Prevalence of oral potentially malignant disorders: A systematic review and meta-analysis.

Oral potentially malignant disorders (OPMD) are chronic conditions, which have a higher risk of transformation to oral squamous cell carcinoma. The aim of this systematic review and meta-analysis was to answer the question: "What is the prevalence of oral potentially malignant disorders among adults?" Studies reporting the prevalence of these conditions (leukoplakia, erythroplakia, oral submucous fibrosis [OSMF], and actinic cheilitis) were selected, only studies in which a clinical assessment and histopathological confirmation were performed were included. Of the 5513 studies, 22 met the inclusion criteria for qualitative and quantitative analyses. The risk of bias (RoB) of the selected studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. Seven studies were classified as high risk, 12 as moderate risk, and 3 as low RoB. The meta-analysis showed that the prevalence of OPMD was 4.47% (95% CI = 2.43-7.08). The most prevalent OPMDs were OSMF (4.96%; 95% CI = 2.28-8.62) and leukoplakia (4.11%; 95% CI = 1.98-6.97). OPMDs were identified more commonly in males (59.99%; 95% CI = 41.27-77.30). Asian and South American/Caribbean populations had the highest prevalence rates of 10.54% (95% CI = 4.60-18.55) and 3.93% (95% CI = 2.43-5.77), respectively. The overall prevalence of OPMD worldwide was 4.47%, and males were more frequently affected by these disorders. The prevalence of OPMD differs between populations; therefore, further population-based studies may contribute to the better understanding of these differences.

Role of gene polymorphisms in gastric cancer and its precursor lesions: current knowledge and perspectives in Latin American countries.

Latin America shows one of the highest incidence rates of gastric cancer in the world, with variations in mortality rates among nations or even within countries belonging to this region. Gastric cancer is the result of a multifactorial complex process, for which a multistep model of carcinogenesis is currently accepted. Additionally to the infection with Helicobacter pylori, that plays a major role, environmental factors as well as genetic susceptibility factors are significant players at different stages in the gastric cancer process. The differences in population origin, demographic structure, socio-economic development, and the impact of globalization lifestyles experienced in Latin America in the last decades, all together offer opportunities for studying in this context the influence of genetic polymorphisms in the susceptibility to gastric cancer. The aim of this article is to discuss current trends on gastric cancer in Latin American countries and to review the available published information about studies of association of gene polymorphisms involved in gastric cancer susceptibility from this region of the world. A total of 40 genes or genomic regions and 69 genetic variants, 58% representing markers involved in inflammatory response, have been used in a number of studies in which predominates a low number of individuals (cases and controls) included. Polymorphisms of IL-1B (-511 C/T, 14 studies; -31 T/C, 10 studies) and IL-1RN (variable number of tandem repeats, 17 studies) are the most represented ones in the reviewed studies. Other genetic variants recently evaluated in large meta-analyses and associated with gastric cancer risk were also analyzed in a few studies [e.g., prostate stem cell antigen (PSCA), CDH1, Survivin]. Further and better analysis centered in gene polymorphisms linked to other covariates, epidemiological studies and the information provided by meta-analyses and genome-wide association studies should help to improve our understanding of gastric cancer etiology in order to develop appropriate health programs in Latin America.

Chlamydia trachomatis as a probable cofactor in human papillomavirus infection in aboriginal women from northeastern Argentina

Objectives: High-risk types of human papillomavirus (HPV) are strongly associated with cervical cancer (CC), and Chlamydia trachomatis (CT), the most frequent sexually transmitted bacterial infection (STBI) worldwide, seems to be a risk factor for HPV infection and for CC. It is also known that both agents are more prevalent in vulnerable communities where lack of adequate primary health care is a cause for concern. The aim of this work was to determine the impact of CT and HPV infections in women belonging to an isolated aboriginal population (Pilaga community) from a poor region in Northern Argentina (province of Formosa). For this purpose, a cross-sectional study was performed in all sexually active Pilaga women, who attended a local community-based gynecological health screening project. The polymerase chain reaction (PCR) method on a cervical brush specimen was used to detect both agents. Results: A total of 227 women (20 percent of the total female population of the Pilaga community) were studied and the overall prevalence was 26.4 percent for CT, 46.7 percent for HPV and 16.3 percent for concurrent infection. CT infection was higher in HPV DNA positive (34.2 percent) than in HPV DNA negative women (19 percent; OR: 2.22/95 percent CI = 1.16-4.28 / p = 0.009) and the most prevalent HPV types were HPV-16 (19.4 percent), 6 and 18 (5.3 percent), 58 (3.5 percent) and 33 (3.1 percent). Conclusions: The prevalence of CT and HPV observed in Pilaga women are among the worst registered in Latin America. Also, data collected suggest that chlamydial infection may play an important role in the natural history of HPV infection. On this respect, we propose that the association between these two agents seems to be more related to a mutual potentiation than to the fact that they share a common route of transmission.

