Swedish and American researchers have found five gene variants strongly linked to aggressive prostate cancer, according to a report by a Swedish daily Gothenburg Post on Wednesday. The findings by the US-Swedish team could transform how prostate cancer is treated by helping doctors identify a subgroup of people whose tumors are more likely to kill them and targeting their tumors accordingly, the report said. The five genetic markers, LEPR, RNASEL, IL4, CRY1 and ARVCF, are single-nucleotide polymorphisms (SNPs). Essentially, they are DNA variations that may be linked to disease. Researchers analyzed DNA in blood samples from 1,309 Seattle-area prostate cancer patients aged 35 to 74 at the time of diagnosis and 22 SNPs were found to be "significantly associated" with prostate cancer-specific mortality. Further examination of the 22 SNPs in a Swedish group of cancer patients with the same age parameters helped identify the five SNPs that were most closely linked to death from prostate cancer, researchers said. Patients who carried four or all five of these genetic markers had a 50 percent higher risk of dying from prostate cancer than patients who had two or fewer markers, according to the study. Researchers at the Karolinska Institute in Stockholm examined the DNA of 2,800 Swedish men for the study to be published in September. Fredrik Wiklund from the Karolinska Institute said the study results will now need to be verified among the general public. Prostate cancer is the second deadliest among men after lung cancer. About 32,000 men died of prostate cancer in the U.S. each year, according to the National Cancer Institute.