My dad had brain tumour surgery (cranatomy) on 1st of july and reports came out as glioblastoma-grade iv. Now I read about the sleep apnea and its role in readmission of tumour. Now I have got two questions. 1.does sleep apnea can be a reason for brain cancer? As he had this osp for years. 2.now after the surgical intervention, will this osp increase the risk of tumour readmission as I read in some research paper.