Dupilumab reduces systemic corticosteroid use and sinonasal surgery rate in CRSwNP.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease with a high symptom burden and poor quality of life. Treatment options include recurrent surgeries and/or frequent systemic corticosteroids (SCS). Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2-mediated inflammation. We report results of pooled analyses from 2 randomised, double-blind, placebo-controlled phase 3 studies (SINUS 24 [NCT02912468]; SINUS-52 [NCT02898454]) to evaluate dupilumab effect versus placebo in adults with CRSwNP with/without SCS use and sinonasal surgery. METHODOLOGY: SINUS-24 patients were randomised 1:1 to subcutaneous dupilumab 300 mg (n=143) or placebo (n=133) every 2 weeks (q2w) for 24 weeks. SINUS-52 patients were randomised 1:1:1 to 52 weeks of subcutaneous dupilumab 300 mg q2w (n=150), 24 weeks q2w followed by 28 weeks of dupilumab 300 mg every 4 weeks (n=145) or 52 weeks of placebo q2w (n=153). RESULTS: Dupilumab reduced the number of patients undergoing sinonasal surgery (82.6%), the need for in-study SCS use (73.9%), and SCS courses (75.3%). Significant improvements were observed with dupilumab vs placebo regardless of prior sinonasal surgery or SCS use in nasal polyp, nasal congestion, Lund-MacKay, and Sinonasal Outcome Test (22-items) scores, and the University of Pennsylvania Smell Identification Test. CONCLUSIONS: Dupilumab demonstrated significant improvements in disease signs and symptoms and reduced the need for sino-nasal surgery and SCS use versus placebo in patients with severe CRSwNP, regardless of SCS use in the previous 2 years, or prior sinonasal surgery.

Short-chain fatty acids induce tissue plasminogen activator in airway epithelial cells via GPR41&43.

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease generally divided based on the presence or absence of nasal polyps (NPs). One of the features of NPs is excessive fibrin deposition, which is associated with down-regulation of tissue plasminogen activator (t-PA) in NPs. As t-PA is expressed in epithelial cells, and epithelium is readily accessible to topical therapies, identifying compounds that can mediate the induction of t-PA would be a potential new strategy for the treatment of NPs. OBJECTIVE: The objective of this study was to determine whether short-chain fatty acids (SCFAs) can induce t-PA in airway epithelial cells via their known receptors GPR41 and GPR43. METHODS: We performed immunohistochemistry (IHC) to determine whether receptors for SCFAs, known as G protein-coupled receptor 41/free fatty acid receptor 3 (GPR41/FFAR3) and GPR43/FFAR2, are expressed in nasal tissue. Primary normal human bronchial epithelial (NHBE) cells were stimulated with different concentrations of SCFAs to test induction of t-PA, which was analysed by expression of mRNA and protein. Mediation of responses by SCFA receptors was evaluated by specific receptor gene silencing with siRNA. RESULTS: Immunohistochemistry study revealed that airway epithelial cells expressed GPR41 and GPR43. Acetic acid, propionic acid, butyric acid and valeric acid significantly induced t-PA expression from two- to tenfolds. The strongest inducer of t-PA from NHBE cells was propionic acid; cells stimulated with propionic acid released t-PA into the supernatant in its active form. Gene silencing of GPR41 and GPR43 revealed that induction of t-PA by SCFAs was dependent upon both GPR41 and GPR43. CONCLUSIONS AND CLINICAL RELEVANCE: Short-chain fatty acids were shown to induce airway epithelial cell expression of t-PA via GPR41 and GPR43. Topical delivery of potent compounds that activate these receptors may have value by reducing fibrin deposition and shrinking nasal polyp growth.

House dust mite sublingual tablet is effective and safe in patients with allergic rhinitis.

