedway Public Address system this year in order to focus on his cancer battle. He still plans to be present at Indianapolis Motor Speedway during the month of May.

“It happened on Christmas night. I awoke with a severe headache,” Jenkins explained during an interview with Indianapolis Motor Speedway President Doug Boles published Tuesday on YouTube. “I made it to one hospital. They did a CT scan and then told me I needed to go someplace else for an MRI because the Crawfordsville hospital didn’t do MRIs.

“The first diagnosis was a stroke. The second diagnosis was we have found two malignant tumors in your right temple and you have brain cancer.”

This is not Jenkins’ first bout with cancer. In 1983, he was diagnosed with colon cancer and was able to overcome the disease.

“I had colon cancer in 1983 and I survived that,” Jenkins said. “With God’s help and my beloved race fans, I’m going to make it.”

The 73-year-old first appeared on the IMS Radio Network in 1979 and later became the voice of the Indianapolis 500 in 1990. He continued in that position through 1998 and has remained involved with the speedway and the Indianapolis 500 in various roles through the years.

In addition to his work at Indianapolis Motor Speedway, Jenkins spent years working for ABC and ESPN covering multiple forms of racing. Jenkins has covered NASCAR, CART, IMSA, Formula One and more during his many years as a television personality and announcer.

Jenkins said it was important for his family to be among the first to find out about his diagnosis. He said he considers race fans his family.

“I don’t have a large family,” Jenkins explained. “I have a niece and a nephew. I consider the first people that I should tell my family and my family is my race fans and people like you (Doug Boles) who contribute to the Indianapolis Motor Speedway and the 500 every year and make it what it is and what it has been since 1911.

“I’m not going to completely retire. I’m going to say I’m cautiously optimistic about working some of the public address this year, but you will not hear me or see me as much as you have during the past few years. I’m going to do all I can because I am going through radiation and chemotherapy to knock this cancer out of my brain.”