Analgesic and nonsteroidal anti-inflammatory use in relation to nonmelanoma skin cancer: a population-based case-control study

Immunomodulators for Non-Melanoma Skin Cancers: Updated Perspectives

Non-melanoma skin cancers (NMSCs) are the most common cancers worldwide and may be associated with significant morbidity and mortality, especially in immunosuppressed populations. Successful management of NMSC must take primary, secondary and tertiary prevention strategies into consideration. In response to an improved understanding of the pathophysiology of NMSC and associated risk factors, multiple systemic and topical immunomodulatory drugs have been developed and integrated into clinical practice. Many of these drugs are efficacious in the prevention and treatment of precursor lesions (actinic keratoses; AKs), low-risk NMSC, and advanced disease. The identification of patients at high risk for the development of NMSC is critical in reducing disease morbidity. Understanding the various treatment options available and their comparative effectiveness is paramount for developing a personalized treatment regimen for such patients. This review article provides an updated overview of the various topical and systemic immunomodulatory drugs available for the prevention and treatment of NMSC, and the published data supporting their use in clinical practice.

The Association Between Aspirin and Basal Cell Carcinoma: A Clinical and Financial Analysis

Background

Nonmelanoma skin cancer (NMSC) is the most common malignancy. Basal cell carcinoma (BCC) comprises about 80% of all NMSCs and its incidence continues to rise. Although BCC rarely leads to metastases or increased mortality, its effects on healthcare costs and quality of life are substantial. Aspirin may prevent the development of basal cell carcinoma (BCC) by the inhibition of cyclooxygenase (COX) enzymes, which are associated with carcinogenesis and inflammation. This study therefore examined the effect of aspirin on the risk of BCC, its clinical outcomes, and its treatment costs.

Methods

A retrospective study (2010 - 2018) was conducted using the Humana Health Insurance Database. International Classification of Disease ninth and 10th codes and National Drug Codes were used to identify BCC diagnoses and aspirin prescriptions. Patients were matched for age, sex, Charlson Comorbidity Score (CCI), and region of residence. Chi-squared, logistic regression, and odds ratio (OR) analyses were utilized to test for significance and to estimate relative risk.

Results

Aspirin use was associated with a decreased incidence of BCC in unmatched (OR = 0.658, 95% confidence interval (CI) 0.526 - 0.820) and matched (OR = 0.54, 95% CI 0.47 - 0.61) analyses. Aspirin was also associated with a decreased BCC risk when stratified by hypertension (P = 3.888 × 10^-5), chronic obstructive pulmonary disease (COPD) (P = 0.014), diabetes (P = 0.049) and tobacco use (P = 0.017). Aspirin use was not associated with risk of BCC when stratified by obesity (P = 0.408). The average paid per patient for BCC treatment was significantly higher for patients in the aspirin use group than in the aspirin nonuse group (P = 0.0087).

Conclusions

While the high incidence and cost of treatment of BCC are demanding both clinically and financially, the low cost of aspirin and its widespread use may have vital implications for its preventative role in this disease. This study concluded that aspirin use was associated with a significantly decreased risk of BCC.

Cutaneous Squamous Cell Carcinoma: From Pathophysiology to Novel Therapeutic Approaches

Cutaneous squamous cell carcinoma (cSCC), a non-melanoma skin cancer, is a keratinocyte carcinoma representing one of the most common cancers with an increasing incidence. cSCC could be in situ (e.g., Bowen’s disease) or an invasive form. A significant cSCC risk factor is advanced age, together with cumulative sun exposure, fair skin, prolonged immunosuppression, and previous skin cancer diagnoses. Although most cSCCs can be treated by surgery, a fraction of them recur and metastasize, leading to death. cSCC could arise de novo or be the result of a progression of the actinic keratosis, an in situ carcinoma. The multistage process of cSCC development and progression is characterized by mutations in the genes involved in epidermal homeostasis and by several alterations, such as epigenetic modifications, viral infections, or microenvironmental changes. Thus, cSCC development is a gradual process with several histological- and pathological-defined stages. Dermoscopy and reflectance confocal microscopy enhanced the diagnostic accuracy of cSCC. Surgical excision is the first-line treatment for invasive cSCC. Moreover, radiotherapy may be considered as a primary treatment in patients not candidates for surgery. Extensive studies of cSCC pathogenic mechanisms identified several pharmaceutical targets and allowed the development of new systemic therapies, including immunotherapy with immune checkpoint inhibitors, such as Cemiplimab, and epidermal growth factor receptor inhibitors for metastatic and locally advanced cSCC. Furthermore, the implementation of prevention measures has been useful in patient management.