BACKGROUND: House dust mite (HDM) is the major indoor allergen for allergic diseases such as allergic rhinitis (AR) and asthma. Although sublingual immunotherapy is a curative treatment for HDM-induced AR, data from large-scale studies are limited. We evaluated the efficacy and safety of HDM tablets in adolescent and adult patients (aged 12-64 years) with HDM-induced AR with or without intermittent asthma. METHODS: In a double-blind trial in Japan, 968 subjects were randomized 1 : 1 : 1 to 300 index of reactivity (IR), 500 IR, or placebo groups. The primary endpoint was the Average Adjusted Symptom Score (AASS) in the last eight weeks of the 52-week treatment. Secondary endpoints included individual nasal and ocular symptom scores, rescue medication use, and the Japanese Rhinoconjunctivitis Quality of Life Questionnaire (JRQLQ) scores. RESULTS: The AASS in the last eight weeks of treatment significantly improved in both the 300 IR and the 500 IR groups compared to that in the placebo group (P < 0.001). In the 300 IR group, the onset of action occurred at week 8-10. All four nasal symptoms significantly improved in both active treatment groups; rescue medication use and JRQLQ outcome improved in the 300 IR group. Most adverse events (AEs) were mild, and 16 serious AEs (SAEs) were reported; however, none of them were drug-related. CONCLUSIONS: One-year treatment with 300 IR and 500 IR HDM tablets was effective without major safety concerns. The recommended therapeutic dose for AR is 300 IR.

Novel scoring system and algorithm for classifying chronic rhinosinusitis: the JESREC Study.

BACKGROUND: Chronic rhinosinusitis (CRS) can be classified into CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP displays more intense eosinophilic infiltration and the presence of Th2 cytokines. Mucosal eosinophilia is associated with more severe symptoms and often requires multiple surgeries because of recurrence; however, even in eosinophilic CRS (ECRS), clinical course is variable. In this study, we wanted to set objective clinical criteria for the diagnosis of refractory CRS. METHODS: This was a retrospective study conducted by 15 institutions participating in the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC). We evaluated patients with CRS treated with endoscopic sinus surgery (ESS), and risk of recurrence was estimated using Cox proportional hazard models. Multiple logistic regression models and receiver operating characteristics curves were constructed to create the diagnostic criterion for ECRS. RESULTS: We analyzed 1716 patients treated with ESS. To diagnose ECRS, the JESREC scoring system assessed unilateral or bilateral disease, the presence of nasal polyps, blood eosinophilia, and dominant shadow of ethmoid sinuses in computed tomography (CT) scans. The cutoff value of the score was 11 points (sensitivity: 83%, specificity: 66%). Blood eosinophilia (>5%), ethmoid sinus disease detected by CT scan, bronchial asthma, aspirin, and nonsteroidal anti-inflammatory drugs intolerance were associated significantly with recurrence. CONCLUSION: We subdivided CRSwNP in non-ECRS, mild, moderate, and severe ECRS according to our algorithm. This classification was significantly correlated with prognosis. It is notable that this algorithm may give useful information to clinicians in the refractoriness of CRS before ESS or biopsy.

Variants in the 17q21 asthma susceptibility locus are associated with allergic rhinitis in the Japanese population.

BACKGROUND: Allergic rhinitis (AR) is a very common disorder peaking in the teenage years that is mediated by hypersensitivity responses to environmental allergens. Although it is well established that the ORMDL3 locus at chromosome 17q21 is associated with susceptibility to bronchial asthma, the genetic influences of the polymorphisms of the locus in allergic rhinitis are unclear. OBJECTIVE: To examine whether the polymorphisms in the 17q21 asthma susceptibility locus are associated with allergic rhinitis in the Japanese population. METHODS: We performed linkage disequilibrium (LD) mapping of the locus using the HapMap database and conducted an association study of the locus with a total of 15 tag SNPs in two independent populations. We further evaluated correlations of genotypes with changes in expression of genes at the region in lymphoblastoid cell lines in the Japanese population and assessed the expression levels of the genes in nasal epithelium and various human tissues. RESULTS: We found a significant association between a total of five polymorphisms in the 17q21 asthma susceptibility locus, rs9303277, rs7216389, rs7224129, rs3744246, and rs4794820, and AR (minimum P(combined)  = 0.00074, rs4794820). The expression level of the ORMDL3 transcript was significantly correlated with the genotype of rs12150079, rs7216389, rs3744246, and rs4794820 with P < 0.01 (minimum P = 0.0058, rs7216389), and ORMDL3 mRNA was highly expressed in nasal epithelium. CONCLUSION: Genetic variants in the 17q21 asthma susceptibility locus are significantly associated with AR in the Japanese population.

Cytosine-phosphate-guanosine-DNA induces CD274 expression in human B cells and suppresses T helper type 2 cytokine production in pollen antigen-stimulated CD4-positive cells.

