What is a breakthrough, anyway?

The first article I saw on this week's Science Magazine article on gene therapy and melanoma was in the Wall Street Journal; their headline reads "Scientists Use Gene Therapy to Shrink Malignant Tumors: Study is Hailed as Potential Cancer Breakthrough." I read the word "breakthrough" and it made me sneeze, as always. So even though the breakthrough was qualified as "potential," I thought it'd be fair to look it up.

The American Heritage Dictionary, 3rd ed., defines "breakthrough" (n), thus: 1. An act of overcoming or penetrating an obstacle or restriction. 2. A military offensive that penetrates an enemy's lines of defense. 3. A major achievement or success that permits further progress, as in technology.

My question to the dictionary editors would be this: how do you define "major" and "permits further progress"? Shouldn't every incremental advance in scientific knowledge permit further progress? According to the press release from the National Institutes of Health, the gene therapy took (i.e., produced major tumor regression) in only two of the 17 patients in whom it was tested (though that didn't stop NIH scientists from hyping the results further). Nobel laureate David Baltimore, who does similar research, pointed out that there were no controls in the study, according to the WSJ, which means that the study can't prove that the treatment worked - although highly unlikely, the tumors could have regressed on their own.

After reading the American Heritage's definition, I feel a little less allergic to the word breakthrough. I'd be willing to accept that this is an important finding from the perspective of scientists; for example, according to NIH Director Elias Zerhouni, "These results represent the first time gene therapy has been used successfully to treat cancer" (again, from the science point of view, I might grant him successful). But what does the word "breakthrough" convey to the casual reader of a newspaper? to someone who wants to invest in cancer-treatment technologies? or to a patient with melanoma who's not in the study? Headline writers love the word; it sells papers. But can it also sell false hope?

For further analysis on news coverage of this story, check out Gary Schwitzer's blog.

breakthrough

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Schwitzer

National Institutes of Health