Martha Rial, Post-Gazette Dr. Amin Kassan shows how a catheter was run through Mayor Bob O'Connor's neck. Click photo for larger image. Related article Zober takes over as deputy mayor at a slow time City Hall takes mayor's absence day-to day Graphic: Mayor O'Connor's Hydrocephalus treatment

Mayor Bob O'Connor's doctors said they should know in seven to 10 days whether he is gaining or losing ground in his battle with a rare form of cancer.

At a news conference yesterday at UPMC Shadyside, doctors said bleeding from tumors in his brain apparently caused a fluid buildup that required urgent surgery over the weekend.

The bleeding could be a side effect of a positive response to treatment, said Dr. Frank Lieberman, chief of neuro-oncology at UPMC Hillman Cancer Center. But Mr. O'Connor's cancer also could get worse, he said.

When the mayor has another MRI scan a week or 10 days from now, doctors will be "able to assess which way things are going," said Dr. Stanley Marks, director of clinical services at the cancer center.

"If he gets clinically better and he's steadily improving, that's an important indication, too," Dr. Lieberman said.

The mayor's doctors agreed that his recovery from brain cancer has been more difficult than they first anticipated. He was diagnosed July 10 with primary central nervous system T-cell lymphoma.

"Right now, we're taking things day to day," Dr. Lieberman said.

"Although the mayor has had a very rocky course, I don't think at this point there is reason to conclude his situation can't be turned around," he said.

"There's nothing we see at this point that precludes him from eventually making a complete recovery."

He said that in his experience with the more common B-cell type of lymphoma, bleeding tumors have been associated with a response to treatment.

Dr. Michael Robertson, director of the lymphoma program at the Indiana University Cancer Center in Indianapolis, said both dying and enlarging brain tumors can cause bleeding. But he said the likely response to treatment for the T-cell type is not well known because the cancer is so rare.

"I think it's a wait and watch kind of situation that should become clear in the next week or two," he said.

The fact that the mayor has had some setbacks is a cause for concern, said Dr. James Rubenstein, assistant professor of medicine at the University of California, San Francisco. Like Dr. Robertson, he does not have direct knowledge of the mayor's condition or his treatment.

But radiographic evidence that the tumors have shrunk is a more important sign, Dr. Rubenstein said.

After the mayor began treatment with the chemotherapy drug methotrexate, tests indicated his tumors had become smaller, Dr. Lieberman noted.

Doctors said the mayor was scheduled to receive another dose of methotrexate yesterday, and Dr. Lieberman said a test yesterday morning showed that the level of cancer cells in his spinal fluid continued to be low.

"That's one reason we're optimistic what we've been seeing recently is a side effect of tumors responding to treatment," he said.

Doctors said the mayor is in a neuro-intensive care unit where he is being monitored for a shunt that was installed Sunday to drain the excess fluid from his brain.

Doctors said that after the shunt was placed during a 30-minute surgery, the mayor showed dramatic improvement, sitting up in bed and talking with family members.

"In the last 24 hours, we're encouraged," Dr. Marks said.

Doctors were uncertain how long the shunt would need to remain in place. While it is currently draining fluid outside the mayor's body, it could be changed to divert the fluid into his abdomen, they said.

Because of the situation, they said plans for continuing physical therapy have been tabled.

Doctors also have had to discontinue another chemotherapy drug, Temodar, because the mayor's liver has had trouble tolerating it, Dr. Marks said.

Doctors had earlier considered transferring him to a rehabilitation facility. Though those plans were changed because of the mayor's fatigue, he had been showing improvement last week, walking the halls and conversing, Dr. Marks said.

But he said that around midday Saturday, the mayor's condition significantly changed. He showed extreme lethargy and severe weakness on his left side.

"On Sunday morning when I saw him, he was really very sleepy and was responding only to very strong stimulation," Dr. Lieberman said, describing him as "stuporous."

"He wasn't comatose. He was not unconscious, but he was very lethargic."

Dr. Amin Kassam, a UPMC neurosurgeon, said he placed a shunt, similar to a soda straw, to drain fluid from a ventricle in the brain through a hole about the size of a quarter opened near the top of the mayor's head just behind the hairline.

The mayor quickly responded, and doctors are "optimistic that level of improvement will continue," Dr. Kassam said.

Without the prompt intervention, the situation could have been life-threatening, Dr. Marks said.

He expressed hope that with the latest methotrexate dose, the mayor will "turn the corner in the next several days."