Some men of African descent may have a higher genetic risk of developing prostate cancer, according to research conducted at the Keck School of Medicine of the University of Southern California (USC).

The genome-wide association study, published in the journal Nature Genetics on May 22, determined a marker of risk for prostate cancer in men of African descent, who tend to more susceptible to prostate cancer than men of non-African descent. The research team was led by Christopher Haiman, ScD., at the USC Norris Comprehensive Cancer Center and Hospital, part of the Keck School.

"This is a novel risk locus for prostate cancer, and the first study of its kind conducted in men of African ancestry," said Haiman, associate professor in the Keck School Department of Preventive Medicine. "We have been trying to figure out why African American men have a greater risk for prostate cancer. These findings may help us better understand if there is a genetic contribution to disparities in risk for this common cancer."

The research looked at common risk alleles for prostate cancer in men of African descent to determine a possible reason for the high incidence of prostate cancer in this population. The research focused on approximately one million single nucleotide polymorphism (SNP) markers across the genome of 3,425 African-American men with prostate cancer and 3,290 African-American male controls.

The research turned up a novel risk variant on chromosome 17q21. The frequency of this marker is 5 percent in men of African ancestry but is rare in other populations.

The discovery builds on findings several years ago by Haiman's team of a risk region on chromosome 8q24, which also contains clues as to why more men in this population are likely to develop prostate cancer.

The findings support the need for additional genome-wide investigations to locate risk markers that are common or rare, which may play a role in racial and ethnic disease disparities, Haiman said.

The research is part of the Multiethnic Cohort study (MEC), conducted between the Keck School and the University of Hawai'i, and funded by the National Cancer Institute.

"Genome-wide association study of prostate cancer in men of African ancestry identifies a susceptibility locus at 17q21"
Christopher A. Haiman, Gary K. Chen, William J. Blot, Sara S. Strom, Sonja I. Berndt, Rick A. Kittles, Benjamin A. Rybicki, William Isaacs, Sue A. Ingles, Janet L. Stanford, W. Ryan Diver, John S. Witte, Ann W. Hsing, Barbara Nemesure, Timothy R. Rebbeck, Kathleen A. Cooney, Jianfeng Xu, Adam S. Kibel, Jennifer J. Hu, Esther M. John, Serigne M. Gueye, Stephen Watya, Lisa B. Signorello, Richard B. Hayes, Zhaoming Wang, Edward Yeboah, Yao Tettey, Qiuyin Cai, Suzanne Kolb, Elaine A. Ostrander, Charnita Zeigler-Johnson, Yuko Yamamura, Christine Neslund-Dudas, Jennifer Haslag-Minoff, William Wu, Venetta Thomas, Glenn O. Allen, Adam Murphy, Bao-Li Chang, S. Lilly Zheng, M. Cristina Leske, Suh-Yuh Wu, Anna M. Ray, Anselm JM Hennis, Michael J. Thun, John Carpten, Graham Casey, Erin N. Carter, Edder R. Duarte, Lucy Y. Xia, Xin Sheng, Peggy Wan, Loreall C. Pooler, Iona Cheng, Kristine R. Monroe, Fredrick Schumacher, Loic Le Marchand, Laurence N. Kolonel, Stephen J. Chanock, David Van Den Berg, Daniel O. Stram, Brian E. Henderson
Nature Genetics, May 2011