The association between nonsteroidal anti-inflammatory drugs and skin cancer: Different responses in American and European populations

OBJECTIVE

To conduct a comprehensive systematic meta-analysis investigating the association of nonsteroidal anti-inflammatory drugs (NSAIDs) and their subtypes with skin cancer (SC) and its subclasses (basal cell carcinoma BCC; squamous cell carcinoma SCC; melanoma; nonmelanoma skin cancer NMSC) in general, American and European populations.

METHODS

PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure and ClinicalTrials.gov were searched up to 24 February 2019. Pooled effect sizes and 95% confidence intervals were used to estimate associations.

RESULTS

Results based on 26 original studies including 223,619 cases and 1,398,507 controls showed both NSAIDs and nonselective Cyclooxygenase (COX) inhibitors to be statistically significantly associated with a reduced risk of SC, BCC, SCC and NMSC but not with melanoma. Conversely, no association was observed between selective Cyclooxygenase 2 (COX-2) inhibitors and SC or its subclasses. Further subgroup analysis showed that the results analyzed for American populations were almost the same as those for the general population. For European populations, neither NSAIDs nor its subtypes correlated significantly with susceptibility to SC or its subclasses.

CONCLUSIONS

The use of NSAIDs might reduce the risk of SC, but many factors including study population, drug subtype, and disease subclass affect the significance of the association.

Associations between aspirin use and the risk of cancers: a meta-analysis of observational studies

Background

Epidemiological studies have clarified the potential associations between regular aspirin use and cancers. However, it remains controversial on whether aspirin use decreases the risk of cancers risks. Therefore, we conducted an updated meta-analysis to assess the associations between aspirin use and cancers.

Methods

The PubMed, Embase, and Web of Science databases were systematically searched up to March 2017 to identify relevant studies. Relative risks (RRs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

Results

A total of 218 studies with 309 reports were eligible for this meta-analysis. Aspirin use was associated with a significant decrease in the risk of overall cancer (RR = 0.89, 95% CI: 0.87–0.91), and gastric (RR = 0.75, 95% CI: 0.65–0.86), esophageal (RR = 0.75, 95% CI: 0.62–0.89), colorectal (RR = 0.79, 95% CI: 0.74–0.85), pancreatic (RR = 0.80, 95% CI: 0.68–0.93), ovarian (RR = 0.89, 95% CI: 0.83–0.95), endometrial (RR = 0.92, 95% CI: 0.85–0.99), breast (RR = 0.92, 95% CI: 0.88–0.96), and prostate (RR = 0.94, 95% CI: 0.90–0.99) cancers, as well as small intestine neuroendocrine tumors (RR = 0.17, 95% CI: 0.05–0.58).

Conclusions

These findings suggest that aspirin use is associated with a reduced risk of gastric, esophageal, colorectal, pancreatic, ovarian, endometrial, breast, and prostate cancers, and small intestine neuroendocrine tumors.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4156-5) contains supplementary material, which is available to authorized users.

Pharmacological TLR4 Antagonism Using Topical Resatorvid Blocks Solar UV-Induced Skin Tumorigenesis in SKH-1 Mice

