The Aetiological Role of Human Papillomavirus in Colorectal Carcinoma: An Iranian Population- Based Case Control Study

Background: Human papillomavirus (HPV) is one of the most common sexually transmitted infectionsworldwide and the association between HPV infection and genital cancers has been well established. This studyconcerned the possible role of HPV infection in colorectal carcinoma (CRC) in the Iranian population. Materialsand
Methods: We examined 80 tissues obtained from patients with colorectal cancer consisting of 58 colon cancersamples and 22 rectal cancer samples and 80 tissues from patients with unremarkable pathologic changes asmatched controls by sex, study center and anatomical sites. HPV infection and genotypes were detected usingnested PCR and sequencing methods, respectively.
Results: HPV DNA was detected in 5/80 (6.25%) cases including1 of 22 (4.54%) patients with rectum cancer and 4 of 58 (6.9%) patients with colon cancer and 1/80 (1.25%) ofcontrols. Furthermore, HPV-18 was detected as the most frequent type and we found no significant correlationbetween prevalence of HPV infection and anatomical sub- sites.
Conclusions: Although a causal relation betweenhuman papillomavirus and colorectal cancer was not found through this study, analysis of medical recordspointed to a possible role for high- risk types of HPV in increasing the potential of aggressiveness in colorectalcancer. This study shows a particular frequency of HPV genotypes in patients with colorectal cancer in Iran.Since HPV vaccines are limited to a few types of virus, using cohort studies in different geographical zones toscreen for patterns of HPV infection in different organs might increase the efficacy and optimization of thecurrent vaccines.