A rural, western Nebraska lawmaker said Monday that he will undergo treatment again for a rare form of cancer that he has faced before.

State Sen. Tom Brewer, of Gordon, said a series of medical tests this spring revealed that his hairy cell leukemia has returned, and he will need chemotherapy to treat it. Brewer said he plans to take some time off from his duties for treatment, and will have to cancel or reschedule some of his upcoming events.

Brewer disclosed his initial diagnosis of the cancer in 2014, when he was a Republican U.S. House candidate in Nebraska’s 3rd Congressional District. Brewer is a former U.S. Army colonel and two-time Purple Heart recipient who served six tours in Afghanistan, including battles where he was shot six times and hit with a rocket-propelled grenade.

“I have been through many fights before, and I plan to overcome this one too,” Brewer said in a news release.

Hairy cell leukemia is a rare, slow-growing cancer that’s generally treatable and has a high survival rate.

Brewer, a member of the Oglala Sioux Tribe, represents the 43rd Legislative District, a geographically huge stretch of rural north-central and northwestern Nebraska that includes most of the Sandhills.