Robert B. Dickson, 54; Professor, Breast Cancer Expert

Robert B. Dickson, a Georgetown University professor whose groundbreaking research led to a deeper understanding of breast cancer, died of a ruptured aorta June 24 at his home in Kensington. He was 54.

Dr. Dickson, whose specialties were pharmacology, biochemistry and cell biology, made several key findings in the ways cancer cells grow. One of his most intriguing discoveries came last year, when he found that chocolate contains properties that may combat breast cancer.

At the time of his death, Dr. Dickson was vice chairman of the department of oncology at Georgetown and, since 2001, co-director of the breast cancer program at the university's Lombardi Comprehensive Cancer Center. Before coming to Georgetown in 1988, he was a researcher at the National Institutes of Health.

"Bob is regarded as one of the world's leading researchers of the science of breast cancer," Anatoly Dritschilo, the interim director of the Lombardi Center, told the Georgetown University publication Blue & Gray this year.

While at the NIH in 1987, Dr. Dickson was the first scientist to demonstrate a link between estrogen, a naturally occurring hormone, and the growth of tumors. That study led to the development of hormone treatments for breast cancer, which is diagnosed in 215,000 American women each year.

In last year's chocolate study, he found that an element in cocoa had the ability to neutralize several proteins that cause cancer cells to uncontrollably divide. While stopping short of encouraging women to gorge on chocolate, Dr. Dickson said: "There are all kinds of chemicals in the food we eat that potentially have effects on cancer cells, and a natural compound in chocolate may be one."

Some of his other research isolated proteins, cell receptors and "growth factors" that contribute to the metastatic spread of breast cancer. He studied how cancer cells can travel throughout the body and invade other organs.

He also identified molecular indicators to predict the spread of breast cancer. This work holds promise for treatments that could reduce the frequency of chemotherapy for breast-cancer patients.

"Every cancer his its own Achilles' heel," he told Georgetown's Blue & Gray, "and breast cancer's is a dependence on hormones and other growth factors."

Dr. Dickson contributed to more than 340 scientific publications, wrote or edited 14 books and journals about breast cancer, and spoke at more than 200 conferences. His work opened auspicious avenues of research for other scientists and has been cited in more than 900 professional papers.

"As a person and as a scientist, he was an exceptional and amazing man," Claudine Isaacs, co-director of the breast-cancer program, said yesterday. "He was selfless in his devotion to his mission. His mission was to cure cancer."

Dr. Dickson was born in Washington and spent his early years in Arlington. He moved with his family across the country, following the assignments of his father, a meteorologist with the National Weather Service. Returning to Northern Virginia in his teens, Dr. Dickson graduated from Fairfax High School.

He was an Eagle Scout and a photographer for his school newspaper and also had a strong early interest in science. In high school, he built a telescope, through which he photographed sunspots.

After receiving a bachelor's degree in chemistry from the College of William and Mary in 1974, he went to graduate school at Yale University. He received a doctorate (and a concurrent master's degree) in pharmacology in 1980. He was a postdoctoral fellow at the NIH's National Cancer Institute for three years, then stayed on as a senior staff fellow and senior investigator until he was named to the Georgetown faculty in 1988.

Since 1993, he had been director of an interdisciplinary tumor biology program at Georgetown, where he supervised the work of more than 100 doctoral students. He directed a large laboratory, with more than two dozen researchers, and was a well-liked figure at the Lombardi Center. He often walked the halls with "Little Mermaid" stickers that his 9-year-old daughter had put on his shirt.

"He was someone who truly had time for everyone," said Isaacs, co-director of the breast-cancer program. "Bob was the consummate collaborator. The people who were collaborating with him will carry his work on."

Last year, other scientists feted Dr. Dickson with a Festschrift, or a collection of articles in his honor. His other interests included offshore diving, archaeology, Shakespearean drama and astronomy. He often set up a telescope in his back yard, inviting neighbors to view the planets and stars.

Survivors include his wife of 14 years, Jane M. Fall-Dickson, and daughter, Natasha Fall-Dickson, both of Kensington; his parents, Robert R. and Marie Dickson of Fairfax City; and a brother.