Purpose: Gastric cancer is a curable disease if diagnosed at early stage. However, most cases are diagnosed at advanced stage because of the lack of screening programs. Therefore, the identification of plasma biomarkers for early detection is necessary.

Evaluation of carcinogenic substances from the environment is a challenge for scientists. Recently, a novel approach based on 10 key characteristics of human carcinogens classified by the International Agency for Research on Cancer (IARC) has emerged. Carcinogenesis depends on different mechanisms and factors, including genetic, infectious (bacteria, viruses) and environmental (chemicals) factors. Endocrine disruptors are exogenous chemicals that can interfere and impair the function of the endocrine system due to their interaction with estrogen receptors or their estrogen signaling pathways inducing adverse effects in the normal mammary development, originating cancer. They are heterogeneous chemicals and include numerous synthetic substances used worldwide in agriculture, industry and consumer products. The most common are plasticizers, such as bisphenol A (BPA), pesticides, such as dichlorodiphenyltrichloroethane, and polychlorinated biphenyls (PCBs). Xenoestrogens appear to serve an important role in the increased incidence of breast cancer in the United States and numerous other countries. Several studies have demonstrated the role of organochlorine xenoestrogens in breast cancer. Therefore, the overall cumulative exposure of women to estrogens results in an increased risk for this type of cancer. Factors like lifestyle and diet also serve a role in the increased incidence of this disease. The aim of the present study was to analyze these chemical compounds based on the key characteristics given by the IARC, with a special focus on breast cancer, to establish whether these compounds are carcinogens, and to create a model for future analysis of other endocrine disruptors.

Oxidative stress in female cancers Oxidative stress in female cancers

Human papillomavirus (HPV) is the etiologic risk factor for cervical cancer. Some studies have suggested an association with a subset of lung tumors, but the etiologic link has not been firmly established. We performed an international pooled analysis of cross-sectional studies (27 datasets, n = 3249 patients) to evaluate HPV DNA prevalence in lung cancer and to investigate viral presence according to clinical and demographic characteristics. HPV16/18 were the most commonly detected, but with substantial variation in viral prevalence between geographic regions. The highest prevalence of HPV16/18 was observed in South and Central America, followed by Asia, North America and Europe (adjusted prevalence rates = 22, 5, 4 and 3%, respectively). Higher HPV16 prevalence was noted in each geographic region compared with HPV18, except in North America. HPV16/18-positive lung cancer was less likely observed among White race (adjusted odds ratio [OR] = 0.33, 95% confidence interval [CI] = 0.12–0.90), whereas no associations were observed with gender, smoking history, age, histology or stage. Comparisons between tumor and normal lung tissue show that HPV was more likely to be present in lung cancer rather than normal lung tissues (OR = 3.86, 95% CI = 2.87–5.19). Among a subset of patients with HPV16-positive tumors, integration was primarily among female patients (93%, 13/14), while the physical status in male cases (N = 14) was inconsistent. Our findings confirm that HPV DNA is present in a small fraction of lung tumors, with large geographic variations. Further comprehensive analysis is needed to assess whether this association reflects a causal relationship.

Cervical, anogenital, and some head and neck cancers (HNC) are etiologically associated with high-risk human papillomavirus (HR-HPV) infection, even though additional cofactors are necessary. Epidemiological studies have established that tobacco smoke (TS) is a cofactor for cervical carcinogenesis because women who smoke are more susceptible to cervical cancer when compared to non-smokers. Even though such a relationship has not been established in HPV-related HNC, a group of HPV positive patients with this malignancy are smokers. TS is a complex mixture of more than 4500 chemical compounds and approximately 60 of them show oncogenic properties such as benzo[α]pyrene (BaP) and nitrosamines, among others. Some of these compounds have been evaluated for carcinogenesis through experimental settings in collaboration with HR-HPV. Here, we conducted a comprehensive review of the suggested molecular mechanisms involved in cooperation with both HR-HPV and TS for epithelial carcinogenesis. Furthermore, we propose interaction models in which TS collaborates with HR-HPV to promote epithelial cancer initiation, promotion, and progression. More studies are warranted to clarify interactions between oncogenic viruses and chemical or physical environmental factors for epithelial carcinogenesis.

Human papillomavirus (HPV) and Epstein Barr virus (EBV) have been found in breast carcinomas (BCs) around the world. In this study, fifty-five BCs from Chile were analyzed for HPV and EBV presence. In addition, HPV-16 viral load/physical status and E6/E7 expressions were determined.