Health disparities: genetics plays an important role in cancer detection, prognosis among minorities

Field’s team found a significant difference between the two groups in the RNA produced by 65 genes. Some of the molecules that were more highly expressed in the African-American patients function in signal transduction (the SOS1 gene), cell division and growth (PSPH gene) and cell proliferation (TSPO gene), Field says. RNA expression that was lower in African-Americans included genes linked with transcription (ZNF228), protein transport (SCAMP4) and the PSD3 gene, “which is believed to be involved in suppressing cancer metastasis,” Field said. Low levels of PSD3 have been linked to poor outcome and tumor progression in ovarian cancer.

Field cautions that the findings need to be validated in an independent set of breast tumors using other techniques.

Gene expression profiling reveals tumor immunobiological differences in prostate cancer between African-American and European-American men: Abstract 512

Prostate cancer appears to be distinctly different in African-American men compared with European-American men, according to researchers at the National Cancer Institute (NCI) who found significant differences in expression of numerous genes in tumor samples taken from the two racial groups.

Many of these genes were related to inflammation and immune system regulation, suggesting that pathogens could be involved in race/ethnic differences that lead to the development of these tumors, the researchers say. Some of the genes were also linked to cancer spread.

Although further study is needed to confirm their hypothesis of possible viral involvement in cancer, the team believes that these novel findings could help explain why both the incidence of, and death rates from, prostate cancer are increased among African-American men.

“We don’t think the worse outcomes we see in African-American prostate cancer patients are due to issues of socioeconomic and sociodemographic differences alone,” said lead author, Tiffany Wallace, Ph.D., a postdoctoral fellow in the Laboratory of Human Carcinogenesis at the NCI. “So we are trying to understand if differences in genetics and biology play a discernable role, and this study suggests they do.”

NCI researchers obtained gene expression profiles from tumors removed during surgery from 33 African-American and 36 European-American patients using gene microarray technology. They also obtained samples of surrounding non-tumor prostate tissue from seven of the African-American and 11 of the European-American patients. They then compared the combined tumor profiles to profiles from non-cancerous tissue, and similar differences in tumor marker expression that other research groups had already detected.