Ravi Zacharias has returned home from hospital after doctors have said there is nothing else they can do to treat his cancer. 

Zacharias' daughter, CEO of Ravi Zacharias International Ministries (RZIM) Sarah Davis, shared an update with their staff about her father's treatment on Friday. 

She said while the tumour in her dad's sacrum has been responding to chemotherapy, the area where the cancer started has worsened. 

"His oncologist informed us that this cancer is very rare in its aggression and that no options for further treatment remain. Medically speaking, they have done all they are able," she said in the statement that was also shared on Zacharias' Facebook page. 

The world renowned US Christian apologist was diagnosed with rare bone cancer in March. The diagnosis came after he underwent emergency spinal repair surgery late February. 

Davis said her father has now left Houston, Texas where he was being treated, and has returned home to his home in Atlanta, Georgia to be close to family "for whatever time the Lord gives us". 

"We know that God has purposed and numbered each of our days, and only He knows how many more Ravi will experience on this earth," she added. 

"One day, likely sooner than later, we will be serving without our beloved founder, though I know his love and legacy will convict and inspire us to service of his Lord even greater than we have seen before. While we are full of so many emotions, we are also at peace, resting in the truth that God knows all and sees all and is sovereign and good. I think of the great joy my dad will have, and I am comforted."

Davis also thanked all those who prayed faithfully for her dad and family. 

"Truly, words fail to convey the depths of our gratitude for your many expressions of love," she said.