The former Antrim boss recently received the news after breaking his arm in an accident.
Darren Gleeson is leaving his role as the manager of the Laois senior hurlers with immediate effect following a cancer diagnosis.
The Tipperary man made the announcement over the weekend - saying the medical advice he's received means it's "essential" he takes the appropriate time to focus on his treatment and recovery.
The former Antrim boss was announced as the new O'Moore County manager as recently as the end of August.
Gleeson says he had "extensive plans" in place and was looking forward to what the future held.
He's also underlining his appreciation for the support of the Laois county board.
Laois GAA meanwhile are thanking Gleeson for the "huge amount of work and enthusiasm" he brought to the role.
The appointment was broadly welcomed when announced.
The two-time All Ireland winning Tipp keeper had already proven an effective manager at inter-county level following his time in Antrim.
Gleeson won two Joe McDonagh Cups and kept the Saffrons in division one hurling for three seasons in his time over the county.
Statement from Darren Gleeson & Laois GAA pic.twitter.com/1KZjRpGq5N
— Laois GAA (@CLGLaois) November 16, 2024
LGFA: Back To Back Wins The Goal For Westmeath
Shane Lowry Records Opening Round 70 At Cognizant Classic
We Hope To Give The Fans Something To Shout About - Ian Ryan
Maher Milking All She Can From Farming And Starring In Offaly Engine Room
NHL: Offaly Face Limerick In Final League Game
Portlaoise Panthers Looking To Continue Good Form In Division One
Shane Lowry In Action In Florida This Week
NHL: Improving Each Week The Goal For Laois
Grainne Walsh Progresses At Strandja Memorial Tournament
Crunch Weekend For Midlands Sides In National Camogie League
James Gormley Named On Irish Squad For FIBA EuroBasket Qualifiers
Portlaoise Panthers Suffer Tough Defeat In Super League
CCFL: St Peter's Extend Their Advantage At Top Of Premier Division
NFL: Relegation Firmly On The Cards For Offaly
Laois "Devastated" By Defeat Despite Delivering "Manliness" - Justin McNulty
Big Camogie Wins for Westmeath and Laois Over The Weekend
Fitzgerald "Relieved" After Squeaking Past Kerry
NHL: Galway Prove Too Strong For Offaly
Former Laois And Offaly GAA Manager Honoured By An Garda Síochána