By Karen Kaplan
October 29, 2013, 1:11 p.m.
Driving a truck for a living can be hazardous to your health if you are diagnosed with prostate cancer, researchers said Tuesday.
Prostate cancer is the most common type of cancer diagnosed in men, and in most cases it’s basically harmless. As the National Cancer Institute says, even patients who never get their tumors treated are likely to die of something other than prostate cancer. So, instead of looking at prostate cancer risk, the researchers who did the new study focused on the risk that the cancer would be aggressive at the time of diagnosis.
They had a hunch that truck drivers might be vulnerable, because previous studies had suggested that long-term exposure to the kind of “whole-body vibration” endured by men working with with heavy equipment could increase prostate cancer risk. It’s not clear why this would be, but one possibility is that the vibration prompts the body to produce more testosterone, which is a known risk factor for prostate cancer, according to a 2012 study published in the Annals of Occupational Hygiene. Another is that vibration can lead toprostatitis, or inflammation of the prostate gland, which may also be linked to prostate cancer, according to the American Cancer Society.
The research team — from the NCI, the Louisiana State University School of Public Health, the University of North Carolina in Chapel Hill and the Roswell Park Cancer Institute in Buffalo, N.Y. — looked at medical records and other data from 2,132 men who were part of the North Carolina-Louisiana Prostate Cancer Project. Along with other health and demographic information, they told interviewers about the two jobs where they had spent the most time in their careers, as well as their most recent job at the time of their diagnosis.
When the researchers crunched the numbers, they found that men who said they spent more time driving a truck than doing anything else were nearly four times more likely than educators to be diagnosed with a prostate cancer considered highly aggressive. (The educators were used as the baseline group because they were deemed to have pretty much no exposure to whole-body vibration.) These aggressive cancers had a PSA level greater than 20 nanograms per milliliter of blood, a Gleason sum of at least 8, or a combination of a Gleason sum of at least 7 and tumors that were stage T3/T4.
Truck driving had the strongest link to an increased risk of aggressive prostate cancer, but it wasn’t the only occupation associated with higher risk. The researchers also found that men who worked at a garden shop for at least six months were 2.33 times more likely than educators to be diagnosed with highly aggressive prostate cancer. That might be due to exposure to pesticides, although men who worked as landscapers, exterminators or in other jobs that involve pesticides were not found to have a heightened risk of aggressive prostate cancer.
The researchers presented their results Tuesday at the American Assn. for Cancer Research’sInternational Conference on Frontiers in Cancer Prevention Research in National Harbor, Md.