By Carolyn Y. Johnson, Globe Staff

Hundreds of people from hospitals, universities, and industry gathered today at Harvard Medical School to discuss the transformative power of health cares latest buzzword, personalized medicine. But the day began on a combative note.

In a keynote talk at the Personalized Medicine Conference, Dr. Ezekiel Emanuel, an oncologist who previously served as a health policy adviser to the Obama administration, called personalized medicine hype, a myth, and unaffordable.

Emanuel, who conceded this wasnt his area of expertise, argued that medicines goal has always been to better target therapies, whether it is choosing the drug to treat a patients specific infection or making a decision about how to treat a cancer patient based on the characteristics of their disease. He showed a slide with his own back of the envelope analysis of a single genetic test to support his argument that personalized medicine isnt significantly extending life and aint saving a dime.

If thats all it means, big deal. Ho hum. Targeting is nothing new, Emanuel said. I dont think thats a revolution.

Emanuels comments spurred lively discussion and disagreement, as well as evidence that contradicted his arguments, such as a 2009 study that showed using a genetic test to target a colon cancer treatment would reduce health care costs.

I disagree completely with Zeke Emanuel, said Dr. John Mendelsohn, past president of the University of Texas MD Anderson Cancer Center, who discussed that centers expanding efforts in identifying the genetic fingerprints of tumors and targeting treatments.

Dr. John Niederhuber, executive vice president of Inova Health System in Falls Church, Va. said that he agreeed with one key point of Emanuels talk: that personalized medicine was being overhyped, potentially giving patients false hope before the science is ready.

Despite the disagreements, when Emanuel polled the audience about what would be likely to have a larger impact on longevity and reduce medical costs, the audience overwhelmingly voted not for genetic tests or personalized treatments, but for cutting calories, smoking, and other behavioral changes.

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