Predicting Risk of Aggressive Prostate Cancer Through Biomarkers in Blood

Elizabeth A. Platz, ScD, MPH

A new study has shown a possible correlation between men with short-ended chromosomes in the immune cells of their blood and an increased risk of developing aggressive prostate cancer, potentially pointing the way toward an accessible biomarker that could help inform treatment and surveillance decisions. An association between smoking and more aggressive disease also was uncovered.

Researchers from Johns Hopkins Medicine in Baltimore presented these findings from a retrospective study at the 12th Annual AACR International Conference on Frontiers in Cancer Prevention Research, held in October in National Harbor, Maryland.

The analysis built upon the team’s earlier research that examined whether alterations in telomere length in surgically treated men with primary prostate cancer could predict whether an individual patient would progress to metastasis and death from the disease (Cancer Discov. 2013;3(10):1130-1141).

“We found that men with prostate cancer who had high variability in the length of telomeres from one prostate cancer cell to another and shorter telomere length in prostate cancer-associated stromal cells were substantially more likely to develop metastases or die of their disease compared with men with prostate cancer harboring neither of these characteristics,” Elizabeth A. Platz, ScD, MPH, a professor in the Department of Epidemiology at Johns Hopkins Bloomberg School of Public Health who presented the most recent findings at the AACR meeting, said in a statement.

In the new study, the goal was to determine whether circulating leukocyte telomere length more accessibly found in the blood could serve as a surrogate for prostate cell telomere length.

The study drew from the 18,018 members of Harvard University’s Health Professionals Follow-up Study, including 441 men who had developed prostate cancer and 421 men who did not develop prostate cancer. The men had provided blood samples in 1993—1995 and were followed through January 2000. The average time of cancer diagnosis was three years from first blood draw.

Using quantitative PCR, investigators measured relative telomere length in leukocytes from the blood samples and categorized these values based on distribution in the control group.

Among men who developed prostate cancer, those with telomeres in the bottom two tertiles for length—the shortest telomeres— were more than twice as likely to develop an aggressive form of prostate cancer (odds ratio [OR] = 2.29, 95% CI 0.99-5.34) when compared with those who had telomeres in the top tertile for length. When the researchers further refined the results into smokers and non-smokers, they found that those who were ever-smokers were more than four times as likely to have developed aggressive prostate cancer (OR = 4.47, 95% CI 0.99-20.2).

Platz EA, Heaphy CM, De Vivo I, et al. Prospective association between circulating leukocyte telomere length and risk of aggressive prostate cancer. Presented at 12th Annual AACR International Conference on Frontiers in Cancer Prevention Research; October 27—30, 2013; National Harbor, MD. Abstract C20.