Objective: The aim of this study was to investigate the characteristics of p16 and PR immunoreactivity and HPV infection in endocervical adenocarcinoma.
Methods: Paraffin blocks of 62 patients with endocervical adnocarcinoma treated in the Cancer Institute and Hospital, Chinese Academy of Medical Sciences from year 2005 to year 2010 were collected. p16 and PR immunostaining and HPV detecting by SPF-10 PCR were conducted on all cases.
Results: HPV infection rate of the 62 endocervical adnocarcinoma cases was 74.2% with four cases combined with CIN3. Among the 46 HPV-positive cases, there were 22 cases of HPV18 infection (47.8%), 14 cases of HPV16 infection (30.4%), one case of HPV59 infection (2.2%). and nine multiple HPV infection cases (19.6%). The mean age of the 16 HPV-negative cases was (49.6 ± 10.5)year, while the mean age of the 46 HPV-positive cases was (42.8 ± 9.7)year, showing a significant difference between the two subgroups (P = 0.022). The positive rate of p16 infection was 80.6%. Association analysis showed that the results of p16 and HPV test were independent to each other (P = 0.077). The positive rate of PR was 3.2%. Among the 62 cases, there were 24 cases containing normal cervical glands, with 19 cases PR-positive in the normal cervical glands and the positive rate was 79.2%. The difference of PR positivity between neoplastic glands and normal glands was statistically significant by Chi-square test (P < 0.01) .
Conclusions: The HPV infection rate of endocervical adnocarcinoma is 74.2%, and the major subtypes were HPV16 and HPV18 infection. p16 immunoreactivity in endocervical adenocarcinoma maybe not the proof of high-risk HPV-related neoplasm. PR staining can be used as a reference designator to differentiate between neoplastic and normal cervical glands.