Gene linked to prostate cancer risk

Researchers at the Hopkins University School of Medicine and the University of Michigan Health System recently discovered the first major gene mutation associated with prostate cancer. This rare and hereditary mutation, they found, is connected to a notably higher risk of the disease.

Although the mutation only affects a small number of prostate cancer cases, investigators showed that men who possess the mutation are up to 20 times more likely to develop the illness. Consequently, the discovery could potentially lead to insights on the development of prostate cancer, helping to identify men who would benefit from earlier screening.

The investigation teams at Hopkins and U-M researched over 200 genes in 94 individuals with the cancer. The study included men who were diagnosed at age 55 and under or men with relatives with prostate cancer. Four of the men possessed a mutation in HOXB13, a key gene in the development of the prostate. After further inquiry of the families of these men, researchers discovered that the same mutation existed in all of their 18 close relatives with prostate cancer.

In a combined effort with Jianfend Xu and Lilly Zheng at Wake Forest University, researches then assessed 5,100 more men with prostate cancer, finding that 72 of these men also had the HOXB13 mutation. Any individual with the mutation also had an increased propensity for having a family member with the disease. Furthermore, only one member of the control group of over 1,000 men without prostate cancer carried the mutation.

Although prostate cancer occurs most often in African-American men, the mutation was found in white families. Two different mutations of the HOXB12 gene, however, were discovered in African-American families. Nevertheless, researchers have been unable to draw clear conclusions from these mutations because only seven of the 94 families under investigation were African-American. African-American men also possess the tendency to have more aggressive forms of prostate cancer and are more likely to be diagnosed at younger ages.

According to researchers, the HOXB13 gene mutation may also help develop genetic testing for prostate cancer. Similar models of this testing exist in the BRCA1 and BRCA2 mutations that occur in women with a high risk of developing breast and ovarian cancer.

The study, which has ended a two decade-long investigation, was published this month in the New England Journal of Medicine as a collaboration between several prominent universities. With its potential to assess high risk patients and possibility to develop a novel means for diagnosing prostate cancer, the investigation characterizes an important component in fully understanding the hereditary nature of the disease.