Gene Breakthroughs Spark a Revolution in Cancer Treatment

Kellie Carey's doctor finally stopped dodging questions about how long she had to live six weeks after he diagnosed her lung cancer.

"Maybe three months," he told her in his office one sunny May morning in 2010, she recalls.

Yet she is still alive, a testament to the most extraordinary decade of progress ever in the long scientific struggle against lung cancer.

Tests found Ms. Carey's lung cancer to be of a rare type that researchers had found just three years earlier by deciphering its genetic code. The 45-year-old businesswoman in 2010 went on a drug Pfizer Inc. was testing for that type. By pinpointing her cancer, the drug probably helped give her years more to live than chemotherapy would have, her doctors say.

That is remarkable because lung cancer for decades defied efforts to find drugs that could extend an average patient's life by even a few weeks.

But an explosion in knowledge about the genetic mutations that cause tumors is just now offering the first real promise of drugs that can control what is the most-common and most-deadly cancer.