Langerhans' cells and smoking in intraepithelial neoplasia of the cervix

The vaginal microbiome: A complex milieu affecting risk of human papillomavirus persistence and cervical cancer

The purpose of this review is to describe the existing literature regarding the relationship between the vaginal microbiome, human papillomavirus persistence, and cervical cancer risk, as well as to discuss factors that mediate these relationships. Data suggest that alterations in the vaginal microbiome affect the risk of human papillomavirus infection and persistence, which has downstream effects on cervical dysplasia and cancer risk. The homeostatic Lactobillus species L. crispatus, L. gasseri, L. jensenii act to promote a healthy vaginal environment, while L. iners and pathogens causing bacterial vaginosis are associated with increased inflammation, human papillomavirus infection, cervical dysplasia, and potentially cancer. There are, however, still several large gaps in the literature, particularly related to the modifiable and non-modifiable factors that affect the vaginal microbiome and ensuing risk of pre-cancerous and cancerous lesions. Evidence currently suggests that endogenous and exogenous hormones, tobacco products, and sexual practices influence vaginal microbiome composition, but the nuances of these relationships and how changes in these factors affect dysplasia risk are yet to be delineated. Other studies examining how diet, exercise, race, socioeconomic status, and genetic factors influence the vaginal microbiome are difficult to interpret in the setting of multiple confounders. Future studies should focus on how changes in these modulatory factors might promote a healthy vaginal microbiome to prevent or treat dysplasia in the lower female genital tract.

TNFR1 single nucleotide polymorphisms are not associated with cervical HPV-induced pre-malignant lesion but regulate in situ cervical TNFR1 expression

TNF-α is involved in HPV infection control by triggering cell signaling through binding in specific receptors TNFR1 and TNFR2. Genetic polymorphisms in these receptors may influence TNF-α signaling. Herein, we investigated TNFR1 rs767455 and rs2234649 single nucleotide polymorphisms, and TNFR1 protein expression in cervical squamous intraepithelial lesions (SIL) to identify their role in cervical pre-malignant development. SIL patients (n = 179) and healthy volunteers (n = 227) were enrolled for TNFR1 genotyping analysis by PCR-RFLP in blood samples and TNFR1 protein expression in cervical tissue by immunohistochemistry. No statistical differences regard genotypes and allelic frequencies for both polymorphisms were observed. Cervical TNFR1-expressing cells were rare in epithelium and basal layer regardless the groups. However, a progressive increase in infiltrating cells was observed in the stromal area, mainly in high SIL (HSIL) group compared to low SIL (LSIL, p < 0.001) and control (p < 0.001) groups. TNFR1-expressing cells frequency was higher in TNFR1 rs767455AG/GG (p < 0.001), and in rs2234649AA (p < 0.001) genotypes carries in HSIL subgroup. These data indicated that TNFR1-expression is abrogated in cervical epithelium, where HPV-induced pre-malignant lesion occurs, increasing its frequency in inflammatory cells in stroma, and is genetically controlled by TNFR1 rs767455AG/GG and rs234649AA genotypes. These biomarkers may be useful to identify cervical precancerous lesions progression.

Food webs in the human body: linking ecological theory to viral dynamics

The dynamics of in-host infections are central to predicting the progression of natural infections and the effectiveness of drugs or vaccines, however, they are not well understood. Here, we apply food web theory to in-host disease networks of the human body that are structured similarly to food web models that treat both predation and competition simultaneously. We show that in-host trade-offs, an under-studied aspect of disease ecology, are fundamental to understanding the outcomes of competing viral strains under differential immune responses. Further, and importantly, our analysis shows that the outcome of competition between virulent and non-virulent strains can be highly contingent on the abiotic conditions prevailing in the human body. These results suggest the alarming idea that even subtle behavioral changes that alter the human body (e.g. weight gain, smoking) may switch the environmental conditions in a manner that suddenly allows a virulent strain to dominate and replace less virulent strains. These ecological results therefore cast new light on the control of disease in the human body, and highlight the importance of longitudinal empirical studies across host variation gradients, as well as, of studies focused on delineating life history trade-offs within hosts.

Smoking cessation counseling in women with genital intraepithelial neoplasia

OBJECTIVE

Cigarette smoking is a risk factor for cervical, vaginal, vulvar, and anal dysplasia. We will study the prevalence of cigarette smoking in patients with genital dysplasia and effect of counseling on smoking cessation.

METHODS

All patients with genital dysplasia were screened for smoking history. One clinician provided smoking cessation counseling using the US Department of Health 5 A's technique: ask patients about their smoking status, advise smokers to quit, assess their readiness to quit, assist with their smoking cessation effort, and arrange for follow-up visits. Patients were informed on how smoking may cause worsening of genital dysplasia and increased risk of progression to cancer. Each patient received 2 counseling sessions, but no pharmacological or psychological interventions. Smoking cessation was evaluated by patient self-report via phone or during clinic visits.

