Polymorphisms in genes related to inflammation, NSAID use, and the risk of prostate cancer among Danish men

Genetic polymorphisms of PPAR genes and human cancers: evidence for gene-environment interactions

Peroxisome proliferator-activated receptors (PPARs) are nuclear transcription factors that play a role in lipid metabolism, cell proliferation, terminal differentiation, apoptosis, and inflammation. Although several cancer models have been suggested to explain PPARs' involvement in tumorigenesis, however, their role is still unclear. In this review, we examined associations of the different PPARs, polymorphisms and various types of cancer with a focus on gene-environment interactions. Reviewed evidence suggests that functional genetic variants of the different PPARs may modulate the relationship between environmental exposure and cancer risk. In addition, this report unveils the scarcity of reliable quantitative environmental exposure data when examining these interactions, and the current gaps in studying gene-environment interactions in many types of cancer, particularly colorectal, prostate, and bladder cancers.

Increased inflammatory potential of diet is associated with increased odds of prostate cancer in Argentinian men

PURPOSE

Various aspects of diet, including specific food items and nutrients, have been shown to modulate inflammation and have been implicated in the etiology of prostate cancer (PrCA). No study examining the role of diet-associated inflammation in PrCA has been conducted in Latin America.

METHOD

We examined the association between the Dietary Inflammatory Index (DII®) and PrCA in a population-based case-control study in Córdoba, Argentina. A total of 153 incident cases of PrCA and 309 controls frequency matched on sex, age (± 5 years), and place of residence were recruited from 2008 to 2015. The DII was developed to determine the inflammatory potential of individuals' diets and was computed from a validated food frequency questionnaire using nutrient data from diet only. Multi-level logistic regression models were fit to evaluate the association between DII scores and PrCA, adjusting for age, body mass index, energy intake, and occupational exposure as first-level covariates and family history of prostate cancer as the second-level variable. Odds ratios were estimated in all subject and stratified by BMI (< 30 vs. ≥ 30 kg/m2).

RESULTS

Men in the most pro-inflammatory group (tertile 3) had 50% higher odds of having PrCA compared to men in the most anti-inflammatory group (tertile 1) (ORtertile3 vs. tertile1 1.50; 95% CI 1.24-1.80). The odds of prostate cancer were higher in obese men (n = 109, ORtertile3 vs. tertile1 1.81; 95% CI 1.45-2.27), while no association was found among non-obese men (n = 375, ORtertile3 vs. tertile1 0.93; 95% CI 0.25-3.51).

CONCLUSIONS

A pro-inflammatory diet, reflected by higher DII scores, was positively associated with PrCA occurrence. Based on these results and those from other studies, steps should be taken to promote a diet rich in anti-inflammatory foods, in order to reduce risk of PrCA and other chronic diseases. Future studies should explore this association in a prospective setting.

Association between Dietary Inflammatory Index and Prostate Cancer in Shiraz Province of Iran

Background: Dietary components like food items and nutrients have been implicated to play a role in modulating inflammation and the development of prostate cancer. Studies examining this association have not been extensively explored in Middle Eastern Countries. Material and Methods: We examined the association between the dietary inflammatory index (DIITM) and prostate cancer in the Shiraz province of Iran. A total of 60 incident cases and 60 controls attending the same hospital as the cases were recruited. The energy adjusted DII (E-DIITM) was computed based on dietary intake assessed using a validated food frequency questionnaire (FFQ). Logistic regression was used to estimate odds ratios. Results: Men with higher E-DII (>0.96) were at higher risk of prostate cancer (OR = 2.55; 95% CI =1.04–6.23) compared to men with E-DII ≤0.96. Conclusion: These data suggest a pro-inflammatory diet, as indicated by increasing DII score, may be a risk factor for prostate cancer in Iranian men.

