The expression and significance of insulin like growth factor-II mRNA binding protein 3 (IMP3) and P16INK4a in adenocarcinoma of the uterine cervix

Objective: To investigate the expression and significance of Insulin like growth factor-II mRNA binding protein 3 (IMP3) and P16INK4a in adenocarcinoma of the uterine cervix. Methods: Immunohistochemical method was used to detect the expression of IMP3(SP method) and P16INK4a (EnVision) in 25 cases of benign endocervical glands (BEG), 15 cases of endocervical adenocarcinoma in situ (AIS) and 56 cases of endocervical adenocarcinoma (ECA). To further assess the level of IMP3 protein expression, in situ hybridization detection of IMP3 mRNA was performed in 25 cases of ECA with IMP3 varying expression. Results: IMP3 expression was detected in 16.00% (4/25) of BEG, 80% (12/15) of AIS and 80.36% (45/56) of ECA, with significant difference among them (P<0.001). While P16INK4a expression was detected in 0.00% (0/25) of BEG, 100% (15/15) of AIS and 83.93% (47/56) of ECA with significant difference among them (P<0.001). IMP3 and P16INK4a positivity was most common in serous carcinoma (100%, 3/3, and 100%, 3/3) of all kinds of ECA, subsequently in the endometrioid carcinoma (85.71%, 6/7 and 71.43%, 5/7) and cervical endocarcinoma (73.91%, 34/46 and 84.78%, 39/46). There was significant difference among IMP3 expression of different differentiated ECA (P<0.05). No association was observed among IMP3 or P16INK4a expression and age, tumor types and tumor FIGO stages (P>0.05). The IMP3+/P16INK4a+ phenotype accounts for 64.29% (36/56) of ECA, while IMP3-/P16INK4a-accounts for 3.57% (2/56). χ2 analysis showed inconsistency between IMP3 and P16INK4a expression in ECA (Kappa value 0.1, P=0.47). Conclusion: IMP3 and P16INK4a would be helpful in identification of benign and malignant endocervical glandular lesions. IMP3 Expression is correlated with differentiation of ECA. Combination of IMP3 and P16INK4a may be useful in diagnosis of ECA.