Valerie Harper’s Brain Cancer ‘Close to Remission,’ Doctor Tells NBC (Video)

Valerie Harper's rare, terminal brain cancer may be close to remission, the actress' neuro-oncologist revealed exclusively on NBC's Today show Thursday morning.

A recent MRI showed that the Rhoda actress' leptomeningeal carcinomatosis is "pretty close to remission," Dr. Jeremy Rudnick told Meredith Vieira in a sneak peek at an upcoming special about Harper's battle.

STORY: Valerie Harper Discusses Her Brain Cancer Diagnosis on 'Today'

That development "defies the odds," Rudnick said, but he cautioned that her condition could change at any time.

"They develop resistance to the therapy," Rudnick said of patients undergoing treatments similar to Harper's. "And it's not a matter of if, it's a matter of when.

So what this news really means is that Harper has more time, during which period hopefully something better will come along.

Harper revealed that has terminal brain cancer in March. Leptomeningeal carcinomatosis is a disease in which cancer cells spread into the membrane surrounding the brain. Her physicians gave her three to six months to live when she was diagnosed Jan. 15.

STORY: Valerie Harper Diagnosed With Brain Cancer

Harper previously beat lung cancer.

Rudnick is one of the Cedars-Sinai Medical Center physicians treating her, along with oncologist Dr. Ronald Natale.

NBC will offer viewers a closer look at Harper's battle with cancer on Valerie's Story - a Meredith Vieira Special, which is set to air on Thursday, Sept. 19 at 10 p.m. after the finale of NBC's new Ryan Seacrest-hosted reality show Million Second Quiz.

It was reported yesterday that Harper could be one of the contestants on the upcoming fall season of ABC's Dancing With the Stars.

Hilary Lewis