After months of radiation and chemotherapy for late-stage throat cancer, actor Michael Douglas is tumor-free, he told NBC's Today Show viewers this morning.
Not a trace of the stage-IV, walnut-sized tumor at the base of his tongue could be detected on medical imaging, Douglas said.
That's a signal, researchers told MedPage Today and ABC News, of complete response to treatment.
Yet they caution 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," Dr. Scott Strome, chair of head and neck surgery at the University of Maryland in Baltimore, wrote 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 Dr. Gregory T. Wolf, chair emeritus of the University of Michigan Hospitals in Ann Arbor.
Prognosis, however, depends significantly on the biology of the tumor.
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.
Dr. Ted Teknos, chair of head and neck surgery at Ohio State University Cancer Center in Columbus, said five-year survival for tumors related to smoking alone is about 30-40 percent.
Patients whose tumor is associated with a combination of HPV and smoking have cure rates somwhere in between those figures.
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.
The next step for the actor will be a follow-up scan in three months, which MedPage Today sources say can provide a good idea about the possibility of a cure, but is by no means absolute. The greatest risk of recurrence is in the first two years.
Douglas had been receiving radiation and chemotherapy at Memorial Sloan Kettering Cancer Center in New York since September.
The actor has reported problems swallowing, a typical side effect of treatment as radiation has closed down salivary ducts. He also reported losing 32 pounds during treatment.
Dr. Christine Gourin, professor of otolaryngology at Johns Hopkins University, said that while labeling Douglas as "cured" is at least five years off, this first step provides some good news.
"We don't know the future," she wrote in an e-mail, "but in the face of a complete response to treatment there is every reason to be optimistic."