SEATTLE -- Paul Allen says his non-Hodgkin's lymphoma is back.
The billionaire Microsoft founder and Seattle Seahawks owner shared the news in a letter posted Monday titled "Tackling a new, personal challenge."
Allen was treated for the same type of cancer in 2009. Allen said he plans to fight it aggressively.
He says a lot has happened in medicine since he overcame the disease nearly a decade ago and that he and his doctors are optimistic that he will see good results from the latest therapies.
Allen says he will continue to stay involved with Vulcan, the Allen Institutes, the Seahawks and Portland Trail Blazers and that he has confidence in leadership teams to manage operations while he's undergoing treatment.
He also says he's grateful for the support he's gotten from family and friends and that he appreciated everyone's support in the past.
The Seahawks tweeted, "Our support is with @PaulGAllen. The 12s are behind you and we believe there is no better fighter for this challenge."
Read Allen's full message below:
I learned recently that the non-Hodgkin’s lymphoma that I was treated for in 2009 has returned. My team of doctors has begun treatment of the disease and I plan on fighting this aggressively.
A lot has happened in medicine since I overcame this disease in 2009. My doctors are optimistic that I will see good results from the latest therapies, as am I.
I will continue to stay involved with Vulcan, the Allen Institutes, the Seahawks and Trail Blazers, as I have in the past. I have confidence in the leadership teams to manage their ongoing operations during my treatment.
I am very grateful for the support I’ve received from my family and friends. And I’ve appreciated the support of everyone on the teams and in the broader community in the past, and count on that support now as I fight this challenge.
Go Seahawks! Go Blazers!
The Associated Press contributed to this report.