Association Between a Dietary Inflammatory Index and Prostate Cancer Risk in Ontario, Canada

BACKGROUND

Evidence exists showing that various aspects of diet are implicated in the etiology of prostate cancer, although results across studies remain inconsistent.

METHODS

We examined the ability of the dietary inflammatory index (DII) to predict prostate cancer in a case-control study conducted in Kingston, Ontario, Canada, between 1997 and 1999. The study included 72 cases of incident primary prostate cancer patients and 302 controls of urology clinic patients who had prostate conditions other than prostate cancer. The DII was computed based on intake of 18 nutrients assessed using a 67-item food frequency questionnaire. Univariate and multivariate logistic regression models were used to estimate odds ratios (ORs).

RESULTS

Men with higher DII scores were at increased risk of prostate cancer using DII score fit both as a continuous [OR = 1.58, 95% confidence interval (CI) 1.05-2.38] and categorical variable [compared to men in the lowest DII quartile, men in the highest quartile were at elevated risk (OR = 3.50, 95% CI 1.25-9.80; ptrend = 0.02)]. There was no significant heterogeneity by weight status, but stronger association was observed in men with body mass index >25 kg/m2 versus <25 kg/m2.

CONCLUSION

These findings suggest that a proinflammatory diet, as indicated by increasing DII score, is a risk factor for prostate cancer.

Association of NF-κB polymorphisms with clinical outcome of non-medullary thyroid carcinoma

The NF-κB inflammatory pathway plays a major role in cancer development and clinical progression. Activation of NF-κB signaling is promoted by NFKB1 and inhibited by NFKBIA. The present study aimed to determine the relevance of NFKB1 rs4648068 and NFKBIA rs2233406 genetic variants for non-medullary thyroid cancer (NMTC) susceptibility, progression and clinical outcome. This case-control and cohort study consists of a Romanian discovery cohort (157 patients and 258 controls) and a Dutch validation cohort (138 patients and 188 controls). In addition, patient cohorts were analyzed further for the association of genetic variants with clinical parameters. Functional studies were performed on human peripheral blood mononuclear cells. No associations were observed between the studied genetic variants and TC susceptibility. Although no statistically significant associations with clinical parameters were observed for NFKB1 rs4648068, the heterozygous genotype of NFKBIA rs2233406 was correlated with decreased radioactive iodide sensitivity requiring higher cumulative dosages to achieve clinical response. These findings were discovered in the Romanian cohort (P < 0.001) and confirmed in the Dutch cohort (P = 0.01). Functional studies revealed that this NFKBIA rs2233406 genotype was associated with elevated TLR4-mediated IL-1β production. In conclusion, genetic variation in NFKBIA, an inhibitor of NF-κB signaling, is associated with clinical response to RAI therapy and with increased production of the pro-inflammatory cytokine IL-1β, providing a potential mechanism for the observed clinical associations. These data suggest that NF-κB signaling is involved in NMTC pathogenesis and that the inflammatory tumor microenvironment could contribute to RAI resistance.

NFKB1 -94insertion/deletion ATTG polymorphism and cancer risk: Evidence from 50 case-control studies

Nuclear factor-kappa B1 (NF-κB1) is a pleiotropic transcription factor and key contributor to tumorigenesis in many types of cancer. Numerous studies have addressed the association of a functional insertion (I)/deletion (D) polymorphism (-94ins/delATTG, rs28362491) in the promoter region of NFKB1 gene with the risk of various types of cancer; however, their conclusions have been inconsistent. We therefore conducted a meta-analysis to reevaluate this association. PubMed, EMBASE, China National Knowledge infrastructure (CNKI), and WANFANG databases were searched through July 2016 to retrieve relevant studies. After careful assessment, 50 case-control studies, comprising 18,299 cases and 23,484 controls were selected. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were used to determine the strength of the association. The NFKB1 -94ins/delATTG polymorphism was associated with a decreased risk of overall cancer in the homozygote model (DD vs. II): OR = 0.75, 95% CI = 0.64-0.87); heterozygote model (ID vs. II): OR = 0.91, 95% CI = 0.83-0.99; recessive model (DD vs. ID/II): OR = 0.81, 95% CI = 0.71-0.91; dominant model (ID/DD vs. II): OR = 0.86, 95% CI = 0.78-0.95; and allele contrast model (D vs. I): OR = 0.88, 95% CI = 0.81-0.95). Subgroup and stratified analyses revealed decreased risks for lung cancer, nasopharyngeal carcinoma, prostate cancer, ovarian cancer, and oral squamous cell carcinoma, and this association held true also for Asians (especially Chinese subjects) in hospital-based studies, and in studies with quality scores less than nine. Well-designed, large-scale case-control studies are needed to confirm these results.