An urgent need exists for the development of more efficacious molecular strategies targeting nonmelanoma skin cancer (NMSC), the most common malignancy worldwide. Inflammatory signaling downstream of Toll-like receptor 4 (TLR4) has been implicated in several forms of tumorigenesis, yet its role in solar UV-induced skin carcinogenesis remains undefined. We have previously shown in keratinocyte cell culture and SKH-1 mouse epidermis that topical application of the specific TLR4 antagonist resatorvid (TAK-242) blocks acute UV-induced AP-1 and NF-κB signaling, associated with downregulation of inflammatory mediators and MAP kinase phosphorylation. We therefore explored TLR4 as a novel target for chemoprevention of UV-induced NMSC. We selected the clinical TLR4 antagonist resatorvid based upon target specificity, potency, and physicochemical properties. Here, we confirm using ex vivo permeability assays that topical resatorvid can be effectively delivered to skin, and using in vivo studies that topical resatorvid can block UV-induced AP-1 activation in mouse epidermis. We also report that in a UV-induced skin tumorigenesis model, topical resatorvid displays potent photochemopreventive activity, significantly suppressing tumor area and multiplicity. Tumors harvested from resatorvid-treated mice display reduced activity of UV-associated signaling pathways and a corresponding increase in apoptosis compared with tumors from control animals. Further mechanistic insight on resatorvid-based photochemoprevention was obtained from unsupervised hierarchical clustering analysis of protein readouts via reverse-phase protein microarray revealing a significant attenuation of key UV-induced proteomic changes by resatorvid in chronically treated high-risk SKH-1 skin prior to tumorigenesis. Taken together, our data identify TLR4 as a novel molecular target for topical photochemoprevention of NMSC. Cancer Prev Res; 11(5); 265-78. ©2018 AACRSee related editorial by Sfanos, p. 251.

Skin microtopography as a measure of photoaging and risk of squamous cell carcinoma of the skin in a US population

BACKGROUND

Skin microtopography as a measure of photoaging is a noninvasive approach to measuring chronic ultraviolet radiation exposure and reflects the degree of dermal elastosis in populations of European descent in the subtropics. Less is known about the utility of this approach in populations at different latitudes, and whether it relates to skin cancer risk.

METHODS

A population-based case-control study of 342 squamous cell carcinoma (SCC) cases and 331 age- and gender-matched controls were evaluated for histologic evidence of solar damage and severity of photoaging based on microtopography on a six-grade scale. Odds ratios (OR) for SCC associated with degree of photoaging were estimated using logistic regression analysis adjusted for potentially confounding factors.

RESULTS

After adjustment for known risk factors, SCC was associated with increasing photoaging grade (OR = 1.7, 95% CI = 0.9-3.0 for severe photoaging; OR = 2.8, 95% CI = 1.6-5.0 for very severe photoaging). Associations remained among those with actinic keratosis (OR = 3.4, 95% CI = 0.9-12.4 for severe photoaging, OR = 5.7, 95% CI = 1.7-19.6 for very severe photoaging).

LIMITATIONS

There was limited statistical power, particularly for subgroup analyses.

CONCLUSION

Our findings provide further evidence of microtopography as an independent, objective indicator of risk of SCC.

Use of acetaminophen in relation to the occurrence of cancer: a review of epidemiologic studies

Acetaminophen has several pharmacologic properties that suggest it could be carcinogenic in human beings. A number of epidemiologic studies have been conducted to examine whether use of acetaminophen actually predisposes to the occurrence of one or more forms of cancer. There are inherent limitations to many of these studies, including the inaccurate identification of users and nonusers of acetaminophen, relatively short follow-up for cancer incidence, and the potential for confounding by indication. The present manuscript reviews the results of epidemiologic studies of acetaminophen use in relation to cancer incidence published through the end of 2015. The limitations of the underlying studies notwithstanding, some interim conclusions can be reached. For all but several forms of cancer, there is no suggestion that persons who have taken acetaminophen are at altered risk, even persons who have consumed a large quantity of the drug or those who have taken it for an extended duration. While in some studies the incidence of renal cell carcinoma has been observed to be increased among acetaminophen users, several other studies have failed to observe any such association; the reason for the discrepant findings is unclear. Some of the small number of studies that have presented data on the incidence of lymphoma, leukemia, and plasma cell disorders have found the risk to be modestly higher in users than nonusers of acetaminophen, but the results of other studies of these malignancies will be needed to gauge the possible role of publication bias as the basis for the positive results.

Skin Cancer Risk Is Modified by KIR/HLA Interactions That Influence the Activation of Natural Killer Immune Cells

