Republican Sen. James Seward on Monday announced he would not seek re-election to a central New York seat he's held since 1987. 

Seward is the latest GOP state lawmaker to announce plans to not run again this year or retire. 

Seward announced last year he would be undergoing another round of treatment for a recurrence of cancer. 

"While I have responded well to cancer treatments, my physicians have advised me that treatments will continue for the foreseeable future limiting my ability to maintain the rigorous schedule needed to campaign for re-election," Seward said in a statement. "This is the right decision for my health, my family, and the people of the 51st Senate District."

He added his decision was based not on the GOP falling into the minority in the chamber, but being able to effectively serve his constituents. 

“I am grateful for the opportunity to serve in the state Senate and sincerely thank the voters for their support and confidence," Seward said. "The sacred trust bestowed in me by those I have had the privilege to represent has always been foremost on my mind."