DVT Link With Prostate Cancer
Life-Threatening Blood Clot A Hidden Complication Of Cancer
Within a month of his prostate cancer diagnosis, G. Peter Gardner, a 56-year-old runner from Delray Beach, Florida, was diagnosed with an eight-inch-long blood clot, or DVT, in his left calf.
DVT is an acronym for Deep Vein Thrombosis, which occurs when a blood clot develops in the veins of extremities, usually the lower leg or thigh and sometimes the arm.
DVT can be a hidden complication of cancer, and can cause significant pain and swelling for months. If not treated, a DVT can lead to a pulmonary embolism, which can be fatal.
Gardner knew very little about DVT or its link to cancer, and he’s not alone. Nearly three-quarters of Americans have never even heard of DVT, according to a survey released at the American Public Health conference in Washington DC (Clinical Advisor, June 2004).
Yet up to 2 million Americans experience a DVT each year, and up to 300,000 of them die when a fragment breaks off, mirgrates to the lungs and blocks a pulmonary artery, according to the Coalition to Prevent DVT.
“Before the DVT diagnosis,” said Gardner, in an interview with Suite101 on July 15, 2008, “I thought older people with poor blood circulation had blood clotting in their legs. I was a half-marathon runner and fit – it never entered my mind that I was at high risk for a blood clotting.”
Cancer Can Alter Blood's Clotting Activity
Cancer can change the coagulation properties in the blood, putting cancer patients at greater risk of developing blood clots. One study showed that cancer patients were four times more likely than the non-cancerous population to develop a DVT (Venous Thromoembolism and Cancer: Risks and Outcomes, 2003).
Some of the cancers in which there has been an association with abnormal clotting activity include stomach, renal, ovarian, lunch, brain, pancreatic, liver, gallbladder, colon, breast, cervical and prostate cancer.
While cancer is a risk factor, other contributing factors to DVTs include trauma, prior DVT, obesity, pregnancy, advanced age, smoking, immobility, use of oral contraceptives and restricted mobiity caused by long-distance air travel.
The latter added to Gardner's risk factors for a DVT.
Air Travel Heightens DVT Risk
A month before the cancer and DVT diagnoses, Gardner took a cross-country airplane trip, which put him in an even more vulnerable situation for developing a DVT.
Airplane travel, by itself, is a high risk factor for DVT. Frequent business travelers suffer 50 times as many clots as found in a non-flying population. Most of these clots dissolve naturally, and many people don’t even know they have them.
Airhealth.org reports that "85 percent of air travel thrombosis victims are athletic, usually endurance athletes like marathoners." People with slower resting blood flow are at greater risk of stagnant blood subject to clotting.
Often Misdiagnosed
Also athletes are more likely to have bruises and sore muscles that can trigger clotting, and Gardner had just spent three days beating his legs up while skiing.
As a result, a DVT often goes misdiagnosed in athletes. Gardner first thought his was a severely sore calf muscle, and later some swelling from a Baker's cyst.
Gardner said he often runs 15 to 25 miles a week, participates in two or three half marathons and perhaps one marathon every year or two. His heart rate from all the running is relatively low, between 55-60 beats per minutes.
Because of his low heart rate and the cramped conditions in the airplane, his blood was more likely to pool in his legs. The cancer may have then heightened the clotting activity, leading to the DVT.
The Prognosis?
As Gardner began nine weeks of radiation treatment for prostate cancer, he also started a regimen of 3-6 months on warfarin, a blood thinner, for the DVT.
Dr. Richard Chang, a researcher at the National Health Institute, wrote to Gardner in an email that about 50 percent of patients have good clinical results, meaning no pain and no swelling, after 3-6 months of treatment. But the warfarin only thins the blood, it doesn’t dissolve the clot.
A natural tPA and plasinogen in the blood flows over the surface of the clot to dissolve it naturally. As long as the clot is only partially occluding the vein – as opposed to a full occlusion or blockage – blood will most likely slowly dissolve the clot over time.
“God or evolution – depending on your world view,” Dr. Chang wrote, “arranged for clotting to be quick to prevent bleeding to death, and clot lysis (dissolving) to be relatively slow.”
Wears Compression Socks
In the meantime, Gardner is wearing compression socks to aid blood flow in his legs and has resumed running. The pain has subsided, but the swelling in the leg is constant.
“Between the cancer, my low heart rate and the cramped plane ride, it was a kind of perfect storm for developing a DVT,” he said.
Additional stories on prostate cancer by Steve Vogel
Treating Prostate Cancer With IGRT
Prostate Cancer: Treatment Choices
Prostate Cancer: Are You At Risk?