Natural killer (NK)-cell phenotype is partially mediated through binding of killer-cell immunoglobulin-like receptors (KIR) with HLA class I ligands. The KIR gene family is highly polymorphic and not well captured by standard genome-wide association study approaches. Here, we tested the hypothesis that variations in KIR gene content combined with HLA class I ligand status is associated with keratinocyte skin cancers using a population-based study of basal cell carcinoma (BCC) and squamous cell carcinomas (SCC). We conducted an interaction analysis of KIR gene content variation and HLA-B (Bw4 vs. Bw6) and HLA-C (C1 vs. C2). KIR centromeric B haplotype was associated with significant risk of multiple BCC tumors (OR, 2.39; 95% confidence interval, 1.10-5.21), and there was a significant interaction between HLA-C and the activating gene KIR2DS3 for BCC (Pinteraction = 0.005). Furthermore, there was significant interaction between HLA-B and telomeric KIR B haplotype (containing the activating genes KIR3DS1 and KIR2DS1) as well as HLA-B and the activating KIR gene KIR2DS5 (Pinteraction 0.001 and 0.012, respectively). Similar but greatly attenuated associations were observed for SCC. Moreover, previous in vitro models demonstrated that p53 is required for upregulation of NK ligands, and accordingly, we observed there was a strong association between the KIR B haplotype and p53 alteration in BCC tumors, with a higher likelihood that KIR B carriers harbor abnormal p53 (P < 0.004). Taken together, our data suggest that functional interactions between KIR and HLA modify risks of BCC and SCC and that KIR encoded by the B genes provides selective pressure for altered p53 in BCC tumors.

Aspirin for the primary prevention of skin cancer: A meta-analysis

Skin cancer is one of the most common cancers worldwide. There are three major skin cancer types: basal cell carcinoma, squamous cell carcinoma and malignant melanoma. General risk factors for skin cancer include fair skin, a history of tanning and sunburn, family history of skin cancer, exposure to ultraviolet rays and a large number of moles. The incidence of skin cancer has increased in the USA in recent years. Aspirin intake is associated with chemoprotection against the development of a number of types of cancer. However, whether aspirin intake can reduce the risk of development of skin cancer is unclear. The present meta-analysis of available human studies is aimed at evaluating the association between aspirin exposure and the risk of skin cancer. All available human observational studies on aspirin intake for the primary prevention of skin cancer were identified by searching MEDLINE (Pubmed), BIOSIS, EMBASE, Cochrane Library and China National Knowledge Infrastructure prior to March 2013. The heterogeneity and publication bias of all studies were evaluated using Cochran's Q and I² statistics, followed by a random-effect model where applicable. The pooled data were analyzed by odds ratios (ORs) and 95% confidence intervals (CIs). A total of eight case-control and five prospective cohort studies from 11 publications were selected for this analysis. There was no evidence of publication bias in these studies. Statistical analyses of the pooled data demonstrated that that a daily dose of 50-400 mg aspirin was significantly associated with a reduced risk of skin cancers (OR, 0.94; 95% CI, 0.90-0.99; P=0.02). Stratification analysis indicated that the continual intake of low dose aspirin (≤150 mg) reduced the risk of developing skin cancer (OR, 0.95; CI, 0.90-0.99; P=0.15) and that aspirin intake was significantly associated with a reduced risk of non-melanoma skin cancers (OR, 0.97; CI, 0.95-0.99; P=0.22). Overall, these findings indicated that aspirin intake was associated with a reduced risk of developing skin cancer. However, more well-designed randomized controlled trials to measure the effects of aspirin intake are required to confirm this.

Nonsteroidal anti-inflammatory drugs and the risk of nonmelanoma skin cancer

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been assigned a promising role in the chemoprevention of various malignancies. However, epidemiological data on the association between NSAID use and nonmelanoma skin cancer (NMSC) are limited. To explore whether patients regularly exposed to systemic NSAIDs are at a reduced risk of basal cell carcinoma (BCC) or squamous cell carcinoma (SCC), we conducted a population-based case-control analysis using the Clinical Practice Research Datalink, a United Kingdom primary care database. We identified 65,398 patients with incident BCC and 7,864 patients with incident SCC diagnosed between 1995 and 2013 and matched 1 and 4 NMSC-free controls to each BCC and SCC case, respectively, on age, sex, general practice, calendar time and years of history in the database. We compared prior NSAID exposure between cases and controls using multivariate conditional logistic regression analyses controlling for several potential confounders. Overall, we found no association between NSAID use and BCC, but when looking exclusively at users of single NSAID substances there was a suggestion of a reduced BCC risk in regular users of aspirin and ibuprofen (adjusted odds ratio [adj. OR]: 0.92, 95% confidence interval [CI]: 0.85-0.99 and adj. OR: 0.61, 95% CI: 0.48-0.78, respectively). The risk of SCC was slightly decreased in regular users of any NSAIDs (adj. OR: 0.89, 95% CI: 0.82-0.97), with the strongest risk reduction observed in current users of coxibs (adj. OR: 0.77, 95% CI: 0.62-0.95). These findings provide evidence that patients predisposed to NMSC might benefit from chemoprevention with NSAIDs.

