Risk Of Cancer Higher After Acute Thrombosis

Arterial thrombosis can have risks for developing disease which are far worse than the blood clot itself, such as cancer, which is especially the case for smoking related forms of cancer, according to researchers. The cancer risk is continuously increased but decreases over time. The first 6 months with 3 times the risk, falling during the next 6 months to 1 in 40, after the first year after the clot has passed the risk of cancer is 15% continuously increased.

Ordinary venous blood clots cause the leg to swell, contracting and becoming red and warm. Arterial blood clot characteristics are almost opposite. This is when the leg becomes cold and pale. Doctors use the 5 P’s in cases of arterial blood clots which are pain, pallor, pulselessness, paraesthesia, and paralysis/paresis. Patients typically lose the leg if arterial thrombosis is not treated quickly.

The study was based on 6,600 patients diagnosed with arterial blood clots in the leg, 772 of which went on to be diagnosed with cancer during a 20 year period. This is the first time known to the researchers where the association between the two have been examined. It was noted the study did not clarify underlying causal mechanisms.

Cancer patients have increased risk of blood clots, the study was unable to determine of the patients had unactive, undetected, and undiagnosed cancer that caused the blood clot, or whether the clot facilitated formation of a latent cancer. Researchers likened it to the classical egg and chicken dilemma.

Blood platelets and coagulation factors change in cancer patients, blood has increased tendency to clot, therefore it is likely that an undetected cancer announces itself through a lower limb arterial thrombosis. It stands to reason that an undetected cancer in close proximity to the arteries supplying the limb grows into the arteries, sending thrombi via the bloodstream into the leg.