Reflux Esophagitis as a Possible Risk Factor in the Development of Pharyngolaryngeal Squamous Cell Carcinoma

Claudin-1/4 as directly target gene of HIF-1α can feedback regulating HIF-1α by PI3K-AKT-mTOR and impact the proliferation of esophageal squamous cell though Rho GTPase and p-JNK pathway

Immunohistochemical microarray comprising 80 patients with esophageal squamous cell carcinoma (ESCC) and discovered that the expression of CLDN1 and CLDN4 were significantly higher in cancer tissues compared to para-cancerous tissues. Furthermore, CLDN4 significantly affected the overall survival of cancer patients. When two ESCC cell lines (TE1, KYSE410) were exposed to hypoxia (0.1% O₂), CLDN1/4 was shown to influence the occurrence and development of esophageal cancer. Compared with the control culture group, the cancer cells cultured under hypoxic conditions exhibited obvious changes in CLDN1 and CLDN4 expression at both the mRNA and protein levels. Through genetic intervention and Chip, we found that HIF-1α could directly regulate the expression of CLDN1 and CLDN4 in cancer cells. Hypoxia can affect the proliferation and apoptosis of cancer cells by regulating the PI3K-Akt-mTOR pathway. Molecular analysis further revealed that CLDN1 and CLDN4 can participate in the regulation process and had a feedback regulatory effect on HIF-1α expression in cancer cells. In vitro cellular experiments and vivo experiments in nude mice further revealed that changes in CLDN4 expression in cancer cells could affect the proliferation of cancer cells via regulation of Rho GTP and p-JNK pathway. Whether CLDN4 can be target for the treatment of ESCC needs further research.

Gastroesophageal reflux disease and head and neck cancers: A systematic review and meta-analysis

PURPOSE

Gastroesophageal reflux disease (GERD) has been associated with head and neck cancer (HNC), including laryngeal and pharyngeal anatomical sites. A systematic review and meta-analysis was performed to examine these associations.

METHODS

Articles were retrieved from the Medline, Web of Science, Scopus, and Embase databases using keywords "gastroesophageal reflux disease", "laryngopharyngeal reflux", "head and neck cancer", and associated variants. Inclusion criteria were English language publications, human subjects, and controlled studies with described development of head and neck cancer among individuals with GERD. 13 studies with a total of 39,824 patients were included.

RESULTS

Overall, presence of GERD was associated with an increased risk of developing HNC (OR = 1.86, 95% Confidence Interval [CI] = 1.27-2.74). This association remained significant with laryngeal cancers (OR = 1.95, 95% CI = 1.33-2.86), but not pharyngeal cancers (OR = 1.56, 95% CI = 0.86-2.83). Subgroup analyses of hypopharyngeal (OR = 2.26, 95% CI = 0.67-7.68) and oropharyngeal subsites (OR = 1.39, 95% CI = 0.51-3.84) were not statistically significant. Meta-analysis of studies that objectively assessed reflux, such as pH monitor placement, showed statistical significance (OR = 2.81, 95% CI = 1.36-5.81), while studies that used subjective reporting or chart review of GERD were not significant (OR = 1.46, 95% CI = 0.89-2.40). Association between H. pylori infection and head and neck cancers was not statistically significant (OR = 2.66, 95% CI = 0.59-11.97).

CONCLUSION

A diagnosis of GERD is associated with a later diagnosis of HNC, but this association is not significant for pharyngeal cancers. Associations of GERD with HNC may be specific to laryngeal cancers.

LEVEL OF EVIDENCE

Systematic review and meta-analysis of case control studies (3a).

Experimental model of smoking and simulation of reflux with acid and pepsin in rats

PURPOSE: To develop experimental models to evaluate the effects of hydrochloric acid associated with the pepsin instilled in the mucosa of the upper esophagus and the esophagogastric junction of young male rats Wistar, simulating injury caused by gastroesophageal reflux on the mucosa of aero-digestive tract in humans as well as the action of the risk exposure of mucosa to cigarette smoke. METHODS: Fifty young male Wistar rats divided in 5 groups with 10 animals each one, respectively simulating pharyngo-laryngeal reflux and gastroesophageal reflux, pharyngo-laryngeal reflux and smoking, smoking only, gastroesophageal reflux and control group. RESULTS: The histopathologic studies no recorded neoplasias, only mild changes and no significant alterations. The hemo-oximetry (carboxyhemoglobin and methemoglobim) and CO2 concentration confirm that the animals were submitted to high intensity of exposure to carcinogens in tobacco and its derivatives. CONCLUSION: The experimental models were highly efficient, practical, easy to use and economical and can be employed in other similar studies to determine the harmful effects by smoking and reflux.

Experimental carcinogenesis on the oropharyngeal mucosa of rats with hydrochloric acid, sodium nitrate and pepsin

PURPOSE: To investigate the carcinogenic action of hydrochloric acid, pepsin and sodium nitrate on the oropharyngeal mucosa of rats, simulating the reflux of gastric contents. METHODS: Eighty-two Wistar rats were divided in seven groups and submitted to 2 or 3 weekly applications of hydrochloric acid, pepsin and sodium nitrate on the pharyngeal mucosa during six months. Study groups comprised 12 animals each. Rats in groups I and II were submitted to 2 (GI) or 3 (GII) weekly applications of 0.1N hydrochloric acid. Groups III and IV were submitted to 2 (GIII) or 3 (GIV) weekly applications of 0.1N hydrochloric acid solution with pepsin. Groups V and VI were submitted to 2 (GV) or 3 (GVI) weekly applications of 0.1N hydrochloric acid and treated with daily nitrate diluted in water. Group VII consisted of 10 animals submitted to 2 weekly applications of filtered water. RESULTS: No dysplasia, intra-epithelial neoplasia or invasive carcinomas were detected. Inflammatory changes were observed in varying degrees and mast cells were more common in Groups V and VI (p=0.006). CONCLUSION: The data of the current study could not corroborate the hypothesis that gastroesophageal and pharyngolaryngeal refluxes are carcinogenic factors to the laryngopharyngeal mucosa, and more studies are necessary in the future.

Hypopharyngeal squamous cell carcinoma bordering ectopic gastric mucosa "inlet patch" of the cervical esophagus

OBJECTIVE

Ectopic gastric mucosa of the cervical esophagus, referred to as inlet patch (IP), is considered to be a common development abnormality of the esophagus. We report here a case of hypopharyngeal squamous cell carcinoma bordering on IP of the cervical esophagus.

METHODS

A 44-year-old female underwent partial pharyngectomy, total laryngectomy, cervical esophagectomy, and bilateral neck dissection under the diagnosis of hypopharyngeal carcinoma.

RESULTS

Resected specimens of the hypopharynx revealed a well-differentiated squamous cell carcinoma in the ulcerative tumorous lesion (3.5 cm x 0.5 cm). A brown patch (2 cm x 1.5 cm) bordering the anal aspect of the tumor comprised ectopic gastric mucosa of fundic type epithelium. Immunohistochemistry revealed the surface mucosal cells of this lesion were strongly positive for human gastric mucin (HGM) and the fundic cells were positive for gastrin.

CONCLUSION

The hypopharyngeal squamous cell carcinoma likely developed in association with chronic irritation due to gastric acid from the IP. To our knowledge, this is the first reported case of squamous cell carcinoma related to IP.