EvidenceUpdates: Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled trials including professional commentaries

Blogger's Note:  registration is free, the benefit of this secondary site (BMJ) is the addition of professional comments

This month's most accessed articles -- EvidenceUpdates
Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled trials

paywalled: Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled trials : The Lancet

Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled trials : The Lancet

Summary

Background

Daily aspirin reduces the long-term risk of death due to cancer. However, the short-term effect is less certain, especially in women, effects on cancer incidence are largely unknown, and the time course of risk and benefit in primary prevention is unclear. We studied cancer deaths in all trials of daily aspirin versus control and the time course of effects of low-dose aspirin on cancer incidence and other outcomes in trials in primary prevention.

Interpretation

Alongside the previously reported reduction by aspirin of the long-term risk of cancer death, the short-term reductions in cancer incidence and mortality and the decrease in risk of major extracranial bleeds with extended use, and their low case-fatality, add to the case for daily aspirin in prevention of cancer.

Commentary: Does aspirin really reduce the risk of colon cancer? : The Lancet

Does aspirin really reduce the risk of colon cancer? : The Lancet

Does aspirin really reduce the risk of colon cancer?

The study by John Burn and colleagues1 is unquestionably a superb piece of work that opens the door to formalised chemoprevention in young carriers of Lynch syndrome. However, setting aside the fact that the primary intention-to-treat analysis was not significant, there is a need to address whether these data are applicable to others at need of chemoprevention.

Specifically, the study included a predominantly young population with a mean age at recruitment in the early 40s and a mean follow-up of 5 years. Therefore the current age of participants is about 50 years. At this age, the frequency and severity of aspirin complications is very low.2 Indeed the number of adverse events quoted in the paper's appendix is only 21 in more than 400 aspirin-taking patients. Moreover, Rothwell and colleagues3 have indicated that, for the general public or those at risk of more common cancers, taking aspirin before 55 years of age will not have a significant benefit. Furthermore, the mean period of treatment is just more than 2 years and although this suggests an impressive effect, it means that the long-term safety is unknown.4

In conclusion, although this study is excellent news for patients with Lynch syndrome, we need data from other large and long-term randomised trials with cancer endpoints such as the AspECT trial to assess the safety of aspirin in an older and more general population.5

Reuters News: Should more patients continue aspirin therapy before surgery? - - ModernMedicine

Should more patients continue aspirin therapy before surgery? - - ModernMedicine

Aspirin and cancer risk: a quantitative review to 2011

Aspirin and cancer risk: a quantitative review to 2011:

Background:
Aspirin has been associated to a reduced risk of colorectal and possibly of a few other common cancers.

Methods:
To provide an up-to-date quantification of this association, we conducted a meta-analysis of all observational studies on aspirin and 12 selected cancer sites published up to September 2011.

Results:
Regular aspirin is associated with a statistically significant reduced risk of colorectal cancer and of other digestive tract cancers, for squamous cell esophageal cancer, for esophageal and gastric cardia adenocarcinoma,, for gastric cancer), with somewhat stronger reductions in risk in case–control than in cohort studies. Modest inverse associations were also observed for breast and prostate cancer, while lung cancer was significantly reduced in case–control studiesbut not in cohort ones. No meaningful overall associations were observed for cancers of the pancreas, endometrium, ovary, bladder, and kidney.

Conclusions:
Observational studies indicate a beneficial role of aspirin on colorectal and other digestive tract cancers; modest risk reductions were also observed for breast and prostate cancer. Results are, however, heterogeneous across studies and dose–risk and duration–risk relationships are still unclear.

text/video: Can Aspirin Reduce Risk for Cancer Metastasis? Cancerwise/MD Anderson

Can Aspirin Reduce Risk for Cancer Metastasis?: Results from a report released today in a leading medical journal indicate that low dose daily aspirin reduces the risk of metastasis of several cancers. According to articles in The Lancet, the protective effect occurs within 3-5 years of beginning aspirin use.

Read more about the study in a post from our Cancer Frontline blog.

