Aspirin May Cut Melanoma Risk
I have previously touched on this before
Thanks to Dr Dowling for bringing this to my attention.
Society for Investigative Dermatology
Source reference: Gamba C, et al “Aspirin is associated with lower melanoma risk in a cohort of postmenopausal women in the Women’s Health Initiative (WHI)” SID 2012; Abstract 236.
By Charles Bankhead, Staff Writer, MedPage Today
Published: May 14, 2012
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston and Dorothy Caputo, MA, BSN, RN, Nurse Planner
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.
An observational study from the Women’s Health Initiative found that postmenopausal women reporting that they take aspirin had a significantly reduced risk of melanoma over 11 years of follow-up compared to non-aspirin users.
Note that taking other nonsteroidal anti-inflammatory drugs (NSAIDs) was not associated with risk of developing melanoma.
RALEIGH, N.C. — The risk of malignant melanoma declined by more than 20% in women who reported using aspirin, a new analysis of the Women’s Health Initiative (WHI) showed.
In addition to the overall benefit, increasing duration of aspirin use was associated with even larger risk reductions, such that women who reported using aspirin for 5 years or more had a 30% lower risk of melanoma compared with nonusers.
Use of non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) did not significantly influence the risk of melanoma, Carol Gamba, BS, reported here at the Society for Investigative Dermatology meeting.
“We found that any use of aspirin was associated with a lower risk of melanoma overall, but also offered greater protection with greater duration of use,” said Gamba, of Stanford University in Stanford, Calif.
“Women who reported any aspirin use had a 21% reduction in the risk of melanoma,” she added.
Observational studies have shown significant associations between use of NSAIDs and lower risks of gastric, colorectal, and breast cancer. Trials of aspirin intervention, as well as meta-analyses of the trials, have demonstrated significant reductions in cancer incidence, metastasis, and cancer mortality in patients taking aspirin, said Gamba.
Epidemiologic studies and clinical trials have yielded inconsistent data regarding associations between NSAID use and melanoma.
NSAIDs, including aspirin, are thought to exert anticancer effects by disrupting signaling in the cyclooxygenase (COX) pathway, and more specifically pro-inflammatory COX-2. Moreover, laboratory studies have shown COX-2 levels correlate with melanoma progression and survival, said Gamba.
The WHI provided a large database for continuing the investigation of potential associations between NSAIDs and melanoma. At study entry, WHI participants provided a large amount of information relevant to their medical history, including medication use.
WHI participants were asked to identify all medications they had taken at least twice a week during the 2 weeks before enrollment, including nonprescription medications. From this information, Gamba and colleagues extracted data about the type, name, frequency, and dosage of NSAIDs the women used, as well as duration of use.
The NSAID analysis included 59,806 WHI participants, all of whom were postmenopausal at entry to the study. Baseline responses showed that 25% of the women used aspirin, 15% used other NSAIDs, and 59% used neither.
Follow-up in the three NSAID-use categories averaged 11 to 12 years. During follow-up, the study participants had 548 new melanoma diagnoses, consisting of 289 in situ lesions and 259 lesions that were invasive at diagnosis.
Separation of all melanoma cases by NSAID category showed that aspirin users accounted for 115 of the cases, other NSAID users for 89, and women who reported no NSAID use accounted for 344 new cases. After adjustment for a variety of demographic and clinical variables, the aspirin group had a 21% lower risk of melanoma compared with nonusers (P=0.01).
The analysis also showed a significant effect of duration of aspirin use on melanoma risk. After stratifying aspirin users into tertiles (<1 year, 1 to 4 years, ≥5 years), the investigators found that each progression to the next highest category was associated with an 11% reduction in melanoma risk, topping out at 30% for the highest-use category.
Gamba pointed out that a negative clinical trial of aspirin to prevent melanoma used low-dose (100 mg) aspirin, whereas 75% of the aspirin users in the WHI analysis used full-strength aspirin.
A different picture emerged from the analysis for users of other NSAIDs. WHI participants who reported any NSAID use had a melanoma risk similar to that of study participants who did not use aspirin or NSAIDs. In contrast to the data for aspirin, increasing duration of other NSAID use did not affect the relative risk, said Gamba.
A separate analysis of women who reported using acetaminophen — a pain reliever that does not inhibit COX-2 — showed no effect on melanoma risk.
Gamba acknowledged the inherent limitations of retrospective and observational studies and of relying on self-reported information from patients. She also pointed out that the findings apply to a population of white, postmenopausal women.