The diagnosis was Stage 4 breast cancer. The prognosis: grave. "I got the impression that it was just like, 'Well, you're going to come here for chemo every week … kind of until you die,'" Erin Howarth said with a sardonic laugh.

That was in November 2008. Howarth was just 31, and she was not ready to give up. She found a new doctor, and a new drug, Avastin. Patients take it in addition to standard chemotherapy.

Within seven months Howarth's cancer was in remission. Today, Howarth is still alive, still on Avastin, still cancer-free. But now, she has a new worry: The Food and Drug Administration is poised to declare Avastin unsuitable to treat her disease.

The FDA is scheduled to decide Avastin's fate on Sept. 17.

"It's going to be a landmark decision," said Howarth's physician, Dr. Susan Minton, an oncologist at the Moffitt Cancer Center in Tampa, Fla. "I am frightened about the impact the potential decision could have on future research."

The theory behind Avastin is pretty simple: Starve cancer cells of what they need in order to grow, blood. In 2008, the New York Times called Avastin "a wonder drug." Doctors initially hoped that the drug would become the magic bullet that would defeat cancer for good.

Since Avastin's debut in 2004, it has become one of the most popular cancer drugs in the world. More than 700,000 patients with advanced colon, lung, kidney or brain cancer have used it.

In 2005, the company that manufactures Avastin, Genentech, sponsored a trial to test its effect on metastatic breast cancer — cancer that spreads to other parts of the body. In the trial, some women were given conventional chemotherapy alone. Others, like Howarth, were treated with a combination of chemotherapy and Avastin.

Avastin extended "progression-free survival" — the length of time that tumors do not grow or worsen — from a median 5.8 months on chemotherapy alone to 11.3 months with the use of Avastin.

In the fight against breast cancer, results like that were a very big deal. As it stands, four out of five women with Stage 4 breast cancer die within five years.

So the FDA gave Avastin an audition, of sorts. In February 2008, it granted accelerated approval for Avastin to be used to treat metastatic breast cancer. Meanwhile, researchers conducted more clinical trials. If the new trials were as impressive as the first, the FDA would grant the drug permanent approval.

But the results shocked the drug's supporters.

Where the first trial delayed cancer growth by 5.5 months, the new results showed a much smaller median improvement, between 0.8 and 2.9 months.

And when it came to actually prolonging life — the FDA's gold standard for cancer drug testing — Avastin failed. In both the initial and second-round trials, the difference in overall survival when patients used Avastin was practically nothing.

Side effects also were a problem. Some patients experienced excessive bleeding, difficulties with wounds healing, abdominal perforation and high blood pressure.

On July 20, an FDA advisory committee voted 12—1 to recommend that the agency remove metastatic breast cancer from the list of approved uses for the drug.

That recommendation was a major blow to Genentech, whose sales of the drug reached $6 billion worldwide in 2009. Charlotte Arnold, a spokeswoman for Genentech, said the most serious side effects are exceedingly rare. More common side effects, such as high blood pressure, do not affect patients' quality of life and can usually be managed by physicians.

"Oncologists have years of experience using Avastin, and they know what to expect," Arnold said.

Howarth thinks it's ridiculous to worry about Avastin's side effects.

"People are like, 'Oh, it's such a dangerous drug,'" Howarth said. "Yeah, well, we have Stage 4 cancer. What's our choice?

One factor clouding the debate over Avastin is money. On average, a year's worth of treatment costs about $96,000. Standard chemotherapy for breast cancer patients costs about $12,000 per year.

"I think that was obviously the elephant in the room," said Dr. Gabriel Hortobagyi, one of the experts brought in to testify at the FDA advisory committee meeting in July. He is chairman of the department of breast medical oncology at the University of Texas MD Anderson Cancer Center. "The FDA is not allowed to address that …"‰, but that was clearly in the background of everyone's mind."

The high cost of Avastin and the drug's modest clinical trial results raise a difficult question: How expensive is too expensive for treatments that offer little added benefit over existing therapy?

Hortobagyi contended that less-than-miraculous results are difficult for the FDA to justify when insurance companies pay exorbitant prices.

"I wonder if the outcome would have been the same if the drug cost $100 a month instead of $100,000 a year," Hortobagyi said.

If the FDA removes metastatic breast cancer treatment this month from Avastin's list of approved uses, doctors will still be allowed to prescribe the drug "off label" to breast cancer patients as they see fit.

But in that case, insurance companies might not provide reimbursement for the treatment. Few people would be able to pay out of pocket.

Natalie Compagni Portis, a clinical psychologist from Oakland, Calif., was a member of the FDA advisory committee who voted against Avastin. For her, she said, the disappointing clinical trial results made the question of cost moot. Who cares how much it costs if it doesn't work?

The Wall Street Journal disagrees. In its lead editorial on Aug. 18, the Journal blasted Portis and other panel members who voted against the drug, arguing that the latest trial results still showed some improvement. It labeled those who voted against the drug "… government-anointed medical patriarchs substituting their own subjective view of Avastin's risks and costs for the value that doctors and patients recognize. If Avastin is rescinded, thousands of dying women will lose more than proverbial false hope in the time they have left. They will lose a genuinely useful medicine.''