Human Papillomavirus Infection and Its Possible Correlation with p63 Expression in Cervical Cancer in Japan, Mongolia, and Myanmar

Although human papillomavirus (HPV) 16 is the cause of cervical cancer in most countries including Japan, the involvement of cervical cancer with HPV types in Mongolian and Myanmar populations is largely unknown. We examined the expression of HPV in formalin-fixed and paraffin-embedded cervical tissues from 40 Japanese, 32 Mongolian, and 30 Myanmar cervical cancer patients. We performed immunohistochemistry using anti-HPV16 and anti-HPV 1, 6, 11, 16, 18 and 31 cocktail and then correlated it with the expression of Ki-67 and p63. HPV 16 was detected in 72%, 65% and 50% of Japanese, Mongolian and Myanmar cervical cancer patients, respectively, whereas 5 (13%) of the 40 patients, 8 (25%) of the 32 patients and 7 (23%) of the 30 patients in HPV 16-negative cancers were positive for other HPV types included in the cocktail, respectively. Ki-67 labeling index (LI) as well as p63 LI was significantly higher in HPV 16-positive patients than in HPV 16-negative ones in the Japanese and Mongolian samples. p63 expression was significantly associated with stage III and IV in Japan and Mongolia. These findings suggest that HPV 16 may be associated with cell proliferative activity and tumor progression, possibly depending upon the expression of p63 in the cervical cancer. In addition, immunohistochemical detection for distinguishing the type of HPV may also be useful for cervical cancer in the clinical setting.