Husband’s Colonoscopy found a tumour

We have private health insurance but today the Dr said best to stick to the NHS for cancer treatment. My husband’s rectal tumour (5cm) was only found through a colonoscopy following the two year screening process. He had no symptoms. He now needs a Cat and MRai scan for staging. I’m concerned about time scales as following the scans there has to be a weekly meeting and only then will we know about ideas for treatment. I’m worrying that we should use private healthcare to get the same more quickly and get the ball rolling. I’d appreciate advice thanks