Co-stimulatory molecules are important for regulating T cell activation and immune response. CD274 [programmed death ligand 1 (PD-L1), B7-H1] has emerged as an important immune modulator that can block T cell receptor signalling. We have investigated whether PD-L1 and other co-stimulatory ligands could be expressed in human B cells stimulated by cytosine-phosphate-guanosine (CpG)-DNA. CpG-DNA strongly induced the co-inhibitory molecule ligand, PD-L1, of human B cells. Results show that nuclear factor-kappa B (NF-κB) signalling is involved directly in CpG-DNA-induced PD-L1 expression in human B cells. We sought to determine the effect of CpG-DNA-treated B cells on T helper type 2 (Th2) cytokine production in Cry j 1 (Japanese pollen antigen)-stimulated human CD4-positive cells from patients with seasonal allergic rhinitis caused by Japanese cedar pollen. CpG-DNA-treated B cells reduced Cry j 1-induced interleukin (IL)-5 and IL-13 production in CD4-positive cells. When the binding of PD-1 to PD-L1 was inhibited by PD-1-immunoglobulin (Ig), this chimera molecule reversed the previously described reductions in IL-5 and IL-13 production. In contrast, the CpG B-treated B cells increased both interferon (IFN)-γ and IL-12 production in the presence of Cry j 1-stimulated CD4-positive cells. CpG-DNA simultaneously reduced the expression of B7RP-1 [also known as inducible co-stimulator ligand (ICOSL), B7-H2] and the ligand of CD30 (CD30L). These results indicate that CpG-DNA induces co-inhibitory molecule ligand PD-L1 expression in human B cells and PD-L1 can suppress Th2 cytokine production in Cry j 1-stimulated CD4-positive cells, while CpG-DNA increased Th1 cytokine production and reduced the expression of co-stimulatory molecule ligands that can promote Th2 inflammatory responses.

Associations between decay-accelerating factor polymorphisms and allergic respiratory diseases.

BACKGROUND: Allergic diseases such as asthma and allergic rhinitis are major causes of morbidity in developed countries. The pathology underlying allergic respiratory diseases is considered to be IgE-mediated type I allergy characterized by mucosal inflammation that occurs in response to allergen exposure. They are common diseases involving a complex inheritance. Complement systems are known to play an important role in allergic diseases. Decay-accelerating factor (DAF) is important for the regulation of the complement system and is a good candidate for determining the susceptibility to allergic diseases. OBJECTIVE: The present study aimed to investigate whether polymorphisms in the DAF gene are associated with allergic respiratory diseases in the Japanese population. METHODS: We performed mutation screenings of DAF and conducted a tag single-nucleotide polymorphisms (SNP) association analysis for 684 unrelated adult individuals with seasonal allergic rhinitis (SAR) with Japanese ceder pollen, 188 mite-sensitive adults with asthma, and 346 unrelated non-allergic healthy controls. RESULTS: DAF is located in the tight linkage disequilibrium (LD) block spanning 62 kb. The tag SNP analysis revealed that rs10746463 was significantly associated with SAR (P=0.00033) and mite-sensitive adult asthma (P=0.044). The rs2564978 and rs3841376 haplotypes, which are located in the promoter region of DAF, were in complete LD with rs10746463 (r2=1). Luciferase reporter assays with constructs containing the 5' flanking regions of DAF showed that the plasmid with rs2564978 C/rs3841376 deletion (the risk haplotype) had a statistically significantly lower transcriptional activity than that containing the rs2564978 T/rs3841376 insertion. CONCLUSIONS: Our results suggest that DAF is one of the genes involved in conferring susceptibility to allergic respiratory diseases and show that decreased levels of DAF may be associated with the enhanced specific IgE responses occurring in allergic diseases in the Japanese population.

Association of serum interleukin-33 level and the interleukin-33 genetic variant with Japanese cedar pollinosis.