Self-reported ethnicity and genetic ancestry in relation to oral cancer and pre-cancer in Puerto Rico.

BACKGROUND: Hispanics are known to be an extremely diverse and genetically admixed ethnic group. The lack of methodologies to control for ethnicity and the unknown admixture in complex study populations of Hispanics has left a gap in understanding certain cancer disparity issues. Incidence rates for oral and pharyngeal cancer (OPC) in Puerto Rico are among the highest in the Western Hemisphere. We conducted an epidemiological study to examine risk and protective factors, in addition to possible genetic susceptibility components, for oral cancer and precancer in Puerto Rico. METHODOLOGY/PRINCIPAL FINDINGS: We recruited 310 Puerto Rico residents who had been diagnosed with either an incident oral squamous cell carcinoma, oral precancer, or benign oral condition. Participants completed an in-person interview and contributed buccal cells for DNA extraction. ABI Biosystem Taqman™ primer sets were used for genotyping 12 ancestry informative markers (AIMs). Ancestral group estimates were generated using maximum likelihood estimation software (LEADMIX), and additional principal component analysis was carried out to detect population substructures. We used unconditional logistic regression to assess the contribution of ancestry to the risk of being diagnosed with either an oral cancer or precancer while controlling for other potential confounders. The maximum likelihood estimates showed that study participants had a group average ancestry contribution of 69.9% European, 24.5% African, and 5.7% detectable Native American. The African and Indigenous American group estimates were significantly higher than anticipated. Neither self-identified ethnicity nor ancestry markers showed any significant associations with oral cancer/precancer risk in our study. CONCLUSIONS/SIGNIFICANCE: The application of ancestry informative markers (AIMs), specifically designed for Hispanics, suggests no hidden population substructure is present based on our sampling and provides a viable approach for the evaluation and control of ancestry in future studies involving Hispanic populations.

Chlamydia trachomatis as a probable cofactor in human papillomavirus infection in aboriginal women from northeastern Argentina.

OBJECTIVES: High-risk types of human papillomavirus (HPV) are strongly associated with cervical cancer (CC), and Chlamydia trachomatis (CT), the most frequent sexually transmitted bacterial infection (STBI) worldwide, seems to be a risk factor for HPV infection and for CC. It is also known that both agents are more prevalent in vulnerable communities where lack of adequate primary health care is a cause for concern. The aim of this work was to determine the impact of CT and HPV infections in women belonging to an isolated aboriginal population (Pilaga community) from a poor region in Northern Argentina (province of Formosa). For this purpose, a cross-sectional study was performed in all sexually active Pilaga women, who attended a local community-based gynecological health screening project. The polymerase chain reaction (PCR) method on a cervical brush specimen was used to detect both agents. RESULTS: A total of 227 women (20% of the total female population of the Pilaga community) were studied and the overall prevalence was 26.4% for CT, 46.7% for HPV and 16.3% for concurrent infection. CT infection was higher in HPV DNA positive (34.2%) than in HPV DNA negative women (19%; OR: 2.22/95% CI = 1.16-4.28 / p = 0.009) and the most prevalent HPV types were HPV-16 (19.4%), 6 and 18 (5.3%), 58 (3.5%) and 33 (3.1%). CONCLUSIONS: The prevalence of CT and HPV observed in Pilaga women are among the worst registered in Latin America. Also, data collected suggest that chlamydial infection may play an important role in the natural history of HPV infection. On this respect, we propose that the association between these two agents seems to be more related to a mutual potentiation than to the fact that they share a common route of transmission.

