"A large observational study has found that men who take aspirin regularly may have a lower risk of dying from prostate cancer. Men who took aspirin regularly after their prostate cancer diagnosis were less likely to die from the disease. However, aspirin did not affect the overall incidence of prostate cancer." The study was presented at ASCO in SF earlier this year.
Aspirin is an antiinflammatory drug & might be supposed to be beneficial in PCa by limiting production of some of the inflammatory metabolites af arachidonic acid triggered by activation of NFkB, which generates COX & LOX enzymes & much else. Aspirin is a more powerful COX-1 inhibitor than it is of COX-2. As such, it is associated with stomach bleeding & emergency room visits.
Aspirin also inhibits platelet aggregation, which is the first step in clot formation. As such it might lower the risk of metastasis. In fact:
"“We think that aspirin probably prevents progression of prostate cancer to metastases,” said Dr. Allard. While the biological basis for this protective effect is unknown, preclinical research suggests aspirin may prevent the spread of cancer to the bone."
Odd that he would be coy about a supposed mechanism when papers have been written on how circulating cancer cells can avoid being zapped, by docking with microclots.
"Among men with prostate cancer, regular aspirin use after diagnosis was associated with a 39% lower risk of dying from prostate cancer. In contrast, use of aspirin before diagnosis did not have a measurable benefit."
(above quotes are from the ASCO release [1])
According to the CDC, aspirin & other antiplatelet drugs account for 13% of the ~100,000 annual ER visits by those 65 & older. [Warfarin accounted for 33%.]
The new findings are from the Physicians’ Health Study. In contrast, a paper from the Health Professionals Follow-up Study, published this month [2] reports:
"Regular aspirin use was not associated with the risk for ... advanced prostate ... cancer."
Par for the course in aspirin studies, of which there are now many.
From an Italian study [3] published last month:
"Use of LDA {low-dose aspirin} was associated with a decreased incidence rate of PCa {36% reduction} ... which was primarily driven by a frequency of LDA use equal to or higher than twice per week ... Such an association was more pronounced {57% reduction} ... when LDA was used for five or more years."
"Our findings indicate that LDA use might be associated with a reduction of risk of PCa in patients with cardio- or cerebrovascular diseases."
But the ASCO study failed to associate aspirin use with PCa incidence.
A 2015 study [4] hypothesized that:
"Regular aspirin use may decrease cancer risk by reducing chronic inflammation."
"Serum levels of 78 inflammatory markers were measured in 1,819 55- to 74-year-old men and women in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial."
"No significant associations were observed between regular aspirin use and the inflammatory markers assessed."
If regular aspirin use had made a difference to those markers, one might expect a slowing down of onset. The lack of proof of an effect on inflammation, is consistent with no effect on incidence.
It should be noted though, that if aspirin had reduced inflammation, it would have lowered PSA & possibly reduced detection of serious PCa.
Far fewer studies have been concerned with survival than incidence. From a 2014 paper [5] from "the American Cancer Society’s Cancer Prevention Study II Nutrition Cohort, a prospective study of cancer incidence ...":
"... prediagnosis aspirin use was not statistically significantly associated with PCSM {prostate cancer-specific mortality} at a mean follow-up of 9.3 years, and postdiagnosis aspirin use was not significantly associated with PCSM at a mean follow-up of 6.4 years.
However, in a subset analysis of high-risk patients (defined as those with {≥ T3 and/or Gleason score ≥ 8)}, postdiagnosis aspirin use was associated with a {40% reduction}.
For low-dose, postdiagnosis aspirin use in high-risk patients, PCSM was found to be significantly reduced {by half}."
"“The main finding is that among this large cohort of men diagnosed with nonmetastatic prostate cancer, those who used aspirin daily and those who did not had about the same risk of dying from prostate cancer,” says Dr.Jacobs. “However, in a subgroup of men diagnosed with potentially more aggressive prostate cancers, risk of dying from prostate cancer appeared somewhat lower among those who took daily aspirin after their diagnosis, even low-dose aspirin.”"
From a 2014 Irish study [6]:
"... aspirin use was associated with a non-significant reduced risk of prostate cancer-specific mortality {-12%} in men with localised prostate cancer. Men receiving higher doses of aspirin {>75 mg} had a statistically significant reduced risk of prostate cancer-specific mortality {-27%}. "
Note that the antiplatelet effect largely occurs at the low 81 mg dose, with little added benefit at higher doses.
Nattokinase would seem to be safer than aspirin, if the protection is related to microclot reduction - IMO.
-Patrick
[1] asco.org/press-center/regul...
[2] ncbi.nlm.nih.gov/pubmed/269...
[3] ncbi.nlm.nih.gov/pubmed/269...
[4] ncbi.nlm.nih.gov/pubmed/257...
[5a] onlinelibrary.wiley.com/doi...
Aspirin could cut cancer patients' death risk by 20%
Understanding Recent Statin Study of Advanced PC Patients
