Cancer detection revolution

Washington -- Intriguing new technologies that allow researchers to peer into the core of cells and detect cancer at its earliest stages hold great promise for personalizing treatment.

For example, cancer biomarkers, molecular profiles and molecular imaging could one day revolutionize breast cancer detection, says a report released June 10 by the Institute of Medicine. But instead of competing with mammography to detect cancer, the new techniques will need to be linked with imaging information to define tumor size and location, according to the report "Saving Women's Lives: Strategies for Improving Breast Cancer Detection and Diagnosis."

"Improving and increasing the use of current mammography technology is the most effective strategy we have right now for further reducing the toll of breast cancer," said Panel Chair Edward Penhoet, PhD, director of science and higher education programs at the Gordon and Betty Moore Foundation in San Francisco.

While the new technologies could provide more personalized screenings and identify women at greatest risk for breast cancer, it is yet to be seen if these technologies will yield results that can replace mammograms.

Meanwhile, there is a need to increase the numbers of medical personnel who can interpret mammograms, the report noted. More than 200,000 new cases of breast cancer will be diagnosed this year, and more than 40,000 women will die from it.

But there aren't enough breast imaging specialists to keep up with the demand. Heavy regulation, fear of lawsuits and low reimbursement are driving radiologists away.

Complexities

With the advance of technology comes a new appreciation for cancer's complexity, said Steven Goodman, MD, PhD, a biostatistician at Johns Hopkins School of Medicine, Baltimore.

Dr. Goodman spoke at a June 9 Capitol Hill briefing, "Predicting the Outcome of Cancer: New Approaches and New Complications." One of a series of briefings by the Congressional Biomedical Research Caucus, it was hosted by the Joint Steering Committee on Public Policy, a coalition of three biomedical research societies.

The very early detection of cancer raises a host of new issues, Dr. Goodman said. "As we see cancer earlier and earlier, we jump to treat it." But how to treat it remains a mystery, and whether this very early stage of the disease will progress to a life-threatening tumor is by no means certain.

"We've got ourselves into a bit of a box," he said. "You can be hurt by learning about an illness too early."

Prostate cancer early detection presents just such a conundrum and sparks complex discussions between physicians and patients. While the prostate specific antigen, or PSA, and digital rectal examination can effectively detect prostate cancer early, there is little evidence that available treatments reduce mortality.

The problem of a test being too sensitive and detecting cancer before it can be physically located with current imaging technology also could be traumatic. "Fulfilling the potential of molecular medicine for breast and other cancers will require collaboration between molecular biologists and scientists from a broad spectrum of disciplines," the IOM report said.

Meanwhile, biotechnology companies are developing targeted cancer drugs to follow in the wake of the success of Gleevec (imatinib mesylate), which has been effective for some patients with chronic myeloid leukemia. The newest drugs are also highly specific, virtually nontoxic and can be taken by mouth, Dr. Goodman said. "For those in whom they work, they are something of a miracle."

These treatment successes, along with early detection and prevention efforts, have produced a continuing and overall decline in the risk of getting and dying from cancer, says the "Annual Report to the Nation on the Status of Cancer from 1975 to 2001," released June 3. This good news translates into a population of 10 million cancer survivors of all ages in the United States and prompted a look by a presidential advisory panel on their continuing health status.

"Our ability to detect cancers early and treat them successfully has improved dramatically over the past 30 years," said panel Chair LaSalle Leffall Jr., MD, a professor of surgery at Howard University in Washington, D.C. "Now we're recognizing that [survivors'] challenges often continue long after their treatment concludes, and some of these challenges vary depending on the survivor's age at diagnosis."

The panel recommends that doctors provide patients with detailed records of disease and treatment. Patients also should be given a plan for follow-up care that includes periodic cancer screenings and examinations for known late effects of the therapy.

The panel also wants the federal government to implement comprehensive health care reform that includes coverage for psychosocial services during and after treatment and reimbursement for follow-up care.