Raymond DuBois, M.D., Ph.D, MD Anderson's provost and executive vice president and a professor of cancer biology and cancer medicine, shares his insights on the study's significance and addresses questions about aspirin dose, and how cancer patients should respond to this news.

abstract: Effects of regular aspirin on long-term cancer incidence and metastasis: a systematic comparison of evidence from observational studies versus randomised trials : The Lancet Oncology

Blogger's Note: the 'risk' refers to the risk of cancer as opposed to the risk/side effects/adverse events/safety of asprin use.

Effects of regular aspirin on long-term cancer incidence and metastasis: a systematic comparison of evidence from observational studies versus randomised trials : The Lancet Oncology

open access: March 12th - Daily aspirin reduces colorectal cancer incidence in patients with Lynch syndrome - Barton - 2012 - CA: A Cancer Journal for Clinicians - Wiley Online Library

Daily aspirin reduces colorectal cancer incidence in patients with Lynch syndrome - Barton - 2012 - CA: A Cancer Journal for Clinicians 

"According to the investigators, this study, along with earlier data, supports the use of aspirin in the chemoprevention treatment of patients with Lynch syndrome, although the dose and timing of use have not been established. A CAPP3 study is planned that will investigate optimizing the dose and duration. (More information can be found at www.CAPP3.org.)"

press release: Evidence strengthens link between NSAIDs and reduced cancer metastasis

"The research, published by Cell Press in the February 14 issue of the journal Cancer Cell, opens new avenues for the design of antimetastatic therapies."

abstract: Aspirin, Nonaspirin Nonsteroidal Anti-inflammatory Drugs, or Acetaminophen and Risk of Ovarian Cancer.

BACKGROUND:

Aspirin, nonaspirin nonsteroidal anti-inflammatory drugs (NA-NSAIDs) and acetaminophen all have biologic effects that might reduce the risk of ovarian cancer. However, epidemiologic data on this question are mixed.

CONCLUSIONS:

Risk reductions of ovarian cancer were observed with use of aspirin or selective cyclooxygenase-2 inhibitors. However, the results should be interpreted with caution due to the inherent study limitations and biases.

EvidenceUpdates: Effect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials - includes professional commentaries

Role of Vitamin and Mineral Supplementation and Aspirin Use in Cancer Survivors — JCO

Note: a recent study indicated a beneficial effect of aspirin use in Lynch Syndrome patients but not in colon cancer patients (those w/o a mutation), search blog for further information on this specific issue "The potential beneficial or adverse effects of dietary supplements and aspirin in survivors of cancer warrant further study."

Role of Vitamin and Mineral Supplementation and Aspirin Use in Cancer Survivors (abstract)

Note: abstract does not reference ovarian cancer "The potential beneficial or adverse effects of dietary supplements and aspirin in survivors of cancer warrant further study."

Medical News: AACR: No NSAID Link to Ovarian Cancer (data taken from California Teachers Study)

WASHINGTON -- Regular use of anti-inflammatory drugs did not reduce the risk of ovarian cancer, a large prospective cohort study showed.

Neither weekly nor daily use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) influenced the relative risk of ovarian cancer, California investigators reported here at the American Association for Cancer Research meeting.

But self-reported daily use of acetaminophen almost doubled the risk of ovarian cancer, they found.

"Our results do not support the hypothesis that these medications reduce the risk of ovarian cancer," Lei Duan, PhD, of City of Hope in Duarte, Calif., and colleagues concluded. "Conversely, the finding that daily acetaminophen use was associated with increased risk of ovarian cancer differs from previous studies and may warrant further investigation."...cont'd
Action Points:

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• Explain to interested patients that regular use of aspirin or nonsteroidal anti-inflammatory drugs did not influence the risk of ovarian cancer.
• Explain that daily use of acetaminophen was associated with an increased risk of ovarian cancer.
• Explain that the findings were based on a retrospective review of a large database and therefore cannot prove that acetaminophen caused the increased risk of ovarian cancer.
• Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.