Beth McDaniel’s oncologist, a bear of a man, hugged her and twirled her around.


“Holy cow, Beth!” Dr. John J. Gohmann exclaimed.

For the first time since a rare cancer appeared eight years before, her lymph nodes had shrunk to a normal size, her skin was no longer bright red and inflamed, and the itchiness that plagued her had subsided.
Mrs. McDaniel, the 69-year-old wife of a retired corporate executive, had gambled on the ultimate in personalized medicine, an approach known as whole genome sequencing, and it seemed to be paying off.

Scientists had compared the entire genetic sequences of the tumor cells invading her body with those in her healthy cells, searching for mutated tumor genes that could be thwarted by drugs approved for other cancers or even other diseases. That had led them to give her an expensive drug approved just a month earlier for melanoma patients. It had never been given to anyone with a blood cell cancer like hers. In theory, the drug should have killed her. Instead, it seemed to have halted or even reversed her cancer.

But would it last? And what would it mean if it did not?

In the end, Mrs. McDaniel’s journey to the edge of genetics research turned out to be a decidedly mixed experience. It was hard — much harder than anyone in her family had imagined — to get the sequencing and analysis done. It was breathtaking to see the results, which indicated that her cancer was driven by a strange gene aberration that could be attacked with a new drug. But it was heartbreaking to see how quickly her cancer recovered from the assault, roaring back in a matter of weeks.

Mrs. McDaniel’s story offers a sobering look at the challenges for this kind of quest for a treatment, even for someone like her, who had both the means and the connections to get the intricate geography of her cancer charted. Her husband, Roger McDaniel, was a former chief executive of two companies involved in semiconductor manufacturing, and the family could afford the approximately $49,000 that the search would cost. They had expected to pay much more, but to their astonishment, Mrs. McDaniel’s insurance company covered almost all the drug costs. And the scientists who did the data analysis did not charge.

From the start, the family knew the odds were against Mrs. McDaniel, but she thought she had little to lose.
“You cannot feel bad if this doesn’t work or I die,” she told her son Timothy, a molecular biologist. “I would have died anyway.”


Scarlet Skin and Infections

Beth McDaniel’s cancer began with itching all over her body. Then her skin turned scarlet and started becoming infected.

In 2005, after she had spent more than a year going from specialist to specialist, a dermatologist figured it out. Mrs. McDaniel, then 62, had Sezary syndrome, a rare T cell lymphoma, in which white blood cells become cancerous and migrate to the skin. All her doctors could tell her was that the disease was incurable, that there was no standard treatment, and that on average patients at her stage die within a few years.

“Of course I was shocked,” Mrs. McDaniel said in an interview last September.

She wept that day as her husband drove her home. And she asked God to help her cope.

Before cancer, she had had a vibrant life, hiking in the mountains, traveling the world, entertaining her wide network of friends. Her disease destroyed all of that. She could not even enjoy her luxuriant garden because sun on her inflamed skin was agony.

Although there is no standard treatment, for five years chemotherapy held her disease at bay. But in the summer of 2010, she got worse, much worse, with hundreds of tumors popping up under her skin. Some grew as large as kiwi fruits and split open.

Her son, Dr. McDaniel, decided he would orchestrate the use of the most advanced techniques of gene sequencing and analysis to take on her cancer. Because of his job — he works for Illumina, a company that does DNA sequencing — Dr. McDaniel had read scientific reports and gone to medical conferences where he heard talks on whole genome sequencing. He noticed that the patients all seemed to have rare cancers.

“Every time I heard one of those stories, I thought, ‘That’s my mom,’ ” he said.

For now, there are not many drugs that can target specific gene mutations in cancer cells.

But the hope is that when more is known and more drugs are developed, doctors will treat cancer by blocking several major genes at once. With several escape routes barred, the cancer will not be able to break free of the drugs stopping its growth.

Full-Time Help From a Son
A version of this article appeared in print on July 9, 2012, on page A1 of the New York edition with the headline: A Treatment’s Tantalizing Promise.