BACKGROUND: IL-33, an IL-1-like cytokine, is a ligand for IL1RL1, which is an important effector molecule of type 2 T helper responses. Although IL-33/IL1RL1 interaction has been suggested to be important in induction of allergic airway inflammation, serum levels of IL-33 and the genetic influences of the polymorphisms of IL-33 in human allergic diseases are unclear. OBJECTIVE: The aim of this study was to examine whether the serum IL-33 level and polymorphisms in IL-33 are associated with Japanese cedar (JC) pollinosis, the most common form of allergic rhinitis, and a major public health problem, in Japan. METHODS: We performed linkage disequilibrium (LD) mapping of the gene using the HapMap database, and two selected tag single nucleotide polymorphisms were genotyped. We conducted an association study of IL-33 (JC pollinosis, n=170; normal controls, n=100) and measured the IL-33 levels in sera of the 270 subjects by ELISA. RESULTS: Serum levels of IL-33 were significantly higher in patients with JC pollinosis (P=0.0018) than in controls. In genetic association analysis, we found a positive association between the polymorphism and JC pollinosis (P=0.048). CONCLUSION: Our results support a role for IL-33 in the pathogenesis of JC pollinosis.

Vasoactive intestinal peptide induces S(alpha)/S(mu) switch circular DNA in human B cells.

Vasoactive intestinal peptide (VIP), a major neurotransmitter of peripheral nerves, has been suggested to function in host defense by regulating local human immune function. Indirect evidence has been marshaled that VIP can function as a switch factor for IgA in human Ig isotype recombination. In this study we directly tested the ability of VIP to function as a factor driving human B cells into IgA producing cells by assessing its ability to induce switch circular DNA representing direct mu to alpha switching. In addition we determined the generation of alpha germ-line transcripts and measured the level of IgA protein produced. Stimulation with VIP and CD40 mAb induced IgA production by human IgD+ B cells while VIP or CD40 alone failed to do so. Stimulation of purified IgD+ B cells with VIP plus CD40 mAb induced generation of switch circular DNA representing in vitro driven isotype switching from mu to alpha. CD40 mAb alone induced alpha germ-line transcripts but not IgA switch circles. Thus VIP, a neurogenic factor, can induce alpha-specific switching in CD40-activated human B cells and may thereby play an important role in directing the humoral immune response at mucosal surfaces.

Expression of granulocyte colony-stimulating factor receptor correlates with prognosis in oral and mesopharyngeal carcinoma.

Granulocyte colony-stimulating factor receptors (G-CSFRs) have been observed on the surface of not only hematopoietic cells but also several cancer cells. The stimulation of G-CSF has been demonstrated to induce proliferation and activation of G-CSFR-positive cells. In this study, we investigated the expression of G-CSFR on the surface of tumor cells and G-CSF production in oral and mesopharyngeal squamous cell carcinoma (SCC) by an immunohistochemical approach. Of 58 oral and mesopharyngeal SCCs, 31 cases (53.4%) and 36 cases (62.1%) were positive for G-CSFR and G-CSF, respectively. There was no association between G-CSFR expression and G-CSF staining. In the group positive for G-CSFR expression, relapse was significantly more likely after primary treatment (P = 0.0069), whereas there was no association between G-CSFR expression and age, sex, tumor size, lymph node metastasis, and clinical stage. Also, the G-CSFR-positive groups had a significantly lower disease-free and overall survival rate than the G-CSFR-negative groups (P = 0.0172 and 0.0188, respectively). However, none of the clinical markers correlated significantly with G-CSF staining, nor did the status of G-CSF production influence the overall survival. The results imply that assessment of G-CSFR may prove valuable in selecting patients with oral and mesopharyngeal SCC for aggressive therapy.

Expression of platelet-derived endothelial cell growth factor in oral and oropharyngeal carcinoma.

Platelet-derived endothelial cell growth factor (PD-ECGF) was isolated as an endothelial cell mitogen from platelets. In this study, we investigated the expression of PD-ECGF and counted microvessels in 58 oral and oropharyngeal squamous cell carcinoma (SCC) specimens by an immunohistochemical technique to examine their prognostic significance and performed tumor in vitro sensitivity to 5-fluorouracil (5-FU) and cisplatin as determined by a bioluminescence assay of the ATP values of tumor cells after continuous exposure. The percentage of PD-ECGF-positive tumor cells (PD-ECGF score) was correlated with the frequency of the recurrence of disease (P=0.0043) but not with sex, tumor size, metastasis, or clinical stage. Overall survival of the high PD-ECGF expression group (>40% PD-ECGF score) was shorter than the low expression (<40%) group (P=0.0365). Vessel count was correlated with lymph node metastasis and clinical stage. The survival of patients with hypervascularity (more than the median of intratumor vessel counts, >82) was shorter than that of those with hypovascularity (vessel count <81, P=0.0446). However, there was no association between PD-ECGF expression and vessel count. Cox proportional multivariate analysis showed that PD-ECGF expression was the most significant independent prognostic indicator for overall survival. The susceptibility to 5-FU cytotoxicity in the extremely high PD-ECGF expression groups (>70% of PD-ECGF score) was significantly higher than that in the low group, whereas there was no difference in their sensitivity to cisplatin. These results showed that carcinoma cells with high PD-ECGF expression were sensitive to 5-FU in spite of poor prognosis. These data provide further information when deciding on adjuvant therapy for oral and oropharyngeal SCCs.

