Human papillomaviruses in intraepithelial neoplasia and squamous cell carcinoma of the conjunctiva: A study from Mozambique
The infection with human papillomavirus (HPV) has been described as a risk factor for squamous cell carcinoma of the conjunctiva (SCCC), although the evidence is conflicting. To assess the relation between HPV infection and intraepithelial neoplasia or SCCC, we evaluated archived material from biopsies of the conjunctiva performed at the Maputo Central Hospital (Mozambique) in patients with suspected eye cancer. The quality of DNA was assessed by PCR using β-globin-specific primers. A total of 22 consecutive biopsies (intraepithelial neoplasia, SCCC, and benign conditions) positive for β-globin were further tested for HPV infection by PCR using the general primers GP5+/GP6+ and CPI/CPII. In addition, PCR with type-specific primers HPV 16 and HPV 18 was performed. Nineteen biopsies corresponded to intraepithelial neoplasia (two low-grade and nine high-grade) or SCCC (n=8), from which 11 (57.9%) tested positive for HPV infection; nine were positive for CPI/CPII, including one case also positive for GP5+/GP6+ and HPV 18, and the remaining two tested positive only for HPV 16. HPV DNA was not detected in any of the three biopsies of benign conditions. These results suggest a stronger association between infection with cutaneous HPV and SCCC than for mucosal HPV. However, further research is required to clarify the relation between HPV and SCCC as well as to understand the potential of the HPV vaccine currently available for cervical cancer to prevent SCCC.