An updated meta-analysis of 37 case-control studies on the association between NFKB1 -94ins/del ATTG promoter polymorphism and cancer susceptibility

As a cell survival signal, nuclear factor-kappa B (NFKB) is associated with the pathogenesis of numerous malignancies. According to several studies, NFKB1 -94ins/del ATTG promoter polymorphism is associated with the risk of different malignancies, but the results were not consistent. Therefore, we performed an updated meta-analysis based on 37 case-control studies from 33 articles (16,271 cases and 22,781 controls) to clarify the relationship. The odds ratio (OR) and 95% confidence interval (CI) were used to determine the strength of the association. We found that the NFKB1 -94ins/del ATTG promoter polymorphism was significantly associated with increased susceptibility to cancer in the recessive (II vs. ID+DD, OR = 1.140, 95% CI = 1.029-1.263, p =0.012), homozygote (II vs. DD, OR = 1.259, 95% CI = 1.068-1.485, p =0.006), and allele (I vs. D, OR = 1.109, 95% CI = 1.025-1.199, p =0.010) genetic models. The subgroup analysis for ethnicity found that the NFKB1 -94ins/del ATTG promoter polymorphism was significantly associated with an increased susceptibility to cancer in Asians and with a decreased susceptibility in Caucasians. The stratified analyses revealed significant associations between the polymorphism and increased susceptibility to ovarian cancer, oral squamous cell carcinoma, and nasopharyngeal carcinoma.

Genetic association between NFKB1 -94 ins/del ATTG Promoter Polymorphism and cancer risk: a meta-analysis of 42 case-control studies

Accumulating evidences have indicated that the functional -94 ins/del ATTG polymorphism in the promoter region of human nuclear factor-kappa B1 (NFKB1) gene may be associated with cancer risk. However, some studies yielded conflicting results. To clarify precise association, we performed a comprehensive meta-analysis of 42 case-control studies involving 43,000 subjects (18,222 cases and 24,778 controls). The overall results suggested that the -94 ins/del ATTG polymorphism had a decreased risk for cancer, reaching significant levels in five genetic models (dominant model: OR = 0.86, 95% CI = 0.79–0.95, P = 0.002; recessive model: OR = 0.84, 95% CI = 0.74–0.94, P = 0.003; homozygous model: OR = 0.77, 95% CI = 0.66–0.90, P = 0.001; heterozygous model: OR = 0.90, 95% CI = 0.83–0.98, P = 0.011; allelic model: OR = 0.89, 95% CI = 0.83–0.96, P = 0.002). Furthermore, the -94 ins/del ATTG polymorphism could confer a decreased or increased risk for cancer development among Asians and Caucasians, respectively. Additionally, the stratification analysis revealed a significant association between the variant and decreased risk of oral, ovarian, and nasopharyngeal cancer in Asians. After we adjusted p values using the Benjamini-Hochberg false discovery rate method to account for multiple comparisons, these associations remained.