Direct evidence that gamma 1 and gamma 3 switching in human B cells is interleukin-10 dependent.

Interleukin-10 (IL-10) has various effects on B cell immunoglobulin (Ig) production. Indirect evidence suggests that IL-10 functions as a switch factor for IgG production. In this study, the switch deleted Ig gene DNA was isolated and characterized, as direct evidence that IL-10 induced isotype switching in human B cells. In addition, 16 chimeric Ig fragments were isolated, representing deleted DNA generated by in vitro isotype switching from mu to gamma in human B cells, following stimulation with IL-10 and anti-CD40 monoclonal antibodies (CD40 mAb). These clones consisted solely of S gamma 1/S mu and S gamma 3/S mu chimeric switch circular DNAs, no S gamma 2/S mu or S gamma 4/S mu switch DNA was observed. In addition, IL-10 alone induced only gamma 1 and gamma 3 germ-line mRNA transcripts, as determined by restriction digestion of the reverse transcription-polymerase chain reaction products. Three modes of mu-gamma 3 isotype switching were detected: (1) direct switching; (2) internal deletion of S mu proceeding mu to gamma 3 switching; and (3) internal deletion of S gamma 3 proceeding mu to gamma 3 switching. These results directly demonstrate that gamma 1 and gamma 3 switching in human B cells is specifically induced by IL-10 in the presence of CD40 mAb.

IL-10 expression is associated with the expression of platelet-derived endothelial cell growth factor and prognosis in oral and oropharyngeal carcinoma.

We investigated the expression of IL-10 in oral and oropharyngeal squamous cell carcinoma (SCC) specimens by an immunohistochemical technique. Of 58 SCC, 13 (22%) and 35 (60%) cases showed intense and moderate positive staining of IL-10, respectively. There was no association between the staining of IL-10 and clinicopathological features. However, the patients with intense staining of IL-10 had a significantly lower overall survival rate than those with moderate or negative staining of IL-10 (P = 0.019). In addition, the patients with intense staining of IL-10 had the highest score of platelet-derived endothelial cell growth factor (PD-ECGF), which is established as a poor prognostic indicator (P = 0.0105). These results suggested that IL-10 contributes to the clinical outcome of oral and oropharyngeal SCC.

Conventional tumor markers are prognostic indicators in patients with head and neck squamous cell carcinoma.

We tested for squamous cell carcinoma-related antigen (SCC), carcinoembryonic antigen (CEA), ferritin, immunosuppressive acid protein (IAP) and sialic acid in the serum from 247 patients with head and neck squamous cell carcinoma prior to therapy. Significant correlations were found between IAP and tumor size, lymph node metastasis, and clinical stage (P<0.0001, P<0.001, and P<0.0001). Also, sialic acid and SCC were also correlated with tumor size, lymph node metastasis, and clinical stage. Moreover IAP, sialic acid and SCC were strongly associated with survival rate (P<0.0001, P = 0.0230 and P = 0.0159). A multivariate Cox proportional hazard model demonstrated that being positive for IAP was an independent predictor for patients with H&NSCC (P = 0.0115). The results indicate that IAP, sialic acid and SCC are useful as prognostic factors.

Expression of hMSH2 correlates with in vitro chemosensitivity to CDDP cytotoxicity in oral and oropharyngeal carcinoma.

We investigated the expression of hMSH2, a human mutS homologue from chromosome 2p, in oral and oropharyngeal squamous cell carcinoma (SCC) by an immunohistochemical technique and performed tumor in vitro chemosensitivity testing. In 58 oral and oropharyngeal SCC, the hMSH2 positive score was inversely associated with tumor size, but not with other clinical parameters. Among five anticancer drugs (cisplatin (CDDP), 5-FU, peplomycin, mitomycin C and doxorubicin), only for CDDP was sensitivity to cytotoxicity correlated with the hMSH2 positive score. The susceptibility of hMSH2-positive tumors to CDDP killing was significantly higher than that of hMSH2-negative tumors. Immunohistochemical results regarding hMSH2 are promising in the evaluation of the sensitivity of cancer cells to CDDP cytotoxicity and enable one to select patients for adjuvant chemotherapy for oral and oropharyngeal SCC.

