New study below [1].
I have a number of old posts on coagulation/nattokinase /D-dimer. Cancer increases the risk of life-threatening coagulation, as well as metastasis. Nattokinase, which can dissolve the fibrin in clots, is thought by many men to be protective, but I suspect that most simply take a 2,000 FU cap & hope for the best. A simple D-dimer test is useful when trying to figure out an appropriate dose. If D-dimer is zero, there is no clot activity. This is why it is the first test done in the ER when someone presents with chest pain. When D-dimer is elevated, it might not be because of a clot, but when using D-dimer to monitor clot activity, it is prudent to assume the worst.
In the new study:
"D-dimer levels were measured in radiation oncology patients, who were diagnosed with prostate, breast or lung cancer, or leukemia, as well as in healthy subjects serving as controls."
"Compared to the pre-radiotherapy measurements, radiation exposure was associated with a significant increase in the D-dimer levels at the on- and post-radiotherapy time points. At the post-radiotherapy time point, D-dimer levels in the patients were not significantly reduced compared to the on-radiotherapy levels, indicating that the risk for developing disseminated intravascular coagulation (DIC) may be increased in some radiation oncology patients."
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"Disseminated intravascular coagulation (DIC) is a condition in which blood clots form throughout the body, blocking small blood vessels. Symptoms may include chest pain, shortness of breath, leg pain, problems speaking, or problems moving parts of the body. As clotting factors and platelets are used up, bleeding may occur. This may include blood in the urine, blood in the stool, or bleeding into the skin. Complications may include organ failure." [2]
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A Chinese study from 2017 is of particular interest [3]:
"The D-dimer levels of forty patients with endometrial cancer were assessed before ... and after ... intensity-modulated radiation therapy (IMRT) ..."
"Multivariate survival analyses showed that D-dimer was independently associated with {overall survival} and {progression free survival} in patients with endometrial cancer."
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I wouldn't be surprised if, sometime in the future, it would be standard practice for men with PCa to receive a D-dimer test at an early stage. This will not happen until there is a drug comparable to nattokinase in terms of safety. Current drugs are too dangerous to be used for prophylaxis.
In the interim, it is up to the patient to demand a D-dimer test. IMO
-Patrick
[1] ncbi.nlm.nih.gov/pubmed/316...
Supplements and Radiation Therapy
Moving into the new area of Expanded use of Radiotherapy
Radiotherapy in the Definitive Management of Oligometastatic Prostate Cancer
Studies re: PSA > 0.5% after RT 
Radiation and Diarrhea 
