Cervical and vulvar cancer risk in relation to the joint effects of cigarette smoking and genetic variation in interleukin 2

Gaps and Opportunities to Improve Prevention of Human Papillomavirus-Related Cancers

Human papillomavirus (HPV) infections cause more than 35,900 cancers annually in the United States. Although cervical cancer is the most prevalent HPV-related malignancy in women, the virus is also responsible for a significant percentage of anal, vaginal, and vulvar cancers. A comprehensive approach to mitigating cervical cancer includes HPV vaccination (primary prevention), screening and treatment of precancerous lesions (secondary prevention), and diagnosis and treatment of invasive cancer (tertiary prevention). Although a successful strategy, there are opportunities to innovate and increase access that can also be adapted to address the unique clinical care gaps that exist with the other anogenital cancers. The Society for Women's Health Research held a series of interdisciplinary meetings and events, during which expert researchers, clinicians, patient advocates, and health care policy leaders evaluated the current landscape of HPV-related cancers and their effects on women's health. This report summarizes the discussions of this working group and areas it identified in which to address gaps in primary and secondary prevention approaches to improve access and health outcomes for women with HPV-related anogenital cancers.

Risk of second primary cancers among survivors of gynecological cancers

OBJECTIVE

Survivors of gynecologic cancers have an increased risk of developing second primary cancers (SPC); however it is unclear which sites have higher risks. We aimed to ascertain risk of SPC among survivors of gynecological cancer, and identify anatomic sites at risk of SPC.

METHODS

We queried the Surveillance, Epidemiology and End Results database (2000-2016) for confirmed cases of index gynecological (cervix uteri [cervical], corpus and uterus [endometrial], ovarian, vaginal, and vulvar) cancers. Risk of SPC was estimated using standardized incidence ratios (SIRs: observed/expected cases) and excess absolute risks (EARs: observed - expected cases) per 10,000 person-years at risk (PYR). SIRs and EARs were stratified by index anatomic site and latency interval.

RESULTS

Among the cohort of 301,210 gynecological cancer survivors, 19,005 (6.31%) developed an SPC (SIR = 1.16; 95% CI, 1.15-1.18 and EAR = 17.2 cases per 10,000 PYR) compared with the general population. All gynecological cancer survivors (except survivors of ovarian) had a significant risk of developing SPC (SIR range 1.06-2.16), with survivors of vulvar cancer having the highest risk (SIR = 2.16; 95% CI, 2.06-2.27; EAR = 139.5 per 10,000 PYR). Risk of SPC was highest within the first 5 years post-diagnosis for survivors of cervical, vulvar and vaginal cancers.

CONCLUSIONS

While most index gynecological cancer sites are associated with increased risk of SPC, risk is highest among survivors of vulvar cancer. These findings have the potential to inform lifelong surveillance recommendations for gynecological cancer survivors.

Epidemiology of vulvar neoplasia in the NIH-AARP Study

OBJECTIVE

To clarify risk factors for rare vulvar neoplasms.

METHODS

Within the NIH-AARP Study, among 201,469 women interviewed in 1995-1996 and followed for a mean of 13.8years, there were 370 diagnoses of incident vulvar neoplasms, including 170 invasive and 198 vulvar intraepithelial neoplasms grade 3 (VIN3). Hazard ratios (HR) and 95% confidence intervals (CI) were calculated via multivariate logistic regression for various demographic, reproductive and lifestyle factors, with separate consideration of relations according to invasiveness, histology and age at diagnosis.

