Association between infection of virulence cagA gene Helicobacter pylori and laryngeal squamous cell carcinoma

BACKGROUND The aim of the study was to evaluate the presence of cagA gene Helicobacter pylori in etiopathogenesis of initiation and development of larynx squamous cell carcinoma (LSCC) and its predictable role as a prognostic factor. MATERIAL AND METHODS The prospective, controlled study involved a series of 75 patients (65 male, 10 female, mean age 59.1 years, range 43 to 79 years) with larynx cancer. Samples of larynx cancerous tissue, each of 10-15 mg, were obtained from fresh tissues and were used for nucleic acid purification. DNA was extracted from 225 samples (larynx tumor - I (75), margin of tumor and normal tissue - II (75) and normal larynx tissue from opposite side to the tumor - III). All samples were subjected to H. pylori ureA detection by the PCR H. pylori diagnostic test. Samples that were positive for ureA H. pylori gene were evaluated for cagA H. pylori gene. RESULTS Presence of H. pylori cagA gene was identified in 46,7% to 49,3% of 75 H. pylori ureA gene-positive larynx cancer depending of tissue location. There was a correlation of high incidence of positive cagA gene in larynx cancer tissue in supraglottic versus subglottic and glottic location. We observed a predominance of cagA gene in LSCC in patients with positive cervical lymph nodes and clinical stage T3 and T4. CONCLUSIONS H. pylori is present in larynx tissue and may be a possible carcinogen or co-carcinogen in LSCC development, but that must be addressed by future investigations. The presence of cagA gene in larynx cancer tissues significantly decreases survival rate and increases the disease recurrence possibilities.