'A time of enormous opportunity'

Cancer-prevention expert John Potter named head of center's Public Health Sciences Division

Renowned epidemiologist Dr. John Potter, head of Fred Hutchinson's Cancer Prevention Research Program, assumed the directorship of the center's Public Health Sciences Division Nov. 1. He replaced Dr. Ross Prentice, whose leadership since 1983 helped establish the division as a premier hub for research in biostatistics, cancer prevention and epidemiology.

"If I were to choose one word that characterizes my enthusiasm for taking on this role, it would be 'opportunity,'" Potter said. "We have the opportunity to build on our existing strengths in generating good hypotheses about the nature of cancer causes and prevention and to combine them with the wealth of information from the genome project and new strategies like microarrays and proteomics. We're at the beginning stages - both in our division and in the field - of a time of enormous "opportunity."

That philosophy, Prentice said, is exactly what distinguishes Potter as the ideal division leader. "

John's interface between population science and laboratory studies is very appropriate for the further development of our division."

Potter, also a professor of epidemiology at the University of Washington, has been involved in the study of colorectal cancer for more than 20 years. With his colleagues, he has made major contributions to the understanding of the dietary factors that increase colorectal cancer risk, such as protein, meat, sugar, alcohol, and obesity in men, as well as those that reduce risk - such as vegetables, vitamin E, folate, calcium and physical activity.

Potter has also been a leader in research that demonstrated the preventive potential of vegetables and fruit. In 1991, he produced the first comprehensive review of cancer, vegetables and fruit that explored both the epidemiologic evidence and the existing literature on possible mechanisms of this preventive effect.

Among his leadership activities in the field of cancer prevention was serving as chair of an international panel of experts convened by the American Institute for Cancer Research. This resulted in publication of a report considered the definitive source for scientists and policymakers on the feasibility of reducing cancer incidence through diet and other environmental factors.

Cancer clues found inside the younger breast

Certain features on normal mammograms of women under age 50 may help doctors predict future breast cancers.

Fred Hutchinson researchers recently found that younger women whose mammograms reveal large regions of breast density or certain types of mineral deposits (calcifications) have a high risk of developing breast cancer.

The finding may let radiologists decide whether a woman is a good candidate for more intensive cancer screening, said Dr. David Thomas, lead author of the study.

Researchers found that a woman's risk of developing future breast cancer increased with the percentage of the area of dense tissue. Women with more than 70 percent dense breast tissue were four times more likely to develop cancer than women with low levels of breast density.

Some types of calcifications also were found to predict subsequent breast cancer, causing a two- to three-fold risk compared to women lacking calcifications.

Most significant was the increased risk - up to 10-times higher - calculated for women with both a high percentage of dense breast tissue and certain types of calcifications.

Study co-author Dr. Constance Lehman, a University of Washington associate professor of radiology and director of breast imaging at the Seattle Cancer Care Alliance, said that women who have these mammographic features need to be particularly vigilant about being screened for breast cancer.

"It's been well-known that density tends to hide cancers on the mammogram. It has also been shown that increased density can put a woman at increased risk for developing cancer," Lehman said. "This study shows certain types of calcifications, combined with increased breast density, are additional risk factors."

New test bridges the diagnostic gap for lupus

The U.S. Food and Drug Administration has cleared for market a new screening test for lupus developed by Fred Hutchinson researchers. The test is considered the first significant diagnostic breakthrough for systemic lupus erythematosis, or SLE, in four decades.

Developed by Dr. Mark Roth, the test is expected to pick up the 20 percent of SLE cases that previously fell through the cracks because they could not be detected by the most widely used screening test. Lupus is a chronic disorder in which a person's immune system attacks the body. SLE is the most severe form, which causes inflammation of connective tissue throughout the body, from the joints to the kidneys. Because symptoms cover a wide range, diagnosis can be difficult.

"This test will improve the ability of doctors to make correct decisions when diagnosing SLE, and we also have evidence that this test is of value in determining where in the body the disease will present itself," said Roth, also an affiliate associate professor of at the University of Washington School of Medicine.

FDA clearance well help facilitate the transfer of the technology to companies that can make the test widely available.

Plant chemical blocks signals that trigger childhood brain cancer

The most common brain cancer in children may have an Achilles' heel - the signal from a protein called Hedgehog, according to a report by scientists at Fred Hutchinson.

The center's Dr. James Olson, as well as scientists from the Johns Hopkins University, have discovered that blocking the growth signals from Hedgehog in laboratory experiments stops medulloblastoma tumors in mice and kills medulloblastoma cells taken from human patients.

