Genomics, cancer and health disparities

KN01

Cancer is a disease of the genome. Over the past 25 years the cancer research community has made steady progress in identifying the hereditary and somatic changes in the genome that predispose to malignancy, but here in 2007 we are poised to see a rapid expansion of that catalog. For hereditary risk, the advent of the HapMap project and low cost genotyping has made it possible to survey the whole genome for risk factors, already revealing hitherto unknown genetic variants for breast cancer, colon cancer, and prostate cancer. For somatic variation, the launching of The Cancer Genome Atlas (TCGA) promises to provide a comprehensive view of recurrent somatic mutations in the common human cancers, beginning with glioblastoma multiforme, ovarian cancer, and squamous cell lung cancer.
 What will these new revelations tell us about cancer and health disparities? Clearly it would be a profound mistake to assume that such disparities primarily arise from genetic differences between groups, since many other environmental, social, and cultural factors are undoubtedly at work. But in at least once instance, the 8q24 variants that confer an increased risk of prostate cancer, the higher frequencies of the risk alleles in African-American men suggests that ancestral geographic origin may be playing a role.
 The debate about genetic vs. environmental origins of health disparities has raged for decades. Cancer research may be in a position to move this field forward more quickly than for many other diseases. With carefully designed, sensitively implemented, and objectively conducted research, we may finally have the chance to get some answers.