RESULTS

From January 2007 to December 2010, 344 patients were referred to our gynecologic oncology clinic for evaluation of genital dysplasia. Patients who were smokers (n=125, 36%) were counseled to cease smoking in 2 counseling sessions, with 100% compliance for attendance. At study analysis (July 2011), 83 patients still smoke and 40 patients quit smoking (smoking cessation rate of 32%). Caucasian patients (P=.0013) and patients with vulvar dyplasia (P=.411) seemed to smoke more than other races and patients with cervical/vaginal dysplasia respectively.

CONCLUSION

Smoking cessation counseling for the genital dysplasia patients who smoked was associated with smoking cessation in 32% of the patients.

Null genotypes of GSTM1 and GSTT1 contribute to risk of cervical neoplasia: an evidence-based meta-analysis

Background and Objectives

Glutathione S-transferases (GSTs) are multifunctional enzymes that play a key role in the detoxification of varieties of both endogenous products of oxidative stress and exogenous carcinogens.

Methods

In this meta-analysis, twenty-five studies were identified by searching PubMed, EMBASE, ISI Web of Science and CBM databases: 23 evaluated GSTM1 and 19 evaluated GSTT1. Crude odds ratios with corresponding 95% confidence intervals were used to estimate the association between GSTM1 and GSTT1 polymorphisms and risk of cervical neoplasia. Subgroup analyses were conducted by pathological history, ethnicity, source of DNA for genotyping, quality score, and matching variable.

Results

The null genotypes of GSTM1 and GSTT1 polymorphisms were associated with a significantly increased risk of cervical neoplasia (for GSTM1: OR = 1.40; 95%CI, 1.19–1.65; for GSTT1: OR = 1.30; 95%CI, 1.05–1.62, respectively). Subgroup analyses showed that the null genotype of GSTM1 increased the risk of cervical neoplasia in Asians, studies with DNA isolation from white blood cells and tissue samples, both high and low quality studies, and matched studies. In GSTM1-GSTT1 interaction analysis, individuals with dual null genotype were associated with a significantly increased risk of cervical neoplasia (OR = 1.72; 95%CI, 1.18–2.51).

Conclusion

These findings indicate that GSTM1 and GSTT1 polymorphisms, particularly GSTM1-GSTT1 interaction, may play critical roles in the development of cervical neoplasia. A conservative manner should be adopted to interpret these results because of obvious heterogeneity between-study, unadjusted data, and relatively small sample size in this meta-analysis. Well designed studies with larger sample size are of great value to confirm these results.

HLA-A alleles and the risk of cervical squamous cell carcinoma in Japanese women

BACKGROUND

We conducted a case-control study to examine the relationship between human leukocyte antigen-A (HLA-A) allele polymorphism and the pathogenesis of cervical neoplasia among Japanese women.

METHODS

A total of 119 patients with invasive cervical squamous cell carcinoma were compared to 119 age- and menopausal status-matched non-cancer controls. Blood samples were taken from all cases and controls and lifestyle information was collected by means of a self-administered questionnaire. The estimated impact of HLA-A alleles on cervical cancer risk was evaluated by unconditional logistic regression models.

RESULTS

The frequency of HLA-A(*)0206 among cases was significantly lower than among controls (P = 0.006). There was an inverse association between A(*)0206 and cervical cancer risk (odds ratio [OR] = 0.31, 95% confidence interval [95% CI] = 0.15 to 0.65, P = 0.002), and a positive association for HLA-A(*)2402 (OR = 1.76, 95% CI = 1.00 to 3.09, P = 0.048). After correction for multiple comparisons, A(*)0206 was significantly associated with reduced cervical cancer risk (corrected P = 0.036). Furthermore, the inverse association between A(*)0206 and cervical cancer risk was independent of smoking status (never smoker: OR = 0.37, 95% CI = 0.15 to 0.90; ever smoker: OR = 0.23, 95% CI = 0.06 to 0.89).

CONCLUSIONS

There was an inverse association between HLA-A(*)0206 and cervical cancer risk among Japanese women, which suggests that HLA-A polymorphism influences cervical cancer risk. Further investigation in other populations is thus warranted.

The interplay between secondhand cigarette smoke, genetics, and cervical cancer: a review of the literature

Research has suggested a link between smoking and cervical cancer; however, little data are available on secondhand smoke (SHS) exposure and cervical cancer risk. This article reviews the literature on the links among smoking, SHS exposure and cervical cancer. The review was based on a search of electronic databases. The research reviewed clearly showed that smoking increases cervical cancer risk through myriad mechanisms that interact with genetics and the pathologic processes leading to cervical cancer. However, less is understood about the role of SHS in cervical cancer. With new technology enabling scientists to examine how genomic structure responds to environmental stimuli, more information should be forthcoming on links between SHS exposure, biomarkers, and genetic changes involved in the development of cervical cancer.