RESULTS

Consistent with descriptive data, we found non-white women at lower risks of vulvar neoplasia than white women (HR=0.59, 95% CI 0.36-0.95). Significant risk factors for VIN3 included being divorced/separated (HR vs. currently married=1.77, 95% CI 1.24-2.51), a current cigarette smoker (3.88, 95% CI 2.64-5.72), a user of oral contraceptives (1.46, 95% CI 1.06-2.01), or a current user of menopausal hormones (1.73, 95% CI 1.24-2.41). Significant risk factors for invasive cancers were being obese (HR for BMI ≥30 vs. <25=1.62, 95% CI 1.10-2.40) or a current smoker (1.86, 95% CI 1.21-2.87). Cigarette smoking was a risk factor mainly for neoplasms shown in other investigations to be HPV-related, namely VIN3 and invasive squamous cell cancers (SCCs) occurring in the younger stratum of cases. In contrast, obesity was primarily associated with the development of invasive SCCs.

CONCLUSIONS

Our results support that vulvar neoplasia is a heterogeneous disease. VIN3 demonstrated risk factors consistent with an HPV-related etiology, while invasive cancers were additionally affected by obesity, suggesting that further attention should focus on the role of chronic inflammatory conditions.

Disturbance of Bcl-2, Bax, Caspase-3, Ki-67 and C-myc expression in acute and subchronic exposure to benzo(a)pyrene in cervix

Epidemiological studies have demonstrated that cigarette smoking is an important cofactor or an independent risk factor for the development of cervical cancer. Benzo(a)pyrene (BaP) is one of the most potent tobacco smoke carcinogens in tobacco smoke. BaP induced DNA damage and over expression in p53 cervical tissue of mice as demonstrated in our previous study. Here we present the findings of exposure to BaP on the expression of Bcl-2, C-myc, Ki-67, Caspase-3 and Bax genes in mouse cervix. Acute intraperitoneal administration of BaP (12.5, 25, 50, 100mg/kg body weight) to ICR female mice induced a significant increase in Bcl-2, C-myc, Ki-67 mRNA and protein level till 72h except in Bcl-2 at 24h with 12.5, 25, 50mg/kg as well as at 48h with 12.5mg/kg body weight post treatment. A significant increase was also seen in Caspase-3 and Bax mRNA and protein level with peak level at 24h and gradual decrease till 72h, however, the expression of caspase-3 increased while that of Bax decreased with increasing dose of Bap after 24h. In sub chronic intraperitoneal and oral gavage administration of BaP (2.5, 5, 10mg/kg body weight), similar significant increase was observed for all the examined genes as compared to the control and vehicle groups, however the expression of Bax decreased in a dose dependent manner. The findings of this study will help in further understanding the molecular mechanism of BaP induced carcinogenesis of cervical cancer.

A candidate gene approach of the calcineurin pathway to identify variants associated with clinical outcomes in renal transplantation

AIM

To investigate the potential influence of variants in genes involved in the calcineurin pathway on the efficacy and toxicity of calcineurin inhibitors in renal transplantation.

MATERIALS & METHODS

Twenty-three polymorphisms in thirteen genes were tested in 381 renal transplant recipients receiving ciclosporin (n = 221) or tacrolimus (n = 160) and mycophenolate mofetil. Data were collected prospectively over the first year post-transplantation.

RESULTS

Multivariate survival analyses revealed no genetic associations with biopsy proven acute graft rejection and serious infections. Donor-recipient Cytomegalovirus mismatch was the only variable associated with serious infection.

CONCLUSION

This large exploratory study casts doubts on the potential interest of genetic biomarkers related to CNI pharmacodynamics but associations with other phenotypes in transplantation deserve further studies.

A population-based case-control study of genetic variation in cytokine genes associated with risk of cervical and vulvar cancers

OBJECTIVE

Persistent infection with oncogenic human papillomavirus (HPV) is known to be the necessary cause of cervical cancer and a majority of vulvar cancers. Persistent HPV infections must evade host immune responses, including cytokines released by activated T-helper (Th) cells. In this study, we investigated the risk of cervical and vulvar cancers associated with common genetic variations in 560 tagging single-nucleotide polymorphisms (SNPs) in candidate cytokine genes.

METHODS

The study included 399 invasive squamous cell carcinomas (SCCs) and 502 in situ or invasive adenocarcinomas (AC) of the cervix; 357 in situ or invasive vulvar SCC; and 1109 controls from the Seattle-area case-control studies of HPV-related cancers. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) using a log additive model, with adjustment for multiple testing.

