Not long ago cancer medicine in the U.S. passed a hopeful milestone: for the first time, the incidence rates for both new cases and deaths in men and women declined, according to an annual report issued in late November from the National Cancer Institute, the American Cancer Society and other leading organizations. Between 1999 and 2005 diagnosis rates dropped annually by about 0.8 percent. Although deaths from some specific conditions have gone up, overall mortality from cancer is on the decline for both men and women of almost all ethnic groups, as it has been since the early 1990s, in large part because of a shrinking toll from malignancies of the lung, prostate, breast and colon.

That good news invites some cautious interpretation. Incidence rates might have fallen because fewer patients are going for mammograms, prostate screening tests and other diagnostic procedures; if so, physicians may not yet be aware of cases that will eventually surface. The drop in the mortality statistics may largely reflect the population’s healthier way of life—most significantly, its decision to kick the tobacco habit. That development is highly welcome, but it may be hard to maintain as a trend: How many other changes can people make that will be so beneficial?

To keep this anticancer momentum, therefore, health care will surely need to step up prevention and treatment in ways that are more tolerable (and affordable) for the general public. The evolving clinical field of nanomedicine may hold many of the answers, as biomedical researchers James R. Heath, Mark E. Davis and Leroy Hood describe in their article (link).

The term “nanomedicine” still conjures up images of teams of microscopic robots performing lifesaving surgery inside our tissues, like the miniaturized submarine crew in the 1966 movie Fantastic Voyage. Given the state of the relevant technologies, any such possibility seems at least decades away. (Personally, I will have more confidence in nanobot surgical teams sometime well after engineers can build, say, crews of autonomous dog-size robots that can keep bridges and tunnels in good repair.) But this does not mean nanomedicine is as vaporous.

Rather, in the same way that nanotechnology is better understood as the application of quantum mechanics to engineering, not the use of atoms as building blocks, nanomedicine might best be viewed as a systemic approach to understanding and maintaining health at the molecular level. As Heath, Davis and Hood explain, the accelerating advance of genomic science makes it easier to identify the hallmarks of illnesses even when no symptoms may be apparent to the patient or clinician. Not only could new blood tests diagnose a nascent liver tumor, for example, but they could also determine to which subcategory of brain tumor it belonged and suggest which gene-focused treatments might be most effective.

Such measures could not always guarantee a cure, but they might someday be able to make often fatal diseases such as cancer and AIDS manageable, much as diabetes is now. The brilliant paradox of nanomedicine is that by focusing on what is extremely small, it can provide a better way to treat a whole person.

Note: The article was originally printed with the title, "A Molecular Checkup".