Human papillomavirus 16-positive uterine cervical squamous cell carcinoma with coinfection with human papillomavirus 34 has a lower incidence in lymph node metastasis than that without coinfection with human papillomavirus 34.

Our earlier study demonstrated high prevalence of multiple human papillomavirus (HPV) infection in patients with invasive uterine cervical cancer, including squamous cell carcinoma (SCC). HPV 16 is the most predominant genotype related to SCC of the uterine cervix. The aim of this study was to reveal the biological significance of multiple HPV infection concerning the tumor progression of invasive uterine cervical SCC. In the present study, the effects of coinfection with genotypes other than HPV 16 on tumor growth and lymph node metastasis of invasive uterine cervical SCC with HPV 16 infection were examined. Although coinfection with most genotypes did not influence tumor progression, the clinical stage of patients coinfected with HPV 16 and HPV 34 was significantly lower than that of those without HPV 34 coinfection (p = 0.0038). Moreover, no patient coinfected with HPV 16 and HPV 34 manifested lymph node metastasis, but about half of the patient population without HPV 34 coinfection did (p = 0.0299). These findings suggested that coinfection with HPV 34 could prevent the tumor progression of invasive uterine cervical SCC with HPV 16 infection.