RESULTS

Statistically significant risks were observed for HPV16-containing SCC of the cervix with the variant allele rs879576 in IL17RA and rs2229094 in TNF [OR, 95% CI and multiple-testing corrected p: 1.91 (1.30-2.79), p=0.018 and 0.61 (0.45-0.83), p=0.02, respectively]. We also observed significantly increased risk of HPV-positive vulvar cancers associated with variant alleles in CSF2 (rs25882 and rs27438, 26-28% increased risk) and IL-12B (rs2569254 and rs3181225, 40-41% increased risk) genes.

CONCLUSIONS

We found that variation in several Th-cytokine genes is significantly associated with cervical and vulvar cancer risk. The strong association between these HPV-related cancers and common variation in cytokine genes in the Th1 and Th17 pathways may be important for development of new therapies.

Association of cytokines in individuals sensitive and insensitive to dust mites in a Brazilian population

Introduction

Allergic reaction to dust mites is a relatively common condition among children, triggering cutaneous and respiratory responses that have a great impact on the health of this population. Anaphylactic hypersensitivity is characterized by an exacerbated response involving the production of regulatory cytokines responsible for stimulating the production of IgE antibodies.

Objective

To investigate an association of variants in cytokine genes (IL1A⁻⁸⁸⁹, IL1B^{−511, +3962}, IL1R¹⁹⁷⁰, IL1RA¹¹¹⁰⁰, IL4RA⁺¹⁹⁰², IL12⁻¹¹⁸⁸, IFNG⁺⁸⁷⁴, TGFB1^{codon 10, codon 25}, TNFA^{−308, −238}, IL2^{−330, +166}, IL4^{−1098, −590, −33}, IL6^{−174, nt565}, and IL10^{−1082, −819, −592}) between patients sensitive to dust mites and a control group.

Methods

A total of 254 patients were grouped as atopic and non-atopic according to sensitivity as evaluated by the Prick Test and to cytokine genotyping by the polymerase chain reaction-sequence specific primers (PCR-SSP) method using the Cytokine Genotyping Kit.

Results

A comparison between individuals allergic to Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Blomia tropicalis and a non-atopic control group showed significant differences between allele and genotype frequencies in the regulatory regions of cytokine genes, with important evidence for IL4⁻⁵⁹⁰ in T/C (10.2% vs. 43.1%, odd ratio [OR] = 0.15, p = 5.2 10⁻⁸, pc = 0.0000011, and 95% confidence interval [95%CI] = 0.07–0.32) and T/T genotypes (42.9% vs. 13.8%, OR = 4.69, p = 2.5 10⁻⁶, pc = 0.000055, and 95%CI = 2.42–9.09). Other associations were observed in the pro-inflammatory cytokines IL1A⁻⁸⁸⁹ (T/T, C, and T) and IL2⁻³³⁰ (G/T and T/T) and the anti-inflammatory cytokines IL4RA⁺¹⁹⁰² (A and G), IL4⁻⁵⁹⁰ (T/C, T/T, C, and T), and IL10⁻⁵⁹² (A/A, C/A, A, and C).

Conclusion

Our results suggest a possible association between single nucleotide polymorphisms (SNPs) in cytokine genes and hypersensitivity to dust mites.

Association of IL-2 polymorphisms and IL-2 serum levels with susceptibility to HBV-related hepatocellular carcinoma in a Chinese Zhuang population

BACKGROUND AND OBJECTIVE

Interleukin-2 (IL-2) is an immunoregulatory cytokine produced by T cells and plays an important role in antitumor immunity. Variations in the DNA sequence of the IL-2 gene may lead to altered cytokine production and/or activity, and thus modulate an individual's susceptibility to hepatitis B virus-related hepatocellular carcinoma (HBV-related HCC). To test this hypothesis, we investigated whether IL-2 gene polymorphisms and its serum levels are associated with HBV-related HCC in a Chinese population.