Non-melanoma skin cancer and NSAID use in women with a history of skin cancer in the Women's Health Initiative

OBJECTIVE

Evidence for the effect of non-steroidal anti-inflammatory drugs (NSAIDs) on non-melanoma skin cancer (NMSC) risk is inconsistent. We prospectively examined whether regular, inconsistent, or no/low-use of NSAIDs is associated with lower NMSC risk among 54,728 postmenopausal Caucasian women in the Women's Health Initiative Observational Study enrolled between 1993 and 1998.

METHODS

Logistic regression models were used to assess odds of NMSC after adjusting for skin type, sun exposure history and indication for NSAID use.

RESULTS

There were 7652 incident cases of NMSC (median follow-up: 6.9years). There was no association between regular NSAID-use and NMSC risk relative to no/low-users. However, in a subgroup analysis of 5325 women with a history of skin cancer (incident NMSC: 1897), odds of NMSC were lower among regular NSAID users whether <5years (OR 0.82, 95% CI: 0.70-0.95) or ≥5years (OR 0.82, 95% CI: 0.69-0.98) of use compared to no/low-users. Inconsistent NSAID use and acetaminophen use were not associated with NMSC risk.

CONCLUSION

Overall, NSAID use was not associated with NMSC risk. However, in women with a history of skin cancer, regular NSAID use was associated with 18% lower odds of NMSC. Future studies on potential chemopreventative effects of NSAIDs should focus on subjects with prior history of NMSC.

No chemopreventive effect of nonsteroidal anti-inflammatory drugs on nonmelanoma skin cancer: evidence from meta-analysis

Background

Nonmelanoma skin cancer (NMSC),which includes squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), is the most common form of cancer, and its incidence is increasing. Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to be chemopreventive for NMSC. However, the results from published studies were controversial.

Methods

We searched the PubMed and Embase databases for relevant studies. Moreover, relevant reviews regarding the use of NSAIDs for NMSC patients were examined for potential inclusive studies. To measure the effects of NSAIDs, the relative risk (RR) was analyzed.

Results

A Total of 8 studies were included in our meta-analysis. We found that NSAIDs use was not associated with a reduced risk of SCC or BCC under the random effects model (pooled RR  =  0.86, 95% CI, 0.73–1.02, P  =  0.085; pooled RR  =  0.94, 95% CI 0.85–1.04, P  =  0.266; respectively).

Conclusion

From the included studies, we found no statistically significant chemopreventive effect on NMSC of NSAIDs. This finding warrants more prospective studies evaluating the relationship between NSAIDs and NMSC.

Oral acetylsalicylic acid and prevalence of actinic keratosis

Objective: To investigate the influence of a regular oral use of acetylsalicylic acid in the prevalence of actinic keratosis. Methods: A case-control study with dermatologic outpatients above 50 years of age assessed between 2009 and 2011. Cases were defined as those who had been under regular use of oral acetylsalicylic acid for more than six consecutive months. The assessment focused on: age, sex, skin-type, tobacco smoking, use of medication, occurrence of individual or family skin cancer, and sunscreen and sun exposure habits. Actinic keratoses were counted in the medial region of the face and upper limbs. Counts were adjusted by co-variables based on a generalized linear model. Results: A total of 74 cases and 216 controls were assessed. The median time of acetylsalicylic acid use was 36 months. Cases differed from controls as to the highest age, highest prevalence of use of angiotensin-converting enzyme inhibitors and fewer keratosis on the face and on the upper limbs (p<0.05). The multivariate model showed that the use of acetylsalicylic acid was associated to lower counts of face actinic keratosis and upper-limb erythematous actinic keratosis (p<0.05), regardless of other risk factors. Conclusion: The regular use of oral acetylsalicylic acid for more than six months was associated to a lower prevalence of actinic keratosis, especially facial and erythematous ones.

