New Danish study [1] below. Yes, yet another aspirin study.
I don't know how these Nordic studies do it. I get how the central health system knows about the "35,600 patients" - but low-dose aspirin usage?
"Use of low-dose aspirin was associated with an OR {odds ratio} for prostate cancer of 0.94 ..."
"Slightly lower ORs were seen with increasing cumulative amount, duration, and consistency of low-dose aspirin use (continuous use, ≥5 years: OR 0.89... ≥10 years: OR 0.86 ..."
"Nonaspirin NSAID use was associated with a slightly increased OR for prostate cancer (1.13 ...); however, this association was confined to localized disease"
What to make of it?
Low-dose aspirin is not taken for inflammation. It is effective against platelet aggregation & should limit microclots. It should therfore reduce metastasis, but that doesn't explain the reduction in incidence. Except that users may have adopted other changes that impact on PCa risk. e.g. if concerned about CVD, they might be on a statin. Or a change of diet.
Chronic NSAID users often have difficulty controlling inflammation, so increased disease does not necessarily mean that NSAIDs did not protect to some extent.
-Patrick
[1] ncbi.nlm.nih.gov/pubmed/275...
Cancer Causes Control. 2016 Aug 9. [Epub ahead of print]
Low-dose aspirin or other nonsteroidal anti-inflammatory drug use and prostate cancer risk: a nationwide study.
Skriver C1, Dehlendorff C2, Borre M3, Brasso K4, Sørensen HT5, Hallas J6, Larsen SB2, Tjønneland A2, Friis S2,5,7.
Author information
1Danish Cancer Society Research Center, Danish Cancer Society, Strandboulevarden 49, 2100, Copenhagen Ø, Denmark. skriver@cancer.dk.
2Danish Cancer Society Research Center, Danish Cancer Society, Strandboulevarden 49, 2100, Copenhagen Ø, Denmark.
3Department of Urology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark.
4Department of Urology, Copenhagen Prostate Cancer Center, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen Ø, Denmark.
5Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, 8200, Aarhus N, Denmark.
6Clinical Pharmacology and Pharmacy, Department of Public Health, University of Southern Denmark, J. B. Winsløws Vej 19, 5000, Odense C, Denmark.
7Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1014, Copenhagen K, Denmark.
Abstract
PURPOSE:
Increasing evidence suggests that aspirin use may protect against prostate cancer. In a nationwide case-control study, using Danish high-quality registry data, we evaluated the association between the use of low-dose aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) and the risk of prostate cancer.
METHODS:
We identified 35,600 patients (cases) with histologically verified prostate cancer during 2000-2012. Cases were matched to 177,992 population controls on age and residence by risk-set sampling. Aspirin and nonaspirin NSAID exposure was defined by type, estimated dose, duration, and consistency of use. We used conditional logistic regression to estimate odds ratios (ORs), with 95 % confidence intervals (CIs), for prostate cancer associated with low-dose aspirin (75-150 mg) or nonaspirin NSAID use, adjusted for potential confounders.
RESULTS:
Use of low-dose aspirin was associated with an OR for prostate cancer of 0.94 (95 % CI 0.91-0.97). Slightly lower ORs were seen with increasing cumulative amount, duration, and consistency of low-dose aspirin use (continuous use, ≥5 years: OR 0.89; 95 % CI 0.82-0.97; ≥10 years: OR 0.86; 95 % CI 0.70-1.06). Nonaspirin NSAID use was associated with a slightly increased OR for prostate cancer (1.13; 95 % CI 1.10-1.15); however, this association was confined to localized disease and did not vary materially with amount, duration, or consistency of nonaspirin NSAID use.
CONCLUSIONS:
Our study indicates that long-term, consistent low-dose aspirin use may provide modest protection against prostate cancer. The slightly increased risk of only localized prostate cancer with nonaspirin NSAID use suggests a noncausal explanation of the observed association.
KEYWORDS:
Aspirin; Case–control study; Epidemiology; Nonsteroidal anti-inflammatory drugs; Prostate neoplasms; Risk
PMID: 27503490 DOI: 10.1007/s10552-016-0785-7