Human papillomavirus in esophageal squamous cell carcinoma in Colombia and Chile.

AIM: To examine the presence of human papillomavirus (HPV) in esophageal squamous cell carcinoma (ESCC) specimens collected from Colombia and Chile located in the northern and southern ends of the continent, respectively. METHODS: We examined 47 and 26 formalin-fixed and paraffin-embedded ESCC specimens from Colombia and Chile, respectively. HPV was detected using GP5+/GP6+ primer pair for PCR, and confirmed by Southern blot analysis. Sequencing analysis of L1 region fragment was used to identify HPV genotype. In addition, P16(INK4A) protein immunostaining of all the specimens was conducted. RESULTS: HPV was detected in 21 ESCC specimens (29%). Sequencing analysis of L1 region fragment identified HPV-16 genome in 6 Colombian cases (13%) and in 5 Chilean cases (19%). HPV-18 was detected in 10 cases (21%) in Colombia but not in any Chilean case. Since Chilean ESCC cases had a higher prevalence of HPV-16 (without statistical significance), but a significantly lower prevalence of HPV-18 than in Colombian cases (P = 0.011) even though the two countries have similar ESCC incidence rates, the frequency of HPV-related ESCC may not be strongly affected by risk factors affecting the incidence of ESCC. HPV-16 genome was more frequently detected in p16 positive carcinomas, although the difference was not statistically significant. HPV-18 detection rate did not show any association with p16 expression. Well-differentiated tumors tended to have either HPV-16 or HPV-18 but the association was not statistically significant. HPV genotypes other than HPV-16 or 18 were not detected in either country. CONCLUSION: HPV-16 and HPV-18 genotypes can be found in ESCC specimens collected from two South American countries. Further studies on the relationship between HPV-16 presence and p16 expression in ESCC would aid understanding of the mechanism underlying the presence of HPV in ESCC.

Human papillomavirus in lung carcinomas among three Latin American countries.

The presence of human papillomavirus (HPV) genome in lung carcinomas has been reported worldwide but its frequency varies from country to country. We examined HPV genome in 36 lung carcinomas, consisting of 14 squamous cell carcinomas, 13 adenocarcinomas, and 9 small cell carcinomas, collected from Colombia, Mexico and Peru. PCR analysis using GP5+/GP6+ primers, combined with Southern blot hybridization, found the presence of HPV genome in 10 (28%) of 36 cases. This percentage is similar to the value of 22% reported by Syrjänen, who conducted a meta-analysis of nearly 2500 lung carcinomas examined to date. Genotype analysis revealed that the most predominant genotype was HPV-16 (7 cases), followed by HPV-18 (2 cases) and HPV-33 (1 case). HPV-16 was more frequently found among female than male cases (P=0.008) but was not detected in any adenocarcinoma cases. On the other hand, HPV-18 and HPV-33 were detected only among male cases. These HPV genotypes were detected only in adenocarcinomas, and all the HPV genotypes detected in this histological type were HPV-18 or HPV-33. The frequency of HPV-16 positive cases among all the HPV positive cases differed in the sexes (P=0.033) and differed in the three histological types (P=0.017). The presence of HPV tended to be more frequent in well-differentiated tumors when squamous cell carcinomas and adenocarcinomas were combined. However, it was not statistically significant (P=0.093). Neither p16 nor p53 expression in carcinoma cells was related to the proportion of HPV-positive cases. In conclusion, high-risk HPV DNA was detected in 28% of lung carcinomas. The predisposition of HPV-16 to female cases and to non-adenomatous carcinomas warrants further investigation.