Decreased expression of Bax is correlated with poor prognosis in oral and oropharyngeal carcinoma.

We investigated the expression of apoptosis-related factors, p53, Bax, Bcl-2, and spontaneous apoptosis in 57 cases of oral and oropharyngeal squamous cell carcinoma (SCC) by immunochemical staining and ApopTag kit. Positive expression of Bax was inversely associated with advanced tumor stage (P = 0.0225), lymph node metastasis (P = 0.0225), clinical stage (P = 0.0083) and poor prognosis (P = 0.0478). Positive expression of p53 was related to poor prognosis (P = 0.0445) and was associated with negative expression of Bax (P = 0.0439). The apoptosis index did not correlate with clinical outcome. These results suggest that abnormality of Bax expression plays an important role in tumor progression in oral and oropharyngeal SCC.

Expression of multidrug resistance-associated protein (MRP) in head and neck squamous cell carcinoma.

We investigated the expression of multidrug resistance-associated protein (MRP) in 115 cases of head and neck squamous cell carcinoma (H&NSCC) by immunohistochemistry and examined the relationship between MRP expression and clinical factors. Thirty-four (30%) of 115 cases of H&NSCC had expression of MRP. The clinical stage was inversely associated with the expression of MRP (P = 0.0090), but not with age, sex, tumor size, metastasis, recurrence, death from disease or overall survival rate for 5 years. In vitro chemosensitivity to five chemotherapeutic agents (cis-diamminedichloroplatinum, 5-fluorouracil, peplomycin, mitomycin C and Adriamycin) was tested by ATP assay and no correlation between the sensitivity of tumor cells to the cytotoxicity of any drug and MRP expression was found. These results suggest that the resistance to anticancer drugs is not dependent only on the expression of MRP in H&NSCC.

Expression of fas (CD95) ligand is correlated with IL-10 and granulocyte colony-stimulating factor expression in oral and oropharyngeal squamous cell carcinoma.

The Fas/Fas ligand (FasL) pathway has been shown to be an important cellular pathway mediating apoptosis. In this study we investigated the expression of Fas and FasL and the rate of spontaneous apoptosis in 58 oral and oropharyngeal squamous cell carcinoma (SCC) by using immunohistochemical techniques. There was no correlation between Fas or FasL expression and clinicopathological factors. The expression of Fas in the tumor did not affect spontaneous apoptosis of the tumor cells. However, FasL expression was associated with IL-10 and granulocyte colony-stimulating factor expression in oral and oropharyngeal SCC. These results suggested that the Fas/FasL system is connected with the expression of various factors including cytokines in tumor cells.

Expression of granulocyte colony-stimulating factor and its receptor in epithelial skin tumors.

Granulocyte colony-stimulating factor receptors (G-CSFR) have been observed on the surface of not only hematopoietic cells but also several cancer cells. In the present study, we investigated the expression of G-CSFR or G-CSF in epithelial skin tumors by immunohistochemical staining. The assessments were defined by the percentage of G-CSFR or G-CSF positive cells and expressed as G-CSFR and G-CSF scores. The G-CSFR score in SCC (77.6+/-20.0%) was significantly higher than that in Bowen's disease (BD) (51.0+/-35.6%), actinic keratosis (AK) (49.3+/-34.6%) or normal skin (30.0+/-32.1%) (P=0.0004, P=0.0003, P<0.0001, respectively). The mean G-CSF score in SCC (56.7+/-27.4%) or in BD (44.1+/-31.4%) was higher than that in normal skin (24.9+/-25.8%) (P=0.0075, P<0.001, respectively). G-CSF expression in AK (29.8+/-31.2%) was lower than that in SCC (P=0.0037). There was significant positive correlation between the G-CSFR score and the G-CSF score (gamma=0.274, P=0.0107) in skin tumors. These findings suggested that the assessment of G-CSFR expression might be associated with carcinogenesis of skin tumors.