Genetic Variations in Inflammatory Response Genes and Their Association with the Risk of Prostate Cancer

Prostate cancer is a common cancer in men. Genetic variations in inflammatory response genes can potentially influence the risk of prostate cancer. We aimed to examine the association between PPARG Pro12Ala, NFKB1 -94 ins/del, NFKBIA -826C/T, COX-1 (50C>T), and COX-2 (-1195G>A) polymorphisms on prostate cancer risk. The genotypes of the polymorphisms were ascertained in 543 prostate cancer patients and 753 controls through PCR-RFLP and the risk association was evaluated statistically using logistic regression analysis. The NFKB1 -94 polymorphism was shown to decrease prostate cancer risk in both heterozygous and homozygous comparison models (odds ratios of 0.74 (95% CI = 0.58-0.96) (P = 0.02) and 0.57 (95% CI = 0.42-0.78) (P < 0.01), resp.). An opposite finding was observed for COX-2 (-1195) polymorphism (odds ratios of 1.58 (95% CI = 1.15-2.18) (P < 0.01) for heterozygous comparison model and 2.08 (95% CI = 1.48-2.92) (P < 0.01) for homozygous comparison model). No association was observed for other polymorphisms. In conclusion, NFKB1 -94 ins/del and COX-2 (-1195G>A) polymorphisms may be, respectively, associated with decreased and increased prostate cancer risk in the Chinese population.

Association and interaction of NFKB1 rs28362491 insertion/deletion ATTG polymorphism and PPP1R13L and CD3EAP related to lung cancer risk in a Chinese population

The nuclear factor of kappa light polypeptide gene enhancer in B cells 1 (NFKB1) gene encodes p105 and p50 kD which are both subunits of the transcription factor NF-kB, involved in a wide variety of diseases and pathological states associated with inflammation, immunity, and tumorigenesis. The NFKB1 rs28362491 polymorphism in the promoter region (-94 insertion/deletion ATTG) has been associated with risk of various cancers. Our study aims were to evaluate the associations of NFKB1 rs28362491 polymorphism and interactions of this single-nucleotide polymorphism (SNP) and PPP1R13L and CD3EAP and smoking duration in relation to lung cancer risk in a Chinese population. The study population consisted of 544 Chinese lung cancer cases and 550 cancer-free matched (age, sex, and ethnicity) controls. No associations were found between NFKB1 rs28362491 and lung cancer risk. CD3EAP rs967591 was associated with increased lung cancer risk in the dominant model [OR (95 % CI) = 1.38 (1.05-1.80), P = 0.018]. The common haplotype containing PPP1R13L rs1970764(G), CD3EAP rs967591(A), and CD3EAP rs735482(C) was associated with lung cancer [adjusted OR (95 % CI) = 1.29 (1.03-1.62), P = 0.028]. Multifactor dimensionality reduction (MDR) analysis revealed two-way and three-way interactions between CD3EAP rs735482 and smoking and between NFKB1 rs28362491, PPP1R13L rs1970764, and smoking. In conclusion, we were able to reproduce previously found associations between PPP1R13L and CD3EAP polymorphisms and lung cancer risk in an increased study group, and we found interactions between NFKB1 rs28362491-PPP1R13L rs1970764 and smoking duration and between CD3EAP rs735482 and smoking duration. These results suggest that these genes and smoking are part of the same biological pathway leading to smoking-induced lung cancer.

Increased Dietary Inflammatory Index (DII) Is Associated With Increased Risk of Prostate Cancer in Jamaican Men