Dysbacteriosis and squamous (pre)neoplasia of immigrants and Dutch women as established in population-based cervical screening.

We examined the statistical relationships between dysbacteriosis and (pre)neoplasia related to age and ethnicity from the cervical screening of almost half a million smears. Data from 445,080 smears were coded according to KOPAC (the Dutch national cervical smear coding system) with nine grades. Prevalence per 100,000 smears and relative risks (RR) were calculated for dysbacteriosis and for squamous abnormalities. Patients were stratified by their probable country of origin. Dutch women had an RR of 0.92 for dysbacteriosis. Surinamese women had the highest RR for dysbacteriosis (RR = 2.36) and Moroccan women had the lowest (RR = 1.00). The same trends were seen for the risks of squamous abnormalities. The data for Turkish women follow the patterns of those for Surinamese women. The RR of dysbacteriosis is highest at 50 yr (1.28) and lowest at 35 yr (0.86). When dysbacteriotic and non-dysbacteriotic smears were compared, dysbacteriosis was observed more frequently in smears with squamous abnormalities (4.1% vs. 2.2%). Dysbacteriosis may warrant more intensive cytological surveillance and changes in lifestyle.

CagA in Barrett's oesophagus in Colombia, a country with a high prevalence of gastric cancer.

BACKGROUND: In the USA, atrophic gastritis and gastric cancer are rare, whereas gastro-oesophageal reflux disease (GERD) is common. Infection with Helicobacter pylori, especially a CagA positive strain, is unusual in patients with GERD/Barrett's oesophagus in the USA. AIM: To examine the relation between Barrett's oesophagus and CagA positive H pylori in Colombia, a country with a high prevalence of CagA positive H pylori associated atrophic gastritis and gastric cancer. METHODS: Helicobacter pylori and CagA status was determined among Colombian patients with long segment Barrett's oesophagus and a control group with simple H pylori gastritis. Helicobacter pylori status was determined using a triple stain and CagA status was determined by immunohistochemistry using a specific rabbit anti-CagA serum. RESULTS: Gastric and oesophageal mucosal biopsies were obtained from 51 patients--39 men (mean age, 57.8 years; SD, 13.1) and 12 women (mean age, 51.8 years; SD, 14.4)--with documented long segment Barrett's oesophagus. The results were compared with 24 Colombian patients with H pylori gastritis without oesophageal disease. Thirty two patients with Barrett's oesophagus had active H pylori infection. CagA status was evaluated in a subset of 23 H pylori infected patients with Barrett's oesophagus, and was positive in eight of these patients compared with 19 of 24 controls (p = 0.01). CONCLUSIONS: Although most Colombian patients with Barrett's oesophagus had H pylori infection, CagA positive infections were unusual. These data illustrate how consistent corpus inflammation reduces acid secretion, which prevents Barrett's oesophagus among those with abnormal gastro-oesophageal reflux barriers.

Preneoplastic lesions and gallbladder cancer: an estimate of the period required for progression.

BACKGROUND & AIMS: Scarce biological information exists about the importance of preneoplastic lesions in gallbladder cancer. The aim of this study was to estimate the time required for the sequence of dysplasia (DY) to carcinoma of the gallbladder. METHODS: Eighty-four cases of DY, 60 cases of early carcinomas (ECs), 181 cases of advanced carcinomas (ACs), and 121 cases of metastatic (ME) gallbladder cancer were analyzed. Age was used as the main parameter. Statistical analysis was performed using analysis of variance and multiple regression analysis. RESULTS: Among all cases, the mean age of female patients was lower than the mean age of male patients (P = 0.001). A significant difference in mean age between sexes by specific type of lesion was also observed (P < 0.001). The mean age was 46.3 years (SD, 16) in the DY group, 57.5 years (SD, 16.7) in the EC group, 59 (SD, 13.7) in the AC group, and 61.1 (SD, 12.1) in the ME group. Multiple regression analysis showed statistically significant differences (r = 0.386; P < 0.001) in the mean age of patients with dysplastic lesions compared with the carcinoma group. CONCLUSIONS: According to these observations, the period required to progress from dysplasia to advanced gallbladder carcinoma would be around 15 years, observing a continuum in the progression of the lesions.