In a darkened slice of a convention center ballroom, Dr. Leisha Emens takes her place in front of hundreds gathered to hear about her latest research.

The Johns Hopkins oncologist doesn't look particularly comfortable in the spotlight. This is no way to really talk to people. She's used to the nonjudgmental ways of a microscope or the one-on-one with a patient. But this is how the game is played.

By speaking at major conferences like this one in late May, the American Society of Clinical Oncology in Chicago, scientists create a buzz around their work, networking with others who may someday help move their research forward.

Emens' hand absently pushes her light-brown hair out of her eyes, her voice with its hint of the South quavering a bit as she begins. Her red pointer jerks across a towering video screen displaying a series of slides. One shows the mouse models that her experimental breast cancer vaccine was tested in. Another shows how it was administered to the first 28 women in her small clinical trial. A third goes over a formula she used to determine which doses of chemotherapy seem to have yielded the best immune responses.

Much of what she is saying would have flown high above the heads of her patients. It flies over many in the room - all that talk of "one-sided Fisher's Exact tests" and "HER-2/neu transgenic mice." But to those in cancer vaccine research, to those who understand what a breakthrough it would be to train the body to attack its own cancer, she is clearly saying, "There's hope here."

Hope is what has drawn 42 women so far to enroll in two small clinical trials being run by Emens, to donate their cancer-stricken bodies to her unproven science. Despite being told it is unlikely, they hope for a cure. She can't even promise she can extend their lives beyond the one to two years that are typical once cancer has spread beyond the breast.

In science, entire careers are spent working toward cures that don't come. Scientific progress comes slowly, if at all. That is the nature of experiments. Every step must be taken deliberately, each one building upon the last. There can be no short cuts. This is how Emens has been trained. This is how Emens operates.

10 years of uncertainty
It was nearly five years from when Emens first began manipulating breast cancer cells to when the first patient was injected. It has been almost five more years since then, and still Emens has few concrete details on whether the vaccine works, no information on whether it will extend lives. She is right on schedule, scientifically speaking.

The women enroll certain that the vaccine will make them better. It may be their last chance at survival. They cannot look to a future 10 or more years away. They have Stage IV cancer. For them, there is no time for protocols of science.

Many put her on a pedestal. One patient calls her a "rock star." They revere her and depend on her. They need assurance that the experiment to which they have devoted so much of their remaining time will amount to something.

One day a week, Emens, 46, sees patients, oftentimes the women who are part of her studies. She opens their charts, sits straight up in her chair and goes over the basics. Beyond that, she volunteers little. There is so much the women feel they need to know, and so little Emens can share.

"These trials are so small," she explains, "you can't say anything with any level of certainty."

Most days, Emens' job is focused on what is being done in the laboratory now and in the future. The blood of the women in her studies is combed for evidence of immune response and for clues about how to better attack cancer down the road. She and her technicians study how mice react to new combinations of chemotherapy or other cancer drugs given to better prepare the immune system to beat back the disease.

But mice don't ask tough questions. They don't hope for miracles. They aren't depending on her for a cure.

Well prepared
Emens arrived at Hopkins in 1998 as an oncology fellow holding a medical degree and a doctorate in cell biology from Baylor College of Medicine in Houston. One of the first doctors she met was Dr. Elizabeth Jaffee, a pancreatic cancer vaccine researcher considered a pioneer in her field.

They had lunch and talked science. Emens soaked up what she could about the prospects for cancer vaccines, the direction in which Hopkins was headed and where it had been.

In 1993, doctors from Hopkins and MIT - including Jaffee - had published a groundbreaking paper describing how they used a protein called granulocyte-macrophage-colony stimulating factor, or GM-CSF, to stimulate an immune response in mice. Not a single mouse got cancer when it was exposed to the protein.

This protein is still central to many of the vaccines in development around the country.

Jaffee - who is just a couple of years older than Emens - became a mentor to Emens. In one of their conversations, Emens told Jaffee why she wanted to focus her life's work on breast cancer.