Prostate cancer is the most common nonskin malignancy, and it accounts for the most cancer deaths among Jamaican males. Diet has been implicated in the etiology of prostate cancer, including through its effects on inflammation. We examined the association between a newly developed dietary inflammatory index (DII) and prostate cancer in a case-control study of 40-80 yr old Jamaican males. A total of 229 incident cases and 250 controls attended the same urology out-patient clinics at 2 major hospitals and private practitioners in the Kingston, Jamaica metropolitan area between March 2005 and July 2007. The DII was computed based on dietary intake assessed using a previously validated food frequency questionnaire (FFQ) that was expanded to assess diet and cancer in this Jamaican population. Multivariable logistic regression was used to estimate odds ratios, with DII as continuous and expressed as quartiles. Logistic regression analysis adjusted for age, total energy intake, education, body mass index, smoking status, physical activity, and family history of prostate cancer. Men in the highest quartile of the DII were at higher risk of prostate cancer [odds ratio (OR) = 2.39; 95% confidence interval (CI) = 1.14-5.04; P(trend) = 0.08] compared to men in the lowest DII quartile. These data suggest a proinflammatory diet, as indicated by increasing DII score, may be a risk factor for prostate cancer in Jamaican men.

Polymorphisms in NFKB1 and NFKBIA Genes Modulate the Risk of Developing Prostate Cancer among Han Chinese

Background

Nuclear factor kappa B (NF-κB) pathway proteins play an important role in modulating inflammation and other carcinogenic processes. Polymorphisms within NF-κB pathway genes may influence cancer risk. This study aimed to examine the association between NFKB19-4 ATTG ins→del, NFKBIA 3′ UTR A→G, -826CT and -881AG polymorphisms and prostate cancer risk among Chinese.

Material/Methods

The polymorphisms were genotyped via PCR-RFLP technique on 936 prostate cancer patients and 936 population-based healthy controls. Logistic regression model was used to measure the risk association present.

Results

With the exception of NFKBIA 3′ UTR polymorphism, the heterozygous and mutant genotypes of the other polymorphisms were significantly associated with prostate cancer risk. For NFKB1 polymorphism, a decreased risk was observed, with adjusted OR: 0.69; 95% CI: 0.44, 0.98; P=0.01 (heterozygous) and adjusted OR: 0.60; 95% CI: 0.37, 0.91; P=0.02 (mutant). NFKBIA -826CT and -881AG polymorphisms were in complete linkage disequilibrium and shared the same risk association, with adjusted OR: 1.34; 95% CI: 1.09, 1.62; P=0.02 (heterozygous) and adjusted OR: 2.83; 95% CI: 1.79, 4.50; P=0.01 (mutants). Interestingly, the impact of the NFKB1 polymorphism was not present in nonsmokers and younger (<60 years) subjects (P<0.05).

Conclusions

In conclusion, polymorphisms in NFKB1 and NFKBIA genes may modulate the risk of developing prostate cancer among Chinese.

Polymorphisms in NFKB1 and TLR4 and interaction with dietary and life style factors in relation to colorectal cancer in a Danish prospective case-cohort study

Maintenance of a balance between commensal bacteria and the mucosal immune system is crucial and intestinal dysbiosis may be a key event in the pathogenesis of colorectal cancer (CRC). The toll-like receptor 4 (TLR4) is an important pattern-recognition receptor that regulates inflammation and barrier function in the gut by a mechanism that involves activation of the nuclear factor-κB (NF-κB) transcription factor. Dietary and life style factors may impact these functions. We therefore used a Danish prospective case-cohort study of 1010 CRC cases and 1829 randomly selected participants from the Danish Diet, Cancer and Health cohort to investigate three polymorphisms in NFKB1 and TLR4 and their possible interactions with diet and life style factors in relation to risk of CRC. Homozygous carriage of the variant allele of the TLR4/rs5030728 polymorphism was associated with increased risk of CRC (incidence rate ratio (IRR) = 1.30; 95% confidence interval (CI): 1.05-1.60; P = 0.02 (gene-dose model); IRR = 1.24; 95%CI: 1.01-1.51; P = 0.04 (recessive model)). Del-carriers of the NFKB1/rs28362491 polymorphism had a 17% (95%CI: 1.03-1.34; P = 0.02) increased risk of CRC compared to homozygous carriers of the ins-allele. However, none of these risk estimates withstood adjustment for multiple comparisons. We found no strong gene-environment interactions between the examined polymorphism and diet and life style factors in relation to CRC risk.

