Stop the presses! Sharks do get cancer. This normally wouldn’t qualify as big medical news, and I barely noticed the item when it appeared not long ago in the New York Daily News. But think of the huge amount of mythology-and business-that has mushroomed out of a single, easy-to-grasp and, as it happens, false anecdote. If sharks are immune to cancer, wishful thinking went, they must make a protein or molecule that prevents cancer from developing. From this appealing little fiction emerged a thriving branch of alternative medicine: the use of shark cartilage to treat cancer.

It’s easy to dismiss the shark-cartilage hypothesis as fairy-tale science. But appealing stories are nonetheless an integral part of the research process, as Peter Medawar shrewdly observed in his book Pluto’s Republic. Scientific theories, he wrote, “begin, if you like, as stories, and the purpose of the critical or rectifying episode in scientific reasoning is precisely to find out whether or not these stories are stories about real life.”Nowadays, telling a good story-whether it holds up or not-has become a big part of contemporary biotech and pharma.

The “story” is a kind of simple, declarative, trademark narrative that creates a feel-good association between a hypothesis, product or company and the consuming public. Those consumers need not buy medicine at the pharmacy. They may instead buy stock or, in the case of venture capitalists, “buy” the story of a startup company by providing seed money and other forms of capital investment.

The story has long been a feature of the biotech and pharmaceutical business. The writer Barry Werth formalized it as a fundamental component of biotech entrepreneurship in his book The Billion-Dollar Molecule, an account of “rational” drug discovery at Vertex Pharmaceuticals in Cambridge,Mass. In California, Shaman Pharmaceuticals always had one of the best stories in the business; inspired by the examples of aspirin and digitalis, Shaman’s declared mission was to discover new medicines in natural compounds derived from plants from the rainforest. After several rounds with the Food and Drug Administration, Shaman transformed itself several years ago into a company primarily devoted to dietary supplements.

When it comes to stories, however, I’m not sure Medawar could have envisioned their current reincarnation as marketing tools. Almost every morning, I hear at least one ad on the radio boasting of a new medical technology or treatment available at various local hospitals.You know the ads I’m talking about: “Joe Smith was in his forties and the father of three children when he went to see his doctor about some minor abdominal pain.He was diagnosed with colon cancer. At first the cancer didn’t respond to treatment. But then he heard about a new treatment at Greater Aesculapians of New York, where doctors told him the combination
of several new drugs might help.His cancer is now gone.He has a lot more time on his hands, and he’s spending it with his kids…”

Journalists have always been shameless purveyors of the well-told anecdote as a means of conveying a larger trend or idea. Clinical researchers, too, have been known to relay the occasional case study at conferences. But use of the heart-warming anecdote has now become a widespread tool of medical advertising, and I’m not so sure that what’s been good for the goose is good for the gander.

There are still a few people left in clinical research to whom “anecdote” remains a dirty word, and “anecdotal” serves as one of the most withering of adjectives, precisely because anecdotes lack the rectifying science about which Medawar wrote. Too much data is left out, too many informational corners are cut. How long has the happy ending endured? How many people didn’t respond to the treatment? My allergist once told me that a prescription drug heavily advertised on television works in less than 50 percent of the people who try it. Funny, but you don’t get that impression from the ads.

The most important thing about an anecdote, whether in science, journalism or marketing, is that it must be true-true not only in the particulars of the small, simple story, but true to the implications of the larger story. The first part is easy, given the intense regulatory scrutiny of drug advertising. But in the larger sense, anecdotes are often misleading, and by making mass-market promises on the basis of a narrowly true anecdote, medical innovators and drug companies may be contributing, in an invisible but pervasive way, to growing public cynicism about health care. Selling lifesaving medical treatments on radio or TV should be more complicated than selling shampoo.