Sinead and her husband Daniel (Rob Mallard) are understandably reeling from this shocking and tragic news after a shadow was cast over their wedding day with the discovery of a lump on Sineads neck.
Heres what we know about her illness and when shell be breathing her last on Corrie.
What type of cancer does Sinead have?
Sinead was initially diagnosed with cervical cancer in 2018.
While she responded well to treatment at first, she turned to holistic methods when she began to fear that chemotherapy would harm her then-unborn child.
She has now discovered that her cancer has returned and is terminal, having spread to her liver and lymph nodes.
When will Sinead die on Corrie?
Sinead has been told that she only has three or four months left to live.
Its not yet been confirmed exactly when her final scenes will air, but theyre due to be shown later this year.
Indeed, actress Katie McGlynn has already filmed Sineads death scenes.
On the subject of her characters demise, Katie has said: I know it sounds very sadistic but I wanted her to die because thats real life and life isnt a fairytale.
Loads of women are dying, so many people are affected by cancer and this storyline triggers so many emotions for so many people because its absolutely heartbreaking.