Association between dietary inflammatory index and prostate cancer among Italian men

Previous studies have shown that various dietary components may be implicated in the aetiology of prostate cancer, although the results remain equivocal. The possible relationship of inflammation derived from dietary exposures with prostate cancer risk has not been investigated. We examined the ability of a newly developed dietary inflammatory index (DII) to predict prostate cancer risk in a case-control study conducted in Italy between 1991 and 2002. A total of 1294 patients aged < 75 years with incident, histologically confirmed carcinoma of the prostate served as cases. A total of 1451 subjects aged < 75 years who were admitted to the same hospitals as cases for a wide spectrum of acute, non-neoplastic conditions served as controls. The DII was computed based on dietary intake assessed using a previously validated seventy-eight-item FFQ. Logistic regression models were used to estimate multivariable OR adjusted for age, study centre, years of education, social class, BMI, smoking status, family history of prostate cancer and total energy intake. Men with higher DII scores had a higher risk of prostate cancer when analysed using the DII as both continuous (OR 1.06, 95% CI 1.00, 1.13) and categorical, i.e., compared with men in the lowest quartile of the DII, men in the third and fourth quartiles were at elevated risk (OR(Quartile 3 v. 1) 1.32, 95% CI 1.03, 1.69 and OR(Quartile 4 v. 1) 1.33, 95% CI 1.01, 1.76; P trend= 0.04). These data suggest that a pro-inflammatory diet, as indicated by the increasing DII score, is a risk factor of prostate cancer in Italian men.

Genetic polymorphisms and plasma levels of interleukin-22 contribute to the development of nonsmall cell lung cancer

Interleukin (IL)-22, a relatively new member of the IL-10 family, has been implicated in inflammation and tumorigenesis. The aim of this study was to identify genetic polymorphisms in IL-22 and to measure plasma levels of IL-22 in patients with nonsmall cell lung cancer (NSCLC). Patients with NSCLC had a significantly higher frequency of IL-22 rs2227484 CT genotype (odds ratio [OR]=1.917, 95% confidence interval [CI] 1.001-3.670, p=0.038) and T allele (OR=1.878, 95% CI 1.010-3.491, p=0.049) as compared with controls. The rs2227484 genotype was associated with a 2.263-fold increased risk for advanced NSCLC (p=0.041). Among different subtypes of NSCLC, these associations were more obvious in the adenocarcinoma. Moreover, patients with high frequencies of genotypic polymorphisms had high plasma levels of IL-22. IL-22 polymorphisms and corresponding high levels of IL-22 in plasma may contribute to the development of NSCLC, especially adenocarcinoma.

Association between NFKB1 -94ins/del ATTG Promoter Polymorphism and Cancer Susceptibility: An Updated Meta-Analysis

Nuclear factor-κB is associated with the pathogenesis of numerous malignancies, and the functional polymorphism −94ins/del ATTG (rs28362491) in the human NFKB1 gene is associated with cancer risk. Previous studies on the association between the −94ins/del ATTG polymorphism and cancer risk reported conflicting results. To clarify this relationship, we performed a meta-analysis of 21 case-control studies involving 6127 cases and 9238 controls. We used pooled odds ratios (ORs) with their 95% confidence intervals (95% CIs) to assess the association. We found that the NFKB1 promoter −94ins/del ATTG polymorphism was significantly associated with cancer risk in four genetic models (ins/ins versus del/del, OR = 1.47, 95% CI = 1.11–1.93; dominant model, OR = 1.26, 95% CI = 1.03–1.53; recessive model, OR = 1.26, 95% CI = 1.05–1.51; ins allele versus del allele, OR = 1.19, 95% CI = 1.05–1.35). Stratified analyses revealed a significant association between the polymorphism and ovarian, oral, and prostate cancers. Similar results were determined in an Asian population and not in a Caucasian population. Thus, our results suggested that the polymorphism can contribute to cancer risk. Moreover, the polymorphism can exert race- and cancer-specific effects on cancer risk. Further large-scale and functional studies are necessary to elucidate this possible effect.

Effect of aspirin and other non-steroidal anti-inflammatory drugs on prostate cancer incidence and mortality: a systematic review and meta-analysis

BACKGROUND

It has been postulated that non-steroidal anti-inflammatory drugs (NSAIDs) use leads to decreased prostate cancer (PCa) risk. In recent years, NSAIDs' role in PCa development has been extensively studied; however, there is not yet a definitive answer. Moreover, the epidemiological results for NSAIDs' effect on PCa-specific mortality have been inconsistent. Therefore, we performed a meta-analysis to examine the controversy.

METHODS

We performed a literature database search and included all published studies conducted in the general population exposed to any NSAID, extracting an odds ratio (OR) or a hazard ratio (HR) with 95% confidence intervals (95% CIs) that compared the incidence of PCa or PCa-specific mortality with non-exposure. We derived a pooled OR or HR using random or fixed effects models, as appropriate. Subgroup analyses were also performed.

RESULTS

Thirty-nine studies (20 case-control and 19 cohort studies) were included in this analysis. Thirty-one studies were available concerning NSAID use and PCa incidence and eight studies on PCa-specific mortality. Compared to non-use, aspirin use was statistically significantly associated with PCa incidence risk, and the association was slightly stronger for advanced PCa than for total PCa (OR = 0.92, 95% CI = 0.87 to 0.97 for total PCa; OR = 0.81, 95% CI = 0.73 to 0.89 for advanced PCa). Aspirin use seems also to be associated with a modest reduction in PCa-specific mortality (HR = 0.86, 95% CI = 0.78 to 0.96 for total PCa; OR = 0.81, 95% CI = 0.71 to 0.92 for advanced PCa). Generally, the pooled effects for any NSAIDs, NA-NSAIDs and cyclooxygenase-2 inhibitors demonstrated no adverse or beneficial effects on PCa development or PCa-specific mortality, but the results were not consistent. The effect estimates did not vary markedly when stratified by study design and study quality but varied by geographic region. Furthermore, long-term aspirin use (≥ 4 years) was also significantly associated with reduced PCa incidence (OR = 0.88, 95% CI 0.79 to 0.99).

CONCLUSIONS

The present meta-analysis provides support for the hypothesis that aspirin use is inversely related to PCa incidence and PCa-specific mortality. The effect estimates, varying by geographic region, deserve further investigation.

NFKB1 -94 insertion/deletion polymorphism and cancer risk: a meta-analysis

Previous studies on the associations of the NFKB1 -94 insertion/deletion polymorphism with cancer risk have produced conflicting results. The purpose of this meta-analysis is to define the effect of the NFKB1 -94 insertion/deletion polymorphism on cancer risk. A search of the literature by PubMed was performed to identify studies based on the predetermined inclusion criteria. Twenty-three studies consisting of 6,494 cases and 9,884 controls were identified and analyzed. Overall, significant association was observed between the polymorphism and cancer risk under all genetic models. Subgroup analysis according to ethnicity and cancer type also detected significant association. The NFKB1 -94 insertion/deletion polymorphism was associated with cancer risk in Asian population (dominant model: OR=1.52, 95 % CI=1.17-1.98; recessive model: OR=1.50, 95 % CI=1.26-1.79; II vs. DD: OR=1.90, 95 % CI=1.37-2.65; ID vs. DD: OR=1.32, 95 % CI=1.05-1.66; I vs. D: OR=1.37, 95 % CI=1.17-1.60), but not in Caucasian population. In addition, significant associations in OC, HCC, and OSCC were observed, but significant associations were not found in BC and LC. The current meta-analysis suggested that NFKB1 -94 insertion/deletion polymorphism may influence cancer risk in Asian population.