METHODS

The +114T/G and -384T/G polymorphisms in the IL-2 gene were examined in 115 cases of chronic hepatitis B (CHB), 67 cases of HBV-related liver cirrhosis (LC), 107 cases of HBV-related HCC, and 105 healthy controls by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. The serum IL-2 levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that there were significant differences in the genotype and allele frequencies of the IL-2 gene +114T/G polymorphism between the HBV-related HCC patients and the healthy controls. The +114 TG and GG genotypes were associated with a significant increased HCC risk as compared with the TT genotype (OR=1.988, 95% CI, 1.034-3.480, P=0.009 for TG genotype, and OR=1.975, 95% CI, 1.012-3.341, P=0.013 for GG genotype, respectively). The +114 G allele was correlated with a significant increased HCC risk as compared with the T allele (OR=1.423, 95% CI, 1.023-1.975, P=0.031). In addition, we found significant decreased serum IL-2 in HBV-related HCC patients (288.6±177.1ng/L) compared with healthy controls (238.2±136.7ng/L) (t=2.32, P=0.021). Genotypes carrying the +114 G variant allele were associated with decreased serum IL-2 levels compared with the homozygous wild-type genotype in HBV-related HCC patients.

CONCLUSION

The results suggested that the IL-2 +114T/G polymorphism may contribute to increased HBV-related HCC risk through regulating the serum IL-2 levels. Further large and well-designed studies in diverse ethnic populations are needed to confirm our results.

PCR based detection of HPV 16 and 18 genotypes in normal oral mucosa of tobacco users and non-users

There is increasing evidence of a causal association between human papillomavirus (HPV) and oral squamous cell carcinoma (OSCC). Several studies have shown that HPV is associated with increased risk of oral cancer independent of exposure to tobacco and alcohol. The association is valid for HPVs 16 and 18, which generally are considered high risk types, because they have been detected in oral dysplastic lesions and cancers. We determined the baseline prevalence of HPVs 16 and 18 in normal oral mucosa of individuals with and without tobacco habit. PCR was used for DNA collected by oral smears to detect HPV 16/18 DNA in normal oral mucosa of 60 healthy individuals who were assigned to two groups of 30 subjects each. One group had a tobacco habit, the other did not. The tobacco user group comprised individuals who were tobacco chewers only. Sixty-five percent of individuals were positive for HPV 16/18 DNA, but HPV 16/18 positivity was less in individuals with tobacco habit than in those without tobacco habit. No significant association was found between the presence of HPVs and gender, age or duration of chewing habit, or between groups with and without a tobacco habit. We propose that HPVs16 and 18 commonly are present in normal oral mucosa and emphasize the importance of distinguishing clinical, subclinical and latent HPV infections when investigating HPVs and OSCC.

Polymerase chain reaction and deoxyribonucleic acid-sequencing based study on distribution of human papillomavirus 16/18 among histopathological types of cervical intra-epithelial neoplasia and primary invasive cervical carcinoma: A scenario in North Bengal, India

Introduction:

Human papillomavirus (HPV) types 16/18 are reportedly most common in cervical cancer (CaCx) with geographical variation of genotypes. HPV16 predominates both in squamous cell carcinoma (SCC) and adenocarcinoma in India, contrary to reported global predominance of HPV18 in the latter. Our study was aimed to determine the occurrence of HPV16/18 among histopathological types of cervical intra-epithelial neoplasia (CIN) and invasive CaCx from North Bengal, India and to identify any major deviation from the known Indian scenario of distribution of HPV16/18 genotypes in cases of SCC and adenocarcinoma.

Materials and Methods:

This was a retrospective, cross-sectional, case-only type of study, in which 40 cases were histopathologically diagnosed as CIN/CaCx, on which polymerase chain reaction (PCR), deoxyribonucleic acid (DNA)-sequencing and bioinformatics by basic search local alignment tool were performed for HPV-genotyping.

