Environmental Factor, November 2009, National Institute of Environmental Health Sciences
Sister Study Exceeds Recruitment Goal: Now the Real Work Begins
By Robin Mackar
NIEHS has many reasons to celebrate this October as it recognizes Breast Cancer Awareness Month. The NIEHS Sister Study(http://www.sisterstudy.org/) began recruiting women for this landmark study during Breast Cancer Awareness month in October 2004 and this October has reached a milestone. It has recruited nearly 51,000 women from all walks of life, whose sisters had breast cancer, to participate in this long-term study focusing on uncovering environmental and genetic factors to help prevent breast cancer.
"What an amazing group of women we have enrolled in this study. Every single one of them should be congratulated for their commitment to participating in research to help identify factors that lead to breast cancer," said Dale Sandler, Ph.D., chief of the Epidemiology Branch at NIEHS and principal investigator of the Sister Study. "We have exceeded our recruitment goal and I'm thrilled with the diversity of age, race, ethnicity and education represented in the cohort."
The women come from all 50 states as well as Puerto Rico, and include women with different ethnic, educational and employment backgrounds. Since the study began in 2004, 50,884 women have enrolled including 4,438 African-American women, 2,631 Hispanic women, and 1,160 women from other racial/ethnic groups. The study also includes 8,230 women aged 65 and over, and 7,212 with a high school degree or less. All of the women in the study have a sister who has been diagnosed with breast cancer. Researchers hope to uncover clues about causes of breast cancer and other diseases by comparing women who develop breast cancer or other conditions while in the study with those who remain disease-free.
"Recruiting more than 50,000 Sister Study participants in five years was a huge accomplishment for the NIEHS," said NIEHS Director Linda Birnbaum, Ph.D. "Over the years, we've received substantial support from a sister NIH agency, the National Center on Minority Health and Health Disparities, whose support enabled our researchers to develop unique strategies to recruit a diverse cohort. We appreciate the value that they and our many community partners and participants place on the promise of this research, and look forward to providing more insight into how to prevent breast cancer and other diseases that are influenced by the environment."
"We owe a debt of gratitude to our participant volunteers who worked so hard to recruit women into the study and to our partner organizations that lent us their support," added Lisa DeRoo, Ph.D., lead investigator of the study. These organizations included the American Cancer Society, the Susan G. Komen for the Cure, the Sisters Network, the Intercultural Cancer Council, the Love/Avon Army of Women, the Breast Cancer Network of Strength, and many more local and national groups interested in breast cancer and women's health.
Sandler points out that sustaining the same level of enthusiasm as the project moves forward is going to be the next challenge. "What we need now is for everyone to realize this is a 10-year study and that the work is really just beginning," Sandler said. The participants are asked to complete a yearly one-page update by mail, e-mail or phone. They are also asked to share more detailed information about changes in their health, jobs and lifestyle every two or three years.
The study has already reported some preliminary findings about how factors such as weight and perceived stress may influence health, and investigators are beginning to use the biological samples participants contributed to learn how some genetic factors may affect breast cancer risk. The researchers point out key results on gene-environment interactions may be just a few years away.
Under the direction of Clarice Weinberg, Ph.D., chief of the Biostatistics Branch at the NIEHS, the researchers are also using the Sister Study as a way to better understand early-onset breast cancer among a targeted subgroup of participants participating in what is called the Two Sisters Study.
(Robin Mackar is the news director in the NIEHS Office of Communications and Public Liaison and a regular contributor to the Environmental Factor.)