Association of human papillomavirus and squamous cell carcinoma of esophagus: A SEER database analysis.

Abstract

e14634 Background: Squamous cell carcinoma (SCC) of the esophagus is generally associated with tobacco and alcohol use. However, there are multiple published reports suggesting a subset of SCC of esophagus is associated with human papillomavirus (HPV) infection. HPV is well known to be associated with SCC of the anus and tonsil. Patients with HPV-positive SCC do well with primary chemoradiation and it is possible subset of esophageal cancer might also do well with primary chemoradiation. Prior analyses of the Surveillance, Epidemiology, and End Results (SEER) database showed that the incidence of these HPV associated SCC in the younger population are increasing. We used the SEER database (1973-2007) to evaluate epidemiological similarities between HPV associated SCCs. Methods: We assessed the association of HPV and SCC of esophagus by evaluating epidemiological similarities between SCC of tonsil, anus, and esophagus among the younger age group (age 20 to 44) and older age group (age above 45) of patients. Patient characteristics, 5-year relative survival, and annual percentage changes (APC) in incidence rates were evaluated. Results: We identified 15,825 SCC of the tonsil, 25,943 SCC of the esophagus, and 9,437 anal SCC. Among the younger age group, a significant increase in the APC was seen in anal SCC (APC= +6.7; 95% CI [5.3,8.0]; p<0.05) and SCC of tonsil (APC= +3.5; 95% CI [2.5,4.5]; p<0.05), whereas the APC of SCC of esophagus in younger age group showed a significant decrease (APC= -2.0; 95% CI [-2.8, -1.1]; p<0.05) (Table). Conclusions: Despite multiple studies suggests SCC of esophagus is associated with HPV infection, the incidence of SCC of the esophagus has not changed in the same manner as SCCs that are strongly associated with HPV. This suggests that in the population studied, SCC of the esophagus may not be associated with HPV. Future work includes identifying subgroups of the patients whose SCC was probably associated with HPV by incorporating factors such as race or sex. Age 20-44 Age ≥ 45 5-year relative survival APC 95% CI 5-year relative survival APC 95% CI Anal SCC 67.2% 6.7* 5.3, 8.0 68.3% 3.5* 3.1, 3.9 Tonsil SCC 70.1% 3.5* 2.5, 4.5 54.1% 0.3* 0.1, 0.6 Esophageal SCC 18.6% -2* -2.8, -1.1 10.4% -2.4* -2.9, -2.0 * p<0.05