Portland Trail Blazers owner Paul Allen has been diagnosed with non-Hodgkin's lymphoma, the second time he's had to fight the disease and third time he's dealt with cancer.

Allen, who announced the news Monday on his web site and through social media, said doctors already have started treatment and he plans on "fighting this aggressively."

"I am very grateful for the support I've received from my family and friends," Allen wrote. "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."

Allen, 65, first encountered non-Hodgkin's lymphoma in November 2009, but overcame the disease through chemotherapy and other medical treatments. He remained in constant communication with the Blazers and his many other businesses and charitable ventures throughout his fight then, and said Monday he would do the same now.

Allen, who typically visits Portland during training camp to watch at least one day of workouts, has not visited this year.

The Blazers owner has overcome cancer twice, including a fight with Hodgkin's disease in 1983. That illness, which Allen fought off with months of radiation treatments, led him to retire from Microsoft, which he co-founded with Bill Gates. Allen bought the Blazers five years later and has been involved in its operations since.

"A lot has happened in medicine since I overcame this disease in 2009," Allen wrote Monday. "My doctors are optimistic that I will see good results from the latest therapies, as am I."

Allen's full release is 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!

Joe Freeman | jfreeman@oregonian.com | 503-294-5183 | @BlazerFreeman