Chief Justice William H. Rehnquist (search), suffering from thyroid cancer and absent from the bench for seven weeks, still plans to preside at President Bush's inauguration on Jan. 20, a Supreme Court spokeswoman said Friday.

The chief justice normally swears in the president, but it had been unclear if Rehnquist would be well enough. Little information about his condition has been released, though it's known he is undergoing the kind of treatment often used for the most serious type of thyroid cancer.

Rehnquist's continued absence from the bench and the dearth of information about his condition fueled speculation the 80-year-old may step aside soon, giving the court its first vacancy in more than a decade, a modern record.

Supreme Court (search) spokeswoman Kathy Arberg said Bush had invited Rehnquist to administer the oath of office and he accepted. Arberg said she did not know if he would be on the bench when the justices return from the holiday break on Jan. 10.

Court-watchers said it's unclear how to read the news. His attendance at the event on the Capitol lawn could be Rehnquist's final hurrah before ending a 33-year career on the Supreme Court or could indicate he's making a remarkable recovery.

"That doesn't tell you very much at all about how he's doing," said Jesse Choper, a University of California-Berkeley law professor who clerked for former Chief Justice Earl Warren. "It could be his last official act. Or if he's feeling well enough to do that, maybe he's well enough to be back in the court."

Rehnquist has been away from court since Oct. 22, when he was hospitalized and then underwent a tracheotomy to help him breathe. Medical experts have said his treatment, a combination of chemotherapy and radiation, is standard for anaplastic thyroid cancer, a particularly aggressive and fatal form.

Dr. Kenneth Burman, a thyroid (search) specialist at Washington Hospital Center who is not involved in the chief justice's treatment, said Rehnquist could be finished with his radiation and chemotherapy by the inauguration. However, he may still have trouble speaking and likely won't want to stay long, Burman said.

Since announcing his illness, Rehnquist has run the nation's highest court from his home in suburban Virginia. He has not been seen at public events, although he has been photographed leaving his home for a medical appointment.

So far Rehnquist has missed arguments in about 25 cases. He plans to rule in those cases by reviewing transcripts of arguments, and relies on his law clerks for research.

"I think this is optimistic news, that the situation is not as dire as predicted and that he perhaps may stay through reminder of the term (in June)," said Washington lawyer Erik Jaffe, a former Supreme Court clerk.