The chemopreventive efficacies of nonsteroidal anti-inflammatory drugs: the relationship of short-term biomarkers to long-term skin tumor outcome

The ultraviolet B (UVB) component of sunlight, which causes DNA damage and inflammation, is the major cause of nonmelanoma skin cancer (NMSC), the most prevalent of all cancers. Nonsteroidal anti-inflammatory drugs (NSAID) and coxibs have been shown to be effective chemoprevention agents in multiple preclinical trials, including NMSC, colon, and urinary bladder cancer. NSAIDs, however, cause gastrointestinal irritation, which led to the recent development of nitric oxide (NO) derivatives that may partially ameliorate this toxicity. This study compared the efficacy of several NSAIDs and NO-NSAIDs on UV-induced NMSC in SKH-1 hairless mice and determined whether various short-term biomarkers were predictive of long-term tumor outcome with these agents. Naproxen at 100 (P = 0.05) and 400 ppm (P < 0.01) in the diet reduced tumor multiplicity by 26% and 63%, respectively. The NO-naproxen at slightly lower molar doses shows similar activities. Aspirin at 60 or 750 ppm in the diet reduced tumor multiplicity by 19% and 50%, whereas the equivalent doses (108 and 1,350 ppm) were slightly less effective. Sulindac at 25 and 150 ppm in the diet, doses far below the human equivalent dose was the most potent NSAID with reductions of 50% and 94%, respectively. In testing short-term biomarkers, we found that agents that reduce UV-induced prostaglandin E2 synthesis and/or inhibit UV-induced keratinocyte proliferation yielded long-term tumor efficacy.

Photosensitizing agents and the risk of non-melanoma skin cancer: a population-based case-control study

It is well-known that ultraviolet (UV) light exposure and a sun sensitive phenotype are risk factors for the development of non-melanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). In this New Hampshire population-based case-control study, we collected data from 5,072 individuals, including histologically-confirmed cases of BCC and SCC, and controls via a personal interview to investigate possible associations between photosensitizing medication use and NMSC. After adjustment for potentially confounding factors (e.g. lifetime number of painful sunburns), we found a modest increase in risk of SCC (OR = 1.2, 95% CI = 1.0–1.4) and BCC (OR = 1.2, 95% CI = 0.9–1.5), in particular early-onset BCC, (≤ 50 years of age) (OR = 1.5, 95% CI = 1.1–2.1) associated with photosensitizing medication use. For SCC the association was strongest amongst those with tendency to sunburn rather than tan. We also specifically found associations with BCC, and especially early-onset BCC, and photosensitizing antimicrobials. In conclusion, certain commonly prescribed photosensitizing medications may enhance the risk of developing SCC, especially in individuals with a sun sensitive phenotype, and may increase the risk of developing BCC and incidence of BCC at a younger age.

Nonsteroidal anti-inflammatory drugs and the risk of skin cancer: a population-based case-control study

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) may prevent the development of cancer by inhibiting cyclooxygenase (COX) enzymes, which are involved in carcinogenesis. Therefore, the authors of this report examined the association between NSAID use and the risk of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and malignant melanoma (MM).

METHODS

From 1991 through 2009, all incident cases of SCC (n = 1974), BCC (n = 13,316), and MM (n = 3242) in northern Denmark were identified. Approximately 10 population controls (n = 178,655) were matched to each case by age, gender, and county of residence. The use of aspirin, other nonselective NSAIDs, or selective COX-2 inhibitors was ascertained through a prescription database. Conditional logistic regression analyses adjusted for potential confounders were used to compute odds ratios as estimates of incidence rate ratios (IRRs).

RESULTS

For NSAIDs overall, ever use (>2 prescriptions) compared with nonuse (≤2 prescriptions) was associated with a decreased risk of SCC (IRR, 0.85; 95% confidence interval [CI], 0.76-0.94) and MM (IRR, 0.87; 95% CI, 0.80-0.95), especially for long-term use (≥7 years) and high-intensity use (>25% prescription coverage during the total duration of use). NSAID use was not associated with a reduced risk of BCC overall (IRR, 0.97; 95% CI, 0.93-1.01), but the risk of BCC at sites other than the head and neck was reduced in association with long-term use (IRR, 0.85; 95% CI, 0.76-0.95) and high-intensity use (IRR, 0.79; 95% CI, 0.69-0.91). All estimates of reduced risk were driven primarily by the use of nonselective NSAIDs and older COX-2 inhibitors (diclofenac, etodolac, and meloxicam).

CONCLUSIONS

The current results indicated that NSAID use may decrease the risk of SCC and MM.