Statistical Analysis:

The distribution of HPV genotypes among cases of SCC and adenocarcinoma was compared by Fisher's exact-test.

Results:

HPV was detected in 97.5% (39/40) cases. HPV16-infected cases (32/39; 82.05%) predominated over HPV18-infected ones (7/39; 17.95%). However, HPV18-only infection was significantly (P = 0.0045, one-sided Fisher's exact test) more among adenocarcinoma (3/4; 75%) than SCC (2/26; 7.69%) contrary to HPV16-only infection (SCC = 24/26, 92.31%; adenocarcinoma = 1/4; 25%) whereas both CIN3 cases were HPV16-positive.

Conclusion:

Predominance of HPV18 over HPV16 in cases of adenocarcinoma in this region was contrasting to that of earlier Indian studies suggesting research on HPV18 related cervical carcinogenesis. PCR and DNA-sequencing could prove to be highly effective tools in HPV detection and genotyping. The study reported HPV16/18 infection in almost 98% of the cases, the knowledge about which might prove useful in future population based studies on HPV genotyping and designing of appropriate HPV-vaccines for this region.

Disease progression and recurrence in women treated for vulvovaginal intraepithelial neoplasia

Objective

The malignant potential of intraepithelial neoplasia of the vulva and vagina after treatment is not well defined. Our objective was to examine risk factors for recurrence and invasive disease.

Methods

Four hundred sixty-four women with biopsy proven high-grade intraepithelial neoplasia of the vulva and vagina were identified in the electronic databases of four colposcopy clinics. Inclusion criteria were a follow-up of more than one year, no history of invasive cancer and no invasive cancer within the first year after initial treatment. We investigated the potential factors associated with recurrence and progression using a logistic regression analysis to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Of the 411 eligible patients, 123 patients (29.9%) recurred later than one year after initial treatment and 24 patients (5.8%) progressed to invasive disease. According to multivariate analyses, the risk factors associated with recurrence were multifocality (OR, 3.33; 95% CI, 2.02 to 5.51), immunosuppression (OR, 2.51; 95% CI, 1.09 to 5.81), excision as initial treatment (vs. laser evaporation; OR, 1.79; 95% CI, 1.11 to 2.91) and smoking (OR, 1.61; 95% CI, 1.02 to 2.55). Risk factors for progression to invasive disease were immunosuppression (OR, 4.00; 95% CI, 1.30 to 12.25), multifocality (OR, 3.05; 95% CI, 1.25 to 7.43) and smoking (OR, 2.97; 95% CI, 1.16 to 7.60), but not treatment modality.

Conclusion

Laser evaporation combined with extensive biopsy is at least as efficacious as initial treatment of intraepithelial neoplasia with excision. Smoking is a risk factor for both recurrence and progression to invasive disease. Hence, smoking cessation should be advised and maintaining a long follow-up period due to late relapses is necessary.

Squamous cell carcinoma of the vulva: a comparison between women 35 years or younger and 90 years or older

OBJECTIVE

This study aimed to compare clinical features, diagnosis, management, and outcomes between women 35 years or younger and 90 years or older with vulvar squamous cell carcinoma referred to Queensland Centre for Gynaecological Cancer between 1983 and 2010.

MATERIALS AND METHODS

Fifty-seven case records, including pathology reports for these 2 groups were reviewed and analyzed using the computer software SPSS 11.0.

RESULTS

Of the cases, 34 were 35 years or younger (mean = 31.6 years), and 23 90 years or older (mean = 92.6 years). International Federation of Gynecology and Obstetrics classification showed grade 1 for 74% in the younger group and 55% for the older group. Patient status showed 22 alive (65%) in the younger group and 4 alive (17%) in the older group. Three younger patients (9%) were dead of disease and 8 (35%) in the older group. Three patients (9%) died of another disease in the younger group and 10 patients (43%) in the older group. Initial treatment was surgical in 30 younger cases (88%) and 18 older cases (78%).

