It's a signal of complete response to treatment, researchers told MedPage Today and ABC News. Yet they warned that the 66-year-old Douglas is hardly out of the woods. "We always hope that our treatments cure the patient but the reality is that even in the absence of detectable disease, he is at risk for recurrence," Scott Strome, chair of head and neck surgery at the University of Maryland in Baltimore, said in an E-mail.
It is typical for this type of cancer even at stage-IV to be in complete remission at this point, according to Gregory T. Wolf, chair emeritus of the University of Michigan Hospitals in Ann Arbor. Tongue-base cancers that are caused by human papillomavirus (HPV) infection "have excellent 'cure' rates [measured by five-year survival] in the range of 70-80 percent, regardless of tumor stage," Wolf said.
But those rates are diminished for patients whose cancer is likely tied to smoking and drinking. It is not clear whether Douglas' cancer was positive for HPV, but the actor has admitted to smoking and drinking rather heavily. If solely based on smoking and drinking, his risk of recurrence is about 50 percent, Wolf estimated.