To test the blocking of Hedgehog signals, Olson used tumor samples from seven patients. Olson's team placed excised tumor cells in a laboratory dish and exposed the cells to cyclopamine, a plant chemical patented by Johns Hopkins and licensed to Curis Inc. Cyclopamine killed up to 99.9 percent of the cancer cells after one week of treatment.

While current treatment options of surgery, radiation and chemotherapy are effective, Olson said, some children still die from these tumors and the treatment can permanently damage those who survive.

Diet lower in fat, calcium may fight prostate cancer's advanced form

A fat-laden diet and high calcium consumption are both well-known suspected risk factors for prostate cancer. However, new findings from Fred Hutchinson researchers suggest that fat and calcium themselves may not cause prostate cancer, as previously thought, but instead may fuel its progression from localized to advanced disease.

While high intake of dietary fat and calcium is associated with an increased risk of clinically significant, advanced prostate cancer, it has no apparent impact on risk of early-stage disease, according to findings by Dr. Alan Kristal and colleagues.

"Our findings clearly show decreased risk for late-stage disease in men with diets that are low in fat and moderate in calcium, perhaps because these diets slow progression of prostate cancer into more aggressive disease," Kristal said. "For men diagnosed with early-stage prostate cancer, this finding could be important because it suggests that moderating fat and calcium consumption may reduce the risk of cancer recurrence following treatment."

Kristal and colleagues found that men who ate lower-fat diets, with fat accounting for no more than 30 percent of their daily calorie intake, had half the risk of late-stage cancer than men who consumed more fat. However, there were no associations of fat intake with early-stage disease.

"As more and more men are diagnosed with early stage disease due to the widespread use of the PSA (prostate-specific antigen) screening test, it becomes increasingly important to consider how dietary or lifestyle changes could decrease their risk of cancer recurrence," said Kristal, also an associate professor of epidemiology at the University of Washington School of Public Health and Community Medicine.

Researchers identify 14 new cancer genes

Using tools afforded by the completion of the human genome, research fellow Dr. Harry Hwang has identified 14 previously unidentified cancer genes.

Working with Dr. Bruce Clurman and colleagues, Hwang identified 21 potential cancer genes, 14 of which had not been previously implicated in cancer. The achievement represents a key step in the quest of cancer biologists to characterize the cellular pathways that distinguish types of cancer.

The genes collaborate with a protein called p27, which shows up in abnormally low levels in lymphomas, breast cancer and other cancers.

Identification of the complete network of genes required for tumor formation, Hwang said, is a first step toward developing specific anti-cancer therapies.

Breast self-exam instruction doesn't reduce cancer deaths, new study indicates

Results of a long-running Fred Hutchinson study raise doubts about the value of teaching a common breast-cancer screening technique, the breast self-exam.

A 12-year trial involving more than 266,000 female factory workers in the mainland Chinese city of Shanghai found that women who received intensive instruction in breast self-exam suffered no fewer deaths from breast cancer than women who did not.

Dr. David Thomas, who led the trial, said that more studies are needed to assess whether breast self-exam reduces breast-cancer mortality in women who perform the technique frequently and competently or in those who receive regular mammograms.

Yet the results make clear that allocating money for large-scale breast self-exam training programs in the absence of mammographic screening has no effect on saving lives.

"On the basis of this trial, I wouldn't say that women should not practice breast self-exam," Thomas said. "Breast self-exam may be helpful for highly motivated women at high risk of breast cancer. However, our findings do show that investing in breast self-exam training programs is not a good use of cancer-prevention funds in developing countries without mammographic screening where public-health resources are limited. If we couldn't see a benefit in Shanghai, where we were able to devote enormous resources to the study of breast self-exam instruction, I doubt we would see a benefit in any other developing country."

Researchers also found that women who received intensive breast self-exam training experienced more benign breast biopsies, potentially adding to health-care costs.

The final results from the study, one of the largest of its kind, were published in the October issue of the Journal of the National Cancer Institute. Thomas worked with many collaborators from Fred Hutchinson and the Station for The Prevention and Treatment of Cancer of the Shanghai Textile Industry Bureau.

The study authors noted that their recommendations for public-health officials and for individual women, particularly those at high risk for breast cancer, are distinct.

"For public-health officials who have to make choices about how to spend prevention funds, breast self-exam instruction programs are an idea that shouldn't be pursued," Thomas said. "Yet for a women with a mother and sisters who have had breast cancer, it's a different story. You would not want to discourage these women from practicing breast self-exam."