CONCLUSIONS

We demonstrated a trend toward younger women presenting with vulvar squamous cell carcinoma and a history of human papillomavirus and vulvar intraepithelial neoplasia. Immune deficiency diseases occurred in 23% of the younger group, but none occurred in the older group, where Alzheimer disease, heart disease, and renal failure (57%) were present. Poorly differentiated tumors and an International Federation of Gynecology and Obstetrics classification of 2 or more resulted in a worse outcome than did better differentiated lesions, irrespective of additional medical conditions.

Investigating a cluster of vulvar cancer in young women: a cross-sectional study of genital human papillomavirus prevalence

BACKGROUND

Vulvar cancer is a relatively rare malignancy, which occurs most often in postmenopausal women. We have previously identified a geographic cluster of vulvar cancer in young Indigenous women living in remote communities in the Arnhem Land region of Australia. In this population, we investigated the prevalence of oncogenic human papillomavirus (HPV) infection in anogenital samples (vulvar/vaginal/perianal area and cervix) and compared the overall, type-specific and multiple infection prevalence between sites.

METHODS

A cross-sectional survey of 551 Indigenous women aged 18-60 years was undertaken in 9 Arnhem Land communities. Women were consented for HPV detection and genotyping collected by a combined vulvar/vaginal/perianal (VVP) sweep swab and a separate PreservCyt endocervical sample collected during Pap cytology screening. HPV DNA testing was undertaken using PCR with broad spectrum L1 consensus PGMY09/11 primers with genotyping of positive samples by Roche Linear Array. The primary outcomes were the prevalence of cervical and VVP high-risk (HR) HPV.

RESULTS

The prevalence of VVP HR-HPV was 39%, which was significantly higher than the cervical HR-HPV prevalence (26%, p<0.0001). HPV-16 was the most common genotype detected in both sites (VVP 11%, cervical 6%). HPV-16 infection peaked in women aged <20 years; however, there was a marked decline in cervical HPV-16 prevalence with age (p=0.007), whereas following an initial decline, the prevalence of VVP HPV-16 remained constant in subsequent age-groups (p=0.835).

CONCLUSIONS

In this population experiencing a cluster of vulvar cancer, the prevalence of cervical oncogenic HPV infection was similar to that reported by studies of other Australian women; however there was a significantly higher prevalence of vulvar/vaginal/perianal infection to cervical. The large discrepancy in HPV prevalence between anogenital sites in this population may represent more persistent infection at the vulva. This needs further investigation, including the presence of possible environmental and/or genetic factors that may impair host immunity.

Impact of cytokine and cytokine receptor gene polymorphisms on cellular immunity after smallpox vaccination

We explored associations between SNPs in cytokine/cytokine receptor genes and cellular immunity in subjects following primary smallpox vaccination. We also analyzed the genotype-phenotype associations discovered in the Caucasian subjects among a cohort of African-Americans. In Caucasians we found 277 associations (p<0.05) between gene SNPs and inter-individual variations in IFN-α, IL-12p40, IL-1β, IL-2, and TNF-α secretion levels. A collection of SNPs in the IL1RN, IL2RB, IL4R, IL6, IL10RB, IL12A, and IL12RB2 genes had consistent associations among both Caucasians and African-Americans. A regulatory SNP (rs452204) in the IL1RN gene was significantly associated with higher levels of IL-2 secretion in an allele dose-dependent manner in both race groups (p=0.05 for Caucasians and p=0.002 for African-Americans). IL12RB2 polymorphism rs3790567 was associated with a dose-related decrease in IL-1β secretion (p=0.009 for Caucasians and p=0.01 for African-Americans). Our results demonstrate that variations in smallpox vaccine-induced cytokine responses are modulated by genetic polymorphisms in cytokine and cytokine receptor genes.

