Colorectal cancer prevalence linked to human papillomavirus: a systematic review with meta-analysis

ABSTRACT:

Introduction:

Colorectal cancer is one of the most prevalent types of tumors worldwide. Deaths caused by these malignant tumors remain high and have stayed practically at the same level for the last few decades. Among the established risk factors for the development of cancer are infections due to pathogens or viruses. Among the viruses, the human papillomavirus (HPV) is the most prevalent, with over 180 strains, 40 of which are directly related to anogenital infections.

Objective:

Systematically assess the main studies which link HPV to colorectal cancer with meta-analysis.

Methods:

The search strategy adopted was the logic based on specific descriptors (English language), in combination with the Boolean operators (AND/OR). The search was conducted in the following databases: PubMed, ScienceDirect, and Scientific Electronic Library Online (SciELO), between April and May 2015.

Results:

1,549 samples were assessed, with 956 (61.7%) being males. Six hundred thirty out of 1,358 cases of colorectal cancer due to HPV were diagnosed (51.9%). From these, 408 of 767 (51.9%) were male and 404 of 598 (67.5%) were linked to HPV 16 and 18, with tumor prevalence in the area of the cervix (253 of 411; 61.3%). From the total of 598 samples for the prevalence estimate of HPV 16 and 18, the number of cases with similar numbers was 204 (31.7%) and 200 (35.8%), respectively. Relatively significant numbers were found in the area of the cervix, 253 (61.3%), and the area of the rectum, 158 (38.7%).

Conclusion:

After conducting the present study, the link between HPV and colorectal cancer was made evident, without a distinction between the sexes, with similar values between HPV 16 and HPV 18.

Keywords:
Colorectal cancer; Human papillomavirus; HPV 16; HPV 18; Prevalence; Epidemiology