Education, tobacco smoking, alcohol consumption, and IL-2 and IL-6 gene polymorphisms in the survival of head and neck cancer

The association of education, tobacco smoking, alcohol consumption, and interleukin-2 (IL-2 +114 and -384) and -6 (IL-6 -174) DNA polymorphisms with head and neck squamous cell carcinoma (HNSCC) was investigated in a cohort study of 445 subjects. IL-2 and IL-6 genotypes were determined by real-time PCR. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) of disease-specific survival according to anatomical sites of the head and neck. Mean age was 56 years and most patients were males (87.6%). Subjects with 5 or more years of schooling had better survival in larynx cancer. Smoking had no effect on HNSCC survival, but alcohol consumption had a statistically significant effect on larynx cancer. IL-2 gene +114 G/T (HR = 0.52; 95%CI = 0.15-1.81) and T/T (HR = 0.22; 95%CI = 0.02-3.19) genotypes were associated with better survival in hypopharynx cancer. IL-2 +114 G/T was a predictor of poor survival in oral cavity/oropharynx cancer and larynx cancer (HR = 1.32; 95%CI = 0.61-2.85). IL-2 -384 G/T was associated with better survival in oral cavity/oropharynx cancer (HR = 0.80; 95%CI = 0.45-1.42) and hypopharynx cancer (HR = 0.68; 95%CI = 0.21-2.20), but an inverse relationship was observed for larynx cancer. IL-6 -174 G/C was associated with better survival in hypopharynx cancer (HR = 0.68; 95%CI = 0.26-1.78) and larynx cancer (HR = 0.93; 95%CI = 0.42-2.07), and C/C reduced mortality in larynx cancer. In general, our results are similar to previous reports on the value of education, smoking, alcohol consumption, and IL-2 and IL-6 genetic polymorphisms for the prognosis of HNSCC, but the risks due to these variables are small and estimates imprecise.

Smoking and cervical cancer

Cervical cancer (CC) is the third most common cancer in women worldwide; however, CC is a preventable disease, and much effort should be done to prevent it. Persistence of high-risk HPV infection is the strongest epidemiologic risk factor for CC, however it is not sufficient for development of the disease it cofactors should be present. In 2004; IARC listed cervical cancer among those causally related to smoking. Smoking interferes with incidence and prevalence of HPV infection and is associated with cervical intraepithelial neoplasia and invasive CC. Multiple factors seem to intervene on cervical carcinogenesis related with tobacco, especially by direct local carcinogenic effect and local immunosuppression. Smoking addition is also closely related with other confounding factors, like unfavorable psychosocial events, systemic immunity, contraception, and nutrition, which got difficult epidemiologic evaluation of smoking role on cervical carcinogenesis. Smoking habits should be taken in account in clinical practice and in research concerning CC.

A novel approach to exploring potential interactions among single-nucleotide polymorphisms of inflammation genes in gliomagenesis: an exploratory case-only study

BACKGROUND

Despite extensive research on the topic, glioma etiology remains largely unknown. Exploration of potential interactions between single-nucleotide polymorphisms (SNP) of immune genes is a promising new area of glioma research. The case-only study design is a powerful and efficient design for exploring possible multiplicative interactions between factors that are independent of one another. The purpose of our study was to use this exploratory design to identify potential pair wise SNP-SNP interactions from genes involved in several different immune-related pathways for investigation in future studies.

METHODS

The study population consisted of two case groups: 1,224 histologic confirmed, non-Hispanic white glioma cases from the United States and a validation population of 634 glioma cases from the United Kingdom. Polytomous logistic regression, in which one SNP was coded as the outcome and the other SNP was included as the exposure, was utilized to calculate the ORs of the likelihood of cases simultaneously having the variant alleles of two different SNPs. Potential interactions were examined only between SNPs located in different genes or chromosomes.

RESULTS

Using this data mining strategy, we found 396 significant SNP-SNP interactions among polymorphisms of immune-related genes that were present in both the U.S. and U.K. study populations.

CONCLUSION

This exploratory study was conducted for the purpose of hypothesis generation, and thus has provided several new hypotheses that can be tested using traditional case-control study designs to obtain estimates of risk.

IMPACT

This is the first study, to our knowledge, to take this novel approach to identifying SNP-SNP interactions relevant to glioma etiology.

Single nucleotide polymorphisms of 8 inflammation-related genes and their associations with smoking-related cancers

Tobacco smoke and its metabolites are carcinogens that increase tissue oxidative stress and induce target tissue inflammation. We hypothesized that genetic variation of inflammatory pathway genes plays a role in tobacco-related carcinogenesis and is modified by tobacco smoking. We evaluated the association of 12 single nucleotide polymorphisms of 8 inflammation-related genes with tobacco-related cancers (lung, oropharynx, larynx, esophagus, stomach, liver, bladder, and kidney) using 3 case-control studies from: Los Angeles (population-based; 611 lung and 553 upper aero-digestive tract cancer cases and 1,040 controls), Taixing, China (population-based; 218 esophagus, 206 stomach, 204 liver cancer cases, and 415 controls), and Memorial Sloan-Kettering Cancer Center (hospital-based; 227 bladder cancer cases and 211 controls). After adjusting for age, education, ethnicity, gender, and tobacco smoking, IL10 rs1800871 was inversely associated with oropharyngeal cancer (CT+TT vs. CC adjusted odds ratio [aOR]: 0.69, 95% confidence interval [CI]: 0.50-0.95), and was positively associated with lung cancer among never smokers (TT vs. CT+CC aOR: 2.5, 95% CI: 1.3-5.1) and inversely with oropharyngeal cancer among ever smokers (CT+TT vs. CC aOR: 0.63, 95% CI: 0.41-0.95). Among all pooled never smokers (588 cases and 816 controls), TNF rs1799964 was inversely associated with smoking-related cancer (CC vs. CT+TT aOR: 0.36, 95% CI: 0.17-0.77). Bayesian correction for multiple comparisons suggests that chance is unlikely to explain our findings (although epigenetic mechanisms may be in effect), which support our hypotheses, suggesting that IL10 rs1800871 is a susceptibility marker for oropharyngeal and lung cancers, and that TNF rs1799964 is associated with smoking-related cancers among never smokers.

Genetic variation in CXCL12 and risk of cervical carcinoma: a population-based case-control study

CXCL12 provides a chemotactic signal-directing leucocyte migration and regulates metastatic behaviour of tumour cells. We conducted a population-based case-control study to test the hypothesis that common genetic variation in CXCL12 individual single nucleotide polymorphism (SNP) alleles and haplotypes] is associated with the risk of cervical carcinoma. Cases (n = 917) were residents of western Washington State diagnosed with invasive squamous cell cervical carcinoma (SCC), invasive adenocarcinoma or adenosquamous carcinoma, or adenocarcinoma in situ of the cervix. Control participants (n = 849) were identified from the source population by random digit telephone dialling and frequency matched to cases on county and age. Nine CXCL12 tagSNPs chosen from the SeattleSNPs database were genotyped. The minor allele of intronic SNP rs266085 was inversely associated with cervical cancer under a recessive genetic effects model (OR = 0.74, 95% CI: 0.56-0.98). Among the ten common haplotypes inferred from the nine tagSNPs, one haplotype defined by minor alleles at 5'-flanking SNP rs17885289 and rs266085, and common alleles at the other seven SNPs occurred among 7.8% of cases and 10.6% of controls (dominant model OR = 0.72, 95% CI: 0.56-0.93; recessive model OR = 0.35, 95% CI: 0.12-0.97; and log-additive model OR = 0.72, 95% CI: 0.57-0.90). A stepwise procedure identified rs17885289, rs266085 and 3'-untranslated region (UTR) SNP rs266093 as the most parsimonious subset of SNPs necessary to define the haplotype inversely associated with cervical cancer risk in our study. A 3'-UTR SNP, rs1801157, previously found to be related to HIV pathogenesis, was not associated with cervical cancer risk. Further population-based studies are warranted to confirm these associations between genetic